U.S. patent application number 16/239320 was filed with the patent office on 2019-05-09 for method of distributing security key context, mobility management entity, and base station.
The applicant listed for this patent is Huawei Technologies Co., Ltd.. Invention is credited to Mingzeng Dai, Yi Guo, Qinghai Zeng, Hongping Zhang, Jian Zhang.
Application Number | 20190141585 16/239320 |
Document ID | / |
Family ID | 50504421 |
Filed Date | 2019-05-09 |
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United States Patent
Application |
20190141585 |
Kind Code |
A1 |
Dai; Mingzeng ; et
al. |
May 9, 2019 |
Method of Distributing Security Key Context, Mobility Management
Entity, and Base Station
Abstract
A method of distributing a security key context, where the
method includes receiving, by a mobility management entity, a first
indication from a primary base station, where the first indication
is used for requesting a path switch from the mobility management
entity and indicating that the path switch is triggered by carrier
aggregation between base stations, processing the path switch
according to the first indication, keeping, according to the first
indication, the security key context for the path switch unchanged,
and sending a second indication to the primary base station to
indicate the primary base station to keep the security key context
unchanged, or sending a third indication to the primary base
station to indicate the primary base station to acquire a quantity
of times of reversal of a next hop chaining counter in the security
key context.
Inventors: |
Dai; Mingzeng; (Shanghai,
CN) ; Zhang; Jian; (Shenzhen, CN) ; Zeng;
Qinghai; (Shanghai, CN) ; Guo; Yi; (Shenzhen,
CN) ; Zhang; Hongping; (Shanghai, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Huawei Technologies Co., Ltd. |
Shenzhen |
|
CN |
|
|
Family ID: |
50504421 |
Appl. No.: |
16/239320 |
Filed: |
January 3, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15193541 |
Jun 27, 2016 |
10200916 |
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16239320 |
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PCT/CN2014/082317 |
Jul 16, 2014 |
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15193541 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 36/0038 20130101;
H04W 36/0069 20180801; H04W 84/042 20130101; H04W 36/12 20130101;
H04W 12/04031 20190101; H04W 76/15 20180201 |
International
Class: |
H04W 36/00 20060101
H04W036/00; H04W 36/12 20060101 H04W036/12; H04W 12/04 20060101
H04W012/04; H04W 76/15 20060101 H04W076/15 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 27, 2013 |
CN |
201310739640.X |
Claims
1. An apparatus, comprising: a receiver configured to receive a
first message from a primary base station, the first message
comprising downlink general packet radio service tunneling protocol
(GTP) information; and a transmitter coupled to the receiver and
configured to send a second message to the primary base station
indicating the primary base station to keep a security key context
unchanged, the second message avoiding carrying the security key
context.
2. The apparatus of claim 1, wherein the downlink GTP information
comprises a tunneling endpoint identifier (TEID) of a downlink GTP
tunnel.
3. The apparatus of claim 1, wherein the transmitter is further
configured to send a message to a serving gateway (SGW), and the
message comprising the GTP information.
4. The apparatus of claim 1, wherein the GTP information is used
for handing over a beaer between the primary base station and a
secondary base station.
5. The apparatus of claim 1, wherein the apparatus is a mobility
management entity (MME).
6. An apparatus, comprising: a transmitter configured to send a
first message to a core network device, the first message
comprising downlink general packet radio service tunneling protocol
(GTP) information; a receiver coupled to the transmitter and
configured to receive a second message from the core network
device; and a processor coupled to the transmitter and the receiver
and configured to keep a security key context unchanged, the second
message avoiding carrying the security key context.
7. The apparatus of claim 6, wherein the processor is further
configured to hand over a bearer to a secondary base station.
8. The apparatus of claim 6, wherein the downlink GTP information
comprises a tunneling endpoint identifier (TEID) of a downlink GTP
tunnel.
9. The apparatus of claim 6, wherein the processor is further
configured to confirm a terminal to complete radio resource control
(RRC) configuration with a secondary base station.
10. The apparatus of claim 6, wherein the core network device is a
mobility management entity (MME).
11. A method, comprising: receiving, by a core network device, a
first message from a primary base station, the first message
comprising downlink general packet radio service tunneling protocol
(GTP) information; and sending, by the core network device, a
second message to the primary base station indicating the primary
base station to keep a security key context unchanged, the second
message avoiding carrying the security key context.
12. The method of claim 11, wherein the downlink GTP information
comprises a tunneling endpoint identifier (TEID) of a downlink GTP
tunnel.
13. The method of claim 11, further comprising sending, by the core
network device, a message to a serving gateway (SGW), and the
message comprising the GTP information.
14. The method of claim 11, wherein the GTP information is used for
handing over a beaer between the primary base station and a
secondary base station.
15. The method of claim 11, wherein the core network device is a
mobility management entity (MME).
16. A method, comprising: sending, by a primary base station, a
first message to a core network device, the first message
comprising downlink general packet radio service tunneling protocol
(GTP) information; receiving, by the primary base station, a second
message from the core network device; and keeping, by the primary
base station, a security key context unchanged, the second message
avoiding carrying the security key context.
17. The method of claim 16, further comprising handing over, by the
primary base station, a bearer to a secondary base station.
18. The method of claim 16, wherein the downlink GTP information
comprises a tunneling endpoint identifier (TEID) of a downlink GTP
tunnel.
19. The method of claim 16, further comprising confirming, by the
primary base station, a terminal to complete radio resource control
(RRC) configuration with a secondary base station.
20. The method of claim 16, wherein the core network device is a
mobility management entity (MME).
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/193,541 filed on Jun. 27, 2016, which is a
continuation of International Patent Application No.
PCT/CN2014/082317 filed on Jul. 16, 2014, which claims priority to
Chinese Patent Application No. 201310739640.X filed on Dec. 27,
2013. All of the afore-mentioned patent applications are hereby
incorporated by reference in their entireties.
TECHNICAL FIELD
[0002] The present disclosure relates to the field of
communications technologies, and in particular, to a method of
distributing a security key context, a mobility management entity
(MME), and a base station.
BACKGROUND
[0003] Carrier aggregation of a long term evolution (LTE) system
may be roughly classified into carrier aggregation in a base
station and carrier aggregation between base stations. Cell
aggregation in a base station is controlled by only one base
station and therefore is relatively simple. The "Release-10"
release of the third generation partnership project (3GPP) supports
the carrier aggregation in a base station but does not support the
carrier aggregation between base stations yet. The carrier
aggregation between base stations may be further classified into
carrier aggregation between macro base stations and carrier
aggregation between a macro base station and a small-cell base
station. The carrier aggregation between base stations is also
referred to as dual connectivity or multiple stream aggregation
(MSA), that is, a user equipment (UE) may simultaneously receive
data from two or more base stations.
[0004] At present, in the carrier aggregation between base
stations, base stations are classified into a primary base station
and a secondary base station, where the primary base station is
mainly responsible for implementing a control function and
transmitting some data, and the secondary base station is mainly
configured to offload data. If the primary base station decides to
hand over a bearer from one base station (for example, the primary
base station) to another base station (for example, the secondary
base station), a path switch procedure needs to be performed to
complete a path switch. At present, a path switch technology is
mainly applied to an X2 handover.
[0005] However, the carrier aggregation between base stations is
different from the X2 handover. A secondary evolved node B (eNB)
may be a small-cell base station, during the carrier aggregation
between base stations, each bearer handover requires a path switch
procedure. Therefore, a possibility of occurrence of a path switch
is far greater than that of the X2 handover, and frequent path
switches easily cause network security to be out of
synchronization, resulting in a call drop of a UE.
SUMMARY
[0006] Embodiments of the present disclosure provide a method of
distributing a security key context, an MME, and a base station,
which are used to improve reliability of a path switch during
carrier aggregation between base stations.
[0007] One aspect of the present disclosure provides an MME,
including a receiving unit configured to receive a first indication
from a primary base station, where the first indication is used for
requesting a path switch from the MME and indicating that the path
switch is triggered by carrier aggregation between base stations,
where the base stations include the primary base station, a path
switch unit configured to process the path switch according to the
first indication, and a sending unit configured to send a second
indication to the primary base station according to the first
indication, where the second indication is used for indicating the
primary base station to keep a security key context for the path
switch unchanged, where the MME keeps the security key context
unchanged according to the first indication, or send a third
indication to the primary base station according to the first
indication such that the primary base station acquires a quantity
of times of reversal of a next hop (NH) chaining counter (NCC) in
the security key context according to the third indication, where
the quantity of times of reversal refers to a quantity of times
that the NCC jumps from a maximum value to a minimum value.
[0008] Based on the first aspect of the present disclosure, in a
first possible implementation manner, the second indication carries
the security key context.
[0009] Based on the first aspect of the present disclosure, in a
second possible implementation manner, the MME further includes a
recording unit configured to record the quantity of times of
reversal of the NCC in the security key context, and the third
indication carries the recorded quantity of times of reversal of
the NCC in the security key context.
[0010] Based on the first aspect of the present disclosure, or the
first possible implementation manner of the first aspect of the
present disclosure, or the second possible implementation manner of
the first aspect of the present disclosure, in a third possible
implementation manner, the sending unit is further configured to
send the first indication to a serving gateway (SGW) such that the
SGW uses an original path according to the first indication when
the path switch fails, and the MME further includes an indication
unit configured to indicate the primary base station to use the
original path when the SGW indicates that the path switch
fails.
[0011] Based on the first aspect of the present disclosure, or the
first possible implementation manner of the first aspect of the
present disclosure, or the second possible implementation manner of
the first aspect of the present disclosure, in a fourth possible
implementation manner, the first indication includes path
information, where the path information includes an identifier of a
first path allocated by the primary base station for the path
switch, an identifier of a second path allocated by a secondary
base station for the path switch, a priority of the first path, and
a priority of the second path, and the base stations include the
secondary base station, and the sending unit is further configured
to send the path information to an SGW such that the SGW switches a
path to the first path or the second path according to a path with
a higher priority when the receiving unit receives the first
indication.
