U.S. patent application number 16/673571 was filed with the patent office on 2020-02-27 for wireless communications method, apparatus, and system.
The applicant listed for this patent is Huawei Technologies Co., Ltd.. Invention is credited to Junren CHANG, Shulan FENG, Yuchun WU, Chen-Xiong ZHANG.
Application Number | 20200068645 16/673571 |
Document ID | / |
Family ID | 56284010 |
Filed Date | 2020-02-27 |
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United States Patent
Application |
20200068645 |
Kind Code |
A1 |
CHANG; Junren ; et
al. |
February 27, 2020 |
WIRELESS COMMUNICATIONS METHOD, APPARATUS, AND SYSTEM
Abstract
A wireless communications method, apparatus, and system
including a terminal is provided. The terminal sets up a connection
to a first base station, and stays in always connected mode. When
the terminal moves in a dense network, handovers of the first base
station can be reduced. Further, when the terminal moves in the
dense network, frequent signaling interaction is reduced, paging
load in the entire network is reduced, and an end-to-end delay in
service setup and transmission is reduced.
Inventors: |
CHANG; Junren; (Beijing,
CN) ; WU; Yuchun; (Beijing, CN) ; FENG;
Shulan; (Beijing, CN) ; ZHANG; Chen-Xiong;
(Shenzhen, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Huawei Technologies Co., Ltd. |
Shenzhen |
|
CN |
|
|
Family ID: |
56284010 |
Appl. No.: |
16/673571 |
Filed: |
November 4, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15640088 |
Jun 30, 2017 |
10477611 |
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16673571 |
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PCT/CN2014/096046 |
Dec 31, 2014 |
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15640088 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L 41/0823 20130101;
H04W 88/06 20130101; H04W 36/0069 20180801; H04W 28/18 20130101;
H04W 36/36 20130101; H04W 76/10 20180201; H04W 76/25 20180201; H04W
36/24 20130101; H04W 24/02 20130101; H04W 76/27 20180201 |
International
Class: |
H04W 76/25 20060101
H04W076/25; H04W 76/10 20060101 H04W076/10; H04W 76/27 20060101
H04W076/27; H04W 24/02 20060101 H04W024/02; H04W 36/24 20060101
H04W036/24; H04W 36/36 20060101 H04W036/36; H04W 36/00 20060101
H04W036/00 |
Claims
1. A terminal, comprising: a processor, configured to set up a
connection to a first base station, and stay in an always connected
mode, wherein the always connected mode maintains the connection to
the first base station; a receiver, configured to receive first
dedicated signaling sent by the first base station, wherein the
first dedicated signaling comprises second base station list
information, and the second base station list information comprises
information about each second base station having context
information of the terminal; and a sender, configured to perform
data transmission through at least one of the first base station
and the second base station according to the second base station
list information.
2. The terminal according to claim 1, wherein the receiver is
further configured to: receive measurement configuration
information sent by the first base station, and complete, according
to the measurement configuration information, a measurement
configuration of a frequency layer corresponding to each base
station of a plurality of base stations, wherein the plurality of
base stations comprise the first base station and the second base
station, and the second base station comprises a master second base
station and a secondary second base station.
3. The terminal according to claim 2, wherein the measurement
configuration information comprises at least one of: measuring a
frequency layer corresponding to the first base station only;
measuring frequency layers corresponding to the first base station
and the master second base station only; and measuring frequency
layers corresponding to the first base station, the master second
base station, and the secondary second base station.
4. The terminal according to claim 3, wherein the measurement
configuration information further comprises at least one of:
determining a first threshold for measuring the frequency layer
corresponding to the first base station only; determining a second
threshold for measuring the frequency layers corresponding to the
first base station and the master second base station only; and
determining a third threshold for measuring the frequency layers
corresponding to the first base station, the master second base
station, and the secondary second base station.
5. The terminal according to claim 4, wherein when QoS of a current
service of the terminal is less than the first threshold, the
receiver is configured to complete, according to the measurement
configuration information, a measurement configuration of a
frequency layer corresponding to each base station, comprises: the
receiver is configured to measure, according to the measurement
configuration information, the frequency layer corresponding to the
first base station only, and obtain a measurement result; when QoS
of a current service of the terminal is greater than the first
threshold but less than the second threshold, the receiver is
configured to complete, according to the measurement configuration
information, a measurement configuration of a frequency layer
corresponding to each base station, comprises: the receiver is
configured to measure, according to the measurement configuration
information, the frequency layer corresponding to the first base
station and the frequency layer corresponding to the master second
base station, and obtain measurement results; and when QoS of a
current service of the terminal is greater than the second
threshold or the third threshold, the receiver is configured to
complete, according to the measurement configuration information, a
measurement configuration of a frequency layer corresponding to
each base station, comprises: the receiver is configured to
measure, according to the measurement configuration information,
the frequency layers corresponding to the first base station, the
master second base station, and the secondary second base station,
and obtain measurement results.
6. The terminal according to claim 2, wherein the receiver is
further configured to: receive an instruction message sent by the
first base station to perform measurement reporting; and determine,
according to the instruction message to perform measurement
reporting, whether to send the measurement result to the first base
station.
7. The terminal according to claim 6, wherein the instruction
message comprises: at least one of instruction information for
measurement reporting of the frequency layer corresponding to the
first base station, instruction information for measurement
reporting of the frequency layer corresponding to the master second
base station, and instruction information for measurement reporting
of the frequency layer corresponding to the secondary second base
station.
8. The terminal according to claim 1, wherein the receiver is
further configured to: receive measurement configuration parameter
information sent by the first base station, and complete, according
to the measurement configuration parameter information, measurement
management of a frequency layer corresponding to each base station
of a plurality of base stations, wherein the the plurality of base
stations comprise the first base station and the second base
stations, and the second base stations comprise a master second
base station and a secondary second base station; wherein the
measurement configuration parameter information comprises at least
one of a measurement configuration parameter of a frequency layer
corresponding to the first base station, a measurement
configuration parameter of a frequency layer corresponding to the
master second base station, and a measurement configuration
parameter of a frequency layer corresponding to the secondary
second base station.
9. The terminal according to claim 8, wherein when QoS of a current
service of the terminal is less than a first threshold, the
receiver is configured to complete, according to the measurement
configuration parameter information, measurement management of a
frequency layer corresponding to each base station, comprises: the
receiver is configured to measure, according to the measurement
configuration parameter of the frequency layer corresponding to the
first base station, the frequency layer of the first base station,
and obtain a first measurement result; when QoS of a current
service of the terminal is greater than a first threshold but less
than a second threshold, the receiver is configured to complete,
according to the measurement configuration parameter information,
measurement management of a frequency layer corresponding to each
base station, comprises: the receiver is configured to measure,
according to the measurement configuration parameter of the
frequency layer corresponding to the first base station, the
frequency layer of the first base station, and obtain a first
measurement result, and at the same time, measure, according to the
measurement configuration parameter of the frequency layer
corresponding to the master second base station, the frequency
layer of the master second base station, and obtain a second
measurement result; when QoS of a current service of the terminal
is greater than a second threshold, the receiver is configured to
complete, according to the measurement configuration parameter
information, measurement management of a frequency layer
corresponding to each base station, comprises: the receiver is
configured to measure, according to the measurement configuration
parameter of the frequency layer corresponding to the secondary
second base station, the frequency layer of the secondary second
base station, and obtain a third measurement result.
10. The terminal according to claim 9, wherein that the receiver is
configured to measure, according to the measurement configuration
parameter of the frequency layer corresponding to the first base
station, the frequency layer of the first base station, comprises:
the receiver is configured to measure, according to the measurement
configuration parameter of the frequency layer corresponding to the
first base station, at least one of the first base station and a
first base station neighboring to the first base station.
11. The terminal according to claim 9, wherein that the receiver is
configured to measure, according to the measurement configuration
parameter of the frequency layer corresponding to the master second
base station, the frequency layer of the master second base
station, comprises: the receiver is configured to measure,
according to the measurement configuration parameter of the
frequency layer corresponding to the master second base station, at
least one of the master second base station and a master second
base station neighboring to the master second base station.
12. The terminal according to claim 9, wherein the sender is
further configured to: compare the obtained second measurement
result with a preset condition, and when the preset condition is
met, send the second measurement result to the first base
station.
13. A base station, wherein the base station is a first base
station, and comprises: a processor, configured to set up a
connection to a terminal, and stay in an always connected mode,
wherein the always connected mode maintains the connection to the
terminal; and a sender, configured to send first dedicated
signaling to the terminal, wherein the first dedicated signaling
comprises second base station list information, and the second base
station list information comprises information about each second
base station having context information of the terminal; and
perform data transmission with the terminal.
14. The base station according to claim 13, wherein the sender is
further configured to: send measurement configuration information
to the terminal, wherein the measurement configuration information
comprises measurement configuration information of a frequency
layer corresponding to each base station of a plurality of base
stations, the plurality of base stations comprise at least one of
the first base station and the second base station, and the second
base station comprise a master second base station and a secondary
second base station.
15. The base station according to claim 14, wherein the measurement
configuration information comprises at least one of: measuring a
frequency layer corresponding to the first base station only;
measuring frequency layers corresponding to the first base station
and the master second base station only; and measuring frequency
layers corresponding to the first base station, the master second
base station, and the secondary second base station.
16. The base station according to claim 15, wherein the measurement
configuration information further comprises at least one of: a
first threshold for measuring the frequency layer corresponding to
the first base station only; a second threshold for measuring the
frequency layers corresponding to the first base station and the
master second base station only; and a third threshold for
measuring the frequency layers corresponding to the first base
station, the master second base station, and the secondary second
base station.
17. The base station according to claim 16, wherein the sender is
further configured to: send, to the terminal, an instruction
message to perform measurement reporting.
18. The base station according to claim 17, wherein the instruction
message comprises: at least one of instruction information for
measurement reporting of the frequency layer corresponding to the
first base station, instruction information for measurement
reporting of the frequency layer corresponding to the master second
base station, and instruction information for measurement reporting
of the frequency layer corresponding to the secondary second base
station.
19. The base station according to claim 13, wherein the sender is
further configured to: send measurement configuration parameter
information to the terminal, wherein the measurement configuration
parameter information comprises at least one of a measurement
configuration parameter of a frequency layer corresponding to the
first base station, a measurement configuration parameter of a
frequency layer corresponding to a master second base station, and
a measurement configuration parameter of a frequency layer
corresponding to a secondary second base station.
20. The base station according to claim 19, wherein the base
station further comprises a receiver, configured to: receive
measurement results sent by the terminal, wherein the measurement
results comprise a first measurement result and a second
measurement result, the first measurement result is obtained by the
terminal by performing a measurement according to the measurement
configuration parameter of the frequency layer corresponding to the
first base station, and the second measurement result is obtained
by the terminal by measuring the master second base station
according to the measurement configuration parameter of the
frequency layer corresponding to the master second base station.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/640,088, filed on Jun. 30, 2017, which is a
continuation of International Application No. PCT/CN2014/096046,
filed on Dec. 31, 2014, all of which are hereby incorporated by
reference in their entireties.
TECHNICAL FIELD
[0002] Embodiments of the present invention relate to
communications technologies, and in particular, to a wireless
communications method, apparatus, and system.
BACKGROUND
[0003] According to a recent forecast, at the end of 2014, a
quantity of wireless mobile devices will exceed a quantity of human
beings for the first time, and at the end of 2018, a quantity of
mobile devices per person in the world will reach 1.4. Data traffic
of mobile services in 2018 will probably reach approximately 10
times that in 2013.
[0004] In the mobile Internet application field, various future
applications such as augmented reality, virtual reality, or
real-time interactive games will enhance user experience to a
higher level. This imposes a higher requirement on a rate of a
transmission network. On the other hand, emergence of mobile
education, mobile health, and driverless cars will impose a greater
challenge on a delay and reliability of future wireless
communication. As new applications of wireless communication emerge
continuously and become increasingly important, the transmission
network certainly also needs to provide effective support through
continuous evolution.
[0005] To better meet development requirements of mobile Internet
services, a fifth-generation mobile communications technology
(5-Generation, 5G for short) network is becoming a hot topic of
research of a current wireless communications network. 5G is a
wireless communications system oriented to years after 2020.
Therefore, with respect to 5G design requirements, a more
challenging target needs to be defined to support development
requirements of mobile services after 2020. Currently, with respect
to 5G service requirements and target design, a data traffic target
is designed according to 1000 times the current data traffic. With
respect to a quantity of terminal devices that can be supported, a
challenging target is to support 100 times the current quantity of
terminal devices. In addition, it is required that a typical data
rate of a terminal should also approach a target of 100 times. In
addition to such a high performance challenge, a zero delay or a
very low delay in comparison with an existing delay is further
required, so as to meet requirements of some special services.
[0006] In a word, performance of 5G is far higher than that of a
fourth-generation mobile communications technology (4-Generation,
4G for short). 5G supports a user-perceived rate of 0.1 Gbps to 1
Gbps, and has a quantity of one million connections per square
kilometer in density, an end-to-end delay in milliseconds, a
traffic density with tens of Tbps per square kilometer, mobility
higher than 500 km per hour, and a peak rate of tens of Gbps. In
addition, deployment and operation efficiency of the 5G-era network
is enhanced significantly, spectral efficiency is enhanced by 5 to
15 times against 4G, and energy efficiency and cost efficiency are
enhanced by more than 100 times. To meet design requirements in the
foregoing aspects, small cells or small-cell base stations are
deployed more densely, forming a so-called ultra dense network (UDN
for short).
[0007] In the UDN network, to provide a rate supported by the
network, a large quantity of small-cell base stations are deployed.
As more small-cell base stations are deployed in the network, cell
changes occur frequently when user equipment (User Equipment, UE
for short) moves in the dense network. However, each cell change
process may relate to signaling interaction processes between the
UE and an evolved NodeB (eUTRAN NodeB, eNB for short), between the
UE and a core network device (such as an MME and an S-GW), and
between the eNB and the core network device. With increase of cell
change processes, a quantity of related signaling also increases.
Especially, when an intelligent terminal supports more services,
with introduction and use of various new services, frequent service
setup and release processes of various services are also caused,
and each service setup and release process also causes signaling to
increase. On the other hand, due to introduction of a large
quantity of machine type devices, for example, increase of a
quantity of intelligent cars and other machine type devices, the
network needs to frequently transmit a large quantity of small data
packets. To transmit a small data packet every time, a service
setup and release process needs to be performed. This also causes
signaling load to increase, and therefore, a large quantity of
resources are consumed every time a small data packet is
transmitted.
[0008] Some ultra high frequency (UHF for short) bands (for
example, a 700 MHz frequency band) that are originally used for
broadcast and television services are allocated to a mobile
operator, and the premium spectrum resources featuring wide
coverage have revolutionary impact on mobile communication.
Therefore, when some UHF frequency bands or other lower frequency
bands are allocated to a mobile service, how to use these spectrum
resources properly and bring features of the spectrum resources
into full play is also a very critical problem.
[0009] In a conventional Long Term Evolution (LTE for short)
technology, every time UE accesses a network, an eNB first needs to
set up a radio resource control (RRC for short) connection, and
then set up a non-access stratum (NAS for short) connection to a
mobility management entity (MME for short) and a serving gateway
(S-GW for short). When the network needs to transmit a service to
the UE, first, the MME delivers a paging notification to a base
station in a paging area or a tracking area, and then the base
station in the paging area or the tracking area sends a paging
message to the UE. In the foregoing small cell network, and
especially in a scenario of dense deployment, a macro network
covers a large quantity of small cells. When the UE moves at a
medium or high moving speed, serving cells change frequently, and
every cell change process relates to a cell measurement, cell
measurement result reporting, and a cell handover command. In
addition, a cell handover process further relates to signaling
interaction processes between the eNB and a network element of the
core network such as the MME or the S-GW.
[0010] In the processes of setting up and releasing various future
services, the UE sets up and releases network connections
frequently, and the UE spends a long time in accessing the network
every time. As the cell network is deployed more densely, cell
changes occur more frequently, and consequently, signaling related
to the cell changes increases abruptly.
[0011] In addition, as a large quantity of small-cell base stations
are deployed in the network, a quantity of base stations in a
paging area is very large. Complying with a conventional paging
mechanism, that is, delivering a paging message on all base
stations in the paging area, also causes paging signaling to
increase abruptly, and therefore, costs of the small-cell base
stations also increase due to increase of paging load. In addition,
the delay in the conventional LTE technology is long. For example,
every time the UE accesses the network, it takes 80 ms+2T_S1. T_S1
is generally in a range of 20 ms to 100 ms, and therefore, a delay
of the UE is approximately 100 ms to 180 ms.
SUMMARY
[0012] Embodiments of the present invention provide a wireless
communications method, apparatus, and system, so as to reduce
frequent signaling interaction when a terminal moves in a dense
network.
[0013] According to a first aspect, an embodiment of the present
invention provides a terminal, including:
[0014] a processing module, configured to set up a connection to a
first base station, and stay in always connected mode, where the
always connected mode is to always keep the connection to the first
base station;
[0015] a receiving module, configured to receive first dedicated
signaling sent by the first base station, where the first dedicated
signaling includes second base station list information, and the
second base station list information includes information about
each second base station having context information of the
terminal; and
[0016] a sending module, configured to perform data transmission
through the first base station and/or the second base station
according to the second base station list information.
[0017] With reference to the first aspect, in a first possible
implementation manner of the first aspect, that the processing
module is configured to set up a connection to a first base
station, and stay in always connected mode, specifically
includes:
[0018] the processing module is configured to always keep the
connection to the first base station within a preset time.
[0019] With reference to the first aspect or the first possible
implementation manner of the first aspect, in a second possible
implementation manner of the first aspect, that the sending module
is configured to perform data transmission through the first base
station includes:
[0020] the sending module is configured to perform only control
signaling transmission through the first base station; or
[0021] the sending module is configured to perform only downlink
data transmission through the first base station; or
[0022] the sending module is configured to perform only downlink
control signaling transmission through the first base station.
[0023] With reference to the first aspect, in a third possible
implementation manner of the first aspect, before the processing
module is configured to set up the connection to the first base
station, and stay in always connected mode, the processing module
is further configured to:
[0024] obtain access frequency information, and determine whether a
connected mode corresponding to the access frequency information is
the always connected mode.
[0025] With reference to the third possible implementation manner
of the first aspect, in a fourth possible implementation manner of
the first aspect, that the processing module is configured to
obtain access frequency information, and determine whether a
connected mode corresponding to the access frequency information is
the always connected mode, specifically includes:
[0026] the processing module is configured to receive system
information sent by the first base station, and obtain, from the
system information, whether the connected mode corresponding to the
access frequency information is the always connected mode; or
[0027] the processing module is configured to obtain, from preset
configuration information, whether the connected mode corresponding
to the access frequency information is the always connected
mode.
[0028] With reference to the third or the fourth possible
implementation manner of the first aspect, in a fifth possible
implementation manner of the first aspect, the processing module is
further configured to select, if the connected mode corresponding
to the access frequency information is the always connected mode, a
first base station corresponding to the access frequency
information to perform access.
[0029] With reference to any one of the first aspect, or the first
to the fifth possible implementation manners of the first aspect,
in a sixth possible implementation manner of the first aspect, the
receiving module is further configured to receive scheduling
information sent by the first base station.
[0030] With reference to any one of the first aspect, or the first
to the fifth possible implementation manners of the first aspect,
in a seventh possible implementation manner of the first aspect,
that the processing module is configured to set up a connection to
the first base station specifically includes:
[0031] the processing module is configured to send a first
indication message to the first base station, where the first
indication message carries indication information about whether to
request to accept working in the always connected mode; and
[0032] receive connection configuration information that is sent by
the first base station according to the first indication message,
where the connection configuration information includes whether to
configure the terminal to work in the always connected mode.
[0033] With reference to the seventh possible implementation manner
of the first aspect, in an eighth possible implementation manner of
the first aspect, the first indication message includes:
[0034] a random access message 3 or a connection setup request
message.
[0035] With reference to any one of the first aspect, or the first
to the eighth possible implementation manners of the first aspect,
in a ninth possible implementation manner of the first aspect, that
the processing module is configured to set up a connection to a
first base station, and stay in always connected mode, specifically
includes:
[0036] the processing module is configured to determine whether
there is any service requirement currently, and if there is no
service requirement currently, keep a connected state with the
first base station, and stay in the always connected mode; or
[0037] if there is a service requirement currently, request the
first base station to set up a corresponding bearer, and perform
data transmission by using the bearer.
[0038] With reference to the ninth possible implementation manner
of the first aspect, in a tenth possible implementation manner of
the first aspect, that the processing module is configured to keep
a connected state with the first base station if there is no
service requirement currently, specifically includes:
[0039] the processing module is configured to keep receiving
scheduling information sent by the first base station if there is
no service requirement currently.
[0040] With reference to the tenth possible implementation manner
of the first aspect, in an eleventh possible implementation manner
of the first aspect, the receiving module is further configured to
receive a discontinuous reception period configured by the first
base station; and
[0041] that the processing module is configured to keep receiving
scheduling information sent by the first base station specifically
includes:
[0042] the processing module is configured to receive, within an
active time of the discontinuous reception period, the scheduling
information sent by the first base station.
[0043] With reference to the sixth or the ninth or the tenth
possible implementation manner of the first aspect, in a twelfth
possible implementation manner of the first aspect, the receiving
module is further configured to:
[0044] receive, according to an instruction of the scheduling
information, second dedicated signaling sent by the first base
station, where the second dedicated signaling includes notification
information, and the notification information is used to notify the
terminal that a bearer needs to be set up for data
transmission.
[0045] With reference to the twelfth possible implementation manner
of the first aspect, in a thirteenth possible implementation manner
of the first aspect, the second dedicated signaling further
includes instruction information, where
[0046] the instruction information includes second instruction
information or third instruction information, the second
instruction information is instruction information instructing to
select at least one second base station to perform data
transmission, and the third instruction information is instruction
information instructing to perform data transmission only through
the first base station; and
[0047] the receiving module is further configured to receive the
second instruction information or the third instruction information
sent by the first base station.
[0048] With reference to the ninth possible implementation manner
of the first aspect, in a fourteenth possible implementation manner
of the first aspect, that the processing module is configured to
request the first base station to set up a corresponding bearer,
and perform data transmission by using the bearer if there is a
service requirement currently, specifically includes:
[0049] if there is a service requirement currently, the processing
module is configured to request the first base station to set up
the corresponding bearer, receive second dedicated signaling sent
by the first base station, where the second dedicated signaling
includes notification information, and the notification information
is used to notify the terminal that the bearer needs to be set up
for data transmission, and perform data transmission by using the
bearer.
[0050] With reference to the fourteenth possible implementation
manner of the first aspect, in a fifteenth possible implementation
manner of the first aspect, the receiving module is further
configured to:
[0051] receive an instruction message sent by the first base
station, where the instruction message includes second instruction
information or third instruction information, the second
instruction information is instruction information instructing to
select at least one second base station to perform data
transmission, and the third instruction information is instruction
information instructing to perform data transmission only through
the first base station.
[0052] With reference to the thirteenth or the fifteenth possible
implementation manner of the first aspect, in a sixteenth possible
implementation manner of the first aspect, the receiving module is
further configured to:
[0053] if the second instruction information sent by the first base
station is received, select, according to the second instruction
information, the at least one second base station to perform data
transmission.
[0054] With reference to the sixteenth possible implementation
manner of the first aspect, in a seventeenth possible
implementation manner of the first aspect, the sending module is
further configured to send information about the selected at least
one second base station to the first base station.
[0055] With reference to the twelfth or the fourteenth possible
implementation manner of the first aspect, in an eighteenth
possible implementation manner of the first aspect, the receiving
module is further configured to:
[0056] after receiving the second dedicated signaling, select at
least one second base station to perform data transmission, and
send information about the selected at least one second base
station to the first base station.
[0057] With reference to the twelfth or the fourteenth possible
implementation manner of the first aspect, in a nineteenth possible
implementation manner of the first aspect, the receiving module is
further configured to:
[0058] after receiving the second dedicated signaling, determine to
perform data transmission only through the first base station.
[0059] With reference to the sixteenth or the nineteenth possible
implementation manner of the first aspect, in a twentieth possible
implementation manner of the first aspect, the sending module is
further configured to:
[0060] if each second base station in the at least one second base
station has the context information of the terminal, send a
scheduling request message to each second base station, and obtain,
by using the scheduling request message, a resource allocated by
each second base station to perform data transmission; or
[0061] if each second base station in the at least one second base
station has the context information of the terminal, perform random
access to each second base station, and obtain a resource allocated
by each second base station to perform data transmission.
[0062] With reference to the twentieth possible implementation
manner of the first aspect, in a twenty-first possible
implementation manner of the first aspect, that the sending module
is configured to perform random access to each second base station,
and obtain a resource allocated by each second base station to
perform data transmission, includes:
[0063] the sending module is configured to perform random access to
each second base station by using unique identifier information
allocated by the first base station, and obtain the resource
allocated by each second base station according to the unique
identifier information to perform data transmission, where the
unique identifier information corresponds to the terminal, and the
unique identifier information is a unique preamble or a combination
of a unique preamble and a random access resource.
[0064] With reference to any one of the sixteenth to the nineteenth
possible implementation manners of the first aspect, in a
twenty-second possible implementation manner of the first aspect,
the sending module is further configured to:
[0065] if each second base station in the at least one second base
station does not have the context information of the terminal,
perform random access to each second base station, and in the
random access process, send, to each second base station, the
context information of the terminal and information about the first
base station to which the terminal has set up the connection.
[0066] With reference to the first aspect, in a twenty-third
possible implementation manner of the first aspect, the processing
module is further configured to:
[0067] after stopping performing data transmission through the
first base station and/or the second base station, continue to work
in always connected mode, and save dedicated configuration
information for setting up the connection to the first base
station.
[0068] With reference to the twenty-third possible implementation
of the first aspect, in a twenty-fourth possible implementation of
the first aspect, the processing module is further configured
to:
[0069] stop maintaining an uplink synchronization timer; or
[0070] after an uplink synchronization timer expires, stop
maintaining the uplink synchronization timer.
[0071] With reference to the first aspect, in a twenty-fifth
possible implementation manner of the first aspect, the receiving
module is further configured to:
[0072] receive a second base station list update message sent by
the first base station, update the second base station list
information according to the second base station list update
message, and obtain updated second base station list
information.
[0073] With reference to the twenty-fifth possible implementation
manner of the first aspect, in a twenty-sixth possible
implementation manner of the first aspect, before the receiving
module is configured to receive the second base station list update
message sent by the first base station, the sending module is
further configured to:
[0074] send a second base station list update request message to
the first base station.
[0075] With reference to the twenty-fifth possible implementation
manner of the first aspect, in a twenty-seventh possible
implementation manner of the first aspect, the second base station
list update message is generated by the first base station
according to location information of the terminal and location
information of each second base station.
[0076] With reference to the twenty-fifth possible implementation
of the first aspect, in a twenty-eighth possible implementation of
the first aspect, the processing module is further configured
to:
[0077] measure each neighboring base station in a network, and if a
neighboring base station whose signal quality is higher than a
first threshold exists, determine whether the updated second base
station list information includes information about the neighboring
base station.
[0078] With reference to the twenty-eighth possible implementation
of the first aspect, in a twenty-ninth possible implementation of
the first aspect, the processing module is further configured
to:
[0079] if the updated second base station list information does not
include the information about the neighboring base station, send a
neighboring base station measurement report to the first base
station, where the neighboring base station measurement report
includes the information about the neighboring base station; or
[0080] if the updated second base station list information does not
include the information about the neighboring base station, send a
second base station list update request message to the first base
station, where the second base station list update request message
includes the information about the neighboring base station; or
[0081] if the updated second base station list information does not
include the information about the neighboring base station, report
to the first base station that the neighboring base station is not
included in the updated second base station list.
[0082] With reference to the twenty-ninth possible implementation
of the first aspect, in a thirtieth possible implementation of the
first aspect, the neighboring base station measurement report
further includes an indication that the neighboring base station
does not have the context information of the terminal, so that the
first base station sends the context information of the terminal to
the neighboring base station.
[0083] With reference to the thirtieth possible implementation of
the first aspect, in a thirty-first possible implementation of the
first aspect, the receiving module is further configured to receive
a response message sent by the first base station, where the
response message is generated by the first base station according
to the neighboring base station measurement report, and learn,
according to the response message, that the neighboring base
station has obtained the context information of the terminal.
[0084] With reference to the first aspect, in a thirty-second
possible implementation manner of the first aspect, the receiving
module is further configured to:
[0085] receive default configuration information sent by the first
base station, where the default configuration information is
configuration information used when the terminal performs initial
data transmission with each second base station; and
[0086] that the sending module is configured to perform data
transmission through the first base station and/or the second base
station according to the second base station list information
specifically includes:
[0087] the sending module is configured to perform, according to
the second base station list information and the default
configuration information, data transmission through a second base
station that has the context information of the terminal.
[0088] With reference to the thirty-second possible implementation
manner of the first aspect, in a thirty-third possible
implementation manner of the first aspect, the default
configuration information is associated with a service type,
quality of service QoS of a service, or a bearer type.
[0089] With reference to the thirty-third possible implementation
manner of the first aspect, in a thirty-fourth possible
implementation manner of the first aspect, the receiving module is
further configured to:
[0090] receive a second base station list update message sent by
the first base station, update the second base station list
information according to the second base station list update
message, and obtain updated second base station list
information.
[0091] With reference to the thirty-second possible implementation
manner of the first aspect, in a thirty-fifth possible
implementation manner of the first aspect, that the sending module
is configured to perform, according to the second base station list
information and the default configuration information, data
transmission through a second base station that has the context
information of the terminal, includes:
[0092] the sending module is configured to perform, according to
the updated second base station list and the default configuration
information, initial data transmission through the second base
station that has the context information of the terminal; and
[0093] receive a reconfiguration message sent by the second base
station, modify, according to the reconfiguration message, default
configuration information corresponding to the terminal, and
perform, by using modified configuration information, data
transmission with the second base station that has the context
information of the terminal.
[0094] With reference to the first aspect, in a thirty-sixth
possible implementation manner of the first aspect, the receiving
module is further configured to:
[0095] receive measurement configuration information sent by the
first base station, and complete, according to the measurement
configuration information, a measurement configuration of a
frequency layer corresponding to each base station, where the base
stations include the first base station and the second base
stations, and the second base stations include a master second base
station and a secondary second base station.
[0096] With reference to the thirty-sixth possible implementation
manner of the first aspect, in a thirty-seventh possible
implementation manner of the first aspect, the measurement
configuration information includes:
[0097] measuring a frequency layer corresponding to the first base
station only; or
[0098] measuring frequency layers corresponding to the first base
station and the master second base station only; or
[0099] measuring frequency layers corresponding to all of the first
base station, the master second base station, and the secondary
second base station.
[0100] With reference to the thirty-seventh possible implementation
manner of the first aspect, in a thirty-eighth possible
implementation manner of the first aspect, the measurement
configuration information further includes:
[0101] determining a first threshold for measuring the frequency
layer corresponding to the first base station only; or
[0102] determining a second threshold for measuring the frequency
layers corresponding to the first base station and the master
second base station only; or
[0103] determining a third threshold for measuring the frequency
layers corresponding to all of the first base station, the master
second base station, and the secondary second base station.
[0104] With reference to the thirty-eighth possible implementation
manner of the first aspect, in a thirty-ninth possible
implementation manner of the first aspect, if QoS of a current
service of the terminal is less than the first threshold, that the
receiving module is configured to complete, according to the
measurement configuration information, a measurement configuration
of a frequency layer corresponding to each base station, includes:
the receiving module is configured to measure, according to the
measurement configuration information, the frequency layer
corresponding to the first base station only, and obtain a
measurement result; or
[0105] if QoS of a current service of the terminal is greater than
the first threshold but less than the second threshold, that the
receiving module is configured to complete, according to the
measurement configuration information, a measurement configuration
of a frequency layer corresponding to each base station, includes:
the receiving module is configured to measure, according to the
measurement configuration information, the frequency layer
corresponding to the first base station and the frequency layer
corresponding to the master second base station, and obtain
measurement results; or
[0106] if QoS of a current service of the terminal is greater than
the second threshold or the third threshold, that the receiving
module is configured to complete, according to the measurement
configuration information, a measurement configuration of a
frequency layer corresponding to each base station, includes: the
receiving module is configured to measure, according to the
measurement configuration information, the frequency layers
corresponding to the first base station, the master second base
station, and the secondary second base station, and obtain
measurement results.
