U.S. patent application number 17/736092 was filed with the patent office on 2022-08-18 for wireless communication method and wireless communication device.
This patent application is currently assigned to Sony Group Corporation. The applicant listed for this patent is Sony Group Corporation. Invention is credited to Mengying SUN, Xiaodong XU, Shiqing ZHANG, Wenbo ZHANG.
Application Number | 20220264691 17/736092 |
Document ID | / |
Family ID | 1000006305882 |
Filed Date | 2022-08-18 |
United States Patent
Application |
20220264691 |
Kind Code |
A1 |
XU; Xiaodong ; et
al. |
August 18, 2022 |
WIRELESS COMMUNICATION METHOD AND WIRELESS COMMUNICATION DEVICE
Abstract
Disclosed in the present invention are a wireless communication
method and a wireless communication device. An electronic device in
communication with a counterpart communication device comprises a
processing circuit, the processing circuit being configured to:
determine the state of a link between the electronic device and the
counterpart communication device by means of measuring a link
maintenance message transmitted by the counterpart communication
device when a predetermined condition relative to the counterpart
communication device is met, but not to transmit a feedback message
for the link maintenance message, wherein the link maintenance
message is used for confirming that the link is maintained between
the electronic device and the counterpart communication device.
Inventors: |
XU; Xiaodong; (Beijing,
CN) ; SUN; Mengying; (Beijing, CN) ; ZHANG;
Shiqing; (Beijing, CN) ; ZHANG; Wenbo;
(Beijing, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Sony Group Corporation |
Tokyo |
|
JP |
|
|
Assignee: |
Sony Group Corporation
Tokyo
JP
|
Family ID: |
1000006305882 |
Appl. No.: |
17/736092 |
Filed: |
May 4, 2022 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
16634583 |
Jan 28, 2020 |
11357069 |
|
|
PCT/CN2018/103738 |
Sep 3, 2018 |
|
|
|
17736092 |
|
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 24/08 20130101;
H04W 76/25 20180201; H04W 76/30 20180201 |
International
Class: |
H04W 76/25 20060101
H04W076/25; H04W 76/30 20060101 H04W076/30; H04W 24/08 20060101
H04W024/08 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 8, 2017 |
CN |
201710805480.2 |
Claims
1. An electronic device at a user equipment side, comprising
circuitry configured to: perform groupcast communication with a
plurality of counterpart communication devices including a first
counterpart communication device and a second counterpart
communication device; not expect to receive, from the first
counterpart communication device, a feedback on a message sent from
the electronic device to the plurality of counterpart communication
devices; and expect to receive, from the second counterpart
communication device, a feedback on the message sent from the
electronic device to the plurality of counterpart communication
devices.
2. The electronic device according to claim 1, wherein the first
counterpart communication device satisfies a predetermined
condition while the second counterpart communication device doesn't
satisfy the predetermined condition.
3. The electronic device according to claim 1, wherein the
circuitry is configured to generate an indication of expectation on
the feedback of the message.
4. The electronic device according to claim 3, wherein the feedback
of the message is an ACK signal if a link between the electronic
device and a counterpart communication device is well
maintained.
5. The electronic device according to claim 1, wherein the
electronic device is implemented as the user equipment.
6. The electronic device according to claim 5, wherein the
plurality of counterpart communication devices are implemented as
user equipment.
7. The electronic device according to claim 6, wherein the
electronic device is a relay user equipment, and the plurality of
counterpart communication devices are remote user equipment.
8. An electronic device at a user equipment side, comprising
circuitry configured to: receive a groupcast message from a
counterpart user equipment; not transmit a feedback on the
groupcast message to the counterpart user equipment if a
predetermined condition between the counterpart user equipment and
the electronic device is satisfied; transmit a feedback on the
groupcast message to the counterpart user equipment if a
predetermined condition between the counterpart user equipment and
the electronic device is not satisfied.
9. The electronic device according to claim 8, wherein the
circuitry is configured to receive an indication of expectation on
the feedback of the message from the counterpart user
equipment.
10. The electronic device according to claim 9, wherein the
feedback of the message is an ACK signal if a link between the
electronic device and the counterpart user equipment is well
maintained.