[0012] A second aspect of the present disclosure provides a base
station, including a sending unit configured to send a first
indication to an MME such that the MME processes a path switch
according to the first indication, where the first indication is
used for requesting the path switch from the MME and indicating
that the path switch is triggered by carrier aggregation between
base stations, a receiving unit configured to receive a second
indication from the MME, or receive a third indication from the
MME, and a processing unit configured to keep a security key
context for the path switch unchanged according to the second
indication when the receiving unit receives the second indication
from the MME, or configured to acquire a quantity of times of
reversal of an NCC in the security key context according to the
third indication when the receiving unit receives the third
indication from the MME, and send the NCC in the security key
context and the quantity of times of reversal of the NCC to the UE
using the sending unit such that the UE derives the security key
according to the NCC and the quantity of times of reversal of the
NCC when a UE needs to derive a security key, where the quantity of
times of reversal refers to a quantity of times that the NCC jumps
from a maximum value to a minimum value.
[0013] Based on the second aspect of the present disclosure, in a
first possible implementation manner, the processing unit is
further configured to record the quantity of times of reversal of
the NCC in the security key context under instruction of the third
indication when the receiving unit receives the third indication
from the MME.
[0014] Based on the second aspect of the present disclosure, in a
second possible implementation manner, the third indication carries
the quantity of times of reversal of the NCC in the security key
context, and the processing unit is further configured to acquire
the quantity of times of reversal of the NCC in the security key
context from the third indication when the receiving unit receives
the third indication from the MME.
[0015] Based on the second aspect of the present disclosure, or the
first possible implementation manner of the second aspect of the
present disclosure, or the second possible implementation manner of
the second aspect of the present disclosure, in a third possible
implementation manner, the first indication is further used for
indicating the MME to instruct an SGW to use an original path when
the path switch fails, and the base station further includes a path
control unit configured to use the original path when the SGW
indicates that the path switch fails, and send a bearer release
message to a secondary base station using the sending unit, to
indicate the secondary base station to release a bearer for which
the current path switch is performed.
[0016] Based on the second aspect of the present disclosure, or the
first possible implementation manner of the second aspect of the
present disclosure, or the second possible implementation manner of
the second aspect of the present disclosure, in a fourth possible
implementation manner, the base station further includes an
allocating unit configured to allocate a first path for the path
switch, an acquiring unit configured to acquire a second path
allocated by a secondary base station for the path switch, and a
priority determining unit configured to determine a priority of the
first path and a priority of the second path, and the sending unit
is further configured to add path information to the first
indication, where the path information includes an identifier of
the first path, an identifier of the second path, the priority of
the first path, and the priority of the second path such that the
MME sends the path information to an SGW, and the SGW switches a
path to the first path or the second path according to a path with
a higher priority.
[0017] A third aspect of the present disclosure provides a method
of distributing a security key context, including receiving, by an
MME, a first indication from a primary base station, where the
first indication is used for requesting a path switch from the MME
and indicating that the path switch is triggered by carrier
aggregation between base stations, where the base stations include
the primary base station, processing, by the MME, the path switch
according to the first indication, and according to the first
indication, keeping, by the MME, a security key context for the
path switch unchanged, and sending a second indication to the
primary base station, where the second indication is used for
indicating the primary base station to keep the security key
context unchanged, or sending, by the MME, a third indication to
the primary base station, where the third indication is used for
indicating the primary base station to acquire a quantity of times
of reversal of an NCC in the security key context, where the
quantity of times of reversal refers to a quantity of times that
the NCC jumps from a maximum value to a minimum value.
[0018] Based on the third aspect of the present disclosure, in a
first possible implementation manner, sending a second indication
to the primary base station includes adding the security key
context to the second indication.
[0019] Based on the third aspect of the present disclosure, in a
second possible implementation manner, the method further includes
recording the quantity of times of reversal of the NCC in the
security key context, and sending, by the MME, a third indication
to the primary base station according to the first indication
includes adding the recorded quantity of times of reversal of the
NCC in the security key context to the third indication.
[0020] Based on the second aspect of the present disclosure, or the
first possible implementation manner of the second aspect of the
present disclosure, or the second possible implementation manner of
the second aspect of the present disclosure, in a third possible
implementation manner, processing, by the MME, the path switch
according to the first indication includes sending the first
indication to an SGW such that the SGW uses an original path
according to the first indication when the path switch fails, and
indicating the primary base station to use the original path when
the SGW indicates that the path switch fails.
[0021] Based on the second aspect of the present disclosure, or the
first possible implementation manner of the second aspect of the
present disclosure, or the second possible implementation manner of
the second aspect of the present disclosure, in a fourth possible
implementation manner, the first indication includes path
information, where the path information includes an identifier of a
first path allocated by the primary base station for the path
switch, an identifier of a second path allocated by a secondary
base station for the path switch, a priority of the first path, and
a priority of the second path, and the base stations include the
secondary base station, and processing, by the MME, the path switch
according to the first indication includes sending the path
information to an SGW such that the SGW switches a path to the
first path or the second path according to a path with a higher
priority.
[0022] A fourth aspect of the present disclosure provides a method
of distributing a security key context, including sending, by a
primary base station, a first indication to an MME such that the
MME processes a path switch according to the first indication,
where the first indication is used for requesting the path switch
from the MME and indicating that the path switch is triggered by
carrier aggregation between base stations, where the base stations
include the primary base station, and receiving, by the primary
base station, a second indication from the MME, and keeping a
security key context for the path switch unchanged under
instruction of the second indication, or receiving, by the primary
base station, a third indication from the MME, acquiring a quantity
of times of reversal of an NCC in the security key context
according to the third indication, and sending the NCC in the
security key context and the quantity of times of reversal of the
NCC to a UE such that the UE derives the security key according to
the NCC and the quantity of times of reversal of the NCC when the
UE needs to derive a security key, where the quantity of times of
reversal refers to a quantity of times that the NCC jumps from a
maximum value to a minimum value.
[0023] Based on the fourth aspect of the present disclosure, in a
first possible implementation manner, acquiring a quantity of times
of reversal of an NCC in the security key context according to the
third indication includes recording the quantity of times of
reversal of the NCC in the security key context under instruction
of the third indication.
[0024] Based on the fourth aspect of the present disclosure, in a
second possible implementation manner, the third indication carries
the quantity of times of reversal of the NCC in the security key
context, and acquiring a quantity of times of reversal of an NCC in
the security key context according to the third indication includes
acquiring the quantity of times of reversal of the NCC in the
security key context from the third indication.
[0025] Based on the fourth aspect of the present disclosure, or the
first possible implementation manner of the fourth aspect of the
present disclosure, or the second possible implementation manner of
the fourth aspect of the present disclosure, in a third possible
implementation manner, the first indication is further used for
indicating the MME to instruct an SGW to use an original path when
the current path switch fails, and the method further includes
using the original path when the SGW indicates that the path switch
fails, and sending a bearer release message to a secondary base
station to indicate the secondary base station to release a bearer
for which the current path switch is performed, where the base
stations include the secondary base station.
[0026] Based on the fourth aspect of the present disclosure, or the
first possible implementation manner of the fourth aspect of the
present disclosure, or the second possible implementation manner of
the fourth aspect of the present disclosure, in a fourth possible
implementation manner, before sending, by a primary base station, a
first indication to an MME, the method includes allocating a first
path for the path switch and determining a priority of the first
path, and acquiring a second path allocated by a secondary base
station for the path switch and determining a priority of the
second path, and sending, by a primary base station, a first
indication to an MME includes adding path information to the first
indication, where the path information includes an identifier of
the first path, an identifier of the second path, the priority of
the first path, and the priority of the second path such that the
MME sends the path information to an SGW, and the SGW switches a
path to the first path or the second path according to a path with
a higher priority.
[0027] It can be seen from the foregoing technical solutions that,
the embodiments of the present disclosure have the following
advantages.
[0028] It can be seen from the foregoing technical solutions that,
in the embodiments of the present disclosure, when a primary base
station sends a first indication to an MME, the MME processes a
path switch according to the first indication, and under
instruction of the first indication, keeps a security key context
for the path switch unchanged and instructs the primary base
station to keep the security key context for the path switch
unchanged, or under instruction of the first indication, indicates
the primary base station to acquire a quantity of times of reversal
of an NCC in the security key context such that synchronization of
the security key context can still be ensured in a case in which a
quantity of times of path switches triggered by carrier aggregation
between base stations is excessively large, thereby improving
reliability of a path switch during carrier aggregation between
base stations.
BRIEF DESCRIPTION OF DRAWINGS
[0029] To describe the technical solutions in some of the
embodiments of the present disclosure more clearly, the following
briefly introduces the accompanying drawings describing some of the
embodiments. The accompanying drawings in the following description
show merely some embodiments of the present disclosure, and a
person of ordinary skill in the art may still derive other drawings
from these accompanying drawings without creative efforts.
[0030] FIG. 1A is a schematic diagram of a network application
scenario of carrier aggregation between base stations according to
the present disclosure;
[0031] FIG. 1B is a schematic diagram of a bearer handover
procedure in an application scenario according to the present
disclosure;
[0032] FIG. 2 is a schematic structural diagram of an embodiment of
an MME according to the present disclosure;
[0033] FIG. 3 is a schematic structural diagram of another
embodiment of an MME according to the present disclosure;
[0034] FIG. 4 is a schematic structural diagram of still another
embodiment of an MME according to the present disclosure;
[0035] FIG. 5 is a schematic structural diagram of an embodiment of
a base station according to the present disclosure;
[0036] FIG. 6 is a schematic structural diagram of another
embodiment of a base station according to the present
disclosure;
[0037] FIG. 7 is a schematic structural diagram of still another
embodiment of a base station according to the present
disclosure;
[0038] FIG. 8 is a schematic structural diagram of still another
embodiment of a base station according to the present
disclosure;
[0039] FIG. 9 is a schematic flowchart of an embodiment of a method
of distributing a security key context according to the present
disclosure;
[0040] FIG. 10 is a schematic flowchart of another embodiment of a
method of distributing a security key context according to the
present disclosure;
[0041] FIG. 11 is a schematic flowchart of still another embodiment
of a method of distributing a security key context according to the
present disclosure;
[0042] FIG. 12 is a schematic flowchart of still another embodiment
of a method of distributing a security key context according to the
present disclosure;
[0043] FIG. 13 is a schematic flowchart of an embodiment of a path
switch indication method according to the present disclosure;
and
[0044] FIG. 14 is a schematic flowchart of another embodiment of a
path switch indication method according to the present
disclosure.