[0107] With reference to any one of the thirty-sixth to the
thirty-ninth possible implementation manners of the first aspect,
in a fortieth possible implementation manner of the first aspect,
the receiving module is further configured to:
[0108] receive an instruction message sent by the first base
station about whether to perform measurement reporting; and
[0109] determine, according to the instruction message about
whether to perform measurement reporting, whether to send the
measurement result to the first base station.
[0110] With reference to the fortieth possible implementation
manner of the first aspect, in a forty-first possible
implementation manner of the first aspect, the instruction message
about whether to perform measurement reporting includes:
[0111] at least one of instruction information for measurement
reporting of the frequency layer corresponding to the first base
station, instruction information for measurement reporting of the
frequency layer corresponding to the master second base station, or
instruction information for measurement reporting of the frequency
layer corresponding to the secondary second base station.
[0112] With reference to the first aspect, in a forty-second
possible implementation manner of the first aspect, the receiving
module is further configured to:
[0113] receive measurement configuration parameter information sent
by the first base station, and complete, according to the
measurement configuration parameter information, measurement
management of a frequency layer corresponding to each base station,
where the base stations include the first base station and the
second base stations, and the second base stations include a master
second base station and a secondary second base station; where
[0114] the measurement configuration parameter information includes
at least one of a measurement configuration parameter of a
frequency layer corresponding to the first base station, a
measurement configuration parameter of a frequency layer
corresponding to the master second base station, or a measurement
configuration parameter of a frequency layer corresponding to the
secondary second base station.
[0115] With reference to the forty-second possible implementation
manner of the first aspect, in a forty-third possible
implementation manner of the first aspect, if QoS of a current
service of the terminal is less than a first threshold, that the
receiving module is configured to complete, according to the
measurement configuration parameter information, measurement
management of a frequency layer corresponding to each base station,
includes: the receiving module is configured to measure, according
to the measurement configuration parameter of the frequency layer
corresponding to the first base station, the frequency layer of the
first base station, and obtain a first measurement result; or
[0116] if QoS of a current service of the terminal is greater than
a first threshold but less than a second threshold, that the
receiving module is configured to complete, according to the
measurement configuration parameter information, measurement
management of a frequency layer corresponding to each base station,
includes: the receiving module is configured to measure, according
to the measurement configuration parameter of the frequency layer
corresponding to the first base station, the frequency layer of the
first base station, and obtain a first measurement result, and at
the same time, measure, according to the measurement configuration
parameter of the frequency layer corresponding to the master second
base station, the frequency layer of the master second base
station, and obtain a second measurement result; or
[0117] if QoS of a current service of the terminal is greater than
a second threshold, that the receiving module is configured to
complete, according to the measurement configuration parameter
information, measurement management of a frequency layer
corresponding to each base station, includes: the receiving module
is configured to measure, according to the measurement
configuration parameter of the frequency layer corresponding to the
secondary second base station, the frequency layer of the secondary
second base station, and obtain a third measurement result.
[0118] With reference to the forty-third possible implementation
manner of the first aspect, in a forty-fourth possible
implementation manner of the first aspect, that the receiving
module is configured to measure, according to the measurement
configuration parameter of the frequency layer corresponding to the
first base station, the frequency layer of the first base station,
specifically includes:
[0119] the receiving module is configured to measure, according to
the measurement configuration parameter of the frequency layer
corresponding to the first base station, the first base station
and/or a first base station neighboring to the first base
station.
[0120] With reference to the forty-third possible implementation
manner of the first aspect, in a forty-fifth possible
implementation manner of the first aspect, that the receiving
module is configured to measure, according to the measurement
configuration parameter of the frequency layer corresponding to the
master second base station, the frequency layer of the master
second base station, specifically includes:
[0121] the receiving module is configured to measure, according to
the measurement configuration parameter of the frequency layer
corresponding to the master second base station, the master second
base station and/or a master second base station neighboring to the
master second base station.
[0122] With reference to the forty-third possible implementation
manner of the first aspect, in a forty-sixth possible
implementation manner of the first aspect, that the receiving
module is configured to measure, according to the measurement
configuration parameter of the frequency layer corresponding to the
secondary second base station, the frequency layer of the secondary
second base station, specifically includes:
[0123] the receiving module is configured to measure, according to
the measurement configuration parameter of the frequency layer
corresponding to the secondary second base station, the secondary
second base station and/or a secondary second base station
neighboring to the secondary second base station.
[0124] With reference to the forty-third possible implementation
manner of the first aspect, in a forty-seventh possible
implementation manner of the first aspect, the sending module is
further configured to:
[0125] send the obtained first measurement result to the first base
station; and
[0126] skip sending the third measurement result to the first base
station.
[0127] With reference to any one of the forty-third to the
forty-seventh possible implementation manners of the first aspect,
in a forty-eighth possible implementation manner of the first
aspect, the sending module is further configured to:
[0128] compare the obtained second measurement result with a preset
condition, and if the preset condition is met, send the second
measurement result to the first base station.
[0129] With reference to the first aspect, in a forty-ninth
possible implementation manner of the first aspect, the receiving
module is further configured to:
[0130] receive a handover command message sent by the current
serving first base station, where the handover command message
includes information about each second base station that is
controlled by a target first base station and has the context
information of the terminal, the current serving first base station
is the first base station that currently performs data transmission
with the terminal, and the target first base station is a target
first base station to which the terminal is handed over from the
current serving first base station.
[0131] With reference to the forty-ninth possible implementation
manner of the first aspect, in a fiftieth possible implementation
manner of the first aspect, the handover command message further
includes instruction information instructing the terminal to skip
performing random access to the target first base station; and
[0132] the processing module does not perform random access to the
target first base station according to the instruction information
instructing to skip performing random access to the target first
base station.
[0133] With reference to the forty-ninth possible implementation
manner of the first aspect, in a fifty-first possible
implementation manner of the first aspect, the sending module is
further configured to:
[0134] select, according to the handover command message, at least
one second base station that has the context information of the
terminal, so as to perform data transmission.
[0135] With reference to the forty-ninth possible implementation
manner of the first aspect, in a fifty-second possible
implementation manner of the first aspect, each second base station
that is controlled by the target first base station and has the
context information of the terminal is controlled by the target
first base station or connected to the target first base
station.
[0136] With reference to the forty-ninth possible implementation
manner of the first aspect, in a fifty-third possible
implementation manner of the first aspect, each second base station
that is controlled by the target first base station and has the
context information of the terminal is controlled by the current
serving first base station and the target first base station
jointly, or has connection relationships with both the current
serving first base station and the target first base station.
[0137] With reference to any one of the forty-ninth to the
fifty-third possible implementation manners of the first aspect, in
a fifty-fourth possible implementation manner of the first aspect,
before the receiving module is configured to receive the handover
command message sent by the current serving first base station, the
receiving module is further configured to:
[0138] measure each first base station in a network, and obtain a
measurement result of each first base station, where the first base
stations include the current serving first base station and
neighboring first base stations, and the neighboring first base
stations include the target first base station.
[0139] With reference to the fifty-fourth possible implementation
manner of the first aspect, in a fifty-fifth possible
implementation manner of the first aspect, the receiving module is
further configured to:
[0140] determine the target first base station according to a
measurement result of the current serving first base station and
measurement results of the neighboring first base stations; and
[0141] send a first handover request message to the current serving
first base station, where the first handover request message
includes information about requesting to be handed over to the
target first base station.
[0142] With reference to the fifty-fourth possible implementation
manner of the first aspect, in a fifty-sixth possible
implementation manner of the first aspect, the sending module is
further configured to send the measurement results of the
neighboring first base stations to the current serving first base
station, so that the current serving first base station determines
whether to perform the handover to the target first base
station.
[0143] With reference to the fifty-first possible implementation
manner of the first aspect, in a fifty-seventh possible
implementation manner of the first aspect, that the sending module
is configured to select, according to the handover command message,
at least one second base station that has the context information
of the terminal, so as to perform data transmission, includes:
[0144] the sending module is configured to preferentially select,
according to the handover command message, a second base station
that provides services under control of the current serving first
base station and has the context information, so as to perform data
transmission, where the second base station is controlled by the
target first base station.
[0145] With reference to the forty-ninth possible implementation
manner of the first aspect, in a fifty-eighth possible
implementation manner of the first aspect, the handover command
message further includes:
[0146] instruction information instructing the terminal to keep
performing data transmission with at least one current serving
second base station, where the current serving second base station
is a second base station that provides data transmission for the
terminal before the handover command is received; and
[0147] the sending module is configured to perform the handover to
the target first base station according to the handover command
message, and at the same time, keep performing data transmission
through the at least one current serving second base station.
[0148] With reference to the fifty-eighth possible implementation
manner of the first aspect, in a fifty-ninth possible
implementation manner of the first aspect, the sending module is
further configured to:
[0149] send a handover complete indication to the current serving
first base station through a second base station controlled by the
current serving first base station.
[0150] With reference to the first aspect, in a sixtieth possible
implementation manner of the first aspect, the sending module is
further configured to:
[0151] measure each first base station in a network, and obtain a
measurement result of each first base station, where the first base
stations include the current serving first base station and
neighboring first base stations;
[0152] determine a target first base station according to the
measurement result, where the target first base station is a target
first base station to which the terminal is handed over from the
current serving first base station; and
[0153] send a handover request message to the target first base
station, where the handover request message includes information
about the current serving first base station and information about
candidate second base stations, where the candidate second base
stations are second base stations that are controlled by the target
first base station or connected to the target first base station
and can provide services for the terminal.
[0154] With reference to the sixtieth possible implementation
manner of the first aspect, in a sixty-first possible
implementation manner of the first aspect, the receiving module is
further configured to:
[0155] receive a handover request acknowledgement message from the
target first base station, where the handover request
acknowledgement message includes a list of second base stations
that are controlled by the target first base station or connected
to the target first base station and have the context information
of the terminal; and
[0156] the sending module is further configured to select,
according to the handover request acknowledgement message, at least
one second base station that has the context information of the
terminal, so as to perform data transmission.
[0157] With reference to the sixty-first possible implementation
manner of the first aspect, in a sixty-second possible
implementation manner of the first aspect, after being configured
to select, according to the handover request acknowledgement
message, the at least one second base station that has the context
information of the terminal, so as to perform data transmission,
the sending module is further configured to:
[0158] send a handover complete indication message to the current
serving first base station; or
[0159] send a handover complete indication message to the current
serving first base station through the target first base
station.
[0160] With reference to the first aspect, in a sixty-third
possible implementation manner of the first aspect, the sending
module is further configured to:
[0161] measure each first base station in a network, and obtain a
measurement result of each first base station, where the first base
stations include the current serving first base station and
neighboring first base stations;
[0162] determine a target first base station according to the
measurement result, where the target first base station is a target
first base station to which the terminal is handed over from the
current serving first base station;
[0163] send a handover request message to the current serving first
base station, where the handover request message includes
information about requesting to be handed over to the target first
base station; and
[0164] receive a handover command message sent by the current
serving first base station.
[0165] With reference to the sixty-third possible implementation
manner of the first aspect, in a sixty-fourth possible
implementation manner of the first aspect, the handover command
message includes instruction information instructing the terminal
to perform the handover to the target first base station and
instruction information instructing the terminal to keep performing
data transmission with at least one current serving second base
station, where the current serving second base station is a second
base station that provides data transmission for the terminal
before the handover command message is received; and
[0166] the sending module is configured to perform the handover to
the target first base station according to the handover command
message, and at the same time, keep performing data transmission
through the at least one current serving second base station.
[0167] With reference to the sixty-fourth possible implementation
manner of the first aspect, in a sixty-fifth possible
implementation manner of the first aspect, the handover command
message further includes bearer reconfiguration information;
and
[0168] the sending module is configured to switch a data
transmission service between the current serving first base station
and the terminal to the current serving second base station
according to the bearer reconfiguration information.
[0169] With reference to the first aspect, in a sixty-sixth
possible implementation manner of the first aspect, before being
configured to perform data transmission through the first base
station and/or the second base station according to the list
information of the second base stations having the context
information, the sending module is further configured to:
[0170] set up a first security mechanism with the first base
station, and set up a second security mechanism with the second
base station.
[0171] With reference to the sixty-sixth possible implementation
manner of the first aspect, in a sixty-seventh possible
implementation manner of the first aspect, that the sending module
is configured to set up a second security mechanism with the second
base station includes:
[0172] the sending module is configured to receive the second base
station list information and security algorithm information sent by
the first base station, where the second base station list
information includes the information about each second base station
having the context information, and the security algorithm
information includes security algorithm information corresponding
to each second base station included in the second base station
list; and
[0173] select at least one second base station from the second base
station list, and obtain, according to a security index
corresponding to the at least one second base station and the
security algorithm information, an encryption key and/or an
integrity protection key corresponding to each second base station;
where
[0174] the second base station corresponds to the security index on
a one-to-one basis.
[0175] With reference to the sixty-seventh possible implementation
manner of the first aspect, in a sixty-eighth possible
implementation manner of the first aspect, that the sending module
is configured to obtain, according to a security index
corresponding to the at least one second base station and the
security algorithm information, an encryption key and/or an
integrity protection key corresponding to each second base station,
includes:
[0176] the sending module is configured to obtain, according to the
security index corresponding to the at least one second base
station, a security key corresponding to the at least one security
index, and obtain a corresponding root key through calculation
according to the security key;
[0177] obtain, by using the root key, an intermediate key
corresponding to the second base station; and
[0178] obtain, according to the intermediate key and the security
algorithm information corresponding to the second base station, the
encryption key and/or the integrity protection key corresponding to
the second base station.
[0179] With reference to the sixty-eighth possible implementation
manner of the first aspect, in a sixty-ninth possible
implementation manner of the first aspect, that the sending module
is configured to perform data transmission through the first base
station and/or the second base station includes:
[0180] the sending module is configured to perform data
transmission through the first base station based on the first
security mechanism, and/or perform data transmission through the
second base station based on the second security mechanism.
[0181] With reference to the sixty-sixth possible implementation
manner of the first aspect, in a seventieth possible implementation
manner of the first aspect, the first security mechanism and the
second security mechanism are associated with each other; and
[0182] that the sending module is configured to obtain, according
to a security index corresponding to the at least one second base
station and the security algorithm information, an encryption key
and/or an integrity protection key corresponding to each second
base station, includes:
[0183] the sending module is configured to obtain, according to the
security index corresponding to the at least one second base
station, a security key and a dynamic count corresponding to the at
least one security index, and obtain a corresponding root key
through calculation according to the security key;
[0184] obtain, by using the root key, an intermediate key
corresponding to the second base station;
[0185] obtain an associated intermediate key according to the
intermediate key and the dynamic count; and
[0186] obtain, according to the associated intermediate key and the
security algorithm information corresponding to the second base
station, the encryption key and/or the integrity protection key
corresponding to the second base station.
[0187] According to a second aspect, an embodiment of the present
invention provides a base station, where the base station is used
as a first base station, and includes:
[0188] a processing module, configured to set up a connection to a
terminal, and stay in always connected mode, where the always
connected mode is to always keep the connection to the terminal;
and
[0189] a sending module, configured to send first dedicated
signaling to the terminal, where the first dedicated signaling
includes second base station list information, and the second base
station list information includes information about each second
base station having context information of the terminal; and
[0190] perform data transmission with the terminal.
[0191] With reference to the second aspect, in a first possible
implementation manner of the second aspect, that the first base
station sets up a connection to a terminal, and stays in always
connected mode, includes:
[0192] the first base station always keeps the connection to the
first base station within a preset time.
[0193] With reference to the second aspect or the first possible
implementation manner of the second aspect, in a second possible
implementation manner of the second aspect, that the sending module
is configured to perform data transmission with the terminal
specifically includes:
[0194] the sending module is configured to transmit only control
signaling to the terminal; or
[0195] transmit only downlink data to the terminal; or
[0196] transmit only downlink control signaling to the
terminal.
[0197] With reference to the second aspect, in a third possible
implementation manner of the second aspect, before being configured
to set up the connection to the terminal, and stay in always
connected mode, the sending module is further configured to:
[0198] send a dedicated message to the terminal, where the
dedicated message carries instruction information instructing the
terminal whether to work in the always connected mode; or
[0199] receive a first indication message sent by the terminal,
where the first indication message carries indication information
about whether the terminal requests to work in the always connected
mode, and determine, according to the first indication message,
whether to configure the terminal to work in the always connected
mode; or
[0200] after receiving a random access preamble sent by the
terminal, send a random access response message to the terminal,
where the random access response message carries instruction
information instructing the terminal whether to work in the always
connected mode, so that the terminal determines, according to the
random access response message, whether to work in the always
connected mode; or
[0201] after receiving a connection setup request message sent by
the terminal, send a connection setup response message to the
terminal, where the connection setup response message carries
instruction information instructing the terminal whether to work in
the always connected mode; or
[0202] after receiving a connection setup request message sent by
the terminal, send a dedicated message to the terminal, where the
dedicated message carries instruction information instructing the
terminal whether to work in the always connected mode.
[0203] With reference to the third possible implementation manner
of the second aspect, in a fourth possible implementation manner of
the second aspect, the first indication message includes:
[0204] a random access message 3 or a connection setup request
message.
[0205] With reference to any one of the second aspect, or the first
to the fourth possible implementation manners of the second aspect,
in a fifth possible implementation manner of the second aspect,
that the sending module is configured to set up a connection to a
terminal, and stay in always connected mode, specifically
includes:
[0206] if no service request message sent by the terminal is
received, the sending module is configured to keep a connected
state with the terminal, and stay in the always connected mode;
or
[0207] if a service request message sent by the terminal is
received, where the service request message includes information
about requesting to set up a corresponding bearer, the sending
module is configured to set up the bearer for the terminal
according to the service request message, so as to perform data
transmission.
[0208] With reference to the fifth possible implementation manner
of the second aspect, in a sixth possible implementation manner of
the second aspect, when no service request message sent by the
terminal is received, the sending module is further configured
to:
[0209] configure a discontinuous reception period for the terminal,
so that the terminal receives, within an active time of the
discontinuous reception period, scheduling information sent by the
first base station.
[0210] With reference to the sixth possible implementation manner
of the second aspect, in a seventh possible implementation manner
of the second aspect, the sending module is further configured
to:
[0211] send the scheduling information to the terminal, where the
scheduling information is used to instruct the terminal to receive
second dedicated signaling; and
[0212] send the second dedicated signaling to the terminal, where
the second dedicated signaling includes a notification message, and
the notification message includes information notifying the
terminal that the bearer needs to be set up for data
transmission.
[0213] With reference to the seventh possible implementation manner
of the second aspect, in an eighth possible implementation manner
of the second aspect, the second dedicated signaling further
includes instruction information, where the instruction information
includes second instruction information or third
[0214] instruction information, the second instruction information
is instruction information instructing the terminal to select at
least one second base station to perform data transmission, and the
third instruction information is instruction information
instructing the terminal to perform data transmission only through
the first base station.
[0215] With reference to the fifth possible implementation manner
of the second aspect, in a ninth possible implementation manner of
the second aspect, if the service request message sent by the
terminal is received, the sending module is further configured
to:
[0216] if the service request message sent by the terminal is
received, send the scheduling information to the terminal, where
the scheduling information is used to instruct the terminal to
receive second dedicated signaling; and
[0217] send the second dedicated signaling to the terminal, where
the second dedicated signaling includes a notification message, and
the notification message includes information notifying the
terminal that the bearer needs to be set up for data transmission,
and perform data transmission with the terminal by using the
bearer.
[0218] With reference to the ninth possible implementation manner
of the second aspect, in a tenth possible implementation manner of
the second aspect, the sending module is further configured to:
[0219] send an instruction message to the terminal, where the
instruction message includes second instruction information or
third instruction information, the second instruction information
is instruction information instructing to select at least one
second base station to perform data transmission, and the third
instruction information is instruction information instructing to
perform data transmission only through the first base station.
[0220] With reference to the eighth or the tenth possible
implementation manner of the second aspect, in an eleventh possible
implementation manner of the second aspect, the base station
further includes a receiving module, configured to:
[0221] receive information sent by the terminal about the selected
at least one second base station, where the information about the
selected at least one second base station is information about each
second base station in the at least one second base station
selected by the terminal according to the second instruction
information.
[0222] With reference to the eleventh possible implementation
manner of the second aspect, in a twelfth possible implementation
manner of the second aspect, the sending module is further
configured to:
[0223] determine whether each second base station in the
information about the selected at least one second base station has
the context information of the terminal; and
[0224] if a second base station that does not have the context
information of the terminal exists, send the context information of
the terminal to the second base station that does not have the
context information of the terminal.
[0225] With reference to any one of the ninth to the twelfth
possible implementation manners of the second aspect, in a
thirteenth possible implementation manner of the second aspect, the
sending module is further configured to:
[0226] allocate a unique preamble or a combination of a unique
preamble and a random access channel resource to the terminal, so
that the terminal obtains, by using the unique preamble or the
combination of the unique preamble and the random access channel
resource, a resource allocated by the second base station, so as to
perform data transmission.
[0227] With reference to the second aspect, in a fourteenth
possible implementation manner of the second aspect, the processing
module is further configured to:
[0228] after the first base station stops performing data
transmission with the terminal, the first base station saves
configuration information for setting up the connection to the
terminal.
[0229] With reference to the second aspect, in a fifteenth possible
implementation manner of the second aspect, the sending module is
further configured to:
[0230] generate a second base station list update message, and send
the second base station list update message to the terminal, where
the second base station list update message includes updated second
base station list information, so that the terminal updates the
second base station list information according to the second base
station list update message.
[0231] With reference to the fifteenth possible implementation
manner of the second aspect, in a sixteenth possible implementation
manner of the second aspect, that the sending module is configured
to generate a second base station list update message includes:
[0232] the sending module is configured to generate the second base
station list update message according to one or more of location
information of the terminal, location information of each second
base station, or a measurement report reported by the terminal.
[0233] With reference to the second aspect, in a seventeenth
possible implementation manner of the second aspect, the base
station further includes a receiving module, configured to:
[0234] receive a neighboring base station measurement report sent
by the terminal, where the neighboring base station measurement
report includes information about a neighboring base station, and
the information about the neighboring base station is not included
in the second base station list information; or
[0235] receive a second base station list update request message
sent by the terminal, where the second base station list update
request message includes information about a neighboring base
station, and the information about the neighboring base station is
not included in the second base station list information; or
[0236] receive a report of the terminal that a neighboring base
station is not included in the second base station list.
[0237] With reference to the seventeenth possible implementation
manner of the second aspect, in an eighteenth possible
implementation manner of the second aspect, the sending module is
further configured to:
[0238] if the neighboring base station does not have the context
information of the terminal, send the context information of the
terminal to the neighboring base station, and send a second base
station list update message to the terminal, where the second base
station list update message includes the information about the
neighboring base station.
[0239] With reference to the seventeenth possible implementation
manner of the second aspect, in a nineteenth possible
implementation manner of the second aspect, the second base station
measurement report further includes information indicating that the
neighboring base station does not have the context information of
the terminal; and
[0240] the sending module is further configured to send the context
information of the terminal to the neighboring base station, and
send a response message to the terminal, where the response message
is generated by the first base station according to the neighboring
base station measurement report, so that the terminal learns,
according to the response message, that the neighboring base
station has obtained the context information of the terminal.
[0241] With reference to the second aspect, in a twentieth possible
implementation manner of the second aspect, the sending module is
further configured to:
[0242] send default configuration information to the terminal and
each second base station separately, where the default
configuration information is associated with a service type,
quality of service QoS of a service, or a bearer type, and the
default configuration information is configuration information used
when the terminal performs initial data transmission with each
second base station.
[0243] With reference to the twentieth possible implementation
manner of the second aspect, in a twenty-first possible
implementation manner of the second aspect, the sending module is
further configured to:
[0244] send a second base station list update message to the
terminal, so that the terminal updates the second base station list
information according to the second base station list update
message and performs, by using updated second base station list
information and the default configuration information, initial data
transmission through a second base station that has the context
information of the terminal.
[0245] With reference to the second aspect, in a twenty-second
possible implementation manner of the second aspect, the sending
module is further configured to:
[0246] send measurement configuration information to the terminal,
where the measurement configuration information includes
measurement configuration information of a frequency layer
corresponding to each base station, the base station includes at
least one of the first base station or the second base stations,
and the second base stations include a master second base station
and a secondary second base station.
[0247] With reference to the twenty-second possible implementation
manner of the second aspect, in a twenty-third possible
implementation manner of the second aspect, the measurement
configuration information includes:
[0248] measuring a frequency layer corresponding to the first base
station only; or
[0249] measuring frequency layers corresponding to the first base
station and the master second base station only; or
[0250] measuring frequency layers corresponding to all of the first
base station, the master second base station, and the secondary
second base station.
[0251] With reference to the twenty-third possible implementation
manner of the second aspect, in a twenty-fourth possible
implementation manner of the second aspect, the measurement
configuration information further includes:
[0252] a first threshold for measuring the frequency layer
corresponding to the first base station only; or
[0253] a second threshold for measuring the frequency layers
corresponding to the first base station and the master second base
station only; or
[0254] a third threshold for measuring the frequency layers
corresponding to all of the first base station, the master second
base station, and the secondary second base station.
[0255] With reference to the twenty-fourth possible implementation
manner of the second aspect, in a twenty-fifth possible
implementation manner of the second aspect, the sending module is
further configured to:
[0256] send, to the terminal, an instruction message about whether
to perform measurement reporting.
[0257] With reference to the twenty-fifth possible implementation
manner of the second aspect, in a twenty-sixth possible
implementation manner of the second aspect, the instruction message
about whether to perform measurement reporting includes:
[0258] at least one of instruction information for measurement
reporting of the frequency layer corresponding to the first base
station, instruction information for measurement reporting of the
frequency layer corresponding to the master second base station, or
instruction information for measurement reporting of the frequency
layer corresponding to the secondary second base station.
[0259] With reference to the second aspect, in a twenty-seventh
possible implementation manner of the second aspect, the sending
module is further configured to:
[0260] send measurement configuration parameter information to the
terminal, where the measurement configuration parameter information
includes at least one of a measurement configuration parameter of a
frequency layer corresponding to the first base station, a
measurement configuration parameter of a frequency layer
corresponding to a master second base station, or a measurement
configuration parameter of a frequency layer corresponding to a
secondary second base station.
[0261] With reference to the twenty-seventh possible implementation
manner of the second aspect, in a twenty-eighth possible
implementation manner of the second aspect, the receiving module is
further configured to:
[0262] receive measurement results sent by the terminal, where the
measurement results include a first measurement result and a second
measurement result, the first measurement result is obtained by the
terminal by performing a measurement according to the measurement
configuration parameter of the frequency layer corresponding to the
first base station, and the second measurement result is obtained
by the terminal by measuring the master second base station
according to the measurement configuration parameter of the
frequency layer corresponding to the master second base
station.
[0263] With reference to the second aspect, in a twenty-ninth
possible implementation manner of the second aspect, the sending
module is further configured to:
[0264] set up a first security mechanism with the terminal, and
assist the second base station in setting up a second security
mechanism with the terminal.
[0265] With reference to the twenty-ninth possible implementation
manner of the second aspect, in a thirtieth possible implementation
manner of the second aspect, that the sending module is configured
to assist the second base station in setting up a second security
mechanism with the terminal includes:
[0266] the sending module is configured to obtain, according to a
security index corresponding to at least one second base station, a
security key corresponding to the at least one security index, and
obtain a corresponding root key through calculation according to
the security key;
[0267] obtain, by using the root key, an intermediate key
corresponding to the second base station; and
[0268] send, to the second base station, the intermediate key
corresponding to the second base station; where
[0269] the security index corresponds to the second base station on
a one-to-one basis.
[0270] With reference to the thirtieth possible implementation
manner of the second aspect, in a thirty-first possible
implementation manner of the second aspect, the base station
further includes a receiving module, configured to:
[0271] receive security algorithm information corresponding to the
second base station and sent by the second base station.
[0272] With reference to the twenty-ninth possible implementation
manner of the second aspect, in a thirty-first possible
implementation manner of the second aspect, the first security
mechanism and the second security mechanism are associated with
each other, and that the sending module is configured to assist the
second base station in setting up a second security mechanism with
the terminal includes:
[0273] the sending module is configured to obtain, according to a
security index corresponding to at least one second base station, a
security key corresponding to the at least one security index, and
obtain a corresponding root key through calculation according to
the security key;
[0274] obtain, by using the root key and a unique count
corresponding to the second base station, an intermediate key
corresponding to the second base station; and
[0275] send, to the second base station, the intermediate key
corresponding to the second base station; where
[0276] the security index corresponds to the second base station on
a one-to-one basis.
[0277] With reference to the thirty-second possible implementation
manner of the second aspect, in a thirty-third possible
implementation manner of the second aspect, the receiving module is
further configured to:
[0278] receive security algorithm information and a dynamic count
corresponding to the second base station and sent by the second
base station.
[0279] According to a third aspect, an embodiment of the present
invention provides a base station, where the base station is used
as a current serving first base station, and includes:
[0280] a processing module, configured to set up a connection to a
terminal, and stay in always connected mode, where the always
connected mode is to always keep the connection to the terminal;
and
[0281] a sending module, configured to send first dedicated
signaling to the terminal, where the first dedicated signaling
includes second base station list information, and the second base
station list information includes information about each second
base station having context information of the terminal; and
[0282] perform data transmission with the terminal.
[0283] With reference to the third aspect, in a first possible
implementation manner of the third aspect, the sending module is
further configured to:
[0284] send a handover command message to the terminal, where the
handover command message includes information about each second
base station that is controlled by a target first base station and
has the context information of the terminal, and the target first
base station is a target first base station to which the terminal
is handed over from the current serving first base station.
[0285] With reference to the first possible implementation manner
of the third aspect, in a second possible implementation manner of
the third aspect, the handover command message further includes
instruction information instructing the terminal to skip performing
random access to the target first base station, so that the
terminal does not perform random access to the target first base
station according to the instruction information.
[0286] With reference to the first possible implementation manner
of the third aspect, in a third possible implementation manner of
the third aspect, before being configured to send the handover
command message to the terminal, the sending module is further
configured to:
[0287] receive a measurement result of each neighboring first base
station that is sent by the terminal, where the measurement result
of each neighboring first base station is obtained by the terminal
by measuring each base station neighboring to the current serving
first base station; and
[0288] determine the target first base station according to the
measurement result of each neighboring first base station.
[0289] With reference to the first possible implementation manner
of the third aspect, in a fourth possible implementation manner of
the third aspect, before being configured to send the handover
command message to the terminal, the sending module is further
configured to:
[0290] receive a first handover request message sent by the
terminal, where the first handover request message includes
information about the target first base station.
[0291] With reference to the first possible implementation manner
of the third aspect, in a fifth possible implementation manner of
the third aspect, the sending module is further configured to:
[0292] send a second handover request message to the target first
base station, where the second handover request message includes
the context information of the terminal and the information about
each second base station that currently has the context information
of the terminal.
[0293] With reference to the fifth possible implementation manner
of the third aspect, in a sixth possible implementation of the
third aspect, the sending module is further configured to:
[0294] send a handover instruction to a second base station
currently providing services for the terminal, so that the second
base station currently providing services for the terminal performs
data transmission according to the handover instruction.
[0295] With reference to the sixth possible implementation manner
of the third aspect, in a seventh possible implementation of the
third aspect, the second base station currently providing services
for the terminal is a second base station that is controlled by the
current serving first base station and has the context information
of the terminal, or a second base station that is connected to the
current serving first base station and has the context information
of the terminal.
[0296] With reference to the sixth possible implementation manner
of the third aspect, in an eighth possible implementation of the
third aspect, that the sending module is configured to send a
handover instruction to a second base station currently providing
services for the terminal, so that the second base station
currently providing services for the terminal performs data
transmission according to the handover instruction, includes: the
sending module is configured to send the handover instruction to
the second base station currently providing services for the
terminal, where the handover instruction includes information about
the target first base station, so that the second base station
currently providing services for the terminal determines, according
to the handover instruction, whether data transmission can be
performed with the terminal under control of the target first base
station.
[0297] With reference to the sixth possible implementation manner
of the third aspect, in a ninth possible implementation of the
third aspect, that the sending module is configured to send a
handover instruction to a second base station currently providing
services for the terminal, so that the second base station
currently providing services for the terminal performs data
transmission according to the handover instruction, includes: the
sending module is configured to send the handover instruction to
the second base station currently providing services for the
terminal, where the handover instruction includes information
instructing to stop performing data transmission with the terminal,
so that the second base station currently providing services for
the terminal stops performing data transmission with the terminal
according to the handover instruction.