11. The electronic device according to claim 8, wherein the
electronic device is implemented as the user equipment.
12. The electronic device according to claim 11, wherein the
electronic device is a remote user equipment, and the counterpart
user equipment is a relay remote user equipment.
13. A method performed by an electronic device at a user equipment
side, comprising: performing groupcast communication with a
plurality of counterpart communication devices including a first
counterpart communication device and a second counterpart
communication device; not expecting to receive, from the first
counterpart communication device, a feedback on a message sent from
the electronic device to the plurality of counterpart communication
devices; and expecting to receive, from the second counterpart
communication device, a feedback on the message sent from the
electronic device to the plurality of counterpart communication
devices.
14. A non-transitory, computer-readable medium storing instructions
that, when executed by a computing device at a user equipment side,
control the computing device to: perform groupcast communication
with a plurality of counterpart communication devices including a
first counterpart communication device and a second counterpart
communication device; not expect to receive, from the first
counterpart communication device, a feedback on a message sent from
the electronic device to the plurality of counterpart communication
devices; and expect to receive, from the second counterpart
communication device, a feedback on the message sent from the
electronic device to the plurality of counterpart communication
devices.
15. A method performed by an electronic device at a user equipment
side, comprising: receiving a groupcast message from a counterpart
user equipment; not transmitting a feedback on the groupcast
message to the counterpart user equipment if a predetermined
condition between the counterpart user equipment and the electronic
device is satisfied; transmitting a feedback on the groupcast
message to the counterpart user equipment if a predetermined
condition between the counterpart user equipment and the electronic
device is not satisfied.
16. A non-transitory, computer-readable medium storing instructions
that, when executed by a computing device at a user equipment side,
control the computing device to: receive a groupcast message from a
counterpart user equipment; not transmit a feedback on the
groupcast message to the counterpart user equipment if a
predetermined condition between the counterpart user equipment and
the electronic device is satisfied; transmit a feedback on the
groupcast message to the counterpart user equipment if a
predetermined condition between the counterpart user equipment and
the electronic device is not satisfied.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S.
application Ser. No. 16/634,583, filed Jan. 28, 2020, which is
based on PCT filing PCT/CN2018/103738, filed Sep. 3, 2018, which
claims priority to CN 201710805480.2, filed Sep. 8, 2017, the
entire contents of each are incorporated herein by reference.
FIELD
[0002] The present disclosure relates to a wireless communication
method and a wireless communication device, and in particular, to a
method for maintaining a link between a relay device and a remote
device and the relevant relay device and remote device.
BACKGROUND
[0003] In recent years, machine-type communication (MTC) devices,
which have low power consumption and low processing capabilities,
are widely used in wireless communication networks. The MTC devices
typically include narrow-band Internet of Things (NB-IoT) devices
and wearable devices, such as smart watch, smart glasses, wireless
point-of-sale (POS) machine and smart meter. The MTC device
generally accesses a network via a relay device. For example, the
relay device may be implemented by a mobile terminal and the MTC
device may be connected with a base station via the mobile
terminal. A link between the MTC device and the relay device is
referred to as a sidelink. The MTC device and the relay device
determine the presence of the sidelink and a state of the sidelink
by periodically transmitting signaling to each other, which is
referred to as link maintenance. the purpose of the link
maintenance is to enable the MTC device and the relay device to
grasp the state of the sidelink and to ensure continuity of
service. Hereinafter, the MTC device is referred to as a remote
device and the sidelink is simply referred to as a link.
[0004] FIG. 1 exemplarily shows a signaling flow of the
conventional link maintenance. As shown in FIG. 1, in step S100, a
device 100 (which may be any one of the remote device and the relay
device) initiating a link maintenance process transmits a link
maintenance message to a counterpart device 200. The counterpart
device 200 measures the received link maintenance message to
determine a state of a link, and in step S200, the counterpart
device 200 transmits an acknowledgement signal ACK to the device
100. The devices 100 and 200 perform link maintenance by repeatedly
performing steps S100 and S200.