DESCRIPTION OF EMBODIMENTS
[0045] Embodiments of the present disclosure provide a method of
distributing a security key context, an MME, and a base
station.
[0046] To make the disclosure objectives, features, and advantages
of the present disclosure clearer and more comprehensible, the
following clearly and completely describes the technical solutions
in the embodiments of the present disclosure with reference to the
accompanying drawings in the embodiments of the present disclosure.
The embodiments described are merely a part rather than all of the
embodiments of the present disclosure. All other embodiments
obtained by a person of ordinary skill in the art based on the
embodiments of the present disclosure without creative efforts
shall fall within the protection scope of the present
disclosure.
[0047] First, a process of carrier aggregation between base
stations in an embodiment of the present disclosure is described.
As shown in FIG. 1A, for an LTE system, FIG. 1A is a schematic
diagram of a network application scenario of carrier aggregation
between base stations. As shown in FIG. 1A, an S1-C interface is
configured to connect an MME and a primary base station (designated
as MeNB), S1-U interfaces are separately configured to connect an
SGW and the primary base station (recorded as an S1-U path 1) and
connect the SGW and a secondary base station (designated as SeNB)
(recorded as an S1-U path 2), and the primary base station is
interconnected with the secondary base station using an X2
interface. When the primary base station decides to hand over a
bearer of a UE to the secondary base station, a path switch
procedure needs to be performed to complete a switch of an S1-U
path, that is, a transmission path of the bearer is switched from
the S1-U path 1 to the S1-U path 2. Using addition of the secondary
base station as an example, a general process is shown in FIG.
1B.
[0048] Step 101: When deciding to offload data to the secondary
base station, the primary base station sends a secondary base
station addition request message to the secondary base station
using the X2 interface, where the message includes a related
parameter of a bearer to be established on the secondary base
station, for example, a standard of the bearer, a quality of
service (QoS) parameter of the bearer, or the like.
[0049] Step 102: If the secondary base station allows bearer
access, the secondary base station sends a secondary base station
addition response message to the primary base station, where the
message carries radio resource control (RRC) protocol configuration
signaling related to access to the secondary base station.
[0050] Step 103: The primary base station generates an RRC
connection reconfiguration message according to the RRC protocol
configuration information that is carried in the secondary base
station addition response message and related to the access to the
secondary base station, and sends the RRC connection
reconfiguration message to the UE.
[0051] Step 104: After receiving the RRC connection reconfiguration
message, the UE completes related RRC configuration according to
the RRC connection reconfiguration message.
[0052] Step 105: The UE synchronizes with the secondary base
station by performing a random access procedure.
[0053] Step 106: The UE sends an RRC connection reconfiguration
complete message to the primary base station such that a switch
success is confirmed.
[0054] Step 107: The primary base station sends a path switch
request message to the MME, where the message carries information
about a downlink general packet radio service tunneling protocol
(GTP) tunnel allocated by the secondary base station for the
current path switch (also referred to as downlink (DL)-GTP
information), where the DL-GTP information includes an endpoint
identifier (tunneling endpoint identifier (TEID)) of the DL-GTP
tunnel and a DL-GTP Internet Protocol (IP) address.
[0055] Step 108: The MME sends a modify bearer request message to
the SGW, where the modify bearer request message includes the
DL-GTP information in step 107.
[0056] Step 109: The SGW completes a downlink path switch according
to the DL-GTP information.
[0057] Step 110: The SGW sends a modify bearer response message to
the MME, where the modify bearer response message carries
information about an uplink GTP tunnel allocated by the SGW for the
current path switch (also referred to as an uplink (UL)-GTP
information), where the UL-GTP information includes a TEID of the
UL-GTP tunnel and an uplink GTP IP address.
[0058] Step 111: The MME sends a path switch request acknowledge
message to the primary base station, where the path switch request
acknowledge message includes the UL-GTP information in step
110.
[0059] Step 112: The primary base station forwards the UL-GTP
information to the secondary base station.
[0060] Step 113: The secondary base station completes an uplink
path switch according to the UL-GTP information.
[0061] An embodiment of the present disclosure further provides an
MME. Referring to FIG. 2, an MME 200 in this embodiment of the
present disclosure includes a receiving unit 201 configured to
receive a first indication from a primary base station, where the
first indication is used for requesting a path switch from the MME
200 and indicating that the path switch is triggered by carrier
aggregation between base stations, where the base stations include
the primary base station, a path switch unit 202 configured to
process the path switch according to the first indication received
by the receiving unit 201, where for a path switch procedure
executed by the path switch unit 202 under trigger of the first
indication, reference may be made to the description in the switch
procedure shown in FIG. 1B, and details are not described herein
again, and a sending unit 203 configured to send a second
indication to the primary base station under instruction of the
first indication received by the receiving unit 201, where the
second indication is used for indicating the primary base station
to keep a security key context for the path switch unchanged.
[0062] In an implementation manner, when confirming that the path
switch performed according to a path switch request message
succeeds, the MME 200 sends a path switch request acknowledge
message to the primary base station using the sending unit 203, and
adds the second indication to the path switch request acknowledge
message. After receiving the path switch request acknowledge
message, the primary base station keeps the security key context
for the path switch unchanged under instruction of the second
indication.
[0063] Alternatively, in another implementation manner, the MME 200
sends a new message to the primary base station, where the message
carries the original security key context or does not carry a
security key context. After receiving a path switch request
acknowledge message, the primary base station keeps the original
security key context unchanged under instruction of the second
indication.
[0064] Optionally, the sending unit 203 adds the security key
context for the path switch to the second indication. After
receiving the second indication, the primary base station stores
the security key context carried in the second indication, and
sends an NCC in the security key context to a UE when determining
that the UE needs to derive a security key (KeNB).
[0065] Optionally, because the primary base station has a record
about the original security key context, an implicit indication
manner is used to instruct the primary base station to keep the
original security key context unchanged. That is, it is agreed on
that the primary base station acquires the security key context
according to the second indication sent by the sending unit 203.
When the original security key context needs to be kept unchanged,
the sending unit 203 does not add the security key context to the
second indication. When the primary base station does not detect a
security key context in the received second indication, the primary
base station keeps the original security key context unchanged, and
sends an NCC in the original security key context to a UE when
determining that the UE needs to derive a KeNB.
[0066] It should be noted that, in this embodiment of the present
disclosure, the MME 200 keeps the security key context for the path
switch unchanged under instruction of the first indication. The
first indication may be carried in a path switch request message or
another new message, which is not limited herein.
[0067] In a path switch procedure, an SGW rejects a path switch
request of a bearer according to a path condition and a local
processing policy. Therefore, if the bearer is a default bearer, UE
detachment may be caused, for example, if the bearer is a necessary
bearer for maintaining a packet data network (PDN) connection, the
PDN connection is released such that a UE may be detached.
[0068] Therefore, optionally, based on the embodiment shown in FIG.
2, the sending unit 203 is further configured to send the first
indication to the SGW such that the SGW uses an original path under
instruction of the first indication when the path switch fails, and
the MME 200 further includes an indication unit configured to
indicate the primary base station to use the original path when the
SGW indicates that the path switch fails. Optionally, when the path
switch fails, the SGW sends, to the MME 200, information indicating
that the path switch fails.
[0069] Optionally, the first indication includes path information,
where the path information includes an identifier of a first path
allocated by the primary base station for the path switch, an
identifier of a second path allocated by a secondary base station
for the path switch, a priority of the first path, and a priority
of the second path, based on the embodiment shown in FIG. 2, the
sending unit 203 is further configured to send the path information
to the SGW such that the SGW switches a path to the first path or
the second path according to a path with a higher priority in the
priority of the first path and the priority of the second path when
the receiving unit 201 receives the first indication.
[0070] It can be seen from the foregoing technical solutions that,
in this embodiment of the present disclosure, when a primary base
station sends a first indication to an MME 200, the MME 200
processes a path switch according to the first indication, and
under instruction of the first indication, keeps a security key
context for the path switch unchanged and indicates the primary
base station to keep the security key context for the path switch
unchanged, or under instruction of the first indication, indicates
the primary base station to acquire a quantity of times of reversal
of an NCC in the security key context such that synchronization of
the security key context can still be ensured in a case in which a
quantity of times of path switches triggered by carrier aggregation
between base stations is excessively large, thereby improving
reliability of a path switch during carrier aggregation between
base stations. Further, this embodiment of the present disclosure
further provides a path switch indication solution such that an
original path is used when the path switch fails or the path switch
is performed in two or more paths according to priorities of the
paths, thereby reducing a possibility of bearer release and UE
detachment that are caused by a path switch failure, and further
improving the reliability of a path switch during the carrier
aggregation between base stations.
[0071] An embodiment of the present disclosure further provides an
MME. Referring to FIG. 3, an MME 300 in this embodiment of the
present disclosure includes a receiving unit 301 configured to
receive a first indication from a primary base station, where the
first indication is used for requesting a path switch from the MME
300 and indicating that the path switch is triggered by carrier
aggregation between base stations, where the base stations include
the primary base station, a path switch unit 302 configured to
process the path switch according to the first indication received
by the receiving unit 301, where for a path switch procedure
executed by the path switch unit 302 under trigger of the first
indication, reference may be made to the description in the switch
procedure shown in FIG. 1B, and details are not described herein
again, and a sending unit 303 configured to send a third indication
to the primary base station under instruction of the first
indication received by the receiving unit 301 such that the primary
base station acquires a quantity of times of reversal of an NCC in
a security key context for the path switch according to the third
indication, where the quantity of times of reversal refers to a
quantity of times that the NCC jumps from a maximum value to a
minimum value.
[0072] Optionally, based on the embodiment shown in FIG. 3, the MME
300 further includes a recording unit (not shown) configured to
record the quantity of times of reversal of the NCC in the security
key context, the sending unit 303 is further configured to add the
quantity, recorded by the recording unit, of times of reversal of
the NCC in the security key context to the third indication.