[0298] With reference to the sixth possible implementation manner
of the third aspect, in a tenth possible implementation of the
third aspect, that the sending module is configured to send a
handover instruction to a second base station currently providing
services for the terminal, so that the second base station
currently providing services for the terminal performs data
transmission according to the handover instruction, includes: the
sending module is configured to send the handover instruction to
the second base station currently providing services for the
terminal, where the handover instruction includes information
instructing to continue to perform data transmission with the
terminal, so that the second base station currently providing
services for the terminal continues to perform data transmission
with the terminal according to the handover instruction.
[0299] With reference to the first possible implementation manner
of the third aspect, in an eleventh possible implementation of the
third aspect, the handover command message further includes second
base station instruction information, and the second base station
instruction information is instruction information instructing the
terminal to keep performing data transmission with at least one
current serving second base station.
[0300] With reference to the third aspect, in a twelfth possible
implementation manner of the third aspect, the sending module is
further configured to:
[0301] send a second base station control negotiation message to a
target first base station, where the second base station control
negotiation message includes information about a second base
station that meets a joint control condition; and
[0302] receive a second base station negotiation response message
sent by the target first base station, where the second base
station negotiation response message is a response message
generated according to the second base station control negotiation
message, and the response message includes information about a
second base station that is determined by the neighboring first
base station and can be jointly controlled, or an acknowledgement
of information about a second base station that is included in the
second base station control negotiation message and can be jointly
controlled.
[0303] With reference to the twelfth possible implementation manner
of the third aspect, in a thirteenth possible implementation manner
of the third aspect, before being configured to send the second
base station control negotiation message to the target first base
station, the sending module is further configured to: obtain,
according to location information of each second base station in a
network and location information of the current serving first base
station and the target first base station, the second base station
that meets the joint control condition, where the second base
station that meets the joint control condition is a second base
station that is controlled by the current serving first base
station and the target first base station jointly.
[0304] With reference to the twelfth or the thirteenth possible
implementation manner of the third aspect, in a fourteenth possible
implementation manner of the third aspect, the sending module is
further configured to:
[0305] after the current serving first base station receives a
first handover request message sent by the terminal, send a second
handover request message to the target first base station according
to the second base station negotiation response message, where the
second handover request message includes the context information of
the terminal and the information about the second base station that
meets the joint control condition.
[0306] According to a fourth aspect, an embodiment of the present
invention provides a wireless communications method, including:
[0307] setting up, by a terminal, a connection to a first base
station, and staying in always connected mode, where the always
connected mode is to always keep the connection to the first base
station;
[0308] receiving, by the terminal, first dedicated signaling sent
by the first base station, where the first dedicated signaling
includes second base station list information, and the second base
station list information includes information about each second
base station having context information of the terminal; and
[0309] performing, by the terminal, data transmission through the
first base station and/or the second base station according to the
second base station list information.
[0310] With reference to the fourth aspect, in a first possible
implementation manner of the fourth aspect, the setting up, by a
terminal, a connection to a first base station, and staying in
always connected mode, includes:
[0311] always keeping, by the terminal, the connection to the first
base station within a preset time.
[0312] With reference to the fourth aspect or the first possible
implementation manner of the fourth aspect, in a second possible
implementation manner of the fourth aspect, the performing data
transmission through the first base station includes:
[0313] performing only control signaling transmission through the
first base station; or
[0314] performing only downlink data transmission through the first
base station; or
[0315] performing only downlink control signaling transmission
through the first base station.
[0316] With reference to the fourth aspect, in a third possible
implementation manner of the fourth aspect, before the setting up,
by a terminal, a connection to a first base station, and staying in
always connected mode, the method further includes:
[0317] obtaining, by the terminal, access frequency information,
and determining whether a connected mode corresponding to the
access frequency information is the always connected mode.
[0318] With reference to the third possible implementation manner
of the fourth aspect, in a fourth possible implementation manner of
the fourth aspect, the obtaining, by the terminal, access frequency
information, and determining whether a connected mode corresponding
to the access frequency information is the always connected mode,
includes:
[0319] receiving system information sent by the first base station,
and obtaining, from the system information, whether the connected
mode corresponding to the access frequency information is the
always connected mode; or
[0320] obtaining, from preset configuration information, whether
the connected mode corresponding to the access frequency
information is the always connected mode.
[0321] With reference to the third or the fourth possible
implementation manner of the fourth aspect, in a fifth possible
implementation manner of the fourth aspect, the method further
includes: if the connected mode corresponding to the access
frequency information is the always connected mode, selecting a
first base station corresponding to the access frequency
information to perform access.
[0322] With reference to any one of the fourth aspect, or the first
to the fifth possible implementation manners of the fourth aspect,
in a sixth possible implementation manner of the fourth aspect, the
setting up a connection to the first base station includes:
[0323] sending a first indication message to the first base
station, where the first indication message carries indication
information about whether to request to accept working in the
always connected mode; and
[0324] receiving connection configuration information that is sent
by the first base station according to the first indication
message, where the connection configuration information includes
whether to configure the terminal to work in the always connected
mode.
[0325] With reference to the sixth possible implementation manner
of the fourth aspect, in a seventh possible implementation manner
of the fourth aspect, the first indication message includes:
[0326] a random access message 3 or a connection setup request
message.
[0327] With reference to any one of the fourth aspect, or the first
to the seventh possible implementation manners of the fourth
aspect, in an eighth possible implementation manner of the fourth
aspect, the method further includes:
[0328] receiving scheduling information sent by the first base
station.
[0329] With reference to any one of the fourth aspect, or the first
to the seventh possible implementation manners of the fourth
aspect, in a ninth possible implementation manner of the fourth
aspect, the setting up a connection to a first base station, and
staying in always connected mode, includes:
[0330] determining whether there is any service requirement
currently, and if there is no service requirement currently,
keeping a connected state with the first base station, and staying
in the always connected mode; or
[0331] if there is a service requirement currently, requesting the
first base station to set up a corresponding bearer, and performing
data transmission by using the bearer.
[0332] With reference to the ninth possible implementation manner
of the fourth aspect, in a tenth possible implementation manner of
the fourth aspect, the keeping a connected state with the first
base station if there is no service requirement currently,
includes:
[0333] if there is no service requirement currently, keeping
receiving scheduling information sent by the first base
station.
[0334] With reference to the tenth possible implementation manner
of the fourth aspect, in an eleventh possible implementation manner
of the fourth aspect, the method further includes: receiving a
discontinuous reception period configured by the first base
station; and
[0335] the keeping receiving scheduling information sent by the
first base station includes:
[0336] receiving, within an active time of the discontinuous
reception period, the scheduling information sent by the first base
station.
[0337] With reference to the eighth or the tenth or the eleventh
possible implementation manner of the fourth aspect, in a twelfth
possible implementation manner of the fourth aspect, the method
further includes:
[0338] receiving, according to an instruction of the scheduling
information, second dedicated signaling sent by the first base
station, where the second dedicated signaling includes notification
information, and the notification information is used to notify the
terminal that a bearer needs to be set up for data
transmission.
[0339] With reference to the twelfth possible implementation manner
of the fourth aspect, in a thirteenth possible implementation
manner of the fourth aspect, the second dedicated signaling further
includes instruction information, where
[0340] the instruction information includes second instruction
information or third instruction information, the second
instruction information is instruction information instructing to
select at least one second base station to perform data
transmission, and the third instruction information is instruction
information instructing to perform data transmission only through
the first base station; and
[0341] the method further includes: receiving the second
instruction information or the third instruction information sent
by the first base station.
[0342] With reference to the ninth possible implementation manner
of the fourth aspect, in a fourteenth possible implementation
manner of the fourth aspect, the requesting the first base station
to set up a corresponding bearer, and performing data transmission
by using the bearer if there is a service requirement currently,
includes:
[0343] if there is a service requirement currently, requesting the
first base station to set up the corresponding bearer, receiving
second dedicated signaling sent by the first base station, where
the second dedicated signaling includes notification information,
and the notification information is used to notify the terminal
that the bearer needs to be set up for data transmission, and
performing data transmission by using the bearer.
[0344] With reference to the fourteenth possible implementation
manner of the fourth aspect, in a fifteenth possible implementation
manner of the fourth aspect, the method further includes:
[0345] receiving an instruction message sent by the first base
station, where the instruction message includes second instruction
information or third instruction information, the second
instruction information is instruction information instructing to
select at least one second base station to perform data
transmission, and the third instruction information is instruction
information instructing to perform data transmission only through
the first base station; and
[0346] receiving the second instruction information or the third
instruction information sent by the first base station.
[0347] With reference to the thirteenth or the fifteenth possible
implementation manner of the fourth aspect, in a sixteenth possible
implementation manner of the fourth aspect, the method further
includes:
[0348] if the second instruction information sent by the first base
station is received, selecting, according to the second instruction
information, the at least one second base station to perform data
transmission.
[0349] With reference to the sixteenth possible implementation
manner of the fourth aspect, in a seventeenth possible
implementation manner of the fourth aspect, the method further
includes: sending information about the selected at least one
second base station to the first base station.
[0350] With reference to the twelfth or the fourteenth possible
implementation manner of the fourth aspect, in an eighteenth
possible implementation manner of the fourth aspect, the method
further includes:
[0351] after receiving the second dedicated signaling, selecting at
least one second base station to perform data transmission, and
sending information about the selected at least one second base
station to the first base station.
[0352] With reference to the twelfth or the fourteenth possible
implementation manner of the fourth aspect, in a nineteenth
possible implementation manner of the fourth aspect, the method
further includes:
[0353] after receiving the second dedicated signaling, determining
to perform data transmission only through the first base
station.
[0354] With reference to the sixteenth or the eighteenth possible
implementation manner of the fourth aspect, in a twentieth possible
implementation manner of the fourth aspect, the method further
includes:
[0355] if each second base station in the at least one second base
station has the context information of the terminal, sending a
scheduling request message to each second base station, and
obtaining, by using the scheduling request message, a resource
allocated by each second base station to perform data transmission;
or
[0356] if each second base station in the at least one second base
station has the context information of the terminal, performing
random access to each second base station, and obtaining a resource
allocated by each second base station to perform data
transmission.
[0357] With reference to the twentieth possible implementation
manner of the fourth aspect, in a twenty-first possible
implementation manner of the fourth aspect, the performing random
access to each second base station, and obtaining a resource
allocated by each second base station to perform data transmission,
includes:
[0358] performing random access to each second base station by
using unique identifier information allocated by the first base
station, and obtaining the resource allocated by each second base
station according to the unique identifier information to perform
data transmission, where the unique identifier information
corresponds to the terminal, and the unique identifier information
is a unique preamble or a combination of a unique preamble and a
random access resource.
[0359] With reference to the sixteenth or the eighteenth possible
implementation manner of the fourth aspect, in a twenty-second
possible implementation manner of the fourth aspect, the method
further includes:
[0360] if each second base station in the at least one second base
station does not have the context information of the terminal,
performing random access to each second base station, and in the
random access process, sending, to each second base station, the
context information of the terminal and information about the first
base station to which the terminal has set up the connection.
[0361] With reference to the fourth aspect, in a twenty-third
possible implementation manner of the fourth aspect, the method
further includes:
[0362] after the terminal stops performing data transmission
through the first base station and/or the second base station,
continuing to work in always connected mode, and saving dedicated
configuration information for setting up the connection to the
first base station.
[0363] With reference to the twenty-third possible implementation
manner of the fourth aspect, in a twenty-fourth possible
implementation manner of the fourth aspect, the method further
includes:
[0364] stopping, by the terminal, maintaining an uplink
synchronization timer; or
[0365] after an uplink synchronization timer expires, stopping, by
the terminal, maintaining the uplink synchronization timer.
[0366] With reference to the fourth aspect, in a twenty-fifth
possible implementation manner of the fourth aspect, after the
performing, by the terminal, data transmission through the first
base station and/or the second base station according to the second
base station list information, the method further includes:
[0367] receiving a second base station list update message sent by
the first base station, updating the second base station list
information according to the second base station list update
message, and obtaining updated second base station list
information.
[0368] With reference to the twenty-fifth possible implementation
manner of the fourth aspect, in a twenty-sixth possible
implementation manner of the fourth aspect, before the receiving a
second base station list update message sent by the first base
station, the method further includes:
[0369] sending, by the terminal, a second base station list update
request message to the first base station.
[0370] With reference to the twenty-fifth possible implementation
manner of the fourth aspect, in a twenty-seventh possible
implementation manner of the fourth aspect, the second base station
list update message is generated by the first base station
according to location information of the terminal and location
information of each second base station.
[0371] With reference to the twenty-fifth possible implementation
manner of the fourth aspect, in a twenty-eighth possible
implementation manner of the fourth aspect, the method further
includes:
[0372] measuring, by the terminal, each neighboring base station in
a network, and if a neighboring base station whose signal quality
is higher than a first threshold exists, determining whether the
updated second base station list information includes information
about the neighboring base station.
[0373] With reference to the twenty-eighth possible implementation
manner of the fourth aspect, in a twenty-ninth possible
implementation manner of the fourth aspect, the method further
includes:
[0374] if the updated second base station list information does not
include the information about the neighboring base station, sending
a neighboring base station measurement report to the first base
station, where the neighboring base station measurement report
includes the information about the neighboring base station; or
[0375] if the updated second base station list information does not
include the information about the neighboring base station, sending
a second base station list update request message to the first base
station, where the second base station list update request message
includes the information about the neighboring base station; or
[0376] if the updated second base station list information does not
include the information about the neighboring base station,
reporting to the first base station that the neighboring base
station is not included in the updated second base station
list.
[0377] With reference to the twenty-ninth possible implementation
of the fourth aspect, in a thirtieth possible implementation of the
fourth aspect, the neighboring base station measurement report
further includes an indication that the neighboring base station
does not have the context information of the terminal, so that the
first base station sends the context information of the terminal to
the neighboring base station.
[0378] With reference to the thirtieth possible implementation of
the fourth aspect, in a thirty-first possible implementation of the
fourth aspect, the method further includes: receiving a response
message sent by the first base station, where the response message
is generated by the first base station according to the neighboring
base station measurement report, and learning, according to the
response message, that the neighboring base station has obtained
the context information of the terminal.
[0379] With reference to the fourth aspect, in a thirty-second
possible implementation manner of the fourth aspect, the method
further includes:
[0380] receiving default configuration information sent by the
first base station, where the default configuration information is
configuration information used when the terminal performs initial
data transmission with each second base station; and
[0381] the performing, by the terminal, data transmission through
the first base station and/or the second base station according to
the second base station list information, includes:
[0382] performing, by the terminal according to the second base
station list information and the default configuration information,
data transmission through a second base station that has the
context information of the terminal.
[0383] With reference to the thirty-second possible implementation
manner of the fourth aspect, in a thirty-third possible
implementation manner of the fourth aspect, the default
configuration information is associated with a service type,
quality of service QoS of a service, or a bearer type.
[0384] With reference to the thirty-third possible implementation
manner of the fourth aspect, in a thirty-fourth possible
implementation manner of the fourth aspect, the method further
includes:
[0385] receiving a second base station list update message sent by
the first base station, updating the second base station list
information according to the second base station list update
message, and obtaining updated second base station list
information.
[0386] With reference to the thirty-fourth possible implementation
manner of the fourth aspect, in a thirty-fifth possible
implementation manner of the fourth aspect, the performing, by the
terminal according to the second base station list information and
the default configuration information, data transmission through a
second base station that has the context information of the
terminal, includes:
[0387] performing, by the terminal according to the updated second
base station list and the default configuration information,
initial data transmission through the second base station that has
the context information of the terminal; and
[0388] receiving a reconfiguration message sent by the second base
station, modifying, according to the reconfiguration message,
default configuration information corresponding to the terminal,
and performing, by using modified configuration information, data
transmission with the second base station that has the context
information of the terminal.
[0389] With reference to the fourth aspect, in a thirty-sixth
possible implementation manner of the fourth aspect, the method
further includes:
[0390] receiving measurement configuration information sent by the
first base station, and completing, according to the measurement
configuration information, a measurement configuration of a
frequency layer corresponding to each base station, where the base
stations include the first base station and the second base
stations, and the second base stations include a master second base
station and a secondary second base station.
[0391] With reference to the thirty-sixth possible implementation
manner of the fourth aspect, in a thirty-seventh possible
implementation manner of the fourth aspect, the measurement
configuration information includes:
[0392] measuring a frequency layer corresponding to the first base
station only; or
[0393] measuring frequency layers corresponding to the first base
station and the master second base station only; or
[0394] measuring frequency layers corresponding to all of the first
base station, the master second base station, and the secondary
second base station.
[0395] With reference to the thirty-seventh possible implementation
manner of the fourth aspect, in a thirty-eighth possible
implementation manner of the fourth aspect, the measurement
configuration information further includes:
[0396] determining a first threshold for measuring the frequency
layer corresponding to the first base station only; or
[0397] determining a second threshold for measuring the frequency
layers corresponding to the first base station and the master
second base station only; or
[0398] determining a third threshold for measuring the frequency
layers corresponding to all of the first base station, the master
second base station, and the secondary second base station.
[0399] With reference to the thirty-eighth possible implementation
manner of the fourth aspect, in a thirty-ninth possible
implementation manner of the fourth aspect, if QoS of a current
service of the terminal is less than the first threshold, the
completing, according to the measurement configuration information,
a measurement configuration of a frequency layer corresponding to
each base station, includes: measuring, according to the
measurement configuration information, the frequency layer
corresponding to the first base station only, and obtaining a
measurement result; or
[0400] if QoS of a current service of the terminal is greater than
the first threshold but less than the second threshold, the
completing, according to the measurement configuration information,
a measurement configuration of a frequency layer corresponding to
each base station, includes: measuring, according to the
measurement configuration information, the frequency layer
corresponding to the first base station and the frequency layer
corresponding to the master second base station, and obtaining
measurement results; or
[0401] if QoS of a current service of the terminal is greater than
the second threshold or the third threshold, the completing,
according to the measurement configuration information, a
measurement configuration of a frequency layer corresponding to
each base station, includes: measuring, according to the
measurement configuration information, the frequency layers
corresponding to the first base station, the master second base
station, and the secondary second base station, and obtaining
measurement results.
[0402] With reference to any one of the thirty-sixth to the
thirty-ninth possible implementation manners of the fourth aspect,
in a fortieth possible implementation manner of the fourth aspect,
the method further includes:
[0403] receiving an instruction message sent by the first base
station about whether to perform measurement reporting; and
[0404] determining, according to the instruction message about
whether to perform measurement reporting, whether to send the
measurement result to the first base station.
[0405] With reference to the fortieth possible implementation
manner of the fourth aspect, in a forty-first possible
implementation manner of the fourth aspect, the instruction message
about whether to perform measurement reporting includes:
[0406] at least one of instruction information for measurement
reporting of the frequency layer corresponding to the first base
station, instruction information for measurement reporting of the
frequency layer corresponding to the master second base station, or
instruction information for measurement reporting of the frequency
layer corresponding to the secondary second base station.
[0407] With reference to the fourth aspect, in a forty-second
possible implementation manner of the fourth aspect, the method
further includes:
[0408] receiving measurement configuration parameter information
sent by the first base station, and completing, according to the
measurement configuration parameter information, measurement
management of a frequency layer corresponding to each base station,
where the base stations include the first base station and the
second base stations, and the second base stations include a master
second base station and a secondary second base station; where
[0409] the measurement configuration parameter information includes
at least one of a measurement configuration parameter of a
frequency layer corresponding to the first base station, a
measurement configuration parameter of a frequency layer
corresponding to the master second base station, or a measurement
configuration parameter of a frequency layer corresponding to the
secondary second base station.
[0410] With reference to the forty-second possible implementation
manner of the fourth aspect, in a forty-third possible
implementation manner of the fourth aspect, if QoS of a current
service of the terminal is less than a first threshold, the
completing, according to the measurement configuration parameter
information, measurement management of a frequency layer
corresponding to each base station, includes: measuring, according
to the measurement configuration parameter of the frequency layer
corresponding to the first base station, the frequency layer of the
first base station, and obtaining a first measurement result;
or
[0411] if QoS of a current service of the terminal is greater than
a first threshold but less than a second threshold, the completing,
according to the measurement configuration parameter information,
measurement management of a frequency layer corresponding to each
base station, includes: measuring, according to the measurement
configuration parameter of the frequency layer corresponding to the
first base station, the frequency layer of the first base station,
and obtaining a first measurement result, and at the same time,
measuring, according to the measurement configuration parameter of
the frequency layer corresponding to the master second base
station, the frequency layer of the master second base station, and
obtaining a second measurement result; or
[0412] if QoS of a current service of the terminal is greater than
a second threshold, the completing, according to the measurement
configuration parameter information, measurement management of a
frequency layer corresponding to each base station, includes:
measuring, according to the measurement configuration parameter of
the frequency layer corresponding to the secondary second base
station, the frequency layer of the secondary second base station,
and obtaining a third measurement result.
[0413] With reference to the forty-third possible implementation
manner of the fourth aspect, in a forty-fourth possible
implementation manner of the fourth aspect, the measuring,
according to the measurement configuration parameter of the
frequency layer corresponding to the first base station, the
frequency layer of the first base station, specifically
includes:
[0414] measuring, according to the measurement configuration
parameter of the frequency layer corresponding to the first base
station, the first base station and/or a first base station
neighboring to the first base station.
[0415] With reference to the forty-third possible implementation
manner of the fourth aspect, in a forty-fifth possible
implementation manner of the fourth aspect, the measuring,
according to the measurement configuration parameter of the
frequency layer corresponding to the master second base station,
the frequency layer of the master second base station, specifically
includes:
[0416] measuring, according to the measurement configuration
parameter of the frequency layer corresponding to the master second
base station, the master second base station and/or a master second
base station neighboring to the master second base station.
[0417] With reference to the forty-third possible implementation
manner of the fourth aspect, in a forty-sixth possible
implementation manner of the fourth aspect, the measuring,
according to the measurement configuration parameter of the
frequency layer corresponding to the secondary second base station,
the frequency layer of the secondary second base station,
specifically includes:
[0418] measuring, according to the measurement configuration
parameter of the frequency layer corresponding to the secondary
second base station, the secondary second base station and/or a
secondary second base station neighboring to the secondary second
base station.
[0419] With reference to the forty-third possible implementation
manner of the fourth aspect, in a forty-seventh possible
implementation manner of the fourth aspect, the method further
includes:
[0420] sending the obtained first measurement result to the first
base station; and
[0421] skipping sending the third measurement result to the first
base station.
[0422] With reference to the forty-sixth or the forty-seventh
possible implementation manner of the fourth aspect, in a
forty-eighth possible implementation manner of the fourth aspect,
the method further includes:
[0423] comparing the obtained second measurement result with a
preset condition, and if the preset condition is met, sending the
second measurement result to the first base station.
[0424] With reference to the fourth aspect, in a forty-ninth
possible implementation manner of the fourth aspect, the method
further includes:
[0425] receiving a handover command message sent by the current
serving first base station, where the handover command message
includes information about each second base station that is
controlled by a target first base station and has the context
information of the terminal, the current serving first base station
is the first base station that currently performs data transmission
with the terminal, and the target first base station is a target
first base station to which the terminal is handed over from the
current serving first base station.
[0426] With reference to the forty-ninth possible implementation
manner of the fourth aspect, in a fiftieth possible implementation
manner of the fourth aspect, the handover command message further
includes instruction information instructing the terminal to skip
performing random access to the target first base station; and
[0427] the terminal does not perform random access to the target
first base station according to the instruction information
instructing to skip performing random access to the target first
base station.
[0428] With reference to the forty-ninth possible implementation
manner of the fourth aspect, in a fifty-first possible
implementation manner of the fourth aspect, the method further
includes:
[0429] selecting, according to the handover command message, at
least one second base station that has the context information of
the terminal, so as to perform data transmission.
[0430] With reference to the forty-ninth possible implementation
manner of the fourth aspect, in a fifty-second possible
implementation manner of the fourth aspect, each second base
station that is controlled by the target first base station and has
the context information of the terminal is controlled by the target
first base station or connected to the target first base
station.
[0431] With reference to the forty-ninth possible implementation
manner of the fourth aspect, in a fifty-third possible
implementation manner of the fourth aspect, each second base
station that is controlled by the target first base station and has
the context information of the terminal is controlled by the
current serving first base station and the target first base
station jointly, or has connection relationships with both the
current serving first base station and the target first base
station.
[0432] With reference to any one of the forty-ninth to the
fifty-third possible implementation manners of the fourth aspect,
in a fifty-fourth possible implementation manner of the fourth
aspect, before the receiving a handover command message sent by the
current serving first base station, the method further
includes:
[0433] measuring each first base station in a network, and
obtaining a measurement result of each first base station, where
the first base stations include the current serving first base
station and neighboring first base stations, and the neighboring
first base stations include the target first base station.
[0434] With reference to the fifty-fourth possible implementation
manner of the fourth aspect, in a fifty-fifth possible
implementation manner of the fourth aspect, the method further
includes:
[0435] determining the target first base station according to a
measurement result of the current serving first base station and
measurement results of the neighboring first base stations; and
[0436] sending a first handover request message to the current
serving first base station, where the first handover request
message includes information about requesting to be handed over to
the target first base station.
[0437] With reference to the fifty-fourth possible implementation
manner of the fourth aspect, in a fifty-sixth possible
implementation manner of the fourth aspect, the method further
includes: sending the measurement results of the neighboring first
base stations to the current serving first base station, so that
the current serving first base station determines whether to
perform the handover to the target first base station.
[0438] With reference to the fifty-first possible implementation
manner of the fourth aspect, in a fifty-seventh possible
implementation manner of the fourth aspect, the selecting,
according to the handover command message, at least one second base
station that has the context information of the terminal, so as to
perform data transmission, includes:
[0439] preferentially selecting a second base station that provides
services under control of the current serving first base station
and has the context information, so as to perform data
transmission, where the second base station is controlled by the
target first base station.
[0440] With reference to the forty-ninth possible implementation
manner of the fourth aspect, in a fifty-eighth possible
implementation manner of the fourth aspect, the handover command
message further includes:
[0441] instruction information instructing the terminal to keep
performing data transmission with at least one current serving
second base station, where the current serving second base station
is a second base station that provides data transmission for the
terminal before the handover command is received; and
[0442] the terminal performs the handover to the target first base
station according to the handover command message, and at the same
time, keeps performing data transmission through the at least one
current serving second base station.
[0443] With reference to the fifty-eighth possible implementation
manner of the first aspect, in a fifty-ninth possible
implementation manner of the first aspect, the method further
includes:
[0444] sending a handover complete indication to the current
serving first base station through a second base station controlled
by the current serving first base station.
[0445] With reference to the fourth aspect, in a sixtieth possible
implementation manner of the fourth aspect, the method further
includes:
[0446] measuring each first base station in a network, and
obtaining a measurement result of each first base station, where
the first base stations include the current serving first base
station and neighboring first base stations;
[0447] determining a target first base station according to the
measurement result, where the target first base station is a target
first base station to which the terminal is handed over from the
current serving first base station; and
[0448] sending a handover request message to the target first base
station, where the handover request message includes information
about the current serving first base station and information about
candidate second base stations, where the candidate second base
stations are second base stations that are controlled by the target
first base station or connected to the target first base station
and can provide services for the terminal.
[0449] With reference to the sixtieth possible implementation
manner of the fourth aspect, in a sixty-first possible
implementation manner of the fourth aspect, the method further
includes:
[0450] receiving a handover request acknowledgement message from
the target first base station, where the handover request
acknowledgement message includes a list of second base stations
that are controlled by the target first base station or connected
to the target first base station and have the context information
of the terminal; and
[0451] selecting, according to the handover request acknowledgement
message, at least one second base station that has the context
information of the terminal, so as to perform data
transmission.
[0452] With reference to the sixty-first possible implementation
manner of the fourth aspect, in a sixty-second possible
implementation manner of the fourth aspect, after the selecting,
according to the handover request acknowledgement message, at least
one second base station that has the context information of the
terminal, so as to perform data transmission, the method further
includes:
[0453] sending a handover complete indication message to the
current serving first base station; or
[0454] sending a handover complete indication message to the
current serving first base station through the target first base
station.
[0455] With reference to the fourth aspect, in a sixty-third
possible implementation manner of the fourth aspect, the method
further includes:
[0456] measuring each first base station in a network, and
obtaining a measurement result of each first base station, where
the first base stations include the current serving first base
station and neighboring first base stations;
[0457] determining a target first base station according to the
measurement result, where the target first base station is a target
first base station to which the terminal is handed over from the
current serving first base station;
[0458] sending a handover request message to the current serving
first base station, where the handover request message includes
information about requesting to be handed over to the target first
base station; and
[0459] receiving a handover command message sent by the current
serving first base station.
[0460] With reference to the sixty-third possible implementation
manner of the fourth aspect, in a sixty-fourth possible
implementation manner of the fourth aspect, the handover command
message includes instruction information instructing the terminal
to perform the handover to the target first base station and
instruction information instructing the terminal to keep performing
data transmission with at least one current serving second base
station, where the current serving second base station is a second
base station that provides data transmission for the terminal
before the handover command message is received; and
[0461] the terminal performs the handover to the target first base
station according to the handover command message, and at the same
time, keeps performing data transmission through the at least one
current serving second base station.
[0462] With reference to the sixty-fourth possible implementation
manner of the fourth aspect, in a sixty-fifth possible
implementation manner of the fourth aspect, the handover command
message further includes bearer reconfiguration information;
and
[0463] the terminal switches a data transmission service between
the current serving first base station and the terminal to the
current serving second base station according to the bearer
reconfiguration information.
[0464] With reference to the fourth aspect, in a sixty-sixth
possible implementation manner of the fourth aspect, before the
performing, by the terminal, data transmission through the first
base station and/or the second base station according to the list
information of the second base stations having the context
information, the method further includes:
[0465] setting up, by the terminal, a first security mechanism with
the first base station, and setting up a second security mechanism
with the second base station.
[0466] With reference to the sixty-sixth possible implementation
manner of the fourth aspect, in a sixty-seventh possible
implementation manner of the fourth aspect, the setting up a second
security mechanism with the second base station includes:
[0467] receiving the second base station list information and
security algorithm information sent by the first base station,
where the second base station list information includes the
information about each second base station having the context
information, and the security algorithm information includes
security algorithm information corresponding to each second base
station included in the second base station list; and
[0468] selecting at least one second base station from the second
base station list, and obtaining, according to a security index
corresponding to the at least one second base station and the
security algorithm information, an encryption key and/or an
integrity protection key corresponding to each second base station;
where
[0469] the second base station corresponds to the security index on
a one-to-one basis.
[0470] With reference to the sixty-seventh possible implementation
manner of the fourth aspect, in a sixty-eighth possible
implementation manner of the fourth aspect, the obtaining,
according to a security index corresponding to the at least one
second base station and the security algorithm information, an
encryption key and/or an integrity protection key corresponding to
each second base station, includes:
[0471] obtaining, according to the security index corresponding to
the at least one second base station, a security key corresponding
to the at least one security index, and obtaining a corresponding
root key through calculation according to the security key;
[0472] obtaining, by using the root key, an intermediate key
corresponding to the second base station; and
[0473] obtaining, according to the intermediate key and the
security algorithm information corresponding to the second base
station, the encryption key and/or the integrity protection key
corresponding to the second base station.
[0474] With reference to the sixty-eighth possible implementation
manner of the fourth aspect, in a sixty-ninth possible
implementation manner of the fourth aspect, the performing data
transmission through the first base station and/or the second base
station includes:
[0475] performing data transmission through the first base station
based on the first security mechanism, and/or performing data
transmission through the second base station based on the second
security mechanism.
[0476] With reference to the sixty-sixth possible implementation
manner of the fourth aspect, in a seventieth possible
implementation manner of the fourth aspect, the first security
mechanism and the second security mechanism are associated with
each other; and
[0477] the obtaining, according to a security index corresponding
to the at least one second base station and the security algorithm
information, an encryption key and/or an integrity protection key
corresponding to each second base station, includes:
[0478] obtaining, according to the security index corresponding to
the at least one second base station, a security key and a dynamic
count corresponding to the at least one security index, and
obtaining a corresponding root key through calculation according to
the security key;
[0479] obtaining, by using the root key, an intermediate key
corresponding to the second base station;
[0480] obtaining an associated intermediate key according to the
intermediate key and the dynamic count; and
[0481] obtaining, according to the associated intermediate key and
the security algorithm information corresponding to the second base
station, the encryption key and/or the integrity protection key
corresponding to the second base station.