[0005] In the flow shown in FIG. 1, a large amount of signaling
overheads and energy consumption are inevitably generated due to
the periodic bidirectional signaling interaction between the remote
device and the relay device, which becomes more prominent in the
case that one relay device are connected with multiple remote
devices at the same time. Furthermore, the bidirectional link
maintenance shown in FIG. 1 is only applicable in a bidirectional
relay mode where the remote device and the relay device may
transmit and receive messages to and from each other. The
bidirectional link maintenance is not applicable in a
unidirectional relay mode. In the unidirectional relay mode, the
relay device can receive a message from the remote device while the
remote device cannot receive a message from the relay device.
Therefore, step S200 shown in FIG. 1 cannot be performed in the
unidirectional relay mode.
SUMMARY
[0006] In view of above, a scheme for implementing link maintenance
between a remote device and a relay device is provided according to
the present disclosure, with which one or more problems described
above may be solved.
[0007] According to an aspect of the present disclosure, an
electronic device performing communication with a counterpart
communication device is provided. The electronic device includes a
processing circuit configured to: when the electronic device and
the counterpart communication device satisfy a predetermined
condition, determine a state of a link between the electronic
device and the counterpart communication device by measuring a link
maintenance message transmitted by the counterpart communication
device, without transmitting a feedback message in response to the
link maintenance message, wherein the link maintenance message is
used for confirmation on link maintenance between the electronic
device and the counterpart communication device.
[0008] According to another aspect of the present disclosure, an
electronic device performing communication with a counterpart
communication device is provided. The electronic device includes a
processing circuit configured to: when the electronic device and
the counterpart communication device satisfy a predetermined
condition, measure a link maintenance message transmitted by the
counterpart communication device, without transmitting a feedback
message in response to the link maintenance message; and notify a
base station of a measurement result, wherein the link maintenance
message is used for confirmation on link maintenance between the
electronic device and the counterpart communication device.
[0009] According to another aspect of the present disclosure, an
electronic device performing communication with a counterpart
communication device is provided. The electronic device includes a
processing circuit configured to: determine a state of a link
between the electronic device and the counterpart communication
device by measuring a link maintenance message transmitted by the
counterpart communication device, wherein the link maintenance
message is used for confirmation on link maintenance between the
electronic device and the counterpart communication device; and
determine, based on the state of the link, a timing at which the
counterpart communication device transmits a next link maintenance
message.
[0010] According to another aspect of the present disclosure, an
electronic device performing communication with a counterpart
communication device is provided. The electronic includes a
processing circuit configured to: determine a state of a link
between the electronic device and the counterpart communication
device by measuring a link maintenance message transmitted by the
counterpart communication device, wherein the link maintenance
message is used for confirmation on link maintenance between the
electronic device and the counterpart communication device;
determine, based on the state of the link, a timing at which the
counterpart communication device transmits a next link maintenance
message; and notify a base station of the determined timing.
[0011] According to another aspect of the present disclosure, an
electronic device performing communication with a counterpart
communication device is provided. The electronic device includes a
processing circuit configured to: measure a link maintenance
message transmitted by the counterpart communication device,
wherein the link maintenance message is used for confirmation on
link maintenance between the electronic device and the counterpart
communication device; notify a base station of a measurement
result; and receive a next link maintenance message from the
counterpart communication device according to a timing notified by
the base station, wherein the timing is determined by the base
station based on the measurement result.
[0012] According to another aspect of the present disclosure, an
electronic device performing communication with multiple
communication devices is provided. The multiple communication
devices are divided into one or more groups. The electronic device
includes a processing circuit configured to: determine, for each
group, a primary communication device of the group; measure a link
maintenance message transmitted by the primary communication device
of each group; and generate a first feedback message based on a
measurement result, which message is to be fed back to each
communication device in the group.
[0013] According to another aspect of the present disclosure, an
electronic device performing communication with multiple
communication devices is provided. The multiple communication
devices are divided into one or more groups, the electronic device
includes a processing circuit configured to: determine, for each
group, a primary communication device of the group; measure a link
maintenance message transmitted by the primary communication device
of each group; and generate a first feedback message for the group
based on a measurement result, which message is to be transmitted
to a base station, wherein the base station transmits the first
feedback message to each communication device in the group.