[0073] In a path switch procedure, an SGW rejects a path switch
request of a bearer according to a path condition and a local
processing policy. Therefore, if the bearer is a default bearer, UE
detachment may be caused, for example, if the bearer is a necessary
bearer for maintaining a PDN connection, the PDN connection is
released such that a UE may be detached.
[0074] Therefore, optionally, based on the embodiment shown in FIG.
3, the sending unit 303 is further configured to send the first
indication to the SGW such that the SGW uses an original path under
instruction of the first indication when the path switch fails, and
the MME 300 further includes an indication unit (not shown)
configured to indicate the primary base station to use the original
path when the SGW indicates that the path switch fails. Optionally,
when the path switch fails, the SGW sends, to the MME 300,
information indicating that the preceding path switch fails.
[0075] Optionally, the first indication includes path information,
where the path information includes an identifier of a first path
allocated by the primary base station for the path switch, an
identifier of a second path allocated by a secondary base station
for the path switch, a priority of the first path, and a priority
of the second path. Based on the embodiment shown in FIG. 3, the
sending unit 303 is further configured to send the path information
to the SGW such that the SGW switches a path to the first path or
the second path according to a path with a higher priority in the
priority of the first path and the priority of the second path when
the receiving unit 301 receives the first indication.
[0076] It can be seen from the foregoing technical solutions that,
in this embodiment of the present disclosure, when a primary base
station sends a first indication to an MME 300, the MME 300
processes a path switch according to the first indication, and
under instruction of the first indication, keeps a security key
context for the path switch unchanged and indicates the primary
base station to keep the security key context for the path switch
unchanged, or under instruction of the first indication, indicates
the primary base station to acquire a quantity of times of reversal
of an NCC in the security key context such that synchronization of
the security key context can still be ensured in a case in which a
quantity of times of path switches triggered by carrier aggregation
between base stations is excessively large, thereby improving
reliability of a path switch during carrier aggregation between
base stations. Further, this embodiment of the present disclosure
further provides a path switch indication solution such that an
original path is used when the path switch fails or the path switch
is performed in two or more paths according to priorities of the
paths, thereby reducing a possibility of bearer release and UE
detachment that are caused by a path switch failure, and further
improving the reliability of a path switch during the carrier
aggregation between base stations.
[0077] An embodiment of the present disclosure provides another
MME. As shown in FIG. 4, an MME 400 in this embodiment of the
present disclosure includes a transceiver apparatus 401 and a
processor 402.
[0078] In some embodiments of the present disclosure, the
transceiver apparatus 401 and the processor 402 may be connected
using a bus or in another manner. As shown in FIG. 4, connection
using a bus is used as an example.
[0079] The processor 402 is configured to process path switch
according to the first indication when the transceiver apparatus
401 receives a first indication from a primary base station, where
for a path switch procedure executed by the processor 402 under
trigger of the first indication, reference may be made to the
description in the switch procedure shown in FIG. 1B, and details
are not described herein again.
[0080] The processor 402 is further configured to control the
transceiver apparatus 401 to send a second indication to the
primary base station and keep a security key context for the path
switch unchanged, where the second indication is used for
indicating the primary base station to keep the security key
context for the path switch unchanged, or control the transceiver
apparatus 401 to send a third indication to the primary base
station such that the primary base station acquires a quantity of
times of reversal of an NCC in the security key context according
to the third indication, where the quantity of times of reversal
refers to a quantity of times that the NCC jumps from a maximum
value to a minimum value.
[0081] If the processor 402 controls the transceiver apparatus 401
to send the second indication to the primary base station and keeps
the security key context unchanged, optionally, the processor 402
adds the security key context to the second indication.
[0082] If the processor 402 controls the transceiver apparatus 401
to send the third indication to the primary base station,
optionally, the processor 402 is further configured to record the
quantity of times of reversal of the NCC in the security key
context, and add the recorded quantity of times of reversal of the
NCC in the security key context to the third indication.
[0083] In an implementation manner, the processor 402 is further
configured to control the transceiver apparatus 401 to send the
first indication to an SGW such that the SGW uses an original path
under instruction of the first indication when the current path
switch fails, and indicate the primary base station to use the
original path when the SGW indicates that the path switch fails.
Optionally, the SGW sends, to the MME 400, information indicating
that the preceding path switch fails when the path switch
fails.
[0084] In another implementation manner, the first indication
includes path information, where the path information includes an
identifier of a first path allocated by the primary base station
for the path switch, an identifier of a second path allocated by a
secondary base station for the path switch, a priority of the first
path, and a priority of the second path. The processor 402 is
further configured to control the transceiver apparatus 401 to send
the path information to the SGW such that the SGW switches a path
to the first path or the second path according to a path with a
higher priority in the priority of the first path and the priority
of the second path.
[0085] It can be seen from the foregoing technical solutions that,
in this embodiment of the present disclosure, when a primary base
station sends a first indication to an MME 400, the MME 400
processes a path switch according to the first indication, and
under instruction of the first indication, keeps a security key
context for the path switch unchanged and indicates the primary
base station to keep the security key context for the path switch
unchanged, or under instruction of the first indication, indicates
the primary base station to acquire a quantity of times of reversal
of an NCC in the security key context such that synchronization of
the security key context can still be ensured in a case in which a
quantity of times of path switches triggered by carrier aggregation
between base stations is excessively large, thereby improving
reliability of a path switch during carrier aggregation between
base stations.
[0086] An embodiment of the present disclosure further provides a
base station. Referring to FIG. 5, a base station 500 in this
embodiment of the present disclosure includes a sending unit 501
configured to send a first indication to an MME such that the MME
processes a path switch according to the first indication, where
the first indication is used for requesting the path switch from
the MME and indicating that the path switch is triggered by carrier
aggregation between base stations, a receiving unit 502 configured
to receive a second indication from the MME, or receive a third
indication from the MME, and a processing unit 503 configured to
keep a security key context for the path switch unchanged according
to the second indication when the receiving unit 502 receives the
second indication from the MME, or configured to acquire a quantity
of times of reversal of an NCC in the security key context
according to the third indication when the receiving unit 502
receives the third indication from the MME, and when a UE needs to
derive a security key, control the sending unit 501 to send the NCC
in the security key context and the quantity of times of reversal
of the NCC to the UE such that the UE derives the security key
according to the NCC in the security key context and the quantity
of times of reversal of the NCC, where the quantity of times of
reversal refers to a quantity of times that the NCC jumps from a
maximum value to a minimum value.
[0087] Optionally, the processing unit 503 is further configured to
record the quantity of times of reversal of the NCC in the security
key context under instruction of the third indication when the
receiving unit 502 receives the third indication from the MME.
[0088] Optionally, the third indication carries the quantity of
times of reversal of the NCC in the security key context, the
processing unit 503 is further configured to acquire the quantity
of times of reversal of the NCC in the security key context from
the third indication when the receiving unit 502 receives the third
indication from the MME.
[0089] In an implementation manner, the first indication is further
used for indicating the MME to instruct an SGW to use an original
path when the path switch fails. The base station 500 in this
embodiment of the present disclosure further includes a path
control unit (not shown) configured to use the original path when
the SGW indicates that the path switch fails, and send a bearer
release message to a secondary base station using the sending unit
501 to indicate the secondary base station to release a bearer for
which the current path switch is performed.
[0090] In another implementation manner, the base station in this
embodiment of the present disclosure further includes an allocating
unit (not shown), an acquiring unit (not shown), and a priority
determining unit (not shown), where the allocating unit is
configured to allocate a first path for the path switch, the
acquiring unit is configured to acquire a second path allocated by
the secondary base station for the path switch, and the priority
determining unit is configured to determine a priority of the first
path and a priority of the second path. The sending unit 501 is
further configured to send path information to the MME, where the
path information includes an identifier of the first path, an
identifier of the second path, the priority of the first path, and
the priority of the second path such that the MME sends the path
information to the SGW, and the SGW switches a path to the first
path or the second path according to a path with a higher
priority.
[0091] It can be seen from the foregoing technical solutions that,
in this embodiment of the present disclosure, when a path switch is
triggered by carrier aggregation between base stations, a base
station 500 sends a first indication to an MME such that the MME
processes the path switch according to the first indication, and
under instruction of the first indication, keeps a security key
context for the path switch unchanged and indicates a primary base
station to keep the security key context for the path switch
unchanged, or under instruction of the first indication, indicates
the primary base station to acquire a quantity of times of reversal
of an NCC in the security key context such that synchronization of
the security key context can still be ensured in a case in which a
quantity of times of path switches triggered by carrier aggregation
between base stations is excessively large, thereby improving
reliability of a path switch during carrier aggregation between
base stations.
[0092] An embodiment of the present disclosure provides another
base station. As shown in FIG. 6, a base station 600 in this
embodiment of the present disclosure includes a transceiver
apparatus 601 and a processor 602.
[0093] In some embodiments of the present disclosure, the
transceiver apparatus 601 and the processor 602 may be connected
using a bus or in another manner. As shown in FIG. 6, connection
using a bus is used as an example.
[0094] The processor 602 is configured to control the transceiver
apparatus 601 to send a first indication to an MME such that the
MME processes a path switch according to the first indication,
where the first indication is used for requesting the path switch
from the MME and indicating that the path switch is triggered by
carrier aggregation between base stations, and when the transceiver
apparatus 601 receives a second indication from the MME, keep a
security key context for the path switch unchanged under
instruction of the second indication, or acquire a quantity of
times of reversal of an NCC in the security key context according
to the third indication when the transceiver apparatus 601 receives
a third indication from the MME, and control the transceiver
apparatus 601 to send the NCC in the security key context and the
quantity of times of reversal of the NCC to the UE such that the UE
derives the security key according to the NCC in the security key
context and the quantity of times of reversal of the NCC when a UE
needs to derive a security key, where the quantity of times of
reversal refers to a quantity of times that the NCC jumps from a
maximum value to a minimum value.
[0095] Optionally, the processor 602 is further configured to
record the quantity of times of reversal of the NCC in the security
key context under instruction of the third indication when the
transceiver apparatus 601 receives the third indication from the
MME.