[0482] According to a fifth aspect, an embodiment of the present
invention provides a wireless communications method, including:
[0483] setting up, by a first base station, a connection to a
terminal, and staying in always connected mode, where the always
connected mode is to always keep the connection to the
terminal;
[0484] sending, by the first base station, first dedicated
signaling to the terminal, where the first dedicated signaling
includes second base station list information, and the second base
station list information includes information about each second
base station having context information of the terminal; and
[0485] performing, by the first base station, data transmission
with the terminal.
[0486] With reference to the fifth aspect, in a first possible
implementation manner of the fifth aspect, the setting up, by a
first base station, a connection to a terminal, and staying in
always connected mode, includes:
[0487] always keeping, by the first base station, the connection to
the first base station within a preset time.
[0488] With reference to the fifth aspect or the first possible
implementation manner of the fifth aspect, in a second possible
implementation manner of the fifth aspect, the performing, by the
first base station, data transmission with the terminal,
specifically includes:
[0489] transmitting, by the first base station, only control
signaling to the terminal; or
[0490] transmitting, by the first base station, only downlink data
to the terminal; or
[0491] transmitting, by the first base station, only downlink
control signaling to the terminal.
[0492] With reference to the fifth aspect, in a third possible
implementation manner of the fifth aspect, before the setting up,
by a first base station, a connection to a terminal, and staying in
always connected mode, the method further includes:
[0493] sending a dedicated message to the terminal, where the
dedicated message carries instruction information instructing the
terminal whether to work in the always connected mode; or
[0494] receiving a first indication message sent by the terminal,
where the first indication message carries indication information
about whether the terminal requests to work in the always connected
mode, and determining, according to the first indication message,
whether to configure the terminal to work in the always connected
mode; or
[0495] after receiving a random access preamble sent by the
terminal, sending a random access response message to the terminal,
where the random access response message carries instruction
information instructing the terminal whether to work in the always
connected mode, so that the terminal determines, according to the
random access response message, whether to work in the always
connected mode; or
[0496] after receiving a connection setup request message sent by
the terminal, sending a connection setup response message to the
terminal, where the connection setup response message carries
instruction information instructing the terminal whether to work in
the always connected mode; or
[0497] after receiving a connection setup request message sent by
the terminal, sending a dedicated message to the terminal, where
the dedicated message carries instruction information instructing
the terminal whether to work in the always connected mode.
[0498] With reference to the third possible implementation manner
of the fifth aspect, in a fourth possible implementation manner of
the fifth aspect, the first indication message includes:
[0499] a random access message 3 or a connection setup request
message.
[0500] With reference to any one of the fifth aspect, or the first
to the fourth possible implementation manners of the fifth aspect,
in a fifth possible implementation manner of the fifth aspect, the
setting up, by a first base station, a connection to a terminal,
and staying in always connected mode, includes:
[0501] if no service request message sent by the terminal is
received, keeping a connected state with the terminal, and staying
in the always connected mode; or
[0502] if a service request message sent by the terminal is
received, where the service request message includes information
about requesting to set up a corresponding bearer, setting up the
bearer for the terminal according to the service request message,
so as to perform data transmission.
[0503] With reference to the fifth possible implementation manner
of the fifth aspect, in a sixth possible implementation manner of
the fifth aspect, when no service request message sent by the
terminal is received, the method further includes:
[0504] configuring a discontinuous reception period for the
terminal, so that the terminal receives, within an active time of
the discontinuous reception period, scheduling information sent by
the first base station.
[0505] With reference to the sixth possible implementation manner
of the fifth aspect, in a seventh possible implementation manner of
the fifth aspect, the method further includes:
[0506] sending the scheduling information to the terminal, where
the scheduling information is used to instruct the terminal to
receive second dedicated signaling; and
[0507] sending the second dedicated signaling to the terminal,
where the second dedicated signaling includes a notification
message, and the notification message includes information
notifying the terminal that the bearer needs to be set up for data
transmission.
[0508] With reference to the seventh possible implementation manner
of the fifth aspect, in an eighth possible implementation manner of
the fifth aspect, the second dedicated signaling further includes
instruction information, where
[0509] the instruction information includes second instruction
information or third instruction information, the second
instruction information is instruction information instructing the
terminal to select at least one second base station to perform data
transmission, and the third instruction information is instruction
information instructing the terminal to perform data transmission
only through the first base station.
[0510] With reference to the fifth possible implementation manner
of the fifth aspect, in a ninth possible implementation manner of
the fifth aspect, if the service request message sent by the
terminal is received, the method further includes:
[0511] if the service request message sent by the terminal is
received, sending the scheduling information to the terminal, where
the scheduling information is used to instruct the terminal to
receive second dedicated signaling; and
[0512] sending the second dedicated signaling to the terminal,
where the second dedicated signaling includes a notification
message, and the notification message includes information
notifying the terminal that the bearer needs to be set up for data
transmission, and performing data transmission with the terminal by
using the bearer.
[0513] With reference to the ninth possible implementation manner
of the fifth aspect, in a tenth possible implementation manner of
the fifth aspect, the method further includes:
[0514] sending an instruction message to the terminal, where the
instruction message includes second instruction information or
third instruction information, the second instruction information
is instruction information instructing to select at least one
second base station to perform data transmission, and the third
instruction information is instruction information instructing to
perform data transmission only through the first base station.
[0515] With reference to the eighth or the tenth possible
implementation manner of the fifth aspect, in an eleventh possible
implementation manner of the fifth aspect, the method further
includes:
[0516] receiving information sent by the terminal about the
selected at least one second base station, where the information
about the selected at least one second base station is information
about each second base station in the at least one second base
station selected by the terminal according to the second
instruction information.
[0517] With reference to the eleventh possible implementation
manner of the fifth aspect, in a twelfth possible implementation
manner of the fifth aspect, the method further includes:
[0518] determining whether each second base station in the
information about the selected at least one second base station has
the context information of the terminal; and
[0519] if a second base station that does not have the context
information of the terminal exists, sending the context information
of the terminal to the second base station that does not have the
context information of the terminal.
[0520] With reference to any one of the ninth to the twelfth
possible implementation manners of the fifth aspect, in a
thirteenth possible implementation manner of the fifth aspect, the
method further includes:
[0521] allocating, by the first base station, a unique preamble or
a combination of a unique preamble and a random access channel
resource to the terminal, so that the terminal obtains, by using
the unique preamble or the combination of the unique preamble and
the random access channel resource, a resource allocated by the
second base station, so as to perform data transmission.
[0522] With reference to the fifth aspect, in a fourteenth possible
implementation manner of the fifth aspect, the method further
includes:
[0523] after the first base station stops performing data
transmission with the terminal, saving, by the first base station,
configuration information for setting up the connection to the
terminal.
[0524] With reference to the fifth aspect, in a fifteenth possible
implementation manner of the fifth aspect, the method further
includes:
[0525] generating a second base station list update message, and
sending the second base station list update message to the
terminal, where the second base station list update message
includes updated second base station list information, so that the
terminal updates the second base station list information according
to the second base station list update message.
[0526] With reference to the fifteenth possible implementation
manner of the fifth aspect, in a sixteenth possible implementation
manner of the fifth aspect, the generating a second base station
list update message includes:
[0527] generating the second base station list update message
according to one or more of location information of the terminal,
location information of each second base station, or a measurement
report reported by the terminal.
[0528] With reference to the fifth aspect, in a seventeenth
possible implementation manner of the fifth aspect, the method
further includes:
[0529] receiving a neighboring base station measurement report sent
by the terminal, where the neighboring base station measurement
report includes information about a neighboring base station, and
the information about the neighboring base station is not included
in the second base station list information; or
[0530] receiving a second base station list update request message
sent by the terminal, where the second base station list update
request message includes information about a neighboring base
station, and the information about the neighboring base station is
not included in the second base station list information; or
[0531] receiving a report of the terminal that a neighboring base
station is not included in the second base station list.
[0532] With reference to the seventeenth possible implementation
manner of the fifth aspect, in an eighteenth possible
implementation manner of the fifth aspect, the method further
includes:
[0533] if the neighboring base station does not have the context
information of the terminal, sending the context information of the
terminal to the neighboring base station, and sending a second base
station list update message to the terminal, where the second base
station list update message includes the information about the
neighboring base station.
[0534] With reference to the seventeenth possible implementation
manner of the fifth aspect, in a nineteenth possible implementation
manner of the fifth aspect, the second base station measurement
report further includes information indicating that the neighboring
base station does not have the context information of the terminal;
and
[0535] the method further includes: sending the context information
of the terminal to the neighboring base station, and sending a
response message to the terminal, where the response message is
generated by the first base station according to the neighboring
base station measurement report, so that the terminal learns,
according to the response message, that the neighboring base
station has obtained the context information of the terminal.
[0536] With reference to the fifth aspect, in a twentieth possible
implementation manner of the fifth aspect, the method further
includes:
[0537] sending default configuration information to the terminal
and each second base station separately, where the default
configuration information is associated with a service type,
quality of service QoS of a service, or a bearer type, and the
default configuration information is configuration information used
when the terminal performs initial data transmission with each
second base station.
[0538] With reference to the twentieth possible implementation
manner of the fifth aspect, in a twenty-first possible
implementation manner of the fifth aspect, the method further
includes:
[0539] sending a second base station list update message to the
terminal, so that the terminal updates the second base station list
information according to the second base station list update
message and performs, by using updated second base station list
information and the default configuration information, initial data
transmission through a second base station that has the context
information of the terminal.
[0540] With reference to the fifth aspect, in a twenty-second
possible implementation manner of the fifth aspect, the method
further includes:
[0541] sending measurement configuration information to the
terminal, where the measurement configuration information includes
measurement configuration information of a frequency layer
corresponding to each base station, the base station includes at
least one of the first base station or the second base stations,
and the second base stations include a master second base station
and a secondary second base station.
[0542] With reference to the twenty-second possible implementation
manner of the fifth aspect, in a twenty-third possible
implementation manner of the fifth aspect, the measurement
configuration information includes:
[0543] measuring a frequency layer corresponding to the first base
station only; or
[0544] measuring frequency layers corresponding to the first base
station and the master second base station only; or
[0545] measuring frequency layers corresponding to all of the first
base station, the master second base station, and the secondary
second base station.
[0546] With reference to the twenty-third possible implementation
manner of the fifth aspect, in a twenty-fourth possible
implementation manner of the fifth aspect, the measurement
configuration information further includes:
[0547] a first threshold for measuring the frequency layer
corresponding to the first base station only; or
[0548] a second threshold for measuring the frequency layers
corresponding to the first base station and the master second base
station only; or
[0549] a third threshold for measuring the frequency layers
corresponding to all of the first base station, the master second
base station, and the secondary second base station.
[0550] With reference to the twenty-fourth possible implementation
manner of the fifth aspect, in a twenty-fifth possible
implementation manner of the fifth aspect, the method further
includes:
[0551] sending, to the terminal, an instruction message about
whether to perform measurement reporting.
[0552] With reference to the twenty-fifth possible implementation
manner of the fifth aspect, in a twenty-sixth possible
implementation manner of the fifth aspect, the instruction message
about whether to perform measurement reporting includes:
[0553] at least one of instruction information for measurement
reporting of the frequency layer corresponding to the first base
station, instruction information for measurement reporting of the
frequency layer corresponding to the master second base station, or
instruction information for measurement reporting of the frequency
layer corresponding to the secondary second base station.
[0554] With reference to the fifth aspect, in a twenty-seventh
possible implementation manner of the fifth aspect, the method
further includes:
[0555] sending measurement configuration parameter information to
the terminal, where the measurement configuration parameter
information includes at least one of a measurement configuration
parameter of a frequency layer corresponding to the first base
station, a measurement configuration parameter of a frequency layer
corresponding to a master second base station, or a measurement
configuration parameter of a frequency layer corresponding to a
secondary second base station.
[0556] With reference to the twenty-seventh possible implementation
manner of the fifth aspect, in a twenty-eighth possible
implementation manner of the fifth aspect, the method further
includes:
[0557] receiving measurement results sent by the terminal, where
the measurement results include a first measurement result and a
second measurement result, the first measurement result is obtained
by the terminal by performing a measurement according to the
measurement configuration parameter of the frequency layer
corresponding to the first base station, and the second measurement
result is obtained by the terminal by measuring the master second
base station according to the measurement configuration parameter
of the frequency layer corresponding to the master second base
station.
[0558] With reference to the fifth aspect, in a twenty-ninth
possible implementation manner of the fifth aspect, the method
further includes:
[0559] setting up, by the first base station, a first security
mechanism with the terminal, and assisting the second base station
in setting up a second security mechanism with the terminal.
[0560] With reference to the twenty-ninth possible implementation
manner of the fifth aspect, in a thirtieth possible implementation
manner of the fifth aspect, the assisting the second base station
in setting up a second security mechanism with the terminal
includes:
[0561] obtaining, according to a security index corresponding to at
least one second base station, a security key corresponding to the
at least one security index, and obtaining a corresponding root key
through calculation according to the security key;
[0562] obtaining, by using the root key, an intermediate key
corresponding to the second base station; and
[0563] sending, to the second base station, the intermediate key
corresponding to the second base station; where
[0564] the security index corresponds to the second base station on
a one-to-one basis.
[0565] With reference to the thirtieth possible implementation
manner of the fifth aspect, in a thirty-first possible
implementation manner of the fifth aspect, the method further
includes:
[0566] receiving security algorithm information corresponding to
the second base station and sent by the second base station.
[0567] With reference to the twenty-ninth possible implementation
manner of the fifth aspect, in a thirty-first possible
implementation manner of the fifth aspect, the first security
mechanism and the second security mechanism are associated with
each other, and the assisting the second base station in setting up
a second security mechanism with the terminal includes:
[0568] obtaining, according to a security index corresponding to at
least one second base station, a security key corresponding to the
at least one security index, and obtaining a corresponding root key
through calculation according to the security key;
[0569] obtaining, by using the root key and a unique count
corresponding to the second base station, an intermediate key
corresponding to the second base station; and
[0570] sending, to the second base station, the intermediate key
corresponding to the second base station; where
[0571] the security index corresponds to the second base station on
a one-to-one basis.
[0572] With reference to the thirty-second possible implementation
manner of the fifth aspect, in a thirty-third possible
implementation manner of the fifth aspect, the method further
includes:
[0573] receiving security algorithm information and a dynamic count
corresponding to the second base station and sent by the second
base station.
[0574] According to a sixth aspect, an embodiment of the present
invention provides a wireless communications method, including:
[0575] setting up, by a current serving first base station, a
connection to a terminal, and staying in always connected mode,
where the always connected mode is to always keep the connection to
the terminal;
[0576] sending, by the current serving first base station, first
dedicated signaling to the terminal, where the first dedicated
signaling includes second base station list information, and the
second base station list information includes information about
each second base station having context information of the
terminal; and
[0577] performing, by the current serving first base station, data
transmission with the terminal.
[0578] With reference to the sixth aspect, in a first possible
implementation manner of the sixth aspect, the method further
includes:
[0579] sending, by the current serving first base station, a
handover command message to the terminal, where the handover
command message includes information about each second base station
that is controlled by a target first base station and has the
context information of the terminal, and the target first base
station is a target first base station to which the terminal is
handed over from the current serving first base station.
[0580] With reference to the first possible implementation manner
of the sixth aspect, in a second possible implementation manner of
the sixth aspect, the handover command message further includes
instruction information instructing the terminal to skip performing
random access to the target first base station, so that the
terminal does not perform random access to the target first base
station according to the instruction information.
[0581] With reference to the first possible implementation manner
of the sixth aspect, in a third possible implementation manner of
the sixth aspect, before the sending, by the current serving first
base station, a handover command message to the terminal, the
method further includes:
[0582] receiving a measurement result of each neighboring first
base station that is sent by the terminal, where the measurement
result of each neighboring first base station is obtained by the
terminal by measuring each base station neighboring to the current
serving first base station; and
[0583] determining the target first base station according to the
measurement result of each neighboring first base station.
[0584] With reference to the first possible implementation manner
of the sixth aspect, in a fourth possible implementation manner of
the sixth aspect, before the sending, by the current serving first
base station, a handover command message to the terminal, the
method further includes:
[0585] receiving a first handover request message sent by the
terminal, where the first handover request message includes
information about the target first base station.
[0586] With reference to the first possible implementation manner
of the sixth aspect, in a fifth possible implementation manner of
the sixth aspect, the method further includes:
[0587] sending a second handover request message to the target
first base station, where the second handover request message
includes the context information of the terminal and the
information about each second base station that currently has the
context information of the terminal.
[0588] With reference to the fifth possible implementation manner
of the sixth aspect, in a sixth possible implementation manner of
the sixth aspect, the method further includes:
[0589] sending a handover instruction to a second base station
currently providing services for the terminal, so that the second
base station currently providing services for the terminal performs
data transmission according to the handover instruction.
[0590] With reference to the sixth possible implementation manner
of the sixth aspect, in a seventh possible implementation of the
sixth aspect, the method further includes: the second base station
currently providing services for the terminal is a second base
station that is controlled by the current serving first base
station and has the context information of the terminal, or a
second base station that is connected to the current serving first
base station and has the context information of the terminal.
[0591] With reference to the sixth possible implementation manner
of the sixth aspect, in an eighth possible implementation of the
sixth aspect, the sending a handover instruction to a second base
station currently providing services for the terminal, so that the
second base station currently providing services for the terminal
performs data transmission according to the handover instruction,
includes: sending the handover instruction to the second base
station currently providing services for the terminal, where the
handover instruction includes information about the target first
base station, so that the second base station currently providing
services for the terminal determines, according to the handover
instruction, whether data transmission can be performed with the
terminal under control of the target first base station.
[0592] With reference to the sixth possible implementation manner
of the sixth aspect, in a ninth possible implementation of the
sixth aspect, the sending a handover instruction to a second base
station currently providing services for the terminal, so that the
second base station currently providing services for the terminal
performs data transmission according to the handover instruction,
includes: sending the handover instruction to the second base
station currently providing services for the terminal, where the
handover instruction includes information instructing to stop
performing data transmission with the terminal, so that the second
base station currently providing services for the terminal stops
performing data transmission with the terminal according to the
handover instruction.
[0593] With reference to the sixth possible implementation manner
of the sixth aspect, in a tenth possible implementation of the
sixth aspect, the sending a handover instruction to a second base
station currently providing services for the terminal, so that the
second base station currently providing services for the terminal
performs data transmission according to the handover instruction,
includes: sending the handover instruction to the second base
station currently providing services for the terminal, where the
handover instruction includes information instructing to continue
to perform data transmission with the terminal, so that the second
base station currently providing services for the terminal
continues to perform data transmission with the terminal according
to the handover instruction.
[0594] With reference to the first possible implementation manner
of the sixth aspect, in an eleventh possible implementation of the
sixth aspect, the handover command message further includes second
base station instruction information, and the second base station
instruction information is instruction information instructing the
terminal to keep performing data transmission with at least one
current serving second base station.
[0595] With reference to the sixth aspect, in a twelfth possible
implementation manner of the sixth aspect, the method further
includes:
[0596] sending a second base station control negotiation message to
a target first base station, where the second base station control
negotiation message includes information about a second base
station that meets a joint control condition; and
[0597] receiving a second base station negotiation response message
sent by the target first base station, where the second base
station negotiation response message is a response message
generated according to the second base station control negotiation
message, and the response message includes information about a
second base station that is determined by the neighboring first
base station and can be jointly controlled, or an acknowledgement
of information about a second base station that is included in the
second base station control negotiation message and can be jointly
controlled.
[0598] With reference to the twelfth possible implementation manner
of the sixth aspect, in a thirteenth possible implementation manner
of the sixth aspect, before the sending a second base station
control negotiation message to a target first base station, the
method further includes: obtaining, according to location
information of each second base station in a network and location
information of the current serving first base station and the
target first base station, the second base station that meets the
joint control condition, where the second base station that meets
the joint control condition is a second base station that is
controlled by the current serving first base station and the target
first base station jointly.
[0599] With reference to the twelfth or the thirteenth possible
implementation manner of the sixth aspect, in a fourteenth possible
implementation manner of the sixth aspect, the method further
includes:
[0600] after the current serving first base station receives a
first handover request message sent by the terminal, sending a
second handover request message to the target first base station
according to the second base station negotiation response message,
where the second handover request message includes the context
information of the terminal and the information about the second
base station that meets the joint control condition.
[0601] According to a seventh aspect, an embodiment of the present
invention provides a wireless communications system, including a
terminal, a first base station, and a second base station, where
the terminal sets up a connection to the first base station, and
stays in always connected mode, where the always connected mode is
to always keep the connection to the first base station;
[0602] the terminal performs data transmission through the first
base station and/or the second base station; and
[0603] the first base station is used for any one of the following
or a combination thereof:
[0604] scheduling and transmission of a service setup message;
or
[0605] generation, scheduling, and transmission of a public
security message; or
[0606] management of bearer setup, modification, and release;
or
[0607] access stratum security control; or
[0608] broadcast service scheduling and transmission.
[0609] With reference to the seventh aspect, in a first possible
implementation manner of the seventh aspect, the terminal includes
the terminal according to any one of the first aspect, or the first
to the seventieth possible implementation manners of the first
aspect.
[0610] With reference to the seventh aspect, in a second possible
implementation manner of the seventh aspect, the first base station
includes the first base station according to any one of the second
aspect, or the first to the thirty-third possible implementation
manners of the second aspect.
[0611] With reference to the seventh aspect, in a third possible
implementation manner of the seventh aspect, the system further
includes a mobility management entity, where the mobility
management entity is connected to the first base station, and
configured for selection of a mobility management entity during a
handover between the communications system and a Long Term
Evolution communications system; or
[0612] configured to select a serving GPRS support node during a
handover between the communications system and a 2G or 3G
communications system.
[0613] According to an eighth aspect, an embodiment of the present
invention provides a wireless communications system, including a
terminal, a first base station, and a second base station, where
the terminal sets up a connection to the first base station, and
stays in always connected mode, where the always connected mode is
to always keep the connection to the first base station;
[0614] the terminal performs data transmission through the first
base station and/or the second base station; and
[0615] the first base station is used for any one of the following
or a combination thereof:
[0616] scheduling and transmission of a service setup message;
or
[0617] generation, scheduling, and transmission of a public
security message; or
[0618] management of bearer setup, modification, and release;
or
[0619] access stratum security control; or
[0620] broadcast service scheduling and transmission; or
[0621] selection of a mobility management entity during a handover
between the communications system and a Long Term Evolution
communications system; or
[0622] selection of a serving GPRS support node during a handover
between the communications system and a 2G or 3G communications
system.
[0623] With reference to the eighth aspect, in a first possible
implementation manner of the eighth aspect, the terminal includes
the terminal according to any one of the first aspect, or the first
to the seventieth possible implementation manners of the first
aspect.
[0624] With reference to the eighth aspect, in a second possible
implementation manner of the eighth aspect, the first base station
includes the first base station according to any one of the second
aspect, or the first to the thirty-third possible implementation
manners of the second aspect.
[0625] The embodiments of the present invention provide a wireless
communications method, a wireless communications apparatus, and a
wireless communications system. A terminal sets up a connection to
a first base station, and stays in always connected mode, so that
the first base station always has context information of the
terminal within a preset time range and keeps downlink
synchronization with the terminal. Therefore, when the terminal
moves in a dense network, handovers of the first base station can
be reduced. Further, when the terminal moves in the dense network,
frequent signaling interaction is reduced, paging load in the
entire network is reduced, and an end-to-end delay in service setup
and transmission is reduced.
BRIEF DESCRIPTION OF DRAWINGS
[0626] To describe technical solutions in embodiments of the
present application more clearly, the following briefly describes
the accompanying drawings=.
[0627] FIG. 1 is a schematic structural diagram of Embodiment 1 of
a wireless communications system according to the present
invention;
[0628] FIG. 2 is a schematic structural diagram of Embodiment 2 of
a wireless communications system according to the present
invention;
[0629] FIG. 3 is a schematic diagram of a protocol stack
architecture 1 between an A-eNB and an MME;
[0630] FIG. 4 is a schematic diagram of a protocol stack
architecture 2 between an A-eNB and an MME;
[0631] FIG. 5 is a schematic structural diagram of Embodiment 1 of
a terminal according to the present invention;
[0632] FIG. 6 is a schematic structural diagram of Embodiment 1 of
a base station according to the present invention;
[0633] FIG. 7 is a signaling flowchart of Embodiment 1 of the
present invention;
[0634] FIG. 8 is a signaling flowchart of Embodiment 2 of the
present invention;
[0635] FIG. 9 is a signaling flowchart of Embodiment 3 of the
present invention;
[0636] FIG. 10 is a signaling flowchart of Embodiment 4 of the
present invention;
[0637] FIG. 11 is a signaling flowchart of Embodiment 5 of the
present invention;
[0638] FIG. 12 is a signaling flowchart of Embodiment 6 of the
present invention;
[0639] FIG. 13 is a signaling flowchart of Embodiment 7 of the
present invention;
[0640] FIG. 14A and FIG. 14B are a signaling flowchart of
Embodiment 8 of the present invention;
[0641] FIG. 15 is a signaling flowchart of Embodiment 9 of the
present invention;
[0642] FIG. 16 is a signaling flowchart of Embodiment 10 of the
present invention;
[0643] FIG. 17 is a signaling flowchart of Embodiment 11 of the
present invention;
[0644] FIG. 18 is a flowchart of Embodiment 1 of a wireless
communications method according to the present invention; and
[0645] FIG. 19 is a flowchart of Embodiment 2 of a wireless
communications method according to the present invention.
DESCRIPTION OF EMBODIMENTS
[0646] To make the objectives, technical solutions, and advantages
of the embodiments of the present invention clearer, the following
clearly and completely describes the technical solutions in the
embodiments of the present invention with reference to the
accompanying drawings in the embodiments of the present invention.
The described embodiments are some but not all of the embodiments
of the present invention. All other embodiments obtained by a
person of ordinary skill in the art based on the embodiments of the
present invention without creative efforts shall fall within the
protection scope of the present invention.
[0647] A main idea of the embodiments of the present invention is
that user equipment (UE for short) is always in a connected state
after entering a network, that is, the UE stays in always connected
mode. In a 3GPP, the connected state is the connected state or an
active state. It should be noted that, herein "always" means
permanence in a relative sense, and not permanence in an absolute
sense, that is, being always in the connected state in a time
range. For example, the time range may be a time from current
power-on to power-off or next power-on of the UE. In the time
range, the UE is in the connected state, that is, "always" in the
embodiments of the present invention is not permanence in an
absolute sense. Therefore, it can be learned that, for being always
in the connected state in a time range in the embodiments of the
present invention, the time range may be different time lengths
such as several minutes, tens of minutes, or several hours. This is
not limited in the embodiments of the present invention. That the
UE stays in always connected mode means that the UE does not enter
an idle state in a time range. In the 3GPP, the idle state is the
idle state. That is, the UE does not enter the idle state any
longer in the time range.
[0648] Whether the UE stays in always connected mode may be
determined by the UE itself, or may be correspondingly controlled
by a network side. In other words, whether the UE does not enter
the idle state forever or does not enter the idle state for a long
time may be determined by the UE itself, or may be correspondingly
controlled by the network side.
[0649] In the following description of the embodiments of the
present invention, unless otherwise specified, "always connected
mode" means being always in the connected state in a time range or
means that the UE does not enter the idle state in a time
range.
[0650] To support and ensure that the UE stays in always connected
mode, a super base station needs to be deployed additionally in the
existing network. The super base station uses low frequency
resources, for example, frequency resources allocated in a UHF
spectrum for use in mobile communication, or other spectrum
resources of low frequencies. The low frequency resources have
features of strong penetration and wide coverage. A coverage radius
of a low-frequency spectrum deployed on the super base station may
be tens of kilometers or other larger radius ranges. The super base
station is defined as an anchor base station (Anchor eUTRAN NodeB,
A-eNB for short), or may be referred to as an engine base station.
Within coverage of an A-eNB, several base stations (eUTRAN NodeB,
eNB for short) having small coverage may exist. Specifically, eNBs
may be further classified into a master base station (Macro eNB,
M-eNB for short) and a secondary base station (Small eNB, S-eNB for
short). When the UE moves within the coverage of the A-eNB, the UE
may randomly select an eNB with good signal quality to perform data
transmission, and the A-eNB is mainly responsible for providing
downlink control signaling transmission and some downlink-specific
services for the UE, for example, a multimedia broadcast multicast
function (Multimedia Broadcast Multicast Service, MBMS for
short).
[0651] With the introduction of the super base station and
deployment of the UHF spectrum resources or other spectrum
resources of low frequency bands on the super base station, the UE
may be within the coverage of the super base station for most
times, so that the UE may keep a connected state with the super
base station for a long time. Herein the so-called keeping a
connected state specifically means that the super base station has
context information of the UE and that the super base station
definitely knows that the UE is within the coverage of the super
base station. Generally, the UE keeps at least downlink
synchronization with the super base station. However, the UE may
also not keep uplink and/or downlink timing synchronization with
the super base station, but performs synchronization according to a
requirement when necessary.
[0652] In the embodiments of the present invention, the network in
which the UE stays in always connected mode and which may have
coverage with a large coverage radius is referred to as an always
connected network (ACN for short), or an always connected system
(ACS for short), or an always active network (ACN for short), or an
always active system (ACS for short), or an always connected state
network (ACSN for short), or an always connected system (ACSS for
short), or an always active state network (AASN for short), or an
always active state system (AASS for short).
[0653] In addition, the staying in always connected mode may also
be referred to as Always ON. Therefore, the network provided in the
embodiments of the present invention may also be referred to as an
always on network (AON for short) or an always on system (AOS for
short) correspondingly.
[0654] In addition, from a perspective of the UE, to avoid frequent
signaling interaction and reduce a delay, each embodiment of the
present invention provides a UE centric method. For a specific
implementation solution, reference may be made to subsequent
embodiments. Therefore, the method and network architecture
provided by the embodiments of the present invention may also be
named a UE centric network, that is, a UE Central Network (UCN for
short) or a UE Central System (UCS for short).
[0655] For ease of description, the network in the following
embodiments is referred to as an AON.
[0656] FIG. 1 is a schematic structural diagram of Embodiment 1 of
a wireless communications system according to the present
invention. A network architecture with an A-eNB introduced in a
current LTE network may be shown in FIG. 1. An AON network includes
UE, an eNB, an A-eNB, an evolved mobility management entity (eUTRAN
Mobility Management Entity, E-MME for short), and a serving gateway
(S-GW for short). The UE accesses the network by using the
AON/A-eNB. The A-eNB is connected to the E-MME by using an S-C
interface. The A-eNB is connected to the S-GW by using an S-X
interface. The E-MME is connected to the S-GW by using an S-Y
interface. Herein the S-GW may be an independent device entity, or
may be integrated with the A-eNB into a public entity. Functions of
the eNB keep consistent with functions of the eNB in the current
LTE network.
[0657] It should be noted that, on a basis of the network
architecture shown in FIG. 1, the A-eNB may include the following
functions:
[0658] (1) radio resource management;
[0659] (2) user plane data IP header compression and
encryption;
[0660] (3) selection of the E-MME;
[0661] (4) routing of user plane data to the S-GW;
[0662] (5) broadcast service scheduling and transmission; and
[0663] (6) mobility measurement configuration and measurement
report configuration.
[0664] Optionally, the A-eNB may also include any one of the
following functions or a combination thereof:
[0665] (7) scheduling and transmission of a service setup message
(the function is similar to a function of a paging message in the
LTE network, that is, sending a notification to the UE when a
service needs to be set up);
[0666] (8) generation, scheduling, and transmission of a public
security message;
[0667] (9) management of EPS bearer setup, modification, and
release;
[0668] (10) access stratum security control; or
[0669] (11) broadcast service scheduling and transmission.
[0670] On a basis of the network architecture shown in FIG. 1,
functions of the E-MME may include the following functions:
[0671] (1) transmission and security of non-access stratum
signaling;
[0672] (2) selection of a packet data network gateway (Packet Data
Network Gateway, PDN GW for short) and the S-GW;
[0673] (3) roaming control; and
[0674] (4) authentication control.