[0014] According to another aspect of the present disclosure, an
electronic device performing communication with multiple
communication devices is provided. The electronic device includes a
processing circuit configured to: based on grouping information
acquired from a base station, group multiple communication devices
and determine a primary communication device for each group,
wherein the base station generates the grouping information based
on positions of multiple communication devices; measure a link
maintenance message transmitted by the primary communication device
of each group; and transmit a measurement result to the base
station.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The present disclosure may be better understood with
reference to the description given hereinafter in conjunction with
the drawings. The same or similar reference numbers are used to
represent the same or similar components throughout the drawings.
The drawings together with the following detailed description are
included in the specification and form a part of the specification,
and are used to illustrate embodiments of the present disclosure
and explain the principle and advantages of the present disclosure.
In the drawings:
[0016] FIG. 1 schematically shows a signaling flow of the
conventional link maintenance;
[0017] FIG. 2A schematically shows an architecture of a
communication system in a bidirectional relay mode;
[0018] FIG. 2B shows a signaling flow of link maintenance according
to a first embodiment of the present disclosure;
[0019] FIG. 3A schematically shows an architecture of a
communication system in a unidirectional relay mode;
[0020] FIG. 3B shows a first signaling flow of link maintenance
according to a second embodiment of the present disclosure;
[0021] FIG. 3C shows a second signaling flow of link maintenance
according to the second embodiment of the present disclosure;
[0022] FIG. 4A shows a first signaling flow of link maintenance
according to a third embodiment of the present disclosure;
[0023] FIG. 4B shows a second signaling flow of link maintenance
according to the third embodiment of the present disclosure;
[0024] FIG. 4C show a third signaling flow of link maintenance
according to the third embodiment of the present disclosure;
[0025] FIG. 4D shows a fourth signaling flow of link maintenance
according to the third embodiment of the present disclosure;
[0026] FIG. 5A shows a first signaling flow of link maintenance
according to a fourth embodiment of the present disclosure;
[0027] FIG. 5B shows a second signaling flow of link maintenance
according to the fourth embodiment of the present disclosure;
[0028] FIG. 5C shows a third signaling flow of link maintenance
according to the fourth embodiment of the present disclosure;
[0029] FIG. 6A schematically shows an architecture of a
communication system to which a fifth embodiment of the present
disclosure is applicable;
[0030] FIG. 6B shows a first signaling flow of link maintenance
according to the fifth embodiment of the present disclosure;
[0031] FIG. 6C shows a second signaling flow of link maintenance
according to the fifth embodiment of the present disclosure;
[0032] FIG. 6D shows a third signaling flow of link maintenance
according to the fifth embodiment of the present disclosure;
[0033] FIG. 6E shows a fourth signaling flow of link maintenance
according to the fifth embodiment of the present disclosure;
[0034] FIG. 7A schematically shows an architecture of a
communication system to which a sixth embodiment according to the
present disclosure is applicable;
[0035] FIG. 7B shows a first signaling flow of link maintenance
according to the sixth embodiment of the present disclosure;
[0036] FIG. 7C shows a second signaling flow of link maintenance
according to the sixth embodiment of the present disclosure;
[0037] FIG. 8A shows a first signaling flow of link maintenance
according to a seventh embodiment of the present disclosure;
[0038] FIG. 8B shows a second signaling flow of link maintenance
according to the seventh embodiment of the present disclosure;
[0039] FIG. 9A shows a first signaling flow of link maintenance
according to an eighth embodiment of the present disclosure;
[0040] FIG. 9B shows a second signaling flow of link maintenance
according to the eighth embodiment of the present disclosure;
[0041] FIG. 10 shows a signaling flow of link maintenance according
to a ninth embodiment of the present disclosure;
[0042] FIG. 11A shows a first signaling flow of link release
according to a tenth embodiment of the present disclosure;
[0043] FIG. 11B shows a second signaling flow of link release
according to the tenth embodiment of the present disclosure;
[0044] FIG. 11C shows a third signaling flow of link release
according to the tenth embodiment of the present disclosure;
[0045] FIG. 12 shows a block diagram of a schematic configuration
of a smart phone as an example of a relay device or a remote
device;
[0046] FIG. 13 shows a block diagram of a schematic configuration
of an eNB as an example of a base station; and
[0047] FIG. 14 shows a block diagram of a schematic configuration
of computer hardware.