[0096] Optionally, the third indication carries the quantity of
times of reversal of the NCC in the security key context. The
processor 602 is further configured to acquire the quantity of
times of reversal of the NCC in the security key context from the
third indication when the transceiver apparatus 601 receives the
third indication from the MME.
[0097] In an implementation manner, the first indication is further
used for indicating the MME to instruct an SGW to use an original
path when the path switch fails. The processor 602 is configured to
use the original path when the SGW indicates that the path switch
fails, and control the transceiver apparatus 601 to send a bearer
release message to a secondary base station, to indicate the
secondary base station to release a bearer for which the current
path switch is performed.
[0098] In another implementation manner, the processor 602 is
further configured to allocate a first path for the path switch and
determine a priority of the first path, acquire a second path
allocated by the secondary base station for the path switch and
determine a priority of the second path, and control the
transceiver apparatus 601 to send path information to the MME,
where the path information includes an identifier of the first
path, an identifier of the second path, the priority of the first
path, and the priority of the second path such that the MME sends
the path information to the SGW, and the SGW switches a path to the
first path or the second path according to a path with a higher
priority.
[0099] It can be seen from the foregoing technical solutions that,
in this embodiment of the present disclosure, when a path switch is
triggered by carrier aggregation between base stations, a base
station 600 sends a first indication to an MME such that the MME
processes the path switch according to the first indication, and
under instruction of the first indication, keeps a security key
context for the path switch unchanged and indicates a primary base
station to keep the security key context for the path switch
unchanged, or under instruction of the first indication, indicates
the primary base station to acquire a quantity of times of reversal
of an NCC in the security key context such that synchronization of
the security key context can still be ensured in a case in which a
quantity of times of path switches triggered by carrier aggregation
between base stations is excessively large, thereby improving
reliability of a path switch during carrier aggregation between
base stations.
[0100] An embodiment of the present disclosure provides another
base station. Referring to FIG. 7, a base station 700 in this
embodiment of the present disclosure includes a determining unit
701 configured to confirm that a UE completes RRC configuration
required by carrier aggregation between base stations, a sending
unit 702 configured to send a path switch indication to an MME such
that the MME sends the path switch indication to an SGW when the
determining unit 701 confirms that the UE completes the RRC
configuration required by the carrier aggregation between base
stations, and the SGW uses an original path under instruction of
the path switch indication when a current path switch fails, a
receiving unit 703 configured to receive information that is from
the MME and indicates that the path switch fails, and a path
control unit 704 configured to use the original path when the
receiving unit 703 receives the information that is from the MME
and indicates that the path switch fails, and send a bearer release
message to a secondary base station using the sending unit 702, to
indicate the secondary base station to release a bearer for which
the current path switch is performed.
[0101] It can be seen from the foregoing technical solutions that,
in this embodiment of the present disclosure, a path switch
indication is sent to an SGW such that the SGW uses an original
path under instruction of the path switch indication when a current
path switch fails, thereby preventing a problem of UE detachment
caused by bearer release due to a path switch failure, and
improving reliability of a path switch during carrier aggregation
between base stations.
[0102] An embodiment of the present disclosure provides another
base station. For a structure of the base station in this
embodiment of the present disclosure, reference may be made to FIG.
6. The base station includes a transceiver apparatus and a
processor.
[0103] The processor is configured to control the transceiver
apparatus to send a path switch indication to an MME such that the
MME sends the path switch indication to an SGW when confirming that
a UE completes RRC configuration required by carrier aggregation
between base stations, and the SGW uses an original path under
instruction of the path switch indication when a current path
switch fails, and use the original path when the transceiver
apparatus receives information that is from the MME and indicates
that the current path switch fails, and control the transceiver
apparatus to send a bearer release message to a secondary base
station, to indicate the secondary base station to release a bearer
for which the current path switch is performed.
[0104] It can be seen from the foregoing technical solutions that,
in this embodiment of the present disclosure, a path switch
indication is sent to an SGW such that the SGW can use an original
path under instruction of the path switch indication when a current
path switch fails, thereby ensuring that a UE can still be attached
even though the path switch fails, and improving reliability of a
path switch during carrier aggregation between base stations.
[0105] An embodiment of the present disclosure provides another
base station. Referring to FIG. 8, a base station 800 in this
embodiment of the present disclosure includes an allocating unit
801 configured to allocate a first path for a current path switch,
an acquiring unit 802 configured to acquire a second path allocated
by a secondary base station for the current path switch, a priority
level determining unit 803 configured to determine a priority of
the first path and a priority of the second path, and a sending
unit 804 configured to send path information to an MME, where the
path information includes an identifier of the first path, an
identifier of the second path, the priority of the first path, and
the priority of the second path such that the MME sends the path
information to an SGW, and the SGW switches a path to the first
path or the second path according to a path with a higher
priority.
[0106] It can be seen from the foregoing technical solutions that,
in this embodiment of the present disclosure, path information is
sent to an SGW such that the SGW switches a path to a first path or
a second path according to a path with a higher priority when a
current path switch fails, thereby ensuring that a UE can still be
attached even though the path switch fails, and improving
reliability of a path switch during carrier aggregation between
base stations.
[0107] An embodiment of the present disclosure provides another
base station, including a transceiver apparatus and a processor.
For a schematic structural diagram thereof, reference may be made
to FIG. 6.
[0108] The processor in this embodiment of the present disclosure
is configured to allocate a first path for a current path switch
and determine a priority of the first path, acquire a second path
allocated by a secondary base station for the current path switch
and determine a priority of the second path, and control the
transceiver apparatus to send path information to an MME, where the
path information includes an identifier of the first path, an
identifier of the second path, the priority of the first path, and
the priority of the second path such that the MME sends the path
information to an SGW, and the SGW switches a path to the first
path or the second path according to a path with a higher
priority.
[0109] It can be seen from the foregoing technical solutions that,
in this embodiment of the present disclosure, path information is
sent to an SGW such that the SGW switches a path to a first path or
a second path according to a path with a higher priority when a
current path switch fails, thereby ensuring that a UE can still be
attached even though the path switch fails, and improving
reliability of a path switch during carrier aggregation between
base stations.
[0110] The following describes a method of distributing a security
key context in an embodiment of the present disclosure using an MME
as an execution body. It should be noted that, the MME in this
embodiment of the present disclosure may be the MME in the
foregoing apparatus embodiments, and operations and steps thereof
may be further implemented by functional modules in the foregoing
apparatus embodiments. Referring to FIG. 9, a method of
distributing a security key context in an embodiment of the present
disclosure includes the following steps.
[0111] Step 901: An MME receives a first indication from a primary
base station.
[0112] The first indication is used for requesting a path switch
from the MME and indicating that the path switch is triggered by
carrier aggregation between base stations, where the base stations
include the primary base station.
[0113] In this embodiment of the present disclosure, when the
primary base station decides to perform a path switch for a bearer
and the path switch is triggered by carrier aggregation between
base stations, the primary base station sends the first indication
to the MME.
[0114] Furthermore, in an implementation manner, when the primary
base station decides to hand over a bearer and confirms that a UE
completes RRC configuration required by carrier aggregation between
base stations (for example, receives an RRC connection
reconfiguration complete indication fed back by the UE or receives
an indication that is fed back by a secondary base station and
indicates successful access of the UE), the primary base station
sends a path switch request message to the MME, and adds the first
indication to the path switch request message.
[0115] Alternatively, in another implementation manner, when the
primary base station decides to perform a path switch for a bearer
and the path switch is triggered by carrier aggregation between
base stations, the primary base station sends the first indication
to the MME by defining a new message.
[0116] The manner of sending the first indication is not limited in
this embodiment of the present disclosure.
[0117] Step 902: The MME processes a path switch according to the
first indication.
[0118] After receiving the first indication, the MME executes
corresponding path switch processing under trigger of the first
indication. For a path switch processing procedure, reference may
be made to the description in the switch procedure shown in FIG.
1B, and details are not described herein again.
[0119] Step 903: The MME keeps a security key context for the path
switch unchanged under instruction of the first indication.
[0120] For a path switch procedure after an X2 handover in an LTE
system, an MME needs to update a security key context {NCC, NH}. An
NCC is used for an NH. A security key KeNB used by an eNB and a UE
is derived based on an NH corresponding to an NCC, and is used for
data encryption/decryption and data integrity check. For the sake
of security, the KeNB cannot be directly transferred between the
eNB and the UE, when an X2 handover occurs, the eNB sends the NCC
to the UE, and the UE derives the corresponding KeNB according to
the NH corresponding to the NCC. At present, it is specified in a
protocol that, in a path switch procedure, an MME adds 1 to an NCC
and delivers the NCC and a corresponding NH to an eNB using a path
switch request acknowledge message, for use by the eNB in a next
switch.
[0121] In this embodiment of the present disclosure, the MME keeps
the security key context for the path switch unchanged under
instruction of the first indication. For example, {NCC, NH} is kept
unchanged, that is, the operation of adding 1 is not executed for
the NCC.
[0122] Step 904: The MME sends a second indication to the primary
base station.
[0123] The second indication is used for indicating the primary
base station to keep the security key context for the path switch
unchanged.
[0124] In an implementation manner, when confirming that the path
switch performed according to the first indication succeeds, the
MME sends a path switch request acknowledge message to the primary
base station, and adds the second indication to the path switch
request acknowledge message. After receiving the path switch
request acknowledge message, the primary base station keeps the
security key context unchanged according to the second
indication.
[0125] Alternatively, in another implementation manner, the MME
sends a new message to the primary base station, where the message
carries the security key context. After receiving the new message,
the primary base station keeps the security key context unchanged
according to the second indication.
[0126] Optionally, the MME adds the security key context to the
second indication. After receiving the second indication, the
primary base station stores the security key context carried in the
second indication, and sends an NCC in the security key context to
a UE when the UE needs to derive a KeNB.
[0127] Optionally, because the primary base station has a record
about an original security key context, an implicit indication
manner is used to instruct the primary base station to keep the
original security key context unchanged. That is, it is agreed on
that the primary base station acquires the security key context
according to the second indication sent by the MME, the MME does
not add the security key context to the second indication when the
security key context needs to be kept unchanged, the primary base
station keeps the security key context unchanged when the primary
base station does not detect a security key context in the received
second indication, and sends an NCC in the security key context to
a UE when the UE needs to derive a KeNB.