[0675] Optionally, the E-MME may also include any one of the
following functions or a combination thereof:
[0676] (5) selection of an MME during a handover between the AON
and LTE; or
[0677] (6) selection of a serving GPRS support node (SGSN for
short) during a handover between the AON and a 2G or 3G system.
[0678] FIG. 2 is a schematic structural diagram of Embodiment 2 of
a wireless communications system according to the present
invention. In addition, a network architecture with an A-eNB
introduced in a current LTE network may be shown in FIG. 2.
Different from FIG. 1, the AON network in the network architecture
shown in FIG. 2 includes UE, an eNB, an A-eNB, and an S-GW. The UE
accesses the network by using the AON/A-eNB, and the A-eNB is
connected to the S-GW by using an S-X interface. Herein the S-GW
may be an independent device entity, or may be integrated with the
A-eNB into a public entity. Functions of the eNB keep consistent
with functions of the eNB in the current LTE network.
[0679] On a basis of the network architecture shown in FIG. 2, the
A-eNB may include the following functions:
[0680] (1) radio resource management; and
[0681] (2) user plane data IP header compression and
encryption.
[0682] On a basis of the network architecture shown in FIG. 2,
functions of the E-MME may include the following functions:
[0683] (1) routing of user plane data to the S-GW;
[0684] (2) broadcast service scheduling and transmission; and
[0685] (3) mobility measurement configuration and measurement
report configuration.
[0686] Optionally, the E-MME may also include any one of the
following functions or a combination thereof:
[0687] (4) scheduling and transmission of a service setup message
(herein a function of the service setup message is similar to a
function of a paging message in the LTE network, that is, sending a
notification to the UE when a service needs to be set up);
[0688] (5) generation, scheduling, and transmission of a public
security message;
[0689] (6) management of EPS bearer setup, modification, and
release;
[0690] (7) transmission and security of non-access stratum
signaling;
[0691] (8) access stratum security control;
[0692] (9) selection of a PDN GW and the S-GW;
[0693] (10) roaming control;
[0694] (11) authentication control;
[0695] (12) broadcast service scheduling and transmission;
[0696] (13) selection of an MME during a handover between the AON
and LTE; or
[0697] (14) selection of an SGSN during a handover between the AON
and a 2G or 3G system.
[0698] FIG. 3 is a schematic diagram of a protocol stack
architecture 1 between an A-eNB and an MME. FIG. 4 is a schematic
diagram of a protocol stack architecture 2 between an A-eNB and an
MME. On a basis of the network architecture shown in FIG. 1, the
protocol stack architecture between UE, the A-eNB, and the MME may
be designed as shown in FIG. 3. However, on a basis of the network
architecture shown in FIG. 2, the protocol stack architecture
between the UE and the A-eNB may be designed as shown in FIG. 4. As
shown in FIG. 4, a function of an original NAS layer may be
implemented at an RRC layer, and therefore, a delay may be further
reduced.
[0699] In the following embodiments, a whole procedure is provided
according to a work process of the UE in the AON network.
[0700] In the following embodiments, the eNB may also be
equivalently replaced with a cell for equivalent implementation.
Generally, the eNB represents a base station, and the base station
may control one or more cells. For example, description of "one or
more eNBs having context information of UE" may also be replaced
and expressed as one or more cells having context information of
UE. For ease of description, unless otherwise specified in the
following embodiments, in a place in which the eNB is used for
description, after the eNB is replaced with a cell for description,
each embodiment may be normally implemented.
[0701] FIG. 5 is a schematic structural diagram of Embodiment 1 of
a terminal according to the present invention. As shown in FIG. 5,
the terminal in this embodiment may include a processing module 11,
a receiving module 12, and a sending module 13. The processing
module 11 is configured to set up a connection to a first base
station, and stay in always connected mode, where the always
connected mode is to always keep the connection to the first base
station. The receiving module 12 is configured to receive first
dedicated signaling sent by the first base station, where the first
dedicated signaling includes second base station list information,
and the second base station list information includes information
about each second base station having context information of the
terminal. The sending module 13 is configured to perform data
transmission through the first base station and/or the second base
station according to the second base station list information.
[0702] Specifically, for explanation and description about the
always connected mode, reference may be made to the foregoing
explanation and description. It may be understood that, that the
terminal sets up a connection to a first base station and stays in
always connected mode means that the first base station has the
context information of the terminal, and that the first base
station definitely knows that the terminal is within coverage of
the first base station. The first base station may be specifically
the A-eNB in the foregoing explanation and description. The
receiving module 12 of the terminal receives the first dedicated
signaling sent by the first base station, the first dedicated
signaling includes the second base station list information, and
the second base station list information includes the information
about each second base station having the context information of
the terminal. That is, the terminal may learn, from the first base
station, each base station having the context information of the
terminal. It should be noted that, within coverage of a first base
station, several base stations (eNB) with small coverage may exist,
and the base station with small coverage may be the second base
station. The terminal performs data transmission through the first
base station, or the second base station, or the first base station
and the second base station according to the second base station
list information.
[0703] In this embodiment of the present invention, a terminal sets
up a connection to a first base station, and stays in always
connected mode, so that the first base station always has context
information of the terminal and keeps downlink synchronization with
the terminal. Therefore, when the terminal moves in a dense
network, handovers of the first base station can be reduced.
Further, when the terminal moves in the dense network, frequent
signaling interaction is reduced, and paging load in the entire
network is reduced. In addition, the terminal receives second base
station list information sent by the first base station, where the
second base station list information includes information about
each second base station having the context information of the
terminal. The terminal may perform data transmission through the
first base station and/or the second base station according to the
second base station list information. Therefore, in comparison with
the conventional art, an end-to-end delay in service setup and
transmission can be reduced effectively.
[0704] Further, on a basis of the structure of the terminal shown
in FIG. 5, that the processing module 11 is configured to set up a
connection to a first base station, and stay in always connected
mode, specifically includes: the processing module is configured to
always keep the connection to the first base station within a
preset time.
[0705] The preset time may be a time that is at least longer than
that of service transmission, for example, a time longer than that
of a call. Alternatively, the always keeping the connection to the
first base station within a preset time means not entering a
conventional idle mode after completion of all service
transmission, but still keeping the connection to the first base
station, or may mean still keeping the connection to the first base
station if no actual data transmission is performed, or still
keeping the connection to the first base station if only a default
bearer is set up but there is no actual data transmission. The
preset time may be different time lengths such as several minutes,
tens of minutes, or several hours. This is not limited in this
embodiment of the present invention.
[0706] Further, that the sending module 13 of the terminal is
configured to perform data transmission through the first base
station may include: the sending module is configured to perform
only control signaling transmission through the first base station;
or the sending module is configured to perform only downlink data
transmission through the first base station; or the sending module
is configured to perform only downlink control signaling
transmission through the first base station.
[0707] Optionally, before the processing module 11 is configured to
set up the connection to the first base station, and stay in always
connected mode, the processing module 11 may be further configured
to: obtain access frequency information, and determine whether a
connected mode corresponding to the access frequency information is
the always connected mode.
[0708] That the processing module 11 is configured to obtain access
frequency information, and determine whether a connected mode
corresponding to the access frequency information is the always
connected mode, may be specifically: the processing module 11 is
configured to receive system information sent by the first base
station, and obtain, from the system information, whether the
connected mode corresponding to the access frequency information is
the always connected mode; or the processing module 11 is
configured to obtain, from preset configuration information,
whether the connected mode corresponding to the access frequency
information is the always connected mode.
[0709] The processing module 11 is further configured to select, if
the connected mode corresponding to the access frequency
information is the always connected mode, a first base station
corresponding to the access frequency information to perform
access.
[0710] The receiving module 12 may be further configured to receive
scheduling information sent by the first base station.
[0711] Optionally, that the processing module 11 is configured to
set up a connection to the first base station may be specifically:
the processing module is configured to send a first indication
message to the first base station, where the first indication
message carries indication information about whether to request to
accept working in the always connected mode; and receive connection
configuration information that is sent by the first base station
according to the first indication message, where the connection
configuration information includes whether to configure the
terminal to work in the always connected mode.
[0712] The first indication message may be: a random access message
3 or a connection setup request message.
[0713] Optionally, that the processing module 11 is configured to
set up a connection to a first base station, and stay in always
connected mode, may be specifically: the processing module is
configured to determine whether there is any service requirement
currently, and if there is no service requirement currently, keep a
connected state with the first base station, and stay in the always
connected mode; or if there is a service requirement currently,
request the first base station to set up a corresponding bearer,
and perform data transmission by using the bearer.
[0714] That the processing module 11 is configured to keep a
connected state with the first base station if there is no service
requirement currently, specifically includes: the processing module
11 is configured to keep receiving scheduling information sent by
the first base station if there is no service requirement
currently.
[0715] The receiving module 12 is further configured to receive a
discontinuous reception period configured by the first base
station; and that the processing module 11 is configured to keep
receiving scheduling information sent by the first base station may
specifically include: the receiving module is configured to
receive, within an active time of the discontinuous reception
period, the scheduling information sent by the first base
station.
[0716] After the receiving module 12 receives the scheduling
information, the receiving module 12 is further configured to:
receive, according to an instruction of the scheduling information,
second dedicated signaling sent by the first base station, where
the second dedicated signaling includes notification information,
and the notification information is used to notify the terminal
that a bearer needs to be set up for data transmission.
[0717] The second dedicated signaling further includes instruction
information, where the instruction information includes second
instruction information or third instruction information, the
second instruction information is instruction information
instructing to select at least one second base station to perform
data transmission, and the third instruction information is
instruction information instructing to perform data transmission
only through the first base station; and the receiving module is
further configured to receive the second instruction information or
the third instruction information sent by the first base
station.
[0718] That the processing module 11 is configured to request the
first base station to set up a corresponding bearer, and perform
data transmission by using the bearer if there is a service
requirement currently, may be specifically: if there is a service
requirement currently, the processing module is configured to
request the first base station to set up the corresponding bearer,
receive second dedicated signaling sent by the first base station,
where the second dedicated signaling includes notification
information, and the notification information is used to notify the
terminal that the bearer needs to be set up for data transmission,
and perform data transmission by using the bearer.
[0719] The receiving module 12 is further configured to: receive an
instruction message sent by the first base station, where the
instruction message includes second instruction information or
third instruction information, the second instruction information
is instruction information instructing to select at least one
second base station to perform data transmission, and the third
instruction information is instruction information instructing to
perform data transmission only through the first base station.
[0720] Further, the receiving module 12 is further configured to:
if the second instruction information sent by the first base
station is received, select, according to the second instruction
information, the at least one second base station to perform data
transmission. Correspondingly, the sending module 13 is further
configured to send information about the selected at least one
second base station to the first base station.
[0721] Different from the foregoing description in which the
receiving module 12 of the terminal selects the at least one second
base station according to the received second instruction
information, where the second instruction information may be
carried in the second dedicated signaling or may be a separate
message, the terminal may further receive the notification
information in the second dedicated signaling. In this way, the
terminal may select the at least one second base station to perform
data transmission, and send the information about the selected at
least one second base station to the first base station, or
determine to perform only data transmission through the first base
station.
[0722] The sending module 13 is further configured to: if each
second base station in the at least one second base station has the
context information of the terminal, send a scheduling request
message to each second base station, and obtain, by using the
scheduling request message, a resource allocated by each second
base station to perform data transmission; or if each second base
station in the at least one second base station has the context
information of the terminal, perform random access to each second
base station, and obtain a resource allocated by each second base
station to perform data transmission.
[0723] That the sending module is configured to perform random
access to each second base station, and obtain a resource allocated
by each second base station to perform data transmission, may be:
the sending module is configured to perform random access to each
second base station by using unique identifier information
allocated by the first base station, and obtain the resource
allocated by each second base station according to the unique
identifier information to perform data transmission, where the
unique identifier information corresponds to the terminal, and the
unique identifier information is a unique preamble or a combination
of a unique preamble and a random access resource.
[0724] The sending module 13 is further configured to: if each
second base station in the at least one second base station does
not have the context information of the terminal, perform random
access to each second base station, and in the random access
process, send, to each second base station, the context information
of the terminal and information about the first base station to
which the terminal has set up the connection.
[0725] Optionally, the processing module 11 is further configured
to: after stopping performing data transmission through the first
base station and/or the second base station, continue to work in
always connected mode, and save dedicated configuration information
for setting up the connection to the first base station.
[0726] Optionally, the processing module 11 is further configured
to: stop maintaining an uplink synchronization timer; or after an
uplink synchronization timer expires, stop maintaining the uplink
synchronization timer.
[0727] The foregoing step in this embodiment is a process of a
method for performing initial access by the terminal. After the
terminal performs initial access, the terminal obtains initial list
information of second base stations having the context information
of the terminal; afterward, the terminal needs to manage the
context information of the terminal on a second base station that
currently provides services for the terminal, and on other second
base stations in time, so that the terminal can quickly use a
second base station to perform data transmission. Therefore, the
receiving module 12 in this embodiment is further configured to:
receive a second base station list update message sent by the first
base station, update the second base station list information
according to the second base station list update message, and
obtain updated second base station list information.
[0728] Optionally, before the receiving module 12 is configured to
receive the second base station list update message sent by the
first base station, the sending module 13 is further configured to:
send a second base station list update request message to the first
base station.
[0729] The second base station list update message is generated by
the first base station according to location information of the
terminal and location information of each second base station.
[0730] Optionally, the processing module 11 is further configured
to: measure each neighboring base station in a network, and if a
neighboring base station whose signal quality is higher than a
first threshold exists, determine whether the updated second base
station list information includes information about the neighboring
base station.
[0731] The processing module is further configured to: if the
updated second base station list information does not include the
information about the neighboring base station, send a neighboring
base station measurement report to the first base station, where
the neighboring base station measurement report includes the
information about the neighboring base station; or if the updated
second base station list information does not include the
information about the neighboring base station, send a second base
station list update request message to the first base station,
where the second base station list update request message includes
the information about the neighboring base station; or if the
updated second base station list information does not include the
information about the neighboring base station, report to the first
base station that the neighboring base station is not included in
the updated second base station list.
[0732] Optionally, the base station measurement report further
includes an indication that the neighboring base station does not
have the context information of the terminal, so that the first
base station sends the context information of the terminal to the
neighboring base station.
[0733] The receiving module 12 is further configured to receive a
response message sent by the first base station, where the response
message is generated by the first base station according to the
neighboring base station measurement report, and learn, according
to the response message, that the neighboring base station has
obtained the context information of the terminal.
[0734] Before the terminal performs data transmission with the base
station, a related configuration further needs to be completed.
Therefore, the receiving module 12 of the terminal in this
embodiment of the present invention is further configured to
receive default configuration information sent by the first base
station, where the default configuration information is
configuration information used when the terminal performs initial
data transmission with each second base station; and that the
sending module 13 is configured to perform data transmission
through the first base station and/or the second base station
according to the second base station list information specifically
includes: the sending module is configured to perform, according to
the second base station list information and the default
configuration information, data transmission through a second base
station that has the context information of the terminal.
[0735] Optionally, the default configuration information is
associated with a service type, quality of service QoS of a
service, or a bearer type.
[0736] The receiving module 12 is further configured to: receive a
second base station list update message sent by the first base
station, update the second base station list information according
to the second base station list update message, and obtain updated
second base station list information. That the sending module 13 is
configured to perform, according to the second base station list
information and the default configuration information, data
transmission through a second base station that has the context
information of the terminal, may be: the sending module is
configured to perform, according to the updated second base station
list and the default configuration information, initial data
transmission through the second base station that has the context
information of the terminal; and receive a reconfiguration message
sent by the second base station, modify, according to the
reconfiguration message, default configuration information
corresponding to the terminal, and perform, by using modified
configuration information, data transmission with the second base
station that has the context information of the terminal.
[0737] In a moving process, the terminal needs to continuously
measure neighboring first base stations and neighboring second base
stations to determine potential first base stations or second base
stations that may be selected. In an actual network, the second
base stations may be classified into a master second base station
and a secondary second base station, where coverage of the master
second base station is large, and coverage of the secondary second
base station is small. To improve measurement efficiency of the
terminal and reduce a power consumption level of the terminal, the
receiving module 12 of the terminal in this embodiment is further
configured to receive measurement configuration information sent by
the first base station, and complete, according to the measurement
configuration information, a measurement configuration of a
frequency layer corresponding to each base station, where the base
stations include the first base station and the second base
stations, and the second base stations include a master second base
station and a secondary second base station.
[0738] The measurement configuration information includes:
measuring a frequency layer corresponding to the first base station
only; or measuring frequency layers corresponding to the first base
station and the master second base station only; or measuring
frequency layers corresponding to all of the first base station,
the master second base station, and the secondary second base
station.
[0739] The measurement configuration information may further
include: determining a first threshold for measuring the frequency
layer corresponding to the first base station only; or determining
a second threshold for measuring the frequency layers corresponding
to the first base station and the master second base station only;
or determining a third threshold for measuring the frequency layers
corresponding to all of the first base station, the master second
base station, and the secondary second base station.
[0740] If QoS of a current service of the terminal is less than the
first threshold, that the receiving module is configured to
complete, according to the measurement configuration information, a
measurement configuration of a frequency layer corresponding to
each base station, includes: the receiving module is configured to
measure, according to the measurement configuration information,
the frequency layer corresponding to the first base station only,
and obtain a measurement result; or if QoS of a current service of
the terminal is greater than the first threshold but less than the
second threshold, that the receiving module 12 is configured to
complete, according to the measurement configuration information, a
measurement configuration of a frequency layer corresponding to
each base station, includes: the receiving module is configured to
measure, according to the measurement configuration information,
the frequency layer corresponding to the first base station and the
frequency layer corresponding to the master second base station,
and obtain measurement results; or if QoS of a current service of
the terminal is greater than the second threshold or the third
threshold, that the receiving module 12 is configured to complete,
according to the measurement configuration information, a
measurement configuration of a frequency layer corresponding to
each base station, includes: the receiving module is configured to
measure, according to the measurement configuration information,
the frequency layers corresponding to the first base station, the
master second base station, and the secondary second base station,
and obtain measurement results.
[0741] The receiving module 12 is further configured to: receive an
instruction message sent by the first base station about whether to
perform measurement reporting; and determine, according to the
instruction message about whether to perform measurement reporting,
whether to send the measurement result to the first base
station.
[0742] The instruction message about whether to perform measurement
reporting may include: at least one of instruction information for
measurement reporting of the frequency layer corresponding to the
first base station, instruction information for measurement
reporting of the frequency layer corresponding to the master second
base station, or instruction information for measurement reporting
of the frequency layer corresponding to the secondary second base
station.
[0743] The receiving module 12 is further configured to: receive
measurement configuration parameter information sent by the first
base station, and complete, according to the measurement
configuration parameter information, measurement management of a
frequency layer corresponding to each base station, where the base
stations include the first base station and the second base
stations, and the second base stations include a master second base
station and a secondary second base station; where the measurement
configuration parameter information includes at least one of a
measurement configuration parameter of a frequency layer
corresponding to the first base station, a measurement
configuration parameter of a frequency layer corresponding to the
master second base station, or a measurement configuration
parameter of a frequency layer corresponding to the secondary
second base station.
[0744] Further, if QoS of a current service of the terminal is less
than a first threshold, that the receiving module is configured to
complete, according to the measurement configuration parameter
information, measurement management of a frequency layer
corresponding to each base station, includes: the receiving module
is configured to measure, according to the measurement
configuration parameter of the frequency layer corresponding to the
first base station, the frequency layer of the first base station,
and obtain a first measurement result; or if QoS of a current
service of the terminal is greater than a first threshold but less
than a second threshold, that the receiving module is configured to
complete, according to the measurement configuration parameter
information, measurement management of a frequency layer
corresponding to each base station, includes: the receiving module
is configured to measure, according to the measurement
configuration parameter of the frequency layer corresponding to the
first base station, the frequency layer of the first base station,
and obtain a first measurement result, and at the same time,
measure, according to the measurement configuration parameter of
the frequency layer corresponding to the master second base
station, the frequency layer of the master second base station, and
obtain a second measurement result; or if QoS of a current service
of the terminal is greater than a second threshold, that the
receiving module is configured to complete, according to the
measurement configuration parameter information, measurement
management of a frequency layer corresponding to each base station,
includes: the receiving module is configured to measure, according
to the measurement configuration parameter of the frequency layer
corresponding to the secondary second base station, the frequency
layer of the secondary second base station, and obtain a third
measurement result.
[0745] That the receiving module 12 is configured to measure,
according to the measurement configuration parameter of the
frequency layer corresponding to the first base station, the
frequency layer of the first base station, specifically includes:
the receiving module is configured to measure, according to the
measurement configuration parameter of the frequency layer
corresponding to the first base station, the first base station
and/or a first base station neighboring to the first base
station.
[0746] That the receiving module 12 is configured to measure,
according to the measurement configuration parameter of the
frequency layer corresponding to the master second base station,
the frequency layer of the master second base station, specifically
includes: the receiving module is configured to measure, according
to the measurement configuration parameter of the frequency layer
corresponding to the master second base station, the master second
base station and/or a master second base station neighboring to the
master second base station.
[0747] The sending module 13 is further configured to: send the
obtained first measurement result to the first base station; and
skip sending the third measurement result to the first base
station.
[0748] The sending module 13 is further configured to: compare the
obtained second measurement result with a preset condition, and if
the preset condition is met, send the second measurement result to
the first base station.
[0749] Further, a large quantity of first base stations exist in a
network. In a moving process of the terminal, on the one hand, the
terminal needs to measure the first base stations; on the other
hand, the terminal may also be handed over according to a
measurement result, so that the terminal is handed over to a more
appropriate first base station. Therefore, this embodiment further
includes managing mobility of the terminal between first base
stations. Specifically, the receiving module 12 of the terminal in
this embodiment is further configured to: receive a handover
command message sent by the current serving first base station,
where the handover command message includes information about each
second base station that is controlled by a target first base
station and has the context information of the terminal, the
current serving first base station is the first base station that
currently performs data transmission with the terminal, and the
target first base station is a target first base station to which
the terminal is handed over from the current serving first base
station.
[0750] The handover command message may further include instruction
information instructing the terminal to skip performing random
access to the target first base station; and the processing module
does not perform random access to the target first base station
according to the instruction information instructing to skip
performing random access to the target first base station.
[0751] The sending module 13 is further configured to: select,
according to the handover command message, at least one second base
station that has the context information of the terminal, so as to
perform data transmission.
[0752] Each second base station that is controlled by the target
first base station and has the context information of the terminal
is controlled by the target first base station or connected to the
target first base station.
[0753] Alternatively, each second base station that is controlled
by the target first base station and has the context information of
the terminal is controlled by the current serving first base
station and the target first base station jointly, or has
connection relationships with both the current serving first base
station and the target first base station.
[0754] Before the receiving module 12 is configured to receive the
handover command message sent by the current serving first base
station, the receiving module 12 is further configured to: measure
each first base station in a network, and obtain a measurement
result of each first base station, where the first base stations
include the current serving first base station and neighboring
first base stations, and the neighboring first base stations
include the target first base station.
[0755] The receiving module 12 is further configured to: determine
the target first base station according to a measurement result of
the current serving first base station and measurement results of
the neighboring first base stations; and send a first handover
request message to the current serving first base station, where
the first handover request message includes information about
requesting to be handed over to the target first base station.
[0756] The sending module 13 is further configured to send the
measurement results of the neighboring first base stations to the
current serving first base station, so that the current serving
first base station determines whether to perform the handover to
the target first base station.
[0757] That the sending module 13 is configured to select,
according to the handover command message, at least one second base
station that has the context information of the terminal, so as to
perform data transmission, includes: the sending module is
configured to preferentially select, according to the handover
command message, a second base station that provides services under
control of the current serving first base station and has the
context information, so as to perform data transmission, where the
second base station is controlled by the target first base
station.
[0758] The handover command message further includes: instruction
information instructing the terminal to keep performing data
transmission with at least one current serving second base station,
where the current serving second base station is a second base
station that provides data transmission for the terminal before the
handover command is received; and the sending module 13 is
configured to perform the handover to the target first base station
according to the handover command message, and at the same time,
keep performing data transmission through the at least one current
serving second base station.
[0759] The sending module 13 is further configured to: send a
handover complete indication to the current serving first base
station through a second base station controlled by the current
serving first base station.
[0760] Optionally, in another possible implementation manner of
managing mobility of the terminal between first base stations, the
sending module 13 of the terminal in this embodiment is further
configured to: measure each first base station in a network, and
obtain a measurement result of each first base station, where the
first base stations include the current serving first base station
and neighboring first base stations; determine a target first base
station according to the measurement result, where the target first
base station is a target first base station to which the terminal
is handed over from the current serving first base station; and
send a handover request message to the target first base station,
where the handover request message includes information about the
current serving first base station and information about candidate
second base stations, where the candidate second base stations are
second base stations that are controlled by the target first base
station or connected to the target first base station and can
provide services for the terminal.
[0761] The receiving module 12 is further configured to: receive a
handover request acknowledgement message from the target first base
station, where the handover request acknowledgement message
includes a list of second base stations that are controlled by the
target first base station or connected to the target first base
station and have the context information of the terminal; and the
sending module 13 is further configured to select, according to the
handover request acknowledgement message, at least one second base
station that has the context information of the terminal, so as to
perform data transmission.
[0762] After being configured to select, according to the handover
request acknowledgement message, the at least one second base
station that has the context information of the terminal, so as to
perform data transmission, the sending module 13 is further
configured to: send a handover complete indication message to the
current serving first base station; or send a handover complete
indication message to the current serving first base station
through the target first base station.
[0763] Optionally, in still another possible implementation manner
of managing mobility of the terminal between first base stations,
the sending module 13 of the terminal in this embodiment is further
configured to: measure each first base station in a network, and
obtain a measurement result of each first base station, where the
first base stations include the current serving first base station
and neighboring first base stations; determine a target first base
station according to the measurement result, where the target first
base station is a target first base station to which the terminal
is handed over from the current serving first base station; send a
handover request message to the current serving first base station,
where the handover request message includes information about
requesting to be handed over to the target first base station; and
receive a handover command message sent by the current serving
first base station.
[0764] The handover command message includes instruction
information instructing the terminal to perform the handover to the
target first base station and instruction information instructing
the terminal to keep performing data transmission with at least one
current serving second base station, where the current serving
second base station is a second base station that provides data
transmission for the terminal before the handover command message
is received; and the sending module 13 is configured to perform the
handover to the target first base station according to the handover
command message, and at the same time, keep performing data
transmission through the at least one current serving second base
station.
[0765] The handover command message further includes bearer
reconfiguration information; and the sending module 13 is
configured to switch a data transmission service between the
current serving first base station and the terminal to the current
serving second base station according to the bearer reconfiguration
information.
[0766] To ensure data security during communication between the
terminal and each base station, a new mechanism for generating a
security key needs to be provided for a network architecture of
embodiments of the present invention. Before the terminal performs
data transmission through the first base station and/or the second
base station according to the list information of the second base
stations having the context information, this embodiment may
further include: the terminal sets up a first security mechanism
with the first base station, and sets up a second security
mechanism with the second base station.
[0767] Specifically, the sending module 13 of the terminal is
further configured to set up the first security mechanism with the
first base station, and set up the second security mechanism with
the second base station.
[0768] That the sending module 13 is configured to set up the
second security mechanism with the second base station may include:
the sending module is configured to receive the second base station
list information and security algorithm information sent by the
first base station, where the second base station list information
includes the information about each second base station having the
context information, and the security algorithm information
includes security algorithm information corresponding to each
second base station included in the second base station list; and
select at least one second base station from the second base
station list, and obtain, according to a security index
corresponding to the at least one second base station and the
security algorithm information, an encryption key and/or an
integrity protection key corresponding to each second base station;
where the second base station corresponds to the security index on
a one-to-one basis.
[0769] That the sending module is configured to obtain, according
to a security index corresponding to the at least one second base
station and the security algorithm information, an encryption key
and/or an integrity protection key corresponding to each second
base station, includes: the sending module is configured to obtain,
according to the security index corresponding to the at least one
second base station, a security key corresponding to the at least
one security index, and obtain a corresponding root key through
calculation according to the security key; obtain, by using the
root key, an intermediate key corresponding to the second base
station; and obtain, according to the intermediate key and the
security algorithm information corresponding to the second base
station, the encryption key and/or the integrity protection key
corresponding to the second base station.
[0770] That the sending module 13 is configured to perform data
transmission through the first base station and/or the second base
station includes: the sending module is configured to perform data
transmission through the first base station based on the first
security mechanism, and/or perform data transmission through the
second base station based on the second security mechanism.
[0771] The first security mechanism and the second security
mechanism are associated with each other; and that the sending
module 13 is configured to obtain, according to a security index
corresponding to the at least one second base station and the
security algorithm information, an encryption key and/or an
integrity protection key corresponding to each second base station,
may include: the sending module is configured to obtain, according
to the security index corresponding to the at least one second base
station, a security key and a dynamic count corresponding to the at
least one security index, and obtain a corresponding root key
through calculation according to the security key; obtain, by using
the root key, an intermediate key corresponding to the second base
station; obtain an associated intermediate key according to the
intermediate key and the dynamic count; and obtain, according to
the associated intermediate key and the security algorithm
information corresponding to the second base station, the
encryption key and/or the integrity protection key corresponding to
the second base station.
[0772] The terminal in this embodiment can effectively reduce
frequent signaling interaction when the terminal moves in a dense
network, eliminate paging load in the entire network, and reduce an
end-to-end delay in service setup and transmission.
[0773] FIG. 6 is a schematic structural diagram of Embodiment 1 of
a base station according to the present invention. As shown in FIG.
6, the base station in this embodiment is used as a first base
station, and may include a processing module 21 and a sending
module 22. The processing module 21 is configured to set up a
connection to a terminal, and stay in always connected mode, where
the always connected mode is to always keep the connection to the
terminal. The sending module 22 is configured to send first
dedicated signaling to the terminal, where the first dedicated
signaling includes second base station list information, and the
second base station list information includes information about
each second base station having context information of the
terminal; and perform data transmission with the terminal.
[0774] In this embodiment of the present invention, a first base
station sets up a connection to a terminal, and stays in always
connected mode, and the first base station always has context
information of the terminal and keeps downlink synchronization with
the terminal. Therefore, when the terminal moves in a dense
network, handovers of the first base station can be reduced.
Further, when the terminal moves in the dense network, frequent
signaling interaction is reduced, and paging load in the entire
network is reduced. In addition, the first base station sends
second base station list information to the terminal, where the
second base station list information includes information about
each second base station having the context information of the
terminal. The terminal may perform data transmission through the
first base station and/or the second base station according to the
second base station list information. Therefore, in comparison with
the conventional art, an end-to-end delay in service setup and
transmission can be reduced effectively.
[0775] Further, on a basis of the structure of the base station
shown in FIG. 6, that the first base station sets up a connection
to a terminal, and stays in always connected mode, includes: the
first base station always keeps the connection to the first base
station within a preset time.
[0776] That the sending module 22 is configured to perform data
transmission with the terminal specifically includes: the sending
module is configured to transmit only control signaling to the
terminal; or transmit only downlink data to the terminal; or
transmit only downlink control signaling to the terminal.
[0777] Before being configured to set up the connection to the
terminal, and stay in always connected mode, the sending module is
further configured to: send a dedicated message to the terminal,
where the dedicated message carries instruction information
instructing the terminal whether to work in the always connected
mode; or receive a first indication message sent by the terminal,
where the first indication message carries indication information
about whether the terminal requests to work in the always connected
mode, and determine, according to the first indication message,
whether to configure the terminal to work in the always connected
mode; or after receiving a random access preamble sent by the
terminal, send a random access response message to the terminal,
where the random access response message carries instruction
information instructing the terminal whether to work in the always
connected mode, so that the terminal determines, according to the
random access response message, whether to work in the always
connected mode; or after receiving a connection setup request
message sent by the terminal, send a connection setup response
message to the terminal, where the connection setup response
message carries instruction information instructing the terminal
whether to work in the always connected mode; or after receiving a
connection setup request message sent by the terminal, send a
dedicated message to the terminal, where the dedicated message
carries instruction information instructing the terminal whether to
work in the always connected mode.
[0778] The first indication message includes: a random access
message 3 or a connection setup request message.