DETAILED DESCRIPTION OF EMBODIMENTS
[0048] Firstly, a first embodiment of the present disclosure is
described with reference to FIG. 2A and FIG. 2B. FIG. 2A
schematically shows an architecture of a communication system in a
bidirectional relay mode. As shown in FIG. 2A, a base station 200
communicates with two relay devices 210 respectively, and each of
the relay devices 210 communicates with a corresponding remote
device 220, such that the remote device 220 can access a network
via the relay device 210. Messages are transmitted between the
relay device 210 and the remote device 220 in a bidirectional
manner.
[0049] FIG. 2B shows a signaling flow of link maintenance according
to the first embodiment of the present disclosure. In the
embodiment, if the relay device 210 and the remote device 220
satisfy at least one of the following conditions: the relay device
210 and the remote device 220 have a mutual trust relationship, and
a connection between the relay device 210 and the remote device 220
has been maintained for a long time period, the device that
receives a link maintenance message may not transmit an
acknowledgement message to the counterpart device.
[0050] Herein, in the case that a connection is established between
the relay device 210 and the remote device 220, the relay device
210 may request the network side to establish a trust relationship
between the relay device 210 and the remote device 220, and the
trust relationship between the relay device 210 and the remote
device 220 may be stored in an entity at the network side, for
example, in a Mobility Management Entity (MME). Furthermore, a
long-time connection means the duration of the connection between
the relay device 210 and the remote device 220 exceeds a
predetermined time period.
[0051] Satisfying one of the above conditions generally means that
there is a stable connection between the relay device 210 and the
remote device 220, and in this case, the signaling interaction may
be omitted. Therefore, as shown in FIG. 2B, in the embodiment, the
relay device 210 transmits a link maintenance message to the remote
device 220 in step S210, and the remote device 220 measures the
received link maintenance message in step S220 to determine a state
of the link. Specifically, the remote device 220 does not feedback
an acknowledgement message to the relay device 210. After a
predetermined time period elapses, the relay device 210 transmits
the next link maintenance message to the remote device 220. The
relay device 210 and the remote device 220 perform link maintenance
by repeatedly performing steps S210 and S220.
[0052] In the embodiment, signaling overheads and energy
consumption may be efficiently reduced by omitting transmission of
the acknowledgement message. In the case that multiple remote
devices 220 are connected to the same relay device 210, this
advantage is more significant.
[0053] In another aspect, in the case that the relay device 210 and
the remote device 220 do not satisfy the above conditions, the
transmission of the acknowledgement message cannot be omitted.
Therefore, three manners for determining whether to omit the
acknowledgement message are provided according to the present
disclosure.
[0054] In a first manner, a link maintenance message transmitted by
the relay device 210 includes an indicator that indicates whether
an acknowledgement message needs to be transmitted, for example,
the link maintenance message includes a field for indicating
whether an acknowledgement message needs to be transmitted. In the
case that the relay device 210 determines that one of the above
conditions is satisfied, the field is set to be a value indicating
that no acknowledgement message needs to be transmitted. Otherwise,
in the case that the relay device 210 determines that none of the
above conditions is satisfied, the field is set to be a value
indicating that an acknowledgement message needs to be
transmitted.
[0055] In a second manner, the relay device 210 and the remote
device 220 each determine whether one of the above conditions is
satisfied. In the case that one of the above conditions is
satisfied, the remote device 220 does not feedback an
acknowledgement message after receiving the link maintenance
message.
[0056] In a third manner, trust relationship and connection state
between the relay device 210 and the remote device 220 are stored
in an entity at the network side. In the case of determining that
one of the above conditions is satisfied, the entity at the network
side instructs, via a base station, the relay device 210 and the
remote device 220 to perform a process in which the acknowledgement
message is omitted.
[0057] A second embodiment according to the present disclosure is
described below in conjunction with FIG. 3A to FIG. 3C. FIG. 3A
schematically shows an architecture of a communication system in a
unidirectional relay mode. As shown in FIG. 3A, a base station 300
communicates with a relay device 310, and the relay device 310
performs unidirectional communication with a remote device 320.