[0128] In a path switch procedure, an SGW rejects a path switch
request of a bearer according to a path condition and a local
processing policy. Therefore, if the bearer is a default bearer, UE
detachment may be caused, for example, if the bearer is a necessary
bearer for maintaining a PDN connection, the PDN connection is
released such that a UE may be detached. To solve the problem, this
embodiment of the present disclosure provides the following two
path switch indication solutions.
[0129] Solution 1: The SGW is indicated, using the first
indication, to use an original path when the path switch fails,
that is, when or after the MME receives the first indication, the
MME sends the first indication to the SGW such that the SGW uses
the original path under instruction of the first indication when
the path switch fails. When the SGW indicates that the path switch
fails (for example, when the MME receives information that is from
the SGW and indicates that the current path switch fails), the
primary base station is indicated to use the original path.
Certainly, in this solution, the primary base station may also
indicate, using another indication, the SGW to use the original
path when the current path switch fails. For example, the primary
base station may send, to the MME in the path switch procedure,
another indication different from the first indication. After
detecting the other indication, the MME sends the other indication
to the SGW such that the SGW uses the original path under
instruction of the other indication when the path switch fails.
[0130] Solution 2: In the path switch procedure, the primary base
station sends path information to the SGW using the MME, where the
path information includes an identifier of a first path allocated
by the primary base station for the path switch (for example, a
TEID of a downlink GTP tunnel allocated by the primary base station
for the path switch), an identifier of a second path allocated by
the secondary base station for the path switch (for example, a TEID
of a downlink GTP tunnel allocated by the secondary base station
for the path switch), a priority of the first path, and a priority
of the second path such that the SGW switches a path to the first
path or the second path according to a path with a higher priority
in the priority of the first path and the priority of the second
path. Optionally, the priority of the first path and the priority
of the second path are set according to an actual condition or are
set by default, for example, it is set by default that a priority
of a path in a path list is higher than a priority of a path
arranged behind the path. Optionally, the path information is
carried in the first indication, or the primary base station may
send the path information to the MME using another message such
that the MME sends the path information to the SGW, which is not
limited herein.
[0131] Alternatively, optionally, during bearer establishment, the
MME indicates the primary base station not to hand over a default
bearer to the secondary base station. Further, the MME may also
indicate, to the primary base station using an identifier of a
default bearer, a specific default bearer that is not handed over
to the secondary base station. When a bearer for which the current
path switch is performed is the default bearer that is indicated by
the MME and is not handed over to the secondary base station, the
primary base station does not hand over the default bearer to the
secondary base station, thereby preventing a problem of UE
detachment caused by a path switch failure of the default
bearer.
[0132] It can be seen from the foregoing technical solutions that,
in this embodiment of the present disclosure, when a primary base
station sends a first indication to an MME, the MME processes a
path switch according to the first indication, and under
instruction of the first indication, keeps a security key context
for the path switch unchanged and indicates the primary base
station to keep the security key context for the path switch
unchanged such that synchronization of the security key context can
still be ensured in a case in which a quantity of times of path
switches triggered by carrier aggregation between base stations is
excessively large, thereby improving reliability of a path switch
during carrier aggregation between base stations. Further, this
embodiment of the present disclosure further provides a path switch
indication solution such that an original path is used when the
path switch fails or the path switch is performed in two or more
paths according to priorities of the paths, thereby reducing a
possibility of bearer release and UE detachment that are caused by
a path switch failure, and further improving the reliability of a
path switch during the carrier aggregation between base
stations.
[0133] The following describes another method of distributing a
security key context in the present disclosure using an MME as an
execution body. It should be noted that, the MME in this embodiment
of the present disclosure may be the MME in the foregoing apparatus
embodiments, and operations and steps thereof may be further
implemented by functional modules in the foregoing apparatus
embodiments. Referring to FIG. 10, a method of distributing a
security key context in an embodiment of the present disclosure
includes the following steps.
[0134] Step 1001: An MME receives a first indication from a primary
base station.
[0135] The first indication is used for requesting a path switch
from the MME and indicating that the path switch is triggered by
carrier aggregation between base stations.
[0136] In this embodiment of the present disclosure, the primary
base station sends the first indication to the MME when the primary
base station decides to perform a path switch for a bearer and the
path switch is triggered by carrier aggregation between base
stations.
[0137] Further, in an implementation manner, when the primary base
station decides to hand over a bearer and confirms that a UE
completes RRC configuration required by carrier aggregation between
base stations (for example, receives an RRC connection
reconfiguration complete indication fed back by the UE or receives
an indication that is fed back by a secondary base station and
indicates successful access of the UE), the primary base station
sends a path switch request message to the MME, and adds the first
indication to the path switch request message.
[0138] Alternatively, in another implementation manner, when the
primary base station decides to perform a path switch for a bearer
and the path switch is triggered by carrier aggregation between
base stations, the primary base station sends the first indication
to the MME by defining a new message.
[0139] The manner of sending the first indication is not limited in
this embodiment of the present disclosure.
[0140] Step 1002: The MME processes a path switch according to the
first indication.
[0141] After receiving the first indication, the MME executes the
corresponding path switch under trigger of the first indication.
Further, for a path switch procedure, reference may be made to the
description in the switch procedure shown in FIG. 1B, and details
are not described herein again.
[0142] Step 1003: The MME sends a third indication to the primary
base station under instruction of the first indication such that
the primary base station acquires a quantity of times of reversal
of an NCC in a security key context for the path switch according
to the third indication.
[0143] In this embodiment of the present disclosure, the MME
updates the NCC according to an original security key context
processing mechanism, that is, adds 1 to the NCC each time a switch
is performed, and then sends the third indication to the primary
base station such that the primary base station acquires the
quantity of times of reversal of the NCC in the security key
context for the path switch according to the third indication,
where the quantity of times of reversal refers to a quantity of
times that the NCC jumps from a maximum value to a minimum
value.
[0144] Optionally, the MME records the quantity of times of
reversal of the NCC, and adds the quantity of times of reversal of
the NCC to the third indication sent to the primary base station
such that the primary base station acquires the quantity of times
of reversal of the NCC from the third indication.
[0145] Optionally, the third indication is carried in a path switch
request acknowledge message, or the MME may send the third
indication to the primary base station using another new message,
which is not limited herein.
[0146] After the reversal of the NCC, even though a value of the
NCC is the same as that before, an NH corresponding to the NCC is
different. Therefore, in this embodiment of the present disclosure,
when a UE needs to derive a security key (for example, when a
handover occurs on the UE), the primary base station sends a
current NCC and a quantity of times of reversal of the NCC to the
UE such that the UE can determine a corresponding NH according to
the received current NCC and the received quantity of times of
reversal of the NCC, and further derive a security key synchronized
with that of the primary base station.
[0147] Description is provided using an example. As shown in Table
1, an initial value of an NCC is 0, a quantity of times of reversal
is 0, and an NH used by the primary base station is an NH1. The UE
determines, according to the quantity 0 of times of reversal, that
the UE needs to use the security key NH1 too. However, if the
quantity of times of reversal is 1, the primary base station and
the UE need to use a key obtained after reversal, that is, an NH
corresponding to the NCC with the value 0 is an NH9 after the NCC
is reversed once, as shown in the following table.
TABLE-US-00001 TABLE 1 NCC value NH 0 NH1 1 NH2 2 NH3 3 NH4 4 NH5 5
NH6 6 NH7 7 NH8 0 NH9 1 NH10
[0148] In a path switch procedure, an SGW rejects a path switch
request of a bearer according to a path condition and a local
processing policy. Therefore, if the bearer is a default bearer, UE
detachment may be caused, for example, if the bearer is a necessary
bearer for maintaining a PDN connection, the PDN connection is
released such that a UE may be detached. To solve the problem, this
embodiment of the present disclosure provides the following two
path switch indication solutions.
[0149] Solution 1: The SGW is indicated, using the first
indication, to use an original path when the path switch fails,
then, when or after the MME receives the first indication, the MME
sends the first indication to the SGW such that the SGW uses the
original path under instruction of the first indication when the
path switch fails. When the SGW indicates that the path switch
fails (for example, when the MME receives information that is from
the SGW and indicates that the current path switch fails), the
primary base station is indicated to use the original path.
Certainly, in this solution, the primary base station may also
indicate, using another indication, the SGW to use the original
path when the current path switch fails. For example, the primary
base station may send, to the MME in the path switch procedure,
another indication different from the first indication. After
detecting the other indication, the MME sends the other indication
to the SGW such that the SGW uses the original path under
instruction of the other indication when the path switch fails.
[0150] Solution 2: In the path switch procedure, the primary base
station sends path information to the SGW using the MME, where the
path information includes an identifier of a first path allocated
by the primary base station for the path switch (for example, a
TEID of a DL-GTP tunnel allocated by the primary base station for
the path switch), an identifier of a second path allocated by the
secondary base station for the path switch (for example, a TEID of
a DL-GTP tunnel allocated by the secondary base station for the
path switch), a priority of the first path, and a priority of the
second path such that the SGW switches a path to the first path or
the second path according to a path with a higher priority in the
priority of the first path and the priority of the second path.
Optionally, the priority of the first path and the priority of the
second path are set according to an actual condition or are set by
default, for example, it is set by default that a priority of a
path in a path list is higher than a priority of a path arranged
behind the path. Optionally, the path information is carried in the
first indication, or the primary base station may send the path
information to the MME using another message such that the MME
sends the path information to the SGW, which is not limited
herein.
[0151] Alternatively, optionally, during bearer establishment, the
MME indicates the primary base station not to hand over a default
bearer to the secondary base station. Further, the MME may also
indicate, to the primary base station using an identifier of a
default bearer, a specific default bearer that is not handed over
to the secondary base station. When a bearer for which the current
path switch is performed is the default bearer that is indicated by
the MME and is not handed over to the secondary base station, the
primary base station does not hand over the default bearer to the
secondary base station, thereby preventing a problem of UE
detachment caused by a path switch failure of the default
bearer.