[0779] That the sending module 22 is configured to set up a
connection to a terminal, and stay in always connected mode, may
specifically include: if no service request message sent by the
terminal is received, the sending module is configured to keep a
connected state with the terminal, and stay in the always connected
mode; or if a service request message sent by the terminal is
received, where the service request message includes information
about requesting to set up a corresponding bearer, the sending
module is configured to set up the bearer for the terminal
according to the service request message, so as to perform data
transmission.
[0780] When no service request message sent by the terminal is
received, the sending module 22 is further configured to: configure
a discontinuous reception period for the terminal, so that the
terminal receives, within an active time of the discontinuous
reception period, scheduling information sent by the first base
station.
[0781] The sending module 22 is further configured to: send the
scheduling information to the terminal, where the scheduling
information is used to instruct the terminal to receive second
dedicated signaling; and send the second dedicated signaling to the
terminal, where the second dedicated signaling includes a
notification message, and the notification message includes
information notifying the terminal that the bearer needs to be set
up for data transmission.
[0782] The second dedicated signaling further includes instruction
information, where the instruction information includes second
instruction information or third instruction information, the
second instruction information is instruction information
instructing the terminal to select at least one second base station
to perform data transmission, and the third instruction information
is instruction information instructing the terminal to perform data
transmission only through the first base station.
[0783] If the service request message sent by the terminal is
received, the sending module may be further configured to: if the
service request message sent by the terminal is received, send the
scheduling information to the terminal, where the scheduling
information is used to instruct the terminal to receive second
dedicated signaling; and send the second dedicated signaling to the
terminal, where the second dedicated signaling includes a
notification message, and the notification message includes
information notifying the terminal that the bearer needs to be set
up for data transmission, and perform data transmission with the
terminal by using the bearer.
[0784] The sending module 22 is further configured to: send an
instruction message to the terminal, where the instruction message
includes second instruction information or third instruction
information, the second instruction information is instruction
information instructing to select at least one second base station
to perform data transmission, and the third instruction information
is instruction information instructing to perform data transmission
only through the first base station.
[0785] Further, the first base station may further include a
receiving module 23, configured to: receive information sent by the
terminal about the selected at least one second base station, where
the information about the selected at least one second base station
is information about each second base station in the at least one
second base station selected by the terminal according to the
second instruction information.
[0786] The sending module 22 is further configured to: determine
whether each second base station in the information about the
selected at least one second base station has the context
information of the terminal; and if a second base station that does
not have the context information of the terminal exists, send the
context information of the terminal to the second base station that
does not have the context information of the terminal.
[0787] The sending module 22 is further configured to: allocate a
unique preamble or a combination of a unique preamble and a random
access channel resource to the terminal, so that the terminal
obtains, by using the unique preamble or the combination of the
unique preamble and the random access channel resource, a resource
allocated by the second base station, so as to perform data
transmission.
[0788] The processing module 21 is further configured to: after the
first base station stops performing data transmission with the
terminal, the first base station saves configuration information
for setting up the connection to the terminal.
[0789] The sending module 22 is further configured to: generate a
second base station list update message, and send the second base
station list update message to the terminal, where the second base
station list update message includes updated second base station
list information, so that the terminal updates the second base
station list information according to the second base station list
update message.
[0790] That the sending module 22 is configured to generate a
second base station list update message includes: the sending
module is configured to generate the second base station list
update message according to one or more of location information of
the terminal, location information of each second base station, or
a measurement report reported by the terminal.
[0791] Further, the base station further includes a receiving
module 23, configured to: receive a neighboring base station
measurement report sent by the terminal, where the neighboring base
station measurement report includes information about a neighboring
base station, and the information about the neighboring base
station is not included in the second base station list
information; or receive a second base station list update request
message sent by the terminal, where the second base station list
update request message includes information about a neighboring
base station, and the information about the neighboring base
station is not included in the second base station list
information; or receive a report of the terminal that a neighboring
base station is not included in the second base station list.
[0792] The sending module 22 is further configured to: if the
neighboring base station does not have the context information of
the terminal, send the context information of the terminal to the
neighboring base station, and send a second base station list
update message to the terminal, where the second base station list
update message includes the information about the neighboring base
station.
[0793] The second base station measurement report further includes
information indicating that the neighboring base station does not
have the context information of the terminal; and the sending
module 22 is further configured to send the context information of
the terminal to the neighboring base station, and send a response
message to the terminal, where the response message is generated by
the first base station according to the neighboring base station
measurement report, so that the terminal learns, according to the
response message, that the neighboring base station has obtained
the context information of the terminal.
[0794] The sending module 22 is further configured to: send default
configuration information to the terminal and each second base
station separately, where the default configuration information is
associated with a service type, quality of service QoS of a
service, or a bearer type, and the default configuration
information is configuration information used when the terminal
performs initial data transmission with each second base
station.
[0795] The sending module 22 is further configured to: send a
second base station list update message to the terminal, so that
the terminal updates the second base station list information
according to the second base station list update message and
performs, by using updated second base station list information and
the default configuration information, initial data transmission
through a second base station that has the context information of
the terminal.
[0796] The sending module 22 is further configured to: send
measurement configuration information to the terminal, where the
measurement configuration information includes measurement
configuration information of a frequency layer corresponding to
each base station, the base station includes at least one of the
first base station or the second base stations, and the second base
stations include a master second base station and a secondary
second base station.
[0797] The measurement configuration information includes:
measuring a frequency layer corresponding to the first base station
only; or measuring frequency layers corresponding to the first base
station and the master second base station only; or measuring
frequency layers corresponding to all of the first base station,
the master second base station, and the secondary second base
station.
[0798] The measurement configuration information further includes:
a first threshold for measuring the frequency layer corresponding
to the first base station only; or a second threshold for measuring
the frequency layers corresponding to the first base station and
the master second base station only; or a third threshold for
measuring the frequency layers corresponding to all of the first
base station, the master second base station, and the secondary
second base station.
[0799] The sending module 22 is further configured to: send, to the
terminal, an instruction message about whether to perform
measurement reporting.
[0800] The instruction message about whether to perform measurement
reporting may include: at least one of instruction information for
measurement reporting of the frequency layer corresponding to the
first base station, instruction information for measurement
reporting of the frequency layer corresponding to the master second
base station, or instruction information for measurement reporting
of the frequency layer corresponding to the secondary second base
station.
[0801] The sending module 22 is further configured to: send
measurement configuration parameter information to the terminal,
where the measurement configuration parameter information includes
at least one of a measurement configuration parameter of the
frequency layer corresponding to the first base station, a
measurement configuration parameter of the frequency layer
corresponding to the master second base station, or a measurement
configuration parameter of the frequency layer corresponding to the
secondary second base station.
[0802] The receiving module 23 is further configured to: receive
measurement results sent by the terminal, where the measurement
results include a first measurement result and a second measurement
result, the first measurement result is obtained by the terminal by
performing a measurement according to the measurement configuration
parameter of the frequency layer corresponding to the first base
station, and the second measurement result is obtained by the
terminal by measuring the master second base station according to
the measurement configuration parameter of the frequency layer
corresponding to the master second base station.
[0803] The sending module 22 is further configured to: set up a
first security mechanism with the terminal, and assist the second
base station in setting up a second security mechanism with the
terminal.
[0804] That the sending module 22 is configured to assist the
second base station in setting up a second security mechanism with
the terminal includes: the sending module is configured to obtain,
according to a security index corresponding to at least one second
base station, a security key corresponding to the at least one
security index, and obtain a corresponding root key through
calculation according to the security key; obtain, by using the
root key, an intermediate key corresponding to the second base
station; and send, to the second base station, the intermediate key
corresponding to the second base station; where the security index
corresponds to the second base station on a one-to-one basis.
[0805] The base station further includes a receiving module 23,
configured to receive security algorithm information corresponding
to the second base station and sent by the second base station.
[0806] The first security mechanism and the second security
mechanism are associated with each other, and that the sending
module 22 is configured to assist the second base station in
setting up a second security mechanism with the terminal may
include: the sending module is configured to obtain, according to a
security index corresponding to at least one second base station, a
security key corresponding to the at least one security index, and
obtain a corresponding root key through calculation according to
the security key; obtain, by using the root key and a unique count
corresponding to the second base station, an intermediate key
corresponding to the second base station; and send, to the second
base station, the intermediate key corresponding to the second base
station; where the security index corresponds to the second base
station on a one-to-one basis.
[0807] The receiving module 23 is further configured to: receive
security algorithm information and a dynamic count corresponding to
the second base station and sent by the second base station.
[0808] Optionally, when the base station shown in FIG. 6 is used as
a current serving first base station, the sending module 22 may be
further configured to: send a handover command message to the
terminal, where the handover command message includes information
about each second base station that is controlled by a target first
base station and has the context information of the terminal, and
the target first base station is a target first base station to
which the terminal is handed over from the current serving first
base station.
[0809] The handover command message may further include instruction
information instructing the terminal to skip performing random
access to the target first base station, so that the terminal does
not perform random access to the target first base station
according to the instruction information.
[0810] Before being configured to send the handover command message
to the terminal, the sending module 22 is further configured to:
receive a measurement result of each neighboring first base station
that is sent by the terminal, where the measurement result of each
neighboring first base station is obtained by the terminal by
measuring each base station neighboring to the current serving
first base station; and determine the target first base station
according to the measurement result of each neighboring first base
station.
[0811] Before being configured to send the handover command message
to the terminal, the sending module is further configured to:
receive a first handover request message sent by the terminal,
where the first handover request message includes information about
the target first base station.
[0812] The sending module 22 is further configured to: send a
second handover request message to the target first base station,
where the second handover request message includes the context
information of the terminal and the information about each second
base station that currently has the context information of the
terminal.
[0813] The sending module is further configured to: send a handover
instruction to a second base station currently providing services
for the terminal, so that the second base station currently
providing services for the terminal performs data transmission
according to the handover instruction.
[0814] The second base station currently providing services for the
terminal is a second base station that is controlled by the current
serving first base station and has the context information of the
terminal, or a second base station that is connected to the current
serving first base station and has the context information of the
terminal.
[0815] That the sending module 22 is configured to send a handover
instruction to a second base station currently providing services
for the terminal, so that the second base station currently
providing services for the terminal performs data transmission
according to the handover instruction, includes: the sending module
is configured to send the handover instruction to the second base
station currently providing services for the terminal, where the
handover instruction includes information about the target first
base station, so that the second base station currently providing
services for the terminal determines, according to the handover
instruction, whether data transmission can be performed with the
terminal under control of the target first base station.
[0816] That the sending module 22 is configured to send a handover
instruction to a second base station currently providing services
for the terminal, so that the second base station currently
providing services for the terminal performs data transmission
according to the handover instruction, includes: the sending module
is configured to send the handover instruction to the second base
station currently providing services for the terminal, where the
handover instruction includes information instructing to stop
performing data transmission with the terminal, so that the second
base station currently providing services for the terminal stops
performing data transmission with the terminal according to the
handover instruction.
[0817] That the sending module 22 is configured to send a handover
instruction to a second base station currently providing services
for the terminal, so that the second base station currently
providing services for the terminal performs data transmission
according to the handover instruction, includes: the sending module
is configured to send the handover instruction to the second base
station currently providing services for the terminal, where the
handover instruction includes information instructing to continue
to perform data transmission with the terminal, so that the second
base station currently providing services for the terminal
continues to perform data transmission with the terminal according
to the handover instruction.
[0818] The handover command message further includes second base
station instruction information, and the second base station
instruction information is instruction information instructing the
terminal to keep performing data transmission with at least one
current serving second base station.
[0819] The sending module 22 is further configured to: send a
second base station control negotiation message to a target first
base station, where the second base station control negotiation
message includes information about a second base station that meets
a joint control condition; and receive a second base station
negotiation response message sent by the target first base station,
where the second base station negotiation response message is a
response message generated according to the second base station
control negotiation message, and the response message includes
information about a second base station that is determined by the
neighboring first base station and can be jointly controlled, or an
acknowledgement of information about a second base station that is
included in the second base station control negotiation message and
can be jointly controlled.
[0820] Before being configured to send the second base station
control negotiation message to the target first base station, the
sending module 22 is further configured to: obtain, according to
location information of each second base station in a network and
location information of the current serving first base station and
the target first base station, the second base station that meets
the joint control condition, where the second base station that
meets the joint control condition is a second base station that is
controlled by the current serving first base station and the target
first base station jointly.
[0821] The sending module 22 is further configured to: after the
current serving first base station receives a first handover
request message sent by the terminal, send a second handover
request message to the target first base station according to the
second base station negotiation response message, where the second
handover request message includes the context information of the
terminal and the information about the second base station that
meets the joint control condition.
[0822] The first base station in this embodiment can effectively
reduce frequent signaling interaction when a terminal moves in a
dense network, eliminate paging load in the entire network, and
reduce an end-to-end delay in service setup and transmission.
[0823] The following uses several specific embodiments to describe
in detail an interaction process between the terminal shown in FIG.
5 and the base station shown in FIG. 6. In the following several
embodiments, an example in which the terminal is UE and the base
station is an A-eNB is specifically used for description.
[0824] FIG. 7 is a signaling flowchart of Embodiment 1 of the
present invention. As shown in FIG. 7, this embodiment mainly
relates to an interaction process in initial access of UE. A method
in this embodiment may include the following steps:
[0825] S201. UE is initially powered on, and selects an A-eNB to
perform access.
[0826] Specifically, the UE may first search for cells, and
preferentially select an A-eNB at an AON network frequency layer to
perform access. Specifically, whether the selected frequency layer
is the AON frequency layer may be preset in the UE, or whether the
frequency layer is the AON frequency layer may be indicated in
system information sent by the AeNB, where a connected mode of a
terminal and corresponding to the AON frequency layer is an always
connected mode (AON mode).
[0827] S202. The UE reports to the A-eNB that an AON mode is
selected for working.
[0828] Specifically, after selecting an A-eNB, the UE performs
random access to the A-eNB to obtain uplink and downlink
synchronization with the AeNB. After successful access, context
information of the UE is created and initial security is activated
on the A-eNB.
[0829] In a related message for accessing the AeNB, for example, in
a random access message 3, or after accessing the AeNB, the UE may
indicate indication information about whether to request to accept
working in AON mode. Alternatively, in a related message for
accessing the AeNB, the AeNB may indicate indication information
about whether the UE may work in AON mode. The AON mode means that
the UE always keeps a connected state with the AeNB. For the
meaning of the always keeping a connected state, reference may be
made to the foregoing explanation. Specifically, whether to work in
AON mode may comply with the following principle. If a current
service of the UE, for example, a VoIP service, requires strong
service continuity, the UE may work according to a conventional
mode (for example, preferentially work on a master base station
(Macro eNB, MeNB for short) according to a conventional mode, or at
least one MeNB exists in selected eNBs). However, if a service of
the UE is insensitive to a delay or a service of the UE is a burst
service, the UE may be caused to work in AON mode. It should be
noted that, in addition to the foregoing principle, other
principles may also be followed. This is not limited herein.
[0830] S203. The A-eNB configures the UE to work in AON mode.
[0831] After the UE accesses the A-eNB and the A-eNB completes the
configuration for the UE, if the UE currently initiates a service,
the UE requests the A-eNB to set up a corresponding bearer for the
UE, and performs data transmission. Alternatively, if the UE has no
service requirement temporarily, the UE may keep the connected
state with the A-eNB only, but does not perform actual service data
transmission.
[0832] When the UE has no data service requirement temporarily, the
UE only needs to receive some information from the A-eNB, for
example, receive system information, or receive scheduling
information. However, to receive the scheduling information, the UE
may listen to only some search spaces in which the A-eNB sends
scheduling information, so as to obtain the scheduling information
from the A-eNB.
[0833] Optionally, the A-eNB may also configure a long
discontinuous reception (Discontinuous Reception, DRX for short)
period for the UE. The UE listens to dedicated signaling, an
emergency call, or other messages of the A-eNB within an active
time of the long DRX period.
[0834] S204. The A-eNB determines that setup of a new service needs
to be initiated to the UE that currently has no service
temporarily.
[0835] S205. The A-eNB notifies, by using dedicated signaling, the
UE to set up a service.
[0836] Specifically, the A-eNB first sends scheduling information
to the UE. After the UE obtains the scheduling information, the UE
receives, according to an instruction of the scheduling
information, the dedicated signaling sent by the A-eNB, where the
dedicated signaling notifies the UE that a new bearer needs to be
set up, so as to receive and/or send new service data. Different
from a current LTE system, when the A-eNB notifies the UE to set up
a new service or a new bearer, the A-eNB does not use a broadcast
message for notification, for example, does not use a paging
message to notify the UE to set up a new service or bearer.
[0837] S206. The UE determines, according to the service that needs
to be set up, that one or more eNBs need to be selected to perform
data transmission.
[0838] Specifically, after the UE receives the dedicated signaling
that is sent by the A-eNB and for setting up the new service, the
UE may determine, according to a feature of the service, whether
the UE needs to select one or more eNBs or perform data
transmission only through the A-eNB. Alternatively, after the UE
receives the dedicated signaling that is sent by the A-eNB and for
setting up the new service or other instruction information
including dedicated signaling, the UE may determine, according to
an instruction of the dedicated signaling, whether the UE needs to
select one or more eNBs or perform data transmission only through
the A-eNB.
[0839] It should be noted that, in the foregoing dedicated
signaling sent by the A-eNB to the UE, the A-eNB may determine,
based on the feature of the service of the UE, whether the UE needs
to select one or more eNBs or perform data transmission only
through the A-eNB, and indicate, in the dedicated signaling,
whether the UE needs to select one or more eNBs to perform data
transmission. Alternatively, the A-eNB may use other separate
dedicated signaling to notify the foregoing instruction
information. This is not limited herein.
[0840] S207. The UE reports the selected one or more eNBs to the
A-eNB.
[0841] Specifically, when the UE determines that one or more eNBs
need to be selected to perform data transmission, the UE notifies
information about the selected one or more eNBs to the A-eNB, so
that the A-eNB delivers, based on the selection reported by the UE,
data through the selected eNBs.
[0842] S208. The A-eNB determines whether each eNB has context
information of the UE.
[0843] Specifically, after the A-eNB receives the information about
the selected eNBs that is sent by the UE, the A-eNB determines
whether each eNB has the context information of the UE.
[0844] The context information of the UE includes a series of
information such as identifier information of the UE in an access
network, capability information of the UE, configuration
information, and other information.
[0845] S209. The A-eNB sends the context information of the UE to
the eNBs.
[0846] Specifically, if the A-eNB determines that one or more eNBs
in the information about the selected eNBs that is sent by the UE
do not have the context information of the UE, the A-eNB sends the
context information of the UE to the eNBs. Optionally, the A-eNB
may also notify the eNBs selected by the UE to provide data
transmission services for the UE, that is, perform data scheduling
and transmission.
[0847] After the UE selects one or more eNBs, if it is determined
that an eNB in the one or more eNBs has the context information of
the UE, the UE may send a scheduling request message to the eNB
that has the context information of the UE, or perform a random
access process to the eNB, so as to instruct the eNB to provide
services for the UE, that is, perform data scheduling and
transmission.
[0848] Specifically, if a data amount is small, for example, for
burst data, the UE may directly initiate a random access process to
the selected eNB, and then perform data transmission by using an
uplink transmission resource provided in a random access response
message in the random access process. To reduce a delay and
accelerate access, allocation of a unique random access resource
may be introduced. That is, the A-eNB allocates a unique preamble
for requesting a resource to the UE that selects the AON mode for
working, or allocates a combination of a unique preamble and a
random access channel resource for requesting a resource. When the
UE performs data transmission with any eNB that the UE needs to
access, the UE requests a resource by using the allocated unique
random access resource. Then, the eNB determines, according to the
unique random access resource, the UE that requests a resource, and
allocates an uplink resource to the UE for data transmission.
[0849] The A-eNB may provide a UE context for the eNBs. In
addition, alternatively, if it is determined that the one or more
eNBs do not have the context information of the UE, the UE may
perform random access to the eNBs, then send the context
information of the UE in a related message in a random access
process to the eNBs (a step shown by a dashed line), and indicate
information about the A-eNB connected to the UE. Therefore, the
eNBs can provide data transmission services for the UE, and can
obtain data of the UE from the A-eNB, or send uplink data of the UE
to the A-eNB. After the eNBs receive the context information of the
UE, the eNBs may send, to the A-eNB, a message indicating that
obtaining the UE context is complete.
[0850] After the UE accesses the selected one or more eNBs, the UE
may start to use the eNBs to receive and send service data.
[0851] To receive downlink data, the UE receives the downlink data
from the selected eNBs, and sorts, on a UE side, data from
different eNBs. Then, the UE feeds back a layer-2 (L2) status
report about a downlink data reception status to the A-eNB, so that
the A-eNB can retransmit, according to the L2 status report, data
that is not successfully transmitted completely. However, a layer-1
(L1) status report is fed back to a corresponding receiving
eNB.
[0852] For uplink data, the UE sends related uplink data packets to
the selected eNBs. Any eNB that receives the data of the UE
forwards all the data of the UE to the A-eNB for sorting
processing, and the A-eNB sends the data to a core network device,
for example, an S-GW or a PDN-GW.
[0853] Further, it should be noted that, after the UE stops service
data transmission or releases the current service, if it is
previously determined that the UE works in AON mode, the UE
continues to save all configuration information between the UE and
the A-eNB. Optionally, the UE may stop maintaining uplink timing,
or after a TAT timer for maintaining uplink timing expires, stop
maintaining uplink synchronization; or the UE may maintain uplink
timing synchronization by sending a uplink signal (for example, an
SRS signal) discontinuously.
[0854] FIG. 8 is a signaling flowchart of Embodiment 2 of the
present invention. As shown in FIG. 8, this embodiment mainly
relates to an interaction process in managing context information
of UE. A method in this embodiment may include the following
steps:
[0855] S301. An A-eNB sends a second base station list update
message to UE.
[0856] Specifically, in a process in which the UE performs data
transmission with the A-eNB and an eNB that provides a service
currently, as the UE moves, the A-eNB needs to update information
about eNBs that have context information of the UE. Specifically,
the A-eNB may complete, with assistance of the UE, a process of
updating a list of second base stations (eNB list) having the
context information of the UE, or the A-eNB itself tracks moving of
the UE to determine eNBs that need to obtain the context
information of the UE, and updates a list of eNBs having the
context information of the UE. For example, the A-eNB may
determine, based on location information of the UE, whether to
update the list of eNBs having the context information of the
UE.
[0857] When the A-eNB needs to update the list of eNBs having the
context information of the UE, the A-eNB sends dedicated signaling
to the UE, so as to notify the UE of an updated list of eNBs having
the context information of the UE.
[0858] S302. The UE continues to measure eNBs in a list and measure
other eNBs.
[0859] Specifically, after the UE obtains the updated list of eNBs
having the context information of the UE, the UE continues to
measure the eNBs in the list and measure other eNBs.
[0860] S303. The UE sends a report message to the A-eNB.
[0861] Specifically, when the UE finds that signal quality of one
or more measured eNBs is higher than a threshold, for example,
higher than a condition that meets a communication requirement, if
the eNBs are not in the list, the UE may report information about
the eNBs to the A-eNB, so as to notify the A-eNB that the eNBs have
a possibility of potentially providing services, but the eNBs do
not have the context information of the UE. Specifically, the UE
may definitely indicate that the eNBs do not have a context of the
UE, or may only indicate that the eNBs can provide services for the
UE, but the A-eNB itself determines which eNBs do not have the
context of the UE.
[0862] S304. The A-eNB sends context information of the UE to the
eNBs.
[0863] Specifically, after receiving the report message sent by the
UE, the A-eNB learns information about the eNBs that can
potentially provide services for the UE but do not have the context
information of the UE, and then sends the context information of
the UE to the eNBs. After the A-eNB sends the context information
of the UE to the eNBs, the A-eNB may send, to the UE, list update
information of eNBs having the context information of the UE. In an
optional manner, for an indication message sent by the UE and
reporting the eNBs that do not have the context information of the
UE, corresponding UE report response or acknowledgement information
(shown by a dashed line in the figure) may be sent to the UE, to
indicate to the UE that the eNBs have successfully obtained the
context information of the UE.
[0864] FIG. 9 is a signaling flowchart of Embodiment 3 of the
present invention. This embodiment mainly relates to an interaction
process in managing configuration information of UE. An application
scenario of this embodiment is specifically: after selecting one or
more eNBs, UE may first perform random access, and then after the
eNBs configure parameters of each layer of L1, L2, and L3 and
configuration information of related bearers and cells for the UE,
the UE performs actual data transmission with the eNBs by using
corresponding configurations. However, in some cases, the UE also
does not need to perform random access to access the eNBs for
synchronization. For example, when coverage of an eNB is small, the
UE may directly use an uplink timing advance 0 to perform uplink
data transmission. In this case, a method in this embodiment may be
used to perform related configurations, so as to support a fast
data transmission process of the UE. As shown in FIG. 9, the method
in this embodiment may include the following steps:
[0865] S401. An A-eNB sends default configuration information to
eNBs having context information of UE, and at the same time, sends
the default configuration information to the UE.
[0866] Specifically, the A-eNB may send the default configuration
information by using dedicated signaling to the eNBs having the
context information of the UE, where the default configuration
information refers to configuration information that may be used
when the UE performs initial data transmission with the eNBs, and
the default configuration information includes configuration
parameters of L1, L2, and L3, and other configuration parameters.
For different services, different QoS levels, or different bearers,
the A-eNB may provide different default configuration information.
That is, the provided default configuration information may be
associated with QoS.
[0867] The A-eNB may provide the default configuration information
for the eNBs when providing the context information of the UE.
Alternatively, separate signaling may be used to provide the
default configuration information for the eNBs.
[0868] In addition, after the UE accesses the A-eNB initially, the
A-eNB may provide the UE with default configuration information
that may be used when the UE performs communication with other
eNBs.
[0869] S402. After initially selecting and accessing an eNB, the UE
uses the default configuration information to perform data
transmission with the selected eNB.
[0870] S403. The eNBs send a reconfiguration message to the UE, and
update the default configuration information.
[0871] Specifically, after the UE uses the default configuration
information to perform data transmission with the selected eNB, the
eNBs may further modify specific configuration parameters for the
UE, and send a reconfiguration message to the UE, so as to modify
corresponding configuration information. After receiving the
reconfiguration message, the UE completes a reconfiguration and
uses new configuration parameters to perform data transmission.
[0872] FIG. 10 is a signaling flowchart of Embodiment 4 of the
present invention. This embodiment mainly relates to an interaction
process in managing configuration information of UE. An application
scenario of this embodiment is specifically: in a moving process of
UE, the UE needs to continuously measure neighboring A-eNBs and
neighboring eNBs, so as to determine eNBs or an A-eNB that may be
selected potentially in the moving process. In an actual network,
eNBs may be further classified into a master second base station
(macro eNB, MeNB for short) and a secondary second base station
(small eNB, SeNB for short), where the MeNB has large coverage and
the SeNB has small coverage. To improve measurement efficiency of
the UE and reduce a power consumption level of the UE, a
measurement in an AON network may be divided to measure three
layers separately. Specifically, a frequency layer corresponding to
the A-eNB is measured, a frequency layer corresponding to the MeNB
is measured, and a frequency layer corresponding to the SeNB is
measured. In this embodiment, the A-eNB determines, according to a
condition, whether to perform a measurement on the foregoing
frequency layer and measurement reporting. As shown in FIG. 10, a
method in this embodiment may include the following steps:
[0873] S501. An A-eNB sends measurement configuration information
to UE.
[0874] The measurement configuration information specifically
includes: measuring a frequency layer corresponding to the A-eNB
only; or measuring frequency layers corresponding to the A-eNB and
an MeNB only; or measuring frequency layers corresponding to all of
the A-eNB, an MeNB, and an SeNB.
[0875] Optionally, the measurement configuration information may
further include: determining a first threshold for measuring the
frequency layer corresponding to the A-eNB only; or determining a
second threshold for measuring the frequency layers corresponding
to the A-eNB and the MeNB only; or determining a third threshold
for measuring the frequency layers corresponding to all of the
A-eNB, the MeNB, and the SeNB.
[0876] S502. The UE completes, according to the measurement
configuration information, a measurement on a frequency layer
corresponding to each base station.
[0877] Specifically, if the measurement configuration information
includes measuring the frequency layer corresponding to the A-eNB
only, or measuring the frequency layers corresponding to the A-eNB
and the MeNB only, or measuring the frequency layers corresponding
to all of the A-eNB, the MeNB, and the SeNB, the UE may determine,
according to the measurement configuration information, whether to
measure the frequency layer corresponding to the A-eNB only, or
measure the frequency layers corresponding to the A-eNB and the
MeNB only, or measure the frequency layers corresponding to all of
the A-eNB, the MeNB, and the SeNB.
[0878] If the measurement configuration information includes
determining the first threshold for measuring the frequency layer
corresponding to the A-eNB only, or determining the second
threshold for measuring the frequency layers corresponding to the
A-eNB and the MeNB only, or determining the third threshold for
measuring the frequency layers corresponding to all of the A-eNB,
the MeNB, and the SeNB, correspondingly, the A-eNB measures,
according to a magnitude relationship between a QoS requirement of
a current service of the terminal and a threshold in the
measurement configuration information, the frequency layer
corresponding to each base station. Specifically, if QoS of the
current service of the terminal is less than the first threshold,
the A-eNB measures, according to the measurement configuration
information, the frequency layer corresponding to the A-eNB only,
and obtains a measurement result; if QoS of the current service of
the terminal is greater than the first threshold but less than the
second threshold, the A-eNB measures, according to the measurement
configuration information, the frequency layer corresponding to the
A-eNB and the frequency layer corresponding to the MeNB, and
obtains measurement results; or if QoS of the current service of
the terminal is greater than the third threshold, the A-eNB
measures, according to the measurement configuration information,
the frequency layers corresponding to the A-eNB, the MeNB, and the
SeNB, and obtains measurement results.
[0879] S503. The A-eNB sends, to the UE, an instruction message
about whether to perform measurement reporting.
[0880] Specifically, configuration parameters for measurement
reporting that are sent by the A-eNB to the UE may include one or
more of parameters such as whether to perform measurement
reporting, or a threshold for measurement reporting, or other
trigger conditions, or other parameters. For example, the
configuration parameters for measurement reporting include
instruction information about whether to perform measurement
reporting.
[0881] The instruction message about whether to perform measurement
reporting may specifically include: at least one of instruction
information for measurement reporting of the frequency layer
corresponding to the A-eNB, instruction information for measurement
reporting of the frequency layer corresponding to the MeNB, or
instruction information for measurement reporting of the frequency
layer corresponding to the SeNB.
[0882] S504. The UE sends a measurement result to the A-eNB
according to the instruction message about whether to perform
measurement reporting.
[0883] Specifically, if the instruction message is an instruction
message for measurement reporting of the frequency layer
corresponding to the A-eNB, the UE sends a measurement result of
measuring the frequency layer corresponding to the A-eNB to the
A-eNB; if the instruction message is the instruction information
for measurement reporting of the frequency layer corresponding to
the MeNB, the UE sends a measurement result of measuring the
frequency layer corresponding to the MeNB to the A-eNB; if the
instruction message is the instruction information for measuring
the frequency layer corresponding to the SeNB, the UE sends a
measurement result of measuring the frequency layer corresponding
to the SeNB to the A-eNB; if the instruction message is the
instruction information for measurement reporting of the frequency
layer corresponding to the A-eNB and measurement reporting of the
frequency layer corresponding to the MeNB, the UE sends a
measurement result of measuring the frequency layer corresponding
to the A-eNB and a measurement result of measuring the frequency
layer corresponding to the MeNB to the A-eNB; if the instruction
message is the instruction information for measurement reporting of
the frequency layer corresponding to the A-eNB, measurement
reporting of the frequency layer corresponding to the MeNB, and
measurement reporting of the frequency layer corresponding to the
SeNB, the UE sends a measurement result of measuring the frequency
layer corresponding to the A-eNB, a measurement result of measuring
the frequency layer corresponding to the MeNB, and a measurement
result of measuring the frequency layer corresponding to the SeNB
to the A-eNB.
[0884] FIG. 11 is a signaling flowchart of Embodiment 5 of the
present invention. This embodiment is another possible
implementation manner of an interaction process in managing
measurement configuration information of UE. A difference between
this embodiment and the embodiment shown in FIG. 10 lies in that UE
itself determines, according to a condition, whether to perform a
measurement on the foregoing frequency layer and measurement
reporting. As shown in FIG. 11, a method in this embodiment may
include the following steps:
[0885] S601. An A-eNB sends measurement configuration information
to UE.