That is, the relay device 310 can receive a message from the remote
device 320, and the remote device 320 cannot receive a message from
the relay device 310. Therefore, the relay device 310 needs to
transmit a message that is to be transmitted to the remote device,
to the base station 300, and then the base station 300 transmits
the message to the remote device 320.
[0058] Similar to the first embodiment, in the second embodiment,
in the case that the relay device 310 and the remote device 320
satisfy one of the above conditions, the transmission of an
acknowledgement message in response to the link maintenance message
may be omitted. Furthermore, in the embodiment, three manners as
described above may be employed to determine whether to perform a
process in which the acknowledgement message is omitted.
[0059] FIG. 3B shows a first signaling flow of link maintenance
according to the second embodiment of the present disclosure. As
shown in FIG. 3B, in step S3101, the remote device 320 transmits a
link maintenance message to the relay device 310. The relay device
310 measures the received link maintenance message and determines a
state of link based on the measurement result. Then, the relay
device 310 transmits the determined link state information to the
base station 300 in step S3201, and the base station 300 transmits
the link state information to the remote device 320 in step S3301,
so that the remote device 320 may be aware of the state of the
link.
[0060] FIG. 3C shows a second signaling flow of link maintenance
according to the second embodiment of the present disclosure. As
shown in FIG. 3C, in step S3102, the remote device 320 transmits a
link maintenance message to the relay device 310. The relay device
310 measures the received link maintenance message and transmits
the measurement result to the base station 300 in step S3202. The
base station 300 determines a state of a link between the relay
device 310 and the remote device 320 based on the received
measurement result, and notifies the remote device 320 of the
determined state of the link in step S3302.
[0061] A third embodiment according to the present disclosure is
described below in conjunction with FIG. 4A to FIG. 4D. Unlike the
first embodiment and the second embodiment, a process in which an
acknowledgement message is omitted is not employed in the third
embodiment. The third embodiment is applicable to the architecture
of the communication system shown in FIG. 2A, that is, a
bidirectional communication may be performed between the relay
device and the remote device.
[0062] FIG. 4A shows a first signaling flow of link maintenance
according to the third embodiment of the present disclosure. As
shown in FIG. 4A, in step S4101, a relay device 410 transmits a
link maintenance message to a remote device 420. The remote device
420 determines a state of link by measuring the received link
maintenance message, and determines a timing at which the relay
device 410 transmits the next link maintenance message based on the
state of link determined currently and the historical states of the
link determined previously, as shown in step S4201.
[0063] Specifically, the remote device 420 measures the received
link maintenance message and determines a level of the state of
link by comparing the measurement result (for example, the
receiving power) and a predetermined threshold. The following Table
1 shows an example of determination of the level of the state of
link
TABLE-US-00001 TABLE 1 level of the state of link condition level 1
measurement result > threshold 2 level 2 threshold 2 >
measurement result > threshold 1
[0064] In Table 1, the threshold 2 is greater than the threshold 1.
In the case that the measurement result is less than the threshold
1, the link is unavailable. In the case that the measurement result
is greater than the threshold 2, the level of the state of link is
level 1. In the case that the measurement result is greater than
the threshold 1 and less than the threshold 2, the level of the
state of link is level 2.
[0065] The remote device 420 may determine a timing for
transmitting the next link maintenance message based on the level
of the state of link determined currently and the level of the
state of link determined previously. The level of the state of link
determined previously is determined by the remote device 420 by
measuring the link maintenance message which was received
previously. Table 2 shows an example of determination of timing. In
Table 2, the remote device 420 determines a timing for transmitting
the next link maintenance message based on the levels of the state
of link determined for the last four times.