[0152] It can be seen from the foregoing technical solutions that,
in this embodiment of the present disclosure, when a primary base
station sends a first indication to an MME, the MME processes a
path switch according to the first indication, and under
instruction of the first indication, indicates the primary base
station to acquire a quantity of times of reversal of an NCC in a
security key context such that synchronization of the security key
context can still be ensured by acquiring an accurate NH using the
quantity of times of reversal of the NCC in a case in which a
quantity of times of path switches triggered by carrier aggregation
between base stations is excessively large, thereby improving
reliability of a path switch during carrier aggregation between
base stations. Further, this embodiment of the present disclosure
further provides a path switch indication solution such that an
original path is used when the path switch fails or the path switch
is performed in two or more paths according to priorities of the
paths, thereby reducing a possibility of bearer release and UE
detachment that are caused by a path switch failure, and further
improving the reliability of a path switch during the carrier
aggregation between base stations.
[0153] The following describes a method of distributing a security
key context in the present disclosure using a primary base station
as an execution body. It should be noted that, the primary base
station in this embodiment of the present disclosure may be the
base station in the foregoing apparatus embodiments, and operations
and steps thereof may be further implemented by functional modules
in the foregoing apparatus embodiments. Referring to FIG. 11, a
method of distributing a security key context in an embodiment of
the present disclosure includes the following steps.
[0154] Step 1101: A primary base station sends a first indication
to an MME.
[0155] The first indication is used for requesting a path switch
from the MME and indicating that the path switch is triggered by
carrier aggregation between base stations such that the MME
processes the path switch according to the first indication.
[0156] Furthermore, in an implementation manner, when the primary
base station decides to hand over a bearer and confirms that a UE
completes RRC configuration required by carrier aggregation between
base stations (for example, receives an RRC connection
reconfiguration complete indication fed back by the UE or receives
an indication that is fed back by a secondary base station and
indicates successful access of the UE), the primary base station
sends a path switch request message to the MME, and adds the first
indication to the path switch request message.
[0157] Alternatively, in another implementation manner, when the
primary base station decides to perform a path switch for a bearer
and the path switch is triggered by carrier aggregation between
base stations, the primary base station sends the first indication
to the MME by defining a new message.
[0158] The manner of sending the first indication is not limited in
this embodiment of the present disclosure.
[0159] After receiving the first indication, the MME executes the
corresponding path switch under trigger of the first indication.
Further, for a path switch procedure, reference may be made to the
description in the switch procedure shown in FIG. 1B, and details
are not described herein again.
[0160] Step 1102: The primary base station receives a second
indication from the MME, and keeps a security key context for a
path switch unchanged according to the second indication.
[0161] In this embodiment of the present disclosure, the second
indication is carried in a path switch request acknowledge message
responding to a path switch request message, or the second
indication may be carried in a new message, which is not limited
herein.
[0162] Optionally, the second indication carries the security key
context. After receiving the second indication, the primary base
station stores the security key context carried in the second
indication, and sends an NCC in the security key context to a UE
when the UE needs to derive a KeNB.
[0163] Optionally, because the primary base station has a record
about an original security key context, an implicit indication
manner is used to instruct the primary base station to keep the
security key context unchanged. That is, it is agreed on that the
primary base station acquires the security key context according to
the second indication sent by the MME. When the security key
context needs to be kept unchanged, the MME does not add the
security key context to the second indication. When the primary
base station does not detect a security key context in the received
second indication, the primary base station keeps the security key
context unchanged, and sends an NCC in the security key context to
a UE when determining that the UE needs to derive a KeNB.
[0164] In a path switch procedure, an SGW rejects a path switch
request of a bearer according to a path condition and a local
processing policy. Therefore, if the bearer is a default bearer, UE
detachment may be caused, for example, if the bearer is a necessary
bearer for maintaining a PDN connection, the PDN connection is
released such that a UE may be detached. To solve the problem, this
embodiment of the present disclosure provides the following two
path switch indication solutions.
[0165] Solution 1: The SGW is indicated, using the first
indication, to use an original path when the current path switch
fails. Then, the MME sends the first indication to the SGW such
that the SGW uses the original path under instruction of the first
indication when the current path switch fails when or after the MME
receives the first indication. When the MME receives information
that is from the SGW and indicates that the current path switch
fails, the MME sends, to the primary base station, the information
indicating that the current path switch fails such that the primary
base station uses the original path, and sends a bearer release
message to the secondary base station, to indicate the secondary
base station to release a bearer for which the current path switch
is performed. Certainly, in this solution, the primary base station
may also indicate, using another indication, the SGW to use the
original path when the current path switch fails. For example, the
primary base station may send, to the MME in the path switch
procedure, another indication different from the first indication.
After detecting the other indication, the MME sends the other
indication to the SGW such that the SGW uses the original path
under instruction of the other indication when the current path
switch fails.
[0166] Solution 2: The primary base station allocates a first path
for the current path switch and determines a priority of the first
path, acquires a second path allocated by the secondary base
station for the current path switch and determines a priority of
the second path, and sends path information to the SGW using the
MME, where the path information includes an identifier of the first
path (for example, a TEID of a downlink GTP tunnel allocated by the
primary base station for the current path switch), an identifier of
the second path (for example, a TEID of a downlink GTP tunnel
allocated by the secondary base station for the current path
switch), the priority of the first path, and the priority of the
second path such that the SGW performs the path switch according to
a path with a higher priority in the priority of the first path and
the priority of the second path, and performs the path switch
according to a path with a lower priority when the path switch
performed according to the path with the higher priority fails.
Optionally, the priority of the first path and the priority of the
second path are set according to an actual condition or are set by
default, for example, it is set by default that a priority of a
path in a path list is higher than a priority of a path arranged
behind the path. Optionally, the path information is carried in the
first indication, or the primary base station may send the path
information to the MME using another message such that the MME
sends the path information to the SGW, which is not limited
herein.
[0167] Alternatively, optionally, during bearer establishment, the
MME indicates the primary base station not to hand over a default
bearer to the secondary base station. Further, the MME may also
indicate, to the primary base station using an identifier of a
default bearer, a specific default bearer that is not handed over
to the secondary base station. When a bearer for which the current
path switch is performed is the default bearer that is indicated by
the MME and is not handed over to the secondary base station, the
primary base station does not hand over the default bearer to the
secondary base station, thereby preventing a problem of UE
detachment caused by a path switch failure of the default
bearer.
[0168] It can be seen from the foregoing technical solutions that,
in this embodiment of the present disclosure, when a path switch is
triggered by carrier aggregation between base stations, a primary
base station sends a first indication to an MME such that the MME
processes the path switch according to the first indication, and
under instruction of the first indication, keeps a security key
context for the path switch unchanged and indicates the primary
base station to keep the security key context unchanged such that
synchronization of the security key context can still be ensured in
a case in which a quantity of times of path switches triggered by
carrier aggregation between base stations is excessively large,
thereby improving reliability of a path switch during carrier
aggregation between base stations. Further, this embodiment of the
present disclosure further provides a path switch indication
solution such that an original path is used when the path switch
fails or the path switch is performed in two or more paths
according to priorities of the paths, thereby reducing a
possibility of bearer release and UE detachment that are caused by
a path switch failure, and further improving the reliability of a
path switch during the carrier aggregation between base
stations.
[0169] The following describes a method of distributing a security
key context in the present disclosure using a primary base station
as an execution body. It should be noted that, the primary base
station in this embodiment of the present disclosure may be the
base station in the foregoing apparatus embodiments, and operations
and steps thereof may be further implemented by functional modules
in the foregoing apparatus embodiments. Referring to FIG. 12, a
method of distributing a security key context in an embodiment of
the present disclosure includes the following steps.
[0170] Step 1201: A primary base station sends a first indication
to an MME.
[0171] The first indication is used for requesting a path switch
from the MME and indicating that the path switch is triggered by
carrier aggregation between base stations such that the MME
processes the path switch according to the first indication.
[0172] Further, in an implementation manner, when the primary base
station decides to hand over a bearer and confirms that a UE
completes RRC configuration required by carrier aggregation between
base stations (for example, receives an RRC connection
reconfiguration complete indication fed back by the UE or receives
an indication that is fed back by a secondary base station and
indicates successful access of the UE), the primary base station
sends a path switch request message to the MME, and adds the first
indication to the path switch request message.
[0173] Alternatively, in another implementation manner, when the
primary base station decides to perform a path switch for a bearer
and the path switch is triggered by carrier aggregation between
base stations, the primary base station sends the first indication
to the MME by defining a new message.
[0174] The manner of sending the first indication is not limited in
this embodiment of the present disclosure.
[0175] After receiving the first indication, the MME executes the
corresponding path switch under trigger of the first indication.
Further, for a path switch procedure, reference may be made to the
description in the switch procedure shown in FIG. 1B, and details
are not described herein again.
[0176] Step 1202: The primary base station receives a third
indication from the MME, and acquires a quantity of times of
reversal of an NCC in a security key context for a path switch
according to the third indication.
[0177] In this embodiment of the present disclosure, the quantity
of times of reversal refers to a quantity of times that the NCC
jumps from a maximum value to a minimum value.
[0178] Optionally, the MME records the quantity of times of
reversal of the NCC, and adds the quantity of times of reversal of
the NCC to the third indication sent to the primary base station
such that the primary base station acquires the quantity of times
of reversal of the NCC from the third indication.
[0179] Optionally, the primary base station records the quantity of
times of reversal of the NCC in the security key context under
instruction of the third indication.
[0180] In this embodiment of the present disclosure, the third
indication is carried in a path switch request acknowledge message
responding to a path switch request message, or the third
indication may be carried in a new message, which is not limited
herein.
[0181] Step 1203: When a UE needs to derive a security key, send
the NCC in the security key context and the quantity of times of
reversal of the NCC to the UE such that the UE derives the security
key according to the current NCC and the quantity of times of
reversal of the NCC.
[0182] The UE is a UE served by the primary base station.
[0183] In a path switch procedure, an SGW rejects a path switch
request of a bearer according to a path condition and a local
processing policy. Therefore, if the bearer is a default bearer, UE
detachment may be caused, for example, if the bearer is a necessary
bearer for maintaining a PDN connection, the PDN connection is
released such that a UE may be detached. To solve the problem, this
embodiment of the present disclosure further provides the following
two path switch indication solutions.