[0886] Specifically, after the UE accesses the A-eNB, the A-eNB may
configure measurement parameters of each layer for the UE, that is,
configure measurement configuration parameters of a frequency layer
of the A-eNB, a frequency layer of an MeNB, and a frequency layer
of an SeNB for the UE separately. Specific measurement
configuration parameters may include a target measurement
frequency, a measurement period, and a measurement quantity, for
example, reference signal received power (RSRP for short),
reference signal received quality (RSRQ for short), and received
signal strength indicator (RSSI for short).
[0887] S602. The UE determines, according to a service, to measure
a frequency layer corresponding to each base station.
[0888] Specifically, when the UE has no active service or a QoS
requirement of a service is lower than a range, the UE selects to
measure the frequency layer of the A-eNB only; when service traffic
of the UE exceeds a range or a QoS requirement of a service is
higher than a range, the UE measures the frequency layer of the
A-eNB and the frequency layer of the MeNB; when service traffic of
the UE exceeds a threshold or a QoS requirement of a service is
higher than a threshold or a required data rate is higher than a
threshold, the UE starts to measure the frequency layer of the
SeNB.
[0889] S603. The UE sends a measurement result to the AeNB.
[0890] Specifically, the UE determines, based on the following
principle, whether to report a corresponding measurement result: A
measurement result of the frequency layer of the AeNB must be
reported; a measurement result of the frequency layer of the MeNB
is reported conditionally, that is, reported only when a preset
condition is met; a measurement result of the frequency layer of
the SeNB is not reported, that is, the UE does not report the
measurement result of the SeNB, but determines, by itself according
to a measurement result, an SeNB that may be selected to perform
data transmission.
[0891] It should be noted that, in another possible implementation
manner, measurement configurations of the frequency layer of the
A-eNB, the frequency layer of the MeNB, and the frequency layer of
the SeNB may also not occur simultaneously, that is, the A-eNB may
configure only one or more of the configurations for the UE. For a
frequency layer that is not configured, the UE may not perform a
measurement. For example, if measurement parameters of the
frequency layer of the MeNB are not configured, the UE may not
measure the frequency layer of the MeNB.
[0892] FIG. 12 is a signaling flowchart of Embodiment 6 of the
present invention. An application scenario of this embodiment is
specifically: in a moving process of UE, on the one hand, the UE
needs to measure an A-eNB; on the other hand, the UE may also be
handed over in time according to a measurement result, so that a
more appropriate target A-eNB is selected. In this embodiment,
using a handover controlled by a network as a principle, a specific
process is as follows:
[0893] S701. UE sends a measurement report to a current serving
A-eNB, or UE sends, to a current serving A-eNB, a request message
for requesting to be handed over to a target A-eNB.
[0894] For the current serving A-eNB (S-AeNB for short), the
measurement report sent by the UE to the S-AeNB includes a
measurement result of a neighboring A-eNB, including a target A-eNB
(T-AeNB for short).
[0895] Optionally, the UE may further add information about one or
more eNBs with good signal quality within coverage of the measured
T-AeNB to the measurement report or the request message.
[0896] S702. The S-AeNB sends a handover request message to the
T-AeNB.
[0897] Specifically, after receiving the measurement report or the
handover request sent by the UE, the S-AeNB determines that the UE
may be handed over to the T-AeNB. In this case, the S-AeNB sends a
handover request message to the T-AeNB, where the handover request
message includes context information of the UE and information
about eNBs that currently have the context information of the UE.
Optionally, the S-AeNB may add information about one or more eNBs
with good signal quality within coverage of the target T-AeNB to
the handover request message.
[0898] S703. The T-AeNB sends a handover request response message
to the S-AeNB.
[0899] Specifically, the T-AeNB performs admission control and
determines whether to allow the UE to perform the handover. If the
UE is allowed to perform the handover, the T-AeNB sends a handover
request response message to the S-AeNB, where the handover request
response message includes information configured for the UE such as
configuration parameters of L1, L2, and L3. In addition, the T-AeNB
may further add, to the handover request response message,
information about one or more eNBs that have the context
information of the UE, and add, to the handover request response
message, information about eNBs that are within coverage of the
T-AeNB and have the context information of the UE. Alternatively,
the T-AeNB may use other separate dedicated messages to send
information about eNBs that are within coverage of the T-AeNB and
have the context information of the UE.
[0900] S704. The S-AeNB sends a handover command message to the
UE.
[0901] Specifically, after receiving the handover request response
message fed back by the T-AeNB, the S-AeNB sends a handover command
message to the UE, where the handover command message instructs the
UE to perform the handover to the T-AeNB. The handover command
message may include the information about the eNBs that are within
coverage of the T-AeNB and have the context information of the
UE.
[0902] S705. The S-AeNB provides a handover instruction message to
eNBs that currently serve the UE.
[0903] In addition, after receiving the handover request response
message fed back by the T-AeNB, the S-AeNB may also provide a
handover instruction message to the eNBs that currently serve the
UE, where the handover instruction message may include information
about the T-AeNB, or instruction information instructing the eNBs
whether to stop providing services for the UE or instructing the
eNBs whether to provide services for the UE under control of the
T-AeNB. The eNBs determine, according to the instruction
information, whether to continue to schedule resources for the UE
to perform data transmission, or the eNBs determine, according to
the included information about the T-AeNB, whether the eNBs need to
provide services for the UE under control of the T-AeNB, or the
eNBs determine, according to the instruction information
instructing the eNBs whether to provide services for the UE under
control of the T-AeNB, whether services need to be provided for the
UE under control of the T-AeNB, and if yes, continue to schedule
resources for the UE to perform data transmission, or if no, stop
scheduling resources for the UE.
[0904] S706. The UE selects one or more eNBs that are within
coverage of the T-AeNB and have context information of the UE, so
as to perform data transmission.
[0905] After the UE receives the handover command message, the UE
selects one or more eNBs that are within coverage of the T-AeNB and
have the context information of the UE, so as to perform data
transmission, where the one or more eNBs may be eNBs that are
within coverage of the S-AeNB and previously provide services for
the UE, and the UE may preferentially select the eNBs that
previously provide services for the UE under control of the S-AeNB.
At the same time, the UE also needs to initiate a random access
process to the T-AeNB, and access the T-AeNB.
[0906] S707. The UE sends a handover complete indication message to
the T-AeNB.
[0907] Specifically, after successfully performing random access to
the T-AeNB, the UE sends a handover complete indication message to
the T-AeNB, so as to indicate that the UE has successfully
completed the handover.
[0908] S708. The T-AeNB sends the handover complete indication
message to the S-AeNB.
[0909] After receiving the handover complete indication message
sent by the UE, the T-AeNB sends the handover complete indication
message to the S-AeNB, so as to notify the S-AeNB that the UE has
successfully completed the handover.
[0910] Alternatively (shown by a dashed line in the figure), after
successfully performing random access to the T-AeNB, the UE may
feed back the handover complete indication message through an eNB
connected to the S-AeNB, in current serving S-AeNBs, and then the
eNB sends the handover complete indication message to the S-AeNB to
notify the S-AeNB that the UE has successfully completed the
handover.
[0911] S709. The S-AeNB releases the context information of the UE
and the information about the eNBs that have the context
information of the UE.
[0912] Specifically, after receiving the handover complete
indication, the S-AeNB may release the context information of the
UE, or first start a timer, and after the timer expires, release a
context of the UE. Herein a purpose of introducing a timer for
delaying releasing the context of the UE is to prevent the UE from
returning to the S-AeNB or reestablishing to the S-AeNB
sometime.
[0913] FIG. 13 is a signaling flowchart of Embodiment 7 of the
present invention. An application scenario of this embodiment is
the same as the application scenario of the embodiment shown in
FIG. 12. In this embodiment, using a handover controlled by UE
itself as a principle, in a handover process, the UE has an active
service that is being performed. A method in this embodiment
specifically includes the following steps:
[0914] S801. UE itself determines to perform a handover.
[0915] Specifically, the UE measures neighboring A-eNBs, and
selects, based on a measurement result, a T-AeNB to which the UE
may be handed over. After an appropriate T-AeNB is selected, the UE
itself determines to perform a handover, and performs random access
to the T-AeNB.
[0916] S802. The UE sends a handover request message to a
T-AeNB.
[0917] The UE reports a handover request to the T-AeNB, so as to
request to access the T-AeNB, where the handover request message
includes information about a current S-AeNB of the UE and/or
information about eNBs that are within coverage of the T-AeNB and
may potentially provide services for the UE, namely, information
about candidate eNBs.
[0918] S803. The T-AeNB sends a handover instruction message to an
S-AeNB.
[0919] After receiving the handover request message from the UE,
the T-AeNB sends a handover instruction message to the S-AeNB,
indicating that the UE will be handed over to the T-AeNB, or after
the UE successfully accesses the T-AeNB, the UE sends a handover
instruction message to the S-AeNB (shown by a dashed line),
indicating that the UE will be handed over to the T-AeNB.
[0920] S804. The T-AeNB sends context information of the UE to
eNBs, and sends a handover request acknowledgement message to the
UE.
[0921] Specifically, after receiving the handover request message
sent by the UE, the T-AeNB determines eNBs that need to be provided
with the context information of the UE, transmits the context
information of the UE to the eNBs, and sends a handover request
acknowledgement message to the UE, so as to notify that the UE can
be handed over. The handover request acknowledgement message
includes the T-AeNB.
[0922] S805. The S-AeNB provides a handover instruction message to
eNBs that currently serve the UE.
[0923] After receiving the handover instruction information, the
S-AeNB provides a handover instruction message to the eNBs that
currently serve the UE, where the handover instruction message may
include information about the T-AeNB, or instruction information
instructing the eNBs whether to stop providing services for the UE
or instructing the eNBs whether to provide services for the UE
under control of the T-AeNB.
[0924] S806. The eNBs determine, according to the instruction
information, whether to continue to send data to the UE.
[0925] Specifically, the eNBs determine, according to the
instruction information, whether to continue to schedule resources
for the UE to perform data transmission, or the eNBs determine,
according to the included information about the T-AeNB, whether the
eNBs need to provide services for the UE under control of the
T-AeNB, or the eNBs determine, according to the instruction
information instructing the eNBs whether to provide services for
the UE under control of the T-AeNB, whether services need to be
provided for the UE under control of the T-AeNB, and if yes,
continue to schedule resources for the UE to perform data
transmission, or if no, stop scheduling resources for the UE.
[0926] S807. The UE sends a handover complete indication message to
the S-AeNB.
[0927] The UE sends a handover complete indication message to the
S-AeNB, or after the T-AeNB receives scheduled uplink data of the
UE, or after the T-AeNB receives a handover complete indication
sent by the UE, the T-AeNB sends the handover complete indication
message to the S-AeNB.
[0928] S808. The UE selects one or more eNBs that are within
coverage of the T-AeNB and have the context information of the UE,
so as to perform data transmission.
[0929] After the UE receives the handover request acknowledgement
message, the UE selects one or more eNBs that are within coverage
of the T-AeNB and have the context information of the UE, so as to
perform data transmission, where the one or more eNBs may be eNBs
that are within coverage of the S-AeNB and previously provide
services for the UE, and the UE may preferentially select the eNBs
that previously provide services for the UE under control of the
S-AeNB.
[0930] S809. The S-AeNB releases the context information of the UE
and the information about the eNBs that have the context
information of the UE.
[0931] After receiving the handover complete indication, the S-AeNB
may release the context information of the UE, or first start a
timer, and after the timer expires, release a context of the UE.
Herein a purpose of introducing a timer for delaying releasing the
context of the UE is to prevent the UE from returning to the S-AeNB
or reestablishing to the S-AeNB sometime.
[0932] FIG. 14A and FIG. 14B are a signaling flowchart of
Embodiment 8 of the present invention. An application scenario of
this embodiment is the same as the application scenario of the
embodiment shown in FIG. 12. In this embodiment, an S-AeNB and a
neighboring A-eNB determine, through negotiation, eNBs that are
jointly controlled. A method in this embodiment specifically
includes the following steps:
[0933] S901. An S-AeNB sends an eNB control negotiation message to
a T-AeNB.
[0934] The S-AeNB and a neighboring AeNB (the T-AeNB is an AeNB
neighboring to the S-AeNB) perform negotiation to determine eNBs
that can be jointly controlled. Specifically, the S-AeNB sends an
eNB control negotiation message to the neighboring A-eNB,
indicating information about potential eNBs that can be jointly
controlled. The S-AeNB may select and determine, according to
location information of the eNBs and location information of the
neighboring AeNB and connection relationships between the eNBs and
the S-AeNB and the neighboring AeNB, the potential eNBs that can be
jointly controlled.
[0935] S902. The T-AeNB sends an eNB control negotiation response
message to the S-AeNB.
[0936] Specifically, after receiving the eNB control negotiation
message, the neighboring A-eNB acknowledges eNBs that can be
jointly controlled, and sends an eNB control negotiation response
message to the S-AeNB, where the response message includes
information about the eNBs that are determined by the neighboring
A-eNB and can be jointly controlled or an acknowledgement of
information about the eNBs that are included in the eNB control
negotiation message and can be jointly controlled.
[0937] In addition to the method for determining eNBs that are
jointly controlled in the foregoing step 1 and step 2, the
determining may also be performed by using an OAM configuration
method (not illustrated in the foregoing figure), that is, both the
S-AeNB and the neighboring A-eNB receive, from OAM, the information
about the eNBs that can be jointly controlled by the S-AeNB and the
neighboring A-eNB. Specifically, the potential eNBs that can be
jointly controlled may be selected and determined according to the
location information of the eNBs and location information of each
A-eNB and connection relationships between the eNBs and the
A-eNB.
[0938] S903. UE sends a measurement report to the S-AeNB, or UE
sends, to the S-AeNB, a request message for requesting to be handed
over to the T-AeNB.
[0939] Specifically, the UE sends, to the S-AeNB, a measurement
report including a measurement result of the neighboring A-eNB, or
the UE sends, to the serving AeNB, a request message for requesting
to be handed over to the T-AeNB. Optionally, the UE may add
information about one or more eNBs with good signal quality within
coverage of the measured T-AeNB to the measurement report or the
request message.
[0940] S904. The S-AeNB sends a handover request message to the
T-AeNB.
[0941] After receiving the measurement report or the handover
request from the UE, the S-AeNB determines that the UE may be
handed over to the T-AeNB, and selects, in a handover process, eNBs
that are jointly controlled by the S-AeNB and the T-AeNB and can
continue to provide services for the UE. Then the S-AeNB sends a
handover request message to the T-AeNB, where the handover request
message includes context information of the UE and information
about the selected eNBs that can provide services for the UE.
[0942] S905. The T-AeNB sends a handover request response message
to the S-AeNB.
[0943] The T-AeNB performs admission control and determines whether
to allow the UE to perform the handover. If the UE is allowed to
perform the handover, the T-AeNB sends a handover request response
message to the S-AeNB, where the handover request response message
includes information configured for the UE such as configuration
parameters of L1, L2, and L3. In addition to the information about
the eNBs that can continue to provide services for the UE, the
T-AeNB may further add, to the handover request message,
information about other selected eNBs that have the context
information of the UE.
[0944] S906. The S-AeNB determines the handover, and switches a
service borne by the S-AeNB to eNBs for transmission.
[0945] S907. The S-AeNB sends a handover command message to the UE,
and sends a handover instruction message to eNBs that do not need
to provide services for the UE any longer.
[0946] After receiving the handover request response message fed
back by the T-AeNB, the S-AeNB sends a handover command message to
the UE, where the handover command message instructs the UE to
perform the handover to the T-AeNB, and the handover command
message instructs the UE to keep data transmission with one or more
current eNBs in the handover process. Alternatively, the S-AeNB may
use other dedicated messages, for example, a reconfiguration
message, instructing the UE to keep data transmission with one or
more current eNBs in the handover process. In addition, the S-AeNB
may also reconfigure the service borne by the current S-AeNB to the
SeNBs for transmission.
[0947] In addition to performing the foregoing operation after
receiving the handover request response message fed back by the
T-AeNB, the S-AeNB may also send a bearer reconfiguration message
to the UE at any time between deciding the handover to receiving
the handover request response message fed back by the T-AeNB, so as
to reconfigure the service currently borne by the S-AeNB to the
SeNBs for transmission.
[0948] In addition, the handover command message may include the
information about the eNBs that are within coverage of the T-AeNB
and have the context information of the UE.
[0949] In addition, after receiving the handover request response
message fed back by the T-AeNB, the S-AeNB may also determine that
the eNBs providing services for the UE are no longer required, and
send a handover instruction message to the eNBs, where the handover
instruction message instructs the eNBs to stop providing services
for the UE.
[0950] S908. The UE initiates a random access process to the
T-AeNB, and accesses the T-AeNB.
[0951] After receiving the handover command message, the UE
continues, according to an instruction of the handover command, to
keep performing data transmission with other indicated one or more
eNBs that keep data transmission. If the handover command instructs
to switch data borne by the S-AeNB to the eNBs, the UE transmits,
through the foregoing eNBs, service data that is originally
transmitted through the S-AeNB. In addition to the one or more eNBs
keeping data transmission and indicated in the handover command,
the UE may further continue to select one or more eNBs that are
within coverage of the T-AeNB and have the context information of
the UE, so as to perform data transmission.
[0952] Alternatively, if the UE receives a bearer reconfiguration
message sent by the S-AeNB before receiving the handover command,
the UE reconfigures service data that is currently transmitted
through the S-AeNB to SeNBs specified in the bearer reconfiguration
message for transmission.
[0953] The UE initiates the random access process to the T-AeNB,
and accesses the T-AeNB.
[0954] S909. The UE sends a handover complete indication message to
the T-AeNB.
[0955] S910. The T-AeNB sends the handover complete indication
message to the S-AeNB.
[0956] S911. The S-AeNB releases context information of the UE and
information about eNBs that have the context information of the
UE.
[0957] A specific implementation process of S909-S911 is the same
as a specific implementation process of S707-S709 in the embodiment
shown in FIG. 11, and is not described again herein.
[0958] FIG. 15 is a signaling flowchart of Embodiment 9 of the
present invention. An application scenario of this embodiment is
the same as the application scenario of the embodiment shown in
FIG. 12. In this embodiment, assuming that there is no active
service in a handover process of UE, a method in this embodiment
specifically includes the following steps:
[0959] S1001. UE sends a measurement report to an S-AeNB, or sends,
to an S-AeNB, a request message for requesting to be handed over to
a T-AeNB.
[0960] Specifically, the UE sends, to the S-AeNB, a measurement
report including a measurement result of a neighboring A-eNB, or
the UE sends, to the S-AeNB, a request message for requesting to be
handed over to the T-AeNB. Optionally, the UE may further add
information about one or more eNBs with good signal quality within
coverage of the measured target T-AeNB to the measurement report or
the request message.
[0961] S1002. The S-AeNB sends a handover request message to the
T-AeNB.
[0962] After receiving the measurement report or the handover
request from the UE, the S-AeNB determines that the UE may be
handed over to the T-AeNB. In this case, the S-AeNB sends a
handover request message to the T-AeNB, where the handover request
message includes information indicating that the UE currently has
no active service. In addition, the handover request message may
further include context information of the UE and information about
eNBs that currently have the context information of the UE.
[0963] S1003. The T-AeNB sends a handover request response message
to the S-AeNB.
[0964] The T-AeNB performs admission control and determines whether
to allow the UE to perform the handover. If the UE is allowed to
perform the handover, the T-AeNB sends a handover request response
message to the S-AeNB, where the handover request response message
includes configuration parameters related to the A-eNB and
configured for the UE. The T-AeNB may further provide the context
information of the UE for the one or more eNBs included in the
handover request message. In addition, the handover request
response message includes the information about the eNBs that are
within coverage of the T-AeNB and have the context information of
the UE and default configuration parameter information related to
the eNBs.
[0965] S1004. The S-AeNB sends a handover command message to the
UE.
[0966] After receiving the handover request response message fed
back by the T-AeNB, the S-AeNB sends a handover command message to
the UE, where the handover command instructs the UE to perform the
handover to the T-AeNB. The handover command message may include
the information about the eNBs that are within coverage of the
T-AeNB and have the context information of the UE. In addition,
optionally, the handover command message may further include
information indicating whether the UE is required to perform random
access to the T-AeNB.
[0967] After receiving the handover command message, the UE
initiates a random access process to the T-AeNB, and accesses the
T-AeNB. Alternatively, if the handover command instructs the UE not
to perform random access, the UE does not perform the handover to
the T-AeNB after successfully performing a configuration required
by the handover command. Alternatively, after receiving the
handover command, if the UE determines that there is no active
service currently, the UE does not perform random access to the
T-AeNB.
[0968] S1005. The UE sends a handover complete indication message
to the S-AeNB.
[0969] After successfully performing random access to the T-AeNB
(if it is determined that random access to the T-AeNB is required)
or after successfully completing the configuration required by the
handover command (if random access to the T-eNB is not required),
the UE sends a handover complete indication message to the S-AeNB,
so as to indicate that the UE has successfully completed the
handover.
[0970] S1006. The S-AeNB sends the handover complete indication
message to the T-AeNB.
[0971] S1007. The S-AeNB releases context information of the UE and
information about eNBs that have the context information of the
UE.
[0972] After receiving the handover complete indication, the S-AeNB
may release the context information of the UE, or first start a
timer, and after the timer expires, release a context of the UE.
Herein a purpose of introducing a timer for delaying releasing the
context of the UE is to prevent the UE from returning to the S-AeNB
or reestablishing to the S-AeNB sometime.
[0973] FIG. 16 is a signaling flowchart of Embodiment 10 of the
present invention. This embodiment mainly resolves a problem of
data security during communication of UE with an A-eNB and eNBs. In
this embodiment, each eNB and the A-eNB have independent security
mechanisms. The A-eNB generates different KASMEs for different eNBs
separately. Therefore, both the UE and a network-side AuC center
need to store multiple different Kis, and each Ki is
correspondingly used in sequence with different eNB selected by the
UE. As shown in FIG. 16, a method in this embodiment may include
the following steps:
[0974] S1101. UE performs random access to an A-eNB, and sets up an
RRC connection to the A-eNB.
[0975] Specifically, the UE accesses the A-eNB by performing a
random access process, and sets up a connection to the A-eNB.
[0976] S1102. The A-eNB sends a security mode activation command
message to the UE.
[0977] The security mode activation command message is used to
instruct the UE to activate security.
[0978] S1103. The UE generates an intermediate key A-KeNB
associated with the A-eNB, and generates encryption and integrity
protection keys K.sub.enc_A and K.sub.int_A based on the A-KeNB and
a security algorithm of the A-eNB.
[0979] After receiving the security mode activation command sent by
the A-eNB, the UE obtains, through calculation according to a K_A,
an IK_A, and a CK_A associated with the A-eNB, a K.sub.ASME_A
corresponding to the A-eNB, then further obtains, through
calculation based on the K.sub.ASME_A, the intermediate key A-KeNB
associated with the A-eNB, and further generates the encryption and
integrity protection keys K.sub.enc_A and K.sub.int_A based on the
A-KeNB and the security algorithm of the A-eNB.
[0980] S1104. The A-eNB sends context information of the UE, a
security index associated with each eNB and the UE, and a generated
KeNB_i to the eNBs.
[0981] Specifically, when the A-eNB provides the context
information of the UE for the eNBs, the A-eNB obtains, through
calculation according to an IK, a CK, and a Ki associated with an
i.sup.th eNB having the context information of the UE, a root key
K.sub.ASME_i corresponding to the i.sup.th eNB, then further
calculates the KeNB_i for the i.sup.th eNB based on the
K.sub.ASME_i, and provides the KeNB_i for the i.sup.th eNB. The IK
and the CK may be public, or each eNB corresponds to a set of IK
and CK.
[0982] S1105. The eNBs indicate security algorithm information.
[0983] In response to security key information sent by the A-eNB,
the eNBs feed back their security algorithms to the A-eNB.
Alternatively, when the eNBs initially set up connection
relationships with the A-eNB or when the eNBs are powered on
initially, the eNBs may report their security algorithms to the
A-eNB.
[0984] S1106. The AeNB sends, to the UE, a list of eNBs having the
context information of the UE, where the list includes security
algorithm information of the eNBs.
[0985] The AeNB sends, to the UE, a list of eNBs having the context
information of the UE, where the list may further include the
security algorithm information of the eNBs. As described above, the
AeNB notifies the security algorithm information of the eNBs to the
UE by using dedicating signaling. In addition, the UE may first
access a selected eNB, and then receive a dedicated message (not
illustrated in the figure) directly sent by the eNB, where the
dedicated message includes an identifier of a security algorithm of
the eNB.
[0986] Alternatively, the UE may obtain identifier information of
security algorithms of the eNBs by reading system information of
the eNBs. Therefore, the eNBs need to broadcast, in system
information, identifiers of the security algorithms used by the
eNB. Alternatively, the AeNB may notify, to the UE in broadcast
mode, identifiers of security algorithms of the eNBs having the
context information of the UE.
[0987] S1107. The UE determines to select one or more eNBs to
perform data transmission, generates an intermediate key KeNB_i
associated with the eNB, and obtains, through calculation based on
the KeNB_i and a security algorithm of the eNB, encryption and/or
integrity protection keys K.sub.enc_i and/or K.sub.int_i used on
the eNB.
[0988] Before the UE selects one or more eNBs to perform data
transmission, the UE first determines corresponding security keys
Ki, IK, and CK according to a security index of the selected eNB,
then obtains, through calculation, the root key K.sub.ASME_i
corresponding to the i.sup.th eNB, further calculates the KeNB_i
for the i.sup.th eNB according to the K.sub.ASME_i, and finally
obtains, through calculation according to the KeNB_i obtained
through calculation and the security algorithm of the eNB,
encryption and/or integrity protection keys K.sub.enc_i and/or
K.sub.int_i used on the eNB.
[0989] S1108. The UE accesses the selected eNB, and uses a
corresponding key to perform data transmission.
[0990] Specifically, after obtaining, through calculation, the
encryption and/or integrity protection keys K.sub.enc_i and/or
K.sub.int_i of the i.sup.th eNB, the UE uses the keys to perform
secure data transmission with the eNB.
[0991] FIG. 17 is a signaling flowchart of Embodiment 11 of the
present invention. This embodiment mainly resolves a problem of
data security during communication of UE with an A-eNB and eNBs. A
difference between this embodiment and the embodiment shown in FIG.
16 lies in that the eNBs and the A-eNB have security mechanisms
that are associated with each other. Specifically, after the UE
selects an eNB, the UE first generates, by using a unique COUNT
(which may be, for example, a unique ID of the eNB, or a frequency
and/or a PCI of the eNB) associated with the eNB and an A-KeNB
between the UE and the AeNB, an intermediate key KeNB associated
with the KeNB, then further generates, based on a variable COUNT
associated with the eNB and marked with C_V, an intermediate key
KeNB* between the UE and the selected eNB, and then further
generates, based on the KeNB*, encryption and/or integrity
protection keys Kenc and/or Kint corresponding to the eNB. As shown
in FIG. 17, a method in this embodiment may include the following
steps:
[0992] S1201. UE performs random access to an A-eNB, and sets up an
RRC connection to the A-eNB.
[0993] The UE accesses the AeNB by performing a random access
process, and sets up a connection to the AeNB.
[0994] S1202. The A-eNB sends a security mode activation command
message to the UE.
[0995] The security mode activation command message is used to
instruct the UE to activate security.
[0996] S1203. The UE generates an intermediate key A-KeNB
associated with the A-eNB, and generates encryption and integrity
protection keys K.sub.enc_A and K.sub.int_A based on the A-KeNB and
a security algorithm of the A-eNB.
[0997] After receiving the security mode activation command sent by
the AeNB, the UE obtains, through calculation according to a K_A,
an IK_A, and a CK_A associated with the A-eNB, a K.sub.ASME_A
corresponding to the AeNB, then further obtains, through
calculation based on the K.sub.ASME_A, the intermediate key A-KeNB
associated with the A-eNB, and further generates the encryption and
integrity protection keys K.sub.enc_A and K.sub.int_A based on the
A-KeNB and the security algorithm of the A-eNB.
[0998] S1204. The A-eNB sends context information of the UE to
eNBs, and the A-eNB generates KeNBs for the eNBs based on the key
A-KeNB between the UE and the A-eNB.
[0999] When providing the context information of the UE for an eNB,
the A-eNB generates an intermediate key KeNB according to a unique
COUNT associated with the eNB, and provides a KeNB for the eNB.
[1000] S1205. The eNBs indicate security algorithm information,
including COUNTs and C_V values.
[1001] After receiving the KeNBs sent by the AeNB, the eNBs feed
back, to the AeNB, their security algorithms and dynamic COUNTs
that should be used currently, namely, C_Vs. An initial value of
the C_V may be an integer, and 1 is added to the value of the C_V
every time a key needs to be updated.
[1002] S1206. The A-eNB sends, to the UE, a list of eNBs having the
context information of the UE, where the list includes security
algorithm information of the eNBs and C_V values that should be
used on the corresponding eNBs.
[1003] The A-eNB sends, to the UE, a list of eNBs having the
context information of the UE, where the list may further include
the security algorithm information of the eNBs and the C_V values
that should be used on the corresponding eNBs. Alternatively, the
UE may first access a selected eNB, and then receive a dedicated
message (not illustrated in the figure) directly sent by the eNB,
where the dedicated message includes an identifier of a security
algorithm of the eNB and/or a C-V value.
[1004] Alternatively, the UE may obtain identifier information of
security algorithms of the eNBs and/or the C-V values by reading
system information of the eNBs. Therefore, the eNBs need to
broadcast, in system information, identifiers of the security
algorithms used by the eNBs and/or the C-V values. Alternatively,
the AeNB may notify, to the UE in broadcast mode, identifiers of
security algorithms of the eNBs having the context information of
the UE and/or the C-V values.
[1005] S1207. The UE determines to select one or more eNBs to
perform data transmission, generates an intermediate key KeNB _i
associated with the eNB, and obtains, through calculation based on
the KeNB_i and a security algorithm of the eNB, encryption and/or
integrity protection keys K.sub.enc_i and/or K.sub.int_i used on
the eNB.
[1006] Before the UE selects one or more eNBs to perform data
transmission, the UE first generates, according to a unique COUNT
corresponding to the selected eNB and the A-KeNB of the AeNB, an
intermediate key KeNB corresponding to the eNB, then further
generates a KeNB* according to an obtained C_V value corresponding
to the eNB and the KeNB obtained through calculation, and then
generates encryption and/or integrity protection keys K.sub.enc
and/or K.sub.int used on the eNB.
[1007] S1208. The UE accesses the selected eNB, and uses a
corresponding key to perform data transmission.
[1008] Specifically, after obtaining, through calculation, the
encryption and/or integrity protection keys K.sub.enc and/or
K.sub.int for the eNB, the UE uses the keys to perform secure data
transmission with the eNB.
[1009] FIG. 18 is a flowchart of Embodiment 1 of a wireless
communications method according to the present invention. As shown
in FIG. 18, this embodiment is performed by a terminal, and the
method in this embodiment may include the following steps:
[1010] Step 1801: A terminal sets up a connection to a first base
station, and stays in always connected mode, where the always
connected mode is to always keep the connection to the first base
station.
[1011] Specifically, for the explanation and description about the
always connected mode, reference may be made to the foregoing
explanation and description. It may be understood that, that a
terminal sets up a connection to a first base station and stays in
always connected mode means that the first base station has context
information of the terminal, and that the first base station
definitely knows that the terminal is within coverage of the first
base station. The first base station may be an A-eNB.
[1012] Step 1802: The terminal receives first dedicated signaling
sent by the first base station, where the first dedicated signaling
includes second base station list information, and the second base
station list information includes information about each second
base station having context information of the terminal.
[1013] It should be noted that, several base stations (eNB) with
small coverage may exist within coverage of a first base station,
where the base stations with small coverage may be second base
stations.
[1014] Step 1803: The terminal performs data transmission through
the first base station and/or the second base station according to
the second base station list information.
[1015] The terminal may obtain, according to the second base
station list information, information about a second base station
having the context information of the terminal, and perform data
transmission through the first base station, or the second base
station, or the first base station and the second base station.
[1016] Further, that a terminal sets up a connection to a first
base station, and stays in always connected mode, may be
specifically: the terminal always keeps the connection to the first
base station within a preset time.
[1017] The preset time may be a time that is at least longer than
that of service transmission, for example, a time longer than that
of a call. Alternatively, the always keeping the connection to the
first base station within a preset time means not entering a
conventional idle mode after completion of all service
transmission, but still keeping the connection to the first base
station, or may mean still keeping the connection to the first base
station if no actual data transmission is performed, or still
keeping the connection to the first base station if only a default
bearer is set up but there is no actual data transmission. The
preset time may be different time lengths such as several minutes,
tens of minutes, or several hours. This is not limited in this
embodiment of the present invention.
[1018] The performing data transmission through the first base
station may be specifically: performing only control signaling
transmission through the first base station; or performing only
downlink data transmission through the first base station; or
performing only downlink control signaling transmission through the
first base station.
[1019] The terminal sets up the connection to the first base
station, and stays in always connected mode, so that the first base
station always has the context information of the terminal within a
preset time range and keeps downlink synchronization with the
terminal. Therefore, when the terminal moves in a dense network,
handovers of the first base station can be reduced. Further, when
the terminal moves in the dense network, frequent signaling
interaction is reduced, paging load in the entire network is
reduced, and an end-to-end delay in service setup and transmission
is reduced. The dense network may include multiple first base
stations and multiple second base stations.
[1020] Further, before step 101, the method may further include:
obtaining, by the terminal, access frequency information, and
determining whether a connected mode corresponding to the access
frequency information is the always connected mode, where different
access frequency information corresponds to different connected
modes.
[1021] Optionally, the obtaining, by the terminal, access frequency
information, and determining whether a connected mode corresponding
to the access frequency information is the always connected mode,
may be specifically: receiving system information sent by the first
base station, and obtaining, from the system information, whether
the connected mode corresponding to the access frequency
information is the always connected mode; or obtaining, from preset
configuration information, whether the connected mode corresponding
to the access frequency information is the always connected
mode.
[1022] Further, if the connected mode corresponding to the access
frequency information is the always connected mode, the terminal
selects a first base station corresponding to the access frequency
information to perform access.
[1023] A specific implementation manner of the setting up a
connection to the first base station may be: sending a first
indication message to the first base station, where the first
indication message carries indication information about whether to
request to accept working in the always connected mode; and
receiving connection configuration information that is sent by the
first base station according to the first indication message, where
the connection configuration information includes whether to
configure the terminal to work in the always connected mode, where
the first indication message may include: a random access message 3
or a connection setup request message.
[1024] Further, the setting up a connection to a first base
station, and staying in always connected mode, may be specifically:
determining whether there is any service requirement currently, and
if there is no service requirement currently, keeping a connected
state with the first base station, and staying in the always
connected mode; or if there is a service requirement currently,
requesting the first base station to set up a corresponding bearer,
and performing data transmission by using the bearer.
[1025] The keeping a connected state with the first base station if
there is no service requirement currently, may be specifically: if
there is no service requirement currently, keeping receiving
scheduling information sent by the first base station.
[1026] Further, the method in this embodiment of the present
invention may further include: receiving a discontinuous reception
period configured by the first base station; and
[1027] correspondingly, the keeping receiving scheduling
information sent by the first base station is specifically:
receiving, within an active time of the discontinuous reception
period, the scheduling information sent by the first base
station.
[1028] Optionally, the method in this embodiment of the present
invention may further include: receiving, according to an
instruction of the scheduling information, second dedicated
signaling sent by the first base station, where the second
dedicated signaling includes notification information, and the
notification information is used to notify the terminal that a
bearer needs to be set up for data transmission.
[1029] Optionally, the second dedicated signaling further includes
instruction information, where
[1030] the instruction information includes second instruction
information or third instruction information, the second
instruction information is instruction information instructing to
select at least one second base station to perform data
transmission, and the third instruction information is instruction
information instructing to perform data transmission only through
the first base station; and
[1031] the method further includes: receiving the second
instruction information or the third instruction information sent
by the first base station.
[1032] Optionally, the requesting the first base station to set up
a corresponding bearer, and performing data transmission by using
the bearer if there is a service requirement currently, may be
specifically:
[1033] if there is a service requirement currently, requesting the
first base station to set up the corresponding bearer, receiving
second dedicated signaling sent by the first base station, where
the second dedicated signaling includes notification information,
and the notification information is used to notify the terminal
that the bearer needs to be set up for data transmission, and
performing data transmission by using the bearer.
[1034] Further, the terminal receives an instruction message sent
by the first base station, where the instruction message includes
second instruction information or third instruction information,
the second instruction information is instruction information
instructing to select at least one second base station to perform
data transmission, and the third instruction information is
instruction information instructing to perform data transmission
only through the first base station; and the terminal receives the
second instruction information or the third instruction information
sent by the first base station.
[1035] Optionally, if the second instruction information sent by
the first base station is received, the terminal selects, according
to the second instruction information, the at least one second base
station to perform data transmission; and
[1036] the terminal sends information about the selected at least
one second base station to the first base station.
[1037] Optionally, the terminal selects at least one second base
station to perform data transmission, and sends information about
the selected at least one second base station to the first base
station.
[1038] Optionally, after the receiving, according to an instruction
of the scheduling information, second dedicated signaling sent by
the first base station, where the second dedicated signaling
includes a notification message, and the notification message is
used to notify that a bearer needs to be set up for data
transmission, the method may further include: determining,
according to the notification message, to perform data transmission
only through the first base station.
[1039] Further, if it is determined and learned that each second
base station in the at least one second base station has the
context information of the terminal, the terminal sends a
scheduling request message to each second base station, and
obtains, by using the scheduling request message, a resource
allocated by each second base station to perform data transmission;
or
[1040] if it is determined and learned that each second base
station in the at least one second base station has the context
information of the terminal, the terminal performs random access to
each second base station, and obtains a resource allocated by each
second base station to perform data transmission.
[1041] The performing random access to each second base station,
and obtaining a resource allocated by each second base station to
perform data transmission, may be specifically: performing random
access to each second base station by using unique identifier
information allocated by the first base station, and obtaining the
resource allocated by each second base station according to the
unique identifier information to perform data transmission, where
the unique identifier information corresponds to the terminal, and
the unique identifier information is a unique preamble or a
combination of a unique preamble and a random access resource.
[1042] Further, if it is determined and learned that each second
base station in the at least one second base station does not have
the context information of the terminal, the terminal performs
random access to each second base station, and in the random access
process, sends, to each second base station, the context
information of the terminal and information about the first base
station to which the terminal has set up the connection.
[1043] Optionally, after the terminal stops performing data
transmission through the first base station and/or the second base
station, the terminal continues to work in always connected mode,
and saves dedicated configuration information for setting up the
connection to the first base station. Further, the terminal stops
maintaining an uplink synchronization timer; or after an uplink
synchronization timer expires, the terminal stops maintaining the
uplink synchronization timer.
[1044] The foregoing step in this embodiment is a process of a
method for performing initial access by the terminal. After the
terminal performs initial access, the terminal obtains initial list
information of second base stations having the context information
of the terminal; afterward, the terminal needs to manage the
context information of the terminal on a second base station that
currently provides services for the terminal, and on other second
base stations in time, so that the terminal can quickly use a
second base station to perform data transmission. Therefore, the
method in this embodiment may further include: after the terminal
performs data transmission through the first base station and/or
the second base station according to the second base station list
information, receiving a second base station list update message
sent by the first base station, updating the second base station
list information according to the second base station list update
message, and obtaining updated second base station list
information.
[1045] Optionally, before the receiving a second base station list
update message sent by the first base station, the method may
further include: sending, by the terminal, a second base station
list update request message to the first base station.
[1046] Optionally, the second base station list update message is
generated by the first base station according to location
information of the terminal and location information of each second
base station.
[1047] Further, after the terminal performs data transmission
through the first base station and/or the second base station
according to the second base station list information, the terminal
measures each neighboring base station in a network, and if a
neighboring base station whose signal quality is higher than a
first threshold exists, determines whether the updated second base
station list information includes information about the neighboring
base station.
[1048] If the updated second base station list information does not
include the information about the neighboring base station, the
terminal sends a neighboring base station measurement report to the
first base station, where the neighboring base station measurement
report includes the information about the neighboring base station;
or if the updated second base station list information does not
include the information about the neighboring base station, the
terminal sends a second base station list update request message to
the first base station, where the second base station list update
request message includes the information about the neighboring base
station; or if the updated second base station list information
does not include the information about the neighboring base
station, the terminal reports, to the first base station, that the
neighboring base station is not included in the updated second base
station list.
[1049] Further, the neighboring base station measurement report may
further include an indication that the neighboring base station
does not have the context information of the terminal, so that the
first base station sends the context information of the terminal to
the neighboring base station.
[1050] Optionally, the method in this embodiment may further
include: receiving a response message sent by the first base
station, where the response message is generated by the first base
station according to the neighboring base station measurement
report, and learning, according to the response message, that the
neighboring base station has obtained the context information of
the terminal.
[1051] Before the terminal performs data transmission with the base
station, a related configuration further needs to be completed.
Therefore, the wireless communications method in this embodiment of
the present invention further includes: receiving default
configuration information sent by the first base station, where the
default configuration information is configuration information used
when the terminal performs initial data transmission with each
second base station; and correspondingly, that the terminal
performs data transmission through the first base station and/or
the second base station according to the second base station list
information, may be specifically: the terminal performs, according
to the second base station list information and the default
configuration information, data transmission through a second base
station that has the context information of the terminal.
[1052] The default configuration information is associated with a
service, quality of service QoS of a service, or a bearer.
[1053] Further, the method in this embodiment may further include:
receiving a second base station list update message sent by the
first base station, updating the second base station list
information according to the second base station list update
message, and obtaining updated second base station list
information.
[1054] Correspondingly, that the terminal performs, according to
the second base station list information and the default
configuration information, data transmission through a second base
station that has the context information of the terminal, may be
specifically: the terminal performs, according to the updated
second base station list and the default configuration information,
initial data transmission through the second base station that has
the context information of the terminal; and receives a
reconfiguration message sent by the second base station, modifies,
according to the reconfiguration message, default configuration
information corresponding to the terminal, and performs, by using
modified configuration information, data transmission with the
second base station that has the context information of the
terminal.
[1055] In a moving process, the terminal needs to continuously
measure neighboring first base stations and neighboring second base
stations to determine potential first base stations or second base
stations that may be selected. In an actual network, the second
base stations may be classified into a master second base station
and a secondary second base station, where coverage of the master
second base station is large, and coverage of the secondary second
base station is small. To improve measurement efficiency of the
terminal and reduce a power consumption level of the terminal, the
method in this embodiment may further include: receiving
measurement configuration information sent by the first base
station, and completing, according to the measurement configuration
information, a measurement configuration of a frequency layer
corresponding to each base station, where the base stations include
the first base station and the second base stations, and the second
base stations include a master second base station and a secondary
second base station.
[1056] Further, the measurement configuration information may
include: measuring a frequency layer corresponding to the first
base station only; or measuring frequency layers corresponding to
the first base station and the master second base station only; or
measuring frequency layers corresponding to all of the first base
station, the master second base station, and the secondary second
base station.
[1057] Optionally, the measurement configuration information may
further include: determining a first threshold for measuring the
frequency layer corresponding to the first base station only; or
determining a second threshold for measuring the frequency layers
corresponding to the first base station and the master second base
station only; or determining a third threshold for measuring the
frequency layers corresponding to all of the first base station,
the master second base station, and the secondary second base
station.
[1058] Further, if QoS of a current service of the terminal is less
than the first threshold, the completing, according to the
measurement configuration information, a measurement configuration
of a frequency layer corresponding to each base station, includes:
measuring, according to the measurement configuration information,
the frequency layer corresponding to the first base station only,
and obtaining a measurement result; or if QoS of a current service
of the terminal is greater than the first threshold but less than
the second threshold, the completing, according to the measurement
configuration information, a measurement configuration of a
frequency layer corresponding to each base station, includes:
measuring, according to the measurement configuration information,
the frequency layer corresponding to the first base station and the
frequency layer corresponding to the master second base station,
and obtaining measurement results; or if QoS of a current service
of the terminal is greater than the second threshold or the third
threshold, the completing, according to the measurement
configuration information, a measurement configuration of a
frequency layer corresponding to each base station, includes:
measuring, according to the measurement configuration information,
the frequency layers corresponding to the first base station, the
master second base station, and the secondary second base station,
and obtaining measurement results.
[1059] Optionally, the method in this embodiment further includes:
receiving an instruction message sent by the first base station
about whether to perform measurement reporting; and determining,
according to the instruction message about whether to perform
measurement reporting, whether to send the measurement result to
the first base station.
[1060] The instruction message about whether to perform measurement
reporting may be: at least one of instruction information for
measurement reporting of the frequency layer corresponding to the
first base station, instruction information for measurement
reporting of the frequency layer corresponding to the master second
base station, or instruction information for measurement reporting
of the frequency layer corresponding to the secondary second base
station.
[1061] To improve measurement efficiency of the terminal and reduce
a power consumption level of the terminal, in another possible
implementation manner, the method in this embodiment may further
include: receiving measurement configuration parameter information
sent by the first base station, and completing, according to the
measurement configuration parameter information, measurement
management of a frequency layer corresponding to each base station,
where the base stations include the first base station and the
second base stations, and the second base stations include a master
second base station and a secondary second base station; where the
measurement configuration parameter information includes at least
one of a measurement configuration parameter of a frequency layer
corresponding to the first base station, a measurement
configuration parameter of a frequency layer corresponding to the
master second base station, or a measurement configuration
parameter of a frequency layer corresponding to the secondary
second base station.
[1062] Further, if QoS of a current service of the terminal is less
than a first threshold, the completing, according to the
measurement configuration parameter information, measurement
management of a frequency layer corresponding to each base station,
includes: measuring, according to the measurement configuration
parameter of the frequency layer corresponding to the first base
station, the frequency layer of the first base station, and
obtaining a first measurement result; or if QoS of a current
service of the terminal is greater than a first threshold but less
than a second threshold, the completing, according to the
measurement configuration parameter information, measurement
management of a frequency layer corresponding to each base station,
includes: measuring, according to the measurement configuration
parameter of the frequency layer corresponding to the first base
station, the frequency layer of the first base station, and
obtaining a first measurement result, and at the same time,
measuring, according to the measurement configuration parameter of
the frequency layer corresponding to the master second base
station, the frequency layer of the master second base station, and
obtaining a second measurement result; or if QoS of a current
service of the terminal is greater than a second threshold, the
completing, according to the measurement configuration parameter
information, measurement management of a frequency layer
corresponding to each base station, includes: measuring, according
to the measurement configuration parameter of the frequency layer
corresponding to the secondary second base station, the frequency
layer of the secondary second base station, and obtaining a third
measurement result.
[1063] Further, the measuring, according to the measurement
configuration parameter of the frequency layer corresponding to the
first base station, the frequency layer of the first base station,
specifically includes: measuring, according to the measurement
configuration parameter of the frequency layer corresponding to the
first base station, the first base station and/or a first base
station neighboring to the first base station.
[1064] The measuring, according to the measurement configuration
parameter of the frequency layer corresponding to the master second
base station, the frequency layer of the master second base
station, specifically includes: measuring, according to the
measurement configuration parameter of the frequency layer
corresponding to the master second base station, the master second
base station and/or a master second base station neighboring to the
master second base station.
[1065] The measuring, according to the measurement configuration
parameter of the frequency layer corresponding to the secondary
second base station, the frequency layer of the secondary second
base station, specifically includes: measuring, according to the
measurement configuration parameter of the frequency layer
corresponding to the secondary second base station, the secondary
second base station and/or a secondary second base station
neighboring to the secondary second base station.
[1066] Further, the terminal sends the obtained first measurement
result to the first base station, but does not send the third
measurement result to the first base station.
[1067] Optionally, the terminal compares the obtained second
measurement result with a preset condition, and if the preset
condition is met, sends the second measurement result to the first
base station.
[1068] A large quantity of first base stations exist in a network.
In a moving process of the terminal, on the one hand, the terminal
needs to measure the first base station; on the other hand, the
terminal may also be handed over according to a measurement result,
so that the terminal is handed over to a more appropriate first
base station. Therefore, this embodiment further includes managing
mobility of the terminal between first base stations. Specifically,
the method in this embodiment further includes: receiving a
handover command message sent by the current serving first base
station, where the handover command message includes information
about each second base station that is controlled by a target first
base station and has the context information of the terminal, the
current serving first base station is the first base station that
currently performs data transmission with the terminal, and the
target first base station is a target first base station to which
the terminal is handed over from the current serving first base
station. Optionally, the handover command message further includes
instruction information instructing the terminal to skip performing
random access to the target first base station; and the terminal
does not perform random access to the target first base station
according to the instruction information instructing to skip
performing random access to the target first base station.
[1069] Optionally, each second base station that is controlled by
the target first base station and has the context information of
the terminal is controlled by the target first base station or
connected to the target first base station. Optionally, each second
base station that is controlled by the target first base station
and has the context information of the terminal is controlled by
the current serving first base station and the target first base
station jointly, or has connection relationships with both the
current serving first base station and the target first base
station.
[1070] Further, the terminal selects, according to the handover
command message, at least one second base station that has the
context information of the terminal, so as to perform data
transmission.
[1071] Further, before the receiving a handover command message
sent by the current serving first base station, the terminal may
further measure each first base station in a network, and obtain a
measurement result of each first base station, where the first base
stations include the current serving first base station and
neighboring first base stations, and the neighboring first base
stations include the target first base station.
[1072] Further, the terminal determines the target first base
station according to a measurement result of the current serving
first base station and measurement results of the neighboring first
base stations; and the terminal sends a first handover request
message to the current serving first base station, where the first
handover request message includes information about requesting to
be handed over to the target first base station. Alternatively, the
terminal sends measurement results of the neighboring first base
stations to the current serving first base station, so that the
current serving first base station determines whether to perform
the handover to the target first base station.
[1073] Further, the selecting, according to the handover command
message, at least one second base station that has the context
information of the terminal, so as to perform data transmission,
may include: preferentially selecting a second base station that
provides services under control of the current serving first base
station and has the context information, so as to perform data
transmission, where the second base station is controlled by the
target first base station.
[1074] Further, the handover command message may further include:
instruction information instructing the terminal to keep performing
data transmission with at least one current serving second base
station, where the current serving second base station is a second
base station that provides data transmission for the terminal
before the handover command is received; and the terminal performs
the handover to the target first base station according to the
handover command message, and at the same time, keeps performing
data transmission through the at least one current serving second
base station.
[1075] Optionally, the terminal sends a handover complete
indication to the current serving first base station through a
second base station controlled by the current serving first base
station.
[1076] In another possible implementation manner of managing
mobility of the terminal between first base stations, the method in
this embodiment may further include: measuring each first base
station in a network, and obtaining a measurement result of each
first base station, where the first base stations include the
current serving first base station and neighboring first base
stations; determining a target first base station according to the
measurement result, where the target first base station is a target
first base station to which the terminal is handed over from the
current serving first base station; and sending a handover request
message to the target first base station, where the handover
request message includes information about the current serving
first base station and information about candidate second base
stations, where the candidate second base stations are second base
stations that are controlled by the target first base station or
connected to the target first base station and can provide services
for the terminal.
[1077] Further, the terminal receives a handover request
acknowledgement message from the target first base station, where
the handover request acknowledgement message includes a list of
second base stations that are controlled by the target first base
station or connected to the target first base station and have the
context information of the terminal; and the terminal selects,
according to the handover request acknowledgement message, at least
one second base station that has the context information of the
terminal, so as to perform data transmission.
[1078] Optionally, after the selecting, according to the handover
request acknowledgement message, at least one second base station
that has the context information of the terminal, so as to perform
data transmission, the method may further include: sending a
handover complete indication message to the current serving first
base station; or sending a handover complete indication message to
the current serving first base station through the target first
base station.
[1079] In still another possible implementation manner of managing
mobility of the terminal between first base stations, the method in
this embodiment may further include: measuring each first base
station in a network, and obtaining a measurement result of each
first base station, where the first base stations include the
current serving first base station and neighboring first base
stations; determining a target first base station according to the
measurement result, where the target first base station is a target
first base station to which the terminal is handed over from the
current serving first base station; sending a handover request
message to the current serving first base station, where the
handover request message includes information about requesting to
be handed over to the target first base station; and receiving a
handover command message sent by the current serving first base
station.
[1080] Further, the handover command message may include
instruction information instructing the terminal to perform the
handover to the target first base station and instruction
information instructing the terminal to keep performing data
transmission with at least one current serving second base station,
where the current serving second base station is a second base
station that provides data transmission for the terminal before the
handover command message is received; and the terminal performs the
handover to the target first base station according to the handover
command message, and at the same time, keeps performing data
transmission through the at least one current serving second base
station.
[1081] Optionally, the handover command message may further include
bearer reconfiguration information; and the terminal switches a
data transmission service between the current serving first base
station and the terminal to the current serving second base station
according to the bearer reconfiguration information.
[1082] To ensure data security during communication between the
terminal and each base station, a new mechanism for generating a
security key needs to be provided for a network architecture of the
present invention. Before the terminal performs data transmission
through the first base station and/or the second base station
according to the list information of the second base stations
having the context information, the method in this embodiment may
further include: setting up, by the terminal, a first security
mechanism with the first base station, and setting up a second
security mechanism with the second base station.
[1083] The setting up a second security mechanism with the second
base station may include: receiving the second base station list
information and security algorithm information sent by the first
base station, where the second base station list information
includes the information about each second base station having the
context information, and the security algorithm information
includes security algorithm information corresponding to each
second base station included in the second base station list; and
selecting at least one second base station from the second base
station list, and obtaining, according to a security index
corresponding to the at least one second base station and the
security algorithm information, an encryption key and/or an
integrity protection key corresponding to each second base station;
where the second base station corresponds to the security index on
a one-to-one basis.
[1084] Further, the obtaining, according to a security index
corresponding to the at least one second base station and the
security algorithm information, an encryption key and/or an
integrity protection key corresponding to each second base station,
may include: obtaining, according to the security index
corresponding to the at least one second base station, a security
key corresponding to the at least one security index, and obtaining
a corresponding root key through calculation according to the
security key; obtaining, by using the root key, an intermediate key
corresponding to the second base station; and obtaining, according
to the intermediate key and the security algorithm information
corresponding to the second base station, the encryption key and/or
the integrity protection key corresponding to the second base
station.
[1085] Further, the performing data transmission through the first
base station and/or the second base station may include: performing
data transmission through the first base station based on the first
security mechanism, and/or performing data transmission through the
second base station based on the second security mechanism.
[1086] Optionally, the first security mechanism and the second
security mechanism are associated with each other; and the
obtaining, according to a security index corresponding to the at
least one second base station and the security algorithm
information, an encryption key and/or an integrity protection key
corresponding to each second base station, may include: obtaining,
according to the security index corresponding to the at least one
second base station, a security key and a dynamic count
corresponding to the at least one security index, and obtaining a
corresponding root key through calculation according to the
security key; obtaining, by using the root key, an intermediate key
corresponding to the second base station; obtaining an associated
intermediate key according to the intermediate key and the dynamic
count; and obtaining, according to the associated intermediate key
and the security algorithm information corresponding to the second
base station, the encryption key and/or the integrity protection
key corresponding to the second base station.
[1087] In this embodiment, on a basis of the network architecture
shown in FIG. 1 or FIG. 2, a terminal sets up a connection to a
first base station, and stays in always connected mode, where the
always connected mode is to always keep the connection to the first
base station; the terminal receives first dedicated signaling sent
by the first base station, where the first dedicated signaling
includes second base station list information, and the second base
station list information includes information about each second
base station having context information of the terminal; and the
terminal performs data transmission through the first base station
and/or the second base station according to the second base station
list information. Because the terminal always keeps the connection
to the first base station within a preset time, this may reduce
frequent signaling interaction effectively when the terminal moves
in a dense network, eliminate paging load in the entire network,
and reduce an end-to-end delay in service setup and
transmission.
[1088] FIG. 19 is a flowchart of Embodiment 2 of a wireless
communications method according to the present invention. As shown
in FIG. 19, this embodiment is performed by a first base station,
and the method in this embodiment may include the following
steps:
[1089] Step 1901: A first base station sets up a connection to a
terminal, and stays in always connected mode, where the always
connected mode is to always keep the connection to the
terminal.
[1090] Step 1902: The first base station sends first dedicated
signaling to the terminal, where the first dedicated signaling
includes second base station list information, and the second base
station list information includes information about each second
base station having context information of the terminal.
[1091] Step 1903: The first base station performs data transmission
with the terminal.
[1092] That a first base station sets up a connection to a
terminal, and stays in always connected mode, includes:
[1093] the first base station always keeps the connection to the
first base station within a preset time.
[1094] Optionally, that the first base station performs data
transmission with the terminal specifically includes: the first
base station transmits only control signaling to the terminal; or
the first base station transmits only downlink data to the
terminal; or the first base station transmits only downlink control
signaling to the terminal.
[1095] Before the first base station sets up the connection to the
terminal, and stays in always connected mode, the method further
includes: sending a dedicated message to the terminal, where the
dedicated message carries instruction information instructing the
terminal whether to work in the always connected mode; or receiving
a first indication message sent by the terminal, where the first
indication message carries indication information about whether the
terminal requests to work in the always connected mode, and
determining, according to the first indication message, whether to
configure the terminal to work in the always connected mode; or
after receiving a random access preamble sent by the terminal,
sending a random access response message to the terminal, where the
random access response message carries instruction information
instructing the terminal whether to work in the always connected
mode, so that the terminal determines, according to the random
access response message, whether to work in the always connected
mode; or after receiving a connection setup request message sent by
the terminal, sending a connection setup response message to the
terminal, where the connection setup response message carries
instruction information instructing the terminal whether to work in
the always connected mode; or after receiving a connection setup
request message sent by the terminal, sending a dedicated message
to the terminal, where the dedicated message carries instruction
information instructing the terminal whether to work in the always
connected mode.
[1096] The first indication message includes: a random access
message 3 or a connection setup request message.
[1097] That a first base station sets up a connection to a
terminal, and stays in always connected mode, includes: if no
service request message sent by the terminal is received, keeping a
connected state with the terminal, and staying in the always
connected mode; or if a service request message sent by the
terminal is received, where the service request message includes
information about requesting to set up a corresponding bearer,
setting up the bearer for the terminal according to the service
request message, so as to perform data transmission.
[1098] When no service request message sent by the terminal is
received, the method further includes: configuring a discontinuous
reception period for the terminal, so that the terminal receives,
within an active time of the discontinuous reception period,
scheduling information sent by the first base station.
[1099] The first base station sends the scheduling information to
the terminal, where the scheduling information is used to instruct
the terminal to receive second dedicated signaling; and the first
base station sends the second dedicated signaling to the terminal,
where the second dedicated signaling includes a notification
message, and the notification message includes information
notifying the terminal that the bearer needs to be set up for data
transmission.
[1100] The second dedicated signaling further includes instruction
information, where the instruction information includes second
instruction information or third instruction information, the
second instruction information is instruction information
instructing the terminal to select at least one second base station
to perform data transmission, and the third instruction information
is instruction information instructing the terminal to perform data
transmission only through the first base station.
[1101] If the service request message sent by the terminal is
received, the method further includes: if the service request
message sent by the terminal is received, sending the scheduling
information to the terminal, where the scheduling information is
used to instruct the terminal to receive second dedicated
signaling; and sending the second dedicated signaling to the
terminal, where the second dedicated signaling includes a
notification message, and the notification message includes
information notifying the terminal that the bearer needs to be set
up for data transmission, and performing data transmission with the
terminal by using the bearer.
[1102] The first base station sends an instruction message to the
terminal, where the instruction message includes second instruction
information or third instruction information, the second
instruction information is instruction information instructing to
select at least one second base station to perform data
transmission, and the third instruction information is instruction
information instructing to perform data transmission only through
the first base station.
[1103] The first base station receives information sent by the
terminal about the selected at least one second base station, where
the information about the selected at least one second base station
is information about each second base station in the at least one
second base station selected by the terminal according to the
second instruction information.
[1104] The first base station determines whether each second base
station in the information about the selected at least one second
base station has the context information of the terminal; and
[1105] if a second base station that does not have the context
information of the terminal exists, the first base station sends
the context information of the terminal to the second base station
that does not have the context information of the terminal.
[1106] The first base station allocates a unique preamble or a
combination of a unique preamble and a random access channel
resource to the terminal, so that the terminal obtains, by using
the unique preamble or the combination of the unique preamble and
the random access channel resource, a resource allocated by the
second base station, so as to perform data transmission.
[1107] After the first base station stops performing data
transmission with the terminal, the first base station saves
configuration information for setting up the connection to the
terminal.
[1108] The first base station generates a second base station list
update message, and sends the second base station list update
message to the terminal, where the second base station list update
message includes updated second base station list information, so
that the terminal updates the second base station list information
according to the second base station list update message.
[1109] The generating a second base station list update message
includes: generating the second base station list update message
according to one or more of location information of the terminal,
location information of each second base station, or a measurement
report reported by the terminal.
[1110] The first base station receives a neighboring base station
measurement report sent by the terminal, where the neighboring base
station measurement report includes information about a neighboring
base station, and the information about the neighboring base
station is not included in the second base station list
information; or
[1111] the first base station receives a second base station list
update request message sent by the terminal, where the second base
station list update request message includes information about a
neighboring base station, and the information about the neighboring
base station is not included in the second base station list
information; or
[1112] the first base station receives a report of the terminal
that a neighboring base station is not included in the second base
station list.
[1113] If the neighboring base station does not have the context
information of the terminal, the first base station sends the
context information of the terminal to the neighboring base
station, and sends a second base station list update message to the
terminal, where the second base station list update message
includes the information about the neighboring base station.
[1114] The second base station measurement report further includes
information indicating that the neighboring base station does not
have the context information of the terminal; and the first base
station sends the context information of the terminal to the
neighboring base station, and sends a response message to the
terminal, where the response message is generated by the first base
station according to the neighboring base station measurement
report, so that the terminal learns, according to the response
message, that the neighboring base station has obtained the context
information of the terminal.
[1115] The first base station sends default configuration
information to the terminal and each second base station
separately, where the default configuration information is
associated with a service type, quality of service QoS of a
service, or a bearer type, and the default configuration
information is configuration information used when the terminal
performs initial data transmission with each second base
station.
[1116] The first base station sends a second base station list
update message to the terminal, so that the terminal updates the
second base station list information according to the second base
station list update message and performs, by using updated second
base station list information and the default configuration
information, initial data transmission through a second base
station that has the context information of the terminal.
[1117] The first base station sends measurement configuration
information to the terminal, where the measurement configuration
information includes measurement configuration information of a
frequency layer corresponding to each base station, the base
station includes at least one of the first base station or the
second base stations, and the second base stations include a master
second base station and a secondary second base station.
[1118] The measurement configuration information includes:
measuring a frequency layer corresponding to the first base station
only; or measuring frequency layers corresponding to the first base
station and the master second base station only; or measuring
frequency layers corresponding to all of the first base station,
the master second base station, and the secondary second base
station.
[1119] The measurement configuration information further includes:
a first threshold for measuring the frequency layer corresponding
to the first base station only; or a second threshold for measuring
the frequency layers corresponding to the first base station and
the master second base station only; or a third threshold for
measuring the frequency layers corresponding to all of the first
base station, the master second base station, and the secondary
second base station.
[1120] The first base station sends, to the terminal, an
instruction message about whether to perform measurement
reporting.
[1121] The instruction message about whether to perform measurement
reporting includes: at least one of instruction information for
measurement reporting of the frequency layer corresponding to the
first base station, instruction information for measurement
reporting of the frequency layer corresponding to the master second
base station, or instruction information for measurement reporting
of the frequency layer corresponding to the secondary second base
station.
[1122] The first base station sends measurement configuration
parameter information to the terminal, where the measurement
configuration parameter information includes at least one of a
measurement configuration parameter of a frequency layer
corresponding to the first base station, a measurement
configuration parameter of a frequency layer corresponding to a
master second base station, or a measurement configuration
parameter of a frequency layer corresponding to a secondary second
base station.
[1123] The first base station receives measurement results sent by
the terminal, where the measurement results include a first
measurement result and a second measurement result, the first
measurement result is obtained by the terminal by performing a
measurement according to the measurement configuration parameter of
the frequency layer corresponding to the first base station, and
the second measurement result is obtained by the terminal by
measuring the master second base station according to the
measurement configuration parameter of the frequency layer
corresponding to the master second base