[0184] Solution 1: The SGW is indicated, using the first
indication, to use an original path when the path switch fails.
Then, the MME sends the first indication to the SGW such that the
SGW uses the original path under instruction of the first
indication when the path switch fails when or after the MME
receives the first indication. When the SGW indicates that the path
switch fails (for example, when the MME receives information that
is from the SGW and indicates that the current path switch fails),
the primary base station is indicated to use the original path.
Certainly, in this solution, the primary base station may also
indicate, using another indication, the SGW to use the original
path when the current path switch fails. For example, the primary
base station may send, to the MME in the path switch procedure,
another indication different from the first indication. After
detecting the other indication, the MME sends the other indication
to the SGW such that the SGW uses the original path under
instruction of the other indication when the path switch fails.
[0185] Solution 2: In the path switch procedure, the primary base
station sends path information to the SGW using the MME, where the
path information includes an identifier of a first path allocated
by the primary base station for the path switch (for example, a
TEID of a DL-GTP tunnel allocated by the primary base station for
the path switch), an identifier of a second path allocated by the
secondary base station for the path switch (for example, a TEID of
a DL-GTP tunnel allocated by the secondary base station for the
path switch), a priority of the first path, and a priority of the
second path such that the SGW switches a path to the first path or
the second path according to a path with a higher priority in the
priority of the first path and the priority of the second path.
Optionally, the priority of the first path and the priority of the
second path are set according to an actual condition or are set by
default, for example, it is set by default that a priority of a
path in a path list is higher than a priority of a path arranged
behind the path. Optionally, the path information is carried in the
first indication, or the primary base station may send the path
information to the MME using another message such that the MME
sends the path information to the SGW, which is not limited
herein.
[0186] Alternatively, optionally, during bearer establishment, the
MME indicates the primary base station not to hand over a default
bearer to the secondary base station. Further, the MME may also
indicate, to the primary base station using an identifier of a
default bearer, a specific default bearer that is not handed over
to the secondary base station. When a bearer for which the current
path switch is performed is the default bearer that is indicated by
the MME and is not handed over to the secondary base station, the
primary base station does not hand over the default bearer to the
secondary base station, thereby preventing a problem of UE
detachment caused by a path switch failure of the default
bearer.
[0187] It can be seen from the foregoing technical solutions that,
in this embodiment of the present disclosure, when a path switch is
triggered by carrier aggregation between base stations, a primary
base station sends a first indication to an MME such that under
instruction of the first indication, the MME processes the path
switch, and indicates the primary base station to acquire a
quantity of times of reversal of an NCC in a security key context
such that synchronization of the security key context can still be
ensured by acquiring an accurate NH using the quantity of times of
reversal of the NCC in a case in which a quantity of times of path
switches triggered by carrier aggregation between base stations is
excessively large, thereby improving reliability of a path switch
during carrier aggregation between base stations. This embodiment
of the present disclosure further provides a path switch indication
solution, which is used to effectively prevent a problem of UE
detachment caused by bearer release due to a path switch failure,
and further improving the reliability of a path switch during the
carrier aggregation between base stations.
[0188] The following describes a path switch indication method in
an embodiment of the present disclosure using a primary base
station as an execution body. It should be noted that, the primary
base station in this embodiment of the present disclosure may be
the base station in the foregoing apparatus embodiments, and
operations and steps thereof may be further implemented by
functional modules in the foregoing apparatus embodiments.
Referring to FIG. 13, the method includes the following steps.
[0189] Step 1301: A primary base station sends a path switch
indication to an SGW through an MME.
[0190] The path switch indication is used for indicating the SGW to
use an original path when a current path switch fails.
[0191] In this embodiment of the present disclosure, when deciding
to offload data, for example, deciding, according to a measurement
report and a load condition to hand over a bearer to a secondary
base station, the primary base station sends a bearer establishment
request message to the secondary base station. If allowing bearer
establishment, the secondary base station allocates a DL-GTP tunnel
for the bearer, and sends DL-GTP information of the DL-GTP tunnel
to the primary base station using a bearer establishment response
message. After receiving the bearer establishment response message,
the primary base station sends the path switch indication to the
MME such that the MME forwards the path switch indication to the
SGW.
[0192] Optionally, after receiving the bearer establishment
response message, the primary base station sends a path switch
request message to the MME, and adds the path switch indication to
the path switch request message.
[0193] Step 1302: When a current path switch fails, the SGW uses an
original path, and sends information indicating that the current
path switch fails to the primary base station through the MME.
[0194] Further, the primary base station sends a bearer release
message to the secondary base station to request the secondary base
station to release the bearer for which the current switch
fails.
[0195] It can be seen from the foregoing technical solutions that,
in this embodiment of the present disclosure, a path switch
indication is sent to an SGW such that the SGW uses an original
path under instruction of the path switch indication when a current
path switch fails, thereby preventing a problem of UE detachment
caused by bearer release due to a path switch failure, and
improving reliability of a path switch during carrier aggregation
between base stations.
[0196] The following describes another path switch indication
method in an embodiment of the present disclosure using a primary
base station as an execution body. It should be noted that, the
primary base station in this embodiment of the present disclosure
may be the base station in the foregoing apparatus embodiments, and
operations and steps thereof may be further implemented by
functional modules in the foregoing apparatus embodiments.
Referring to FIG. 14, the method includes the following steps.
[0197] Step 1401: A primary base station sends path information to
an SGW through an MME.
[0198] The path information includes an identifier of a first path
allocated by the primary base station for a current path switch
(for example, a TEID of a downlink GTP tunnel allocated by the
primary base station for the current path switch), an identifier of
a second path allocated by a secondary base station for the current
path switch (for example, a TEID of a DL-GTP tunnel allocated by
the secondary base station for the current path switch), a priority
of the first path, and a priority of the second path.
[0199] In this embodiment of the present disclosure, when deciding
to offload data, for example, deciding, according to a measurement
report and a load condition, to hand over a bearer to the secondary
base station, the primary base station sends a bearer establishment
request message to the secondary base station. If allowing bearer
establishment, the secondary base station allocates a DL-GTP tunnel
(that is, the second path) for the bearer, and sends DL-GTP
information of the downlink GTP tunnel to the primary base station
using a bearer establishment response message. After receiving the
bearer establishment response message, the primary base station
allocates a DL-GTP tunnel (that is, the first path) for the bearer,
and sends the path information to the MME such that the MME
forwards the path information to the SGW. Optionally, the priority
of the first path and the priority of the second path in the path
information are set according to an actual condition or are set by
default, for example, it is set by default that a priority of a
path in a path list is higher than a priority of a path arranged
behind the path.
[0200] Step 1402: The SGW switches a path to a first path or a
second path according to a path with a higher priority.
[0201] Step 1403: When the path switch succeeds, the SGW sends a
switch success indication to the primary base station through the
MME.
[0202] The switch success indication carries information about a
path used when the current path switch succeeds.
[0203] Step 1404: The primary base station performs a corresponding
operation according to the switch success indication.
[0204] If the switch success indication indicates that the path
used when the current path switch succeeds is the first path
allocated by the primary base station, the primary base station
triggers the secondary base station to release bearer information
related to the current path switch such that the bearer is
maintained on the primary base station. If the switch success
indication indicates that the path used when the current path
switch succeeds is the second path allocated by the secondary base
station, the primary base station sends, to the secondary base
station, UL-GTP information allocated by the SGW such that the
bearer is handed over to the secondary base station.
[0205] It can be seen from the foregoing technical solutions that,
in this embodiment of the present disclosure, path information is
sent to an SGW such that the SGW performs a path switch according
to a path with a higher priority in path priorities in the path
information when a current path switch fails, and performs the path
switch according to a path with a lower priority when the path
switch performed according to the path with the higher priority
fails, thereby preventing a problem of UE detachment caused by
bearer release due to a path switch failure, and improving
reliability of a path switch during carrier aggregation between
base stations.
[0206] An embodiment of the present disclosure further provides a
computer storage medium, where the computer storage medium stores a
program, and the program performs some or all of the steps recorded
in the foregoing method embodiments.
[0207] In the several embodiments provided in the present
application, it should be understood that the disclosed apparatus
and method may be implemented in other manners. For example, the
described apparatus embodiment is merely exemplary. For example,
the unit division is merely logical function division and may be
other division in actual implementation. For example, a plurality
of units or components may be combined or integrated into another
system, or some features may be ignored or not performed. In
addition, the displayed or discussed mutual couplings or direct
couplings or communication connections may be implemented through
some interfaces. The indirect couplings or communication
connections between the apparatuses or units may be implemented in
electronic, mechanical, or other forms.
[0208] The units described as separate parts may or may not be
physically separate, and parts displayed as units may or may not be
physical units, may be located in one position, or may be
distributed on a plurality of network units. Some or all of the
units may be selected according to actual needs to achieve the
objectives of the solutions of the embodiments.
[0209] In addition, functional units in the embodiments of the
present disclosure may be integrated into one processing unit, or
each of the units may exist alone physically, or two or more units
are integrated into one unit. The integrated unit may be
implemented in a form of hardware, or may be implemented in a form
of a software functional unit.
[0210] When the integrated unit is implemented in the form of a
software functional unit and sold or used as an independent
product, the integrated unit may be stored in a computer-readable
storage medium. Based on such an understanding, the technical
solutions of the present disclosure essentially, or the part
contributing to other approaches, or all or some of the technical
solutions may be implemented in the form of a software product. The
software product is stored in a storage medium and includes several
instructions for instructing a computer device (which may be a
personal computer, a server, or a network device) to perform all or
some of the steps of the methods described in the embodiments of
the present disclosure. The foregoing storage medium includes any
medium that can store program code, such as a universal serial bus
(USB) flash drive, a removable hard disk, a read-only memory (ROM),
a random access memory (RAM), a magnetic disk, or an optical
disc.
[0211] The method of distributing a security key context, the path
switch indication method, the MME, and the base station provided by
the present disclosure are described above in detail. A person of
ordinary skill in the art may, based on the idea of the present
disclosure, make modifications with respect to the specific
implementation manners and the application scope. Therefore, the
content of this specification shall not be construed as a
limitation to the present disclosure.
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