TABLE-US-00002 TABLE 2 level level level measured measured measured
level measured multiple of for the for the for the currently (for
minimum (t-3)th time (t-2)th time (t-1)th time the t-th time) time
unit any any any level 2 1 any any level 2 level 1 2 any level 2
level 1 level 1 4 level 2 level 1 level 1 level 1 8 level 1 level 1
level 1 level 1 16
[0066] In Table 2, the timing for transmitting the next link
maintenance message is defined by a multiple of the minimum time
unit (e.g., 1, 2, 4, etc.). For example, as shown in the first row
of the table, regardless of the levels of the state of link
determined for the last three times, the next link maintenance
message is transmitted when one minimum time unit elapses as long
as the level of the state of link determined currently is level 2.
For example, as shown in the fourth row of the table, in the case
that the level of the state of link is determined to be level 1 for
all of the last four times, the next link maintenance message is
transmitted when 16 minimum time units elapse.
[0067] It is to be noted that, Table 1 and Table 2 only show
examples of determination of the level of the state of link and
determination of transmission timing. It is easy for those skilled
in the art to design different schemes according to actual
requirement.
[0068] After determining a timing for transmitting the next link
maintenance message, the remote device 420 includes the determined
timing in an acknowledgement message to transmit to the relay
device 410 in step S4301. Then, in step S4401, the remote device
420 and the relay device 410 start a timer, an expiration time of
which corresponds to the timing determined by the remote device 420
to transmit the next link maintenance message. It is to be noted
that, the time taken for signal transmission from the remote device
420 to the relay device 410 is short with respect to the duration
of the timer, and therefore the time taken for signal transmission
may be ignored. It may be considered that the remote device 420 and
the relay device 410 start the timer at the same time.
[0069] During the timer is started, the relay device 410 does not
transmit a link maintenance message, and the remote device 420 also
does not monitor the link maintenance message. When the timer
expires, the relay device 410 transmits the next link maintenance
message in step S4501. Then, steps S4201 to S4401 are repeated.
[0070] FIG. 4B shows a second signaling flow of link maintenance
according to the third embodiment of the present disclosure. In the
embodiment, the relay device 410 and the remote device 420 store in
advance the same table for determining transmission of the timing,
such as Table 1 and Table 2 described above. As shown in FIG. 4B,
in step S4102, the relay device 410 transmits a link maintenance
message to the remote device 420. The remote device 420 determines
a state of a link by measuring the received link maintenance
message and determines, based on the state of link determined
currently and historical states of the link determined previously,
a timing at which the relay device 410 transmits the next link
maintenance message, as shown in step S4202. Steps S4102 and S4202
are the same as steps S4101 and S4202 shown in FIG. 4A and the
description thereof is omitted here.
[0071] In step S4302, the remote device 420 transmits an
acknowledgement message to the relay device 410 in response to the
link maintenance message, and the acknowledgement message does not
include the timing determined by the remote device 420. In step
S4502, the remote device 420 starts a timer, an expiration time of
which corresponds to the determined timing.
[0072] In step S4402, the relay device 410 measures the received
acknowledgement message, determines the current level of the state
of link, and determines a timing for transmitting the next link
maintenance message based on the level of the state of link
determined currently and the levels of the historical state of link
determined based on the acknowledgement message received
previously. Since the relay device 410 and the remote device 420
use the same table, it may be considered that the same timing is
determined by the relay device 410 and the timing determined by the
remote device 420. Then, in step S4502, the relay device 410 starts
the timer corresponding to the determined timing. Since the time
taken for information processing by the relay device 410 and the
remote device 420 and the time taken for signal transmission of the
relay device 410 and the remote device 420 are short with respect
to the duration of the timer, the time taken for information
processing and the time taken for signal transmission may be
ignored. It may be considered that the relay device 410 and the
remote device 420 start the timer at the same time.
[0073] When the timer expires, in step S4602, the relay device 410
transmits a next link maintenance message to the remote device 420.
Then, steps S4202 to 54502 are repeated.
[0074] FIG. 4C shows a third signaling flow of link maintenance
according to the third embodiment of the present disclosure. As
shown in FIG. 4C, in step S4103, the remote device 420 transmits a
link maintenance message to the relay device 410. The relay device
410 determines a level of a state of link by measuring the received
link maintenance message, and determines a timing at which the
remote device 420 transmits the next link maintenance message based
on the level of the state of link determined currently and the
levels of the historical states of link determined previously, as
shown in step S4203. The manner for determining the timing is the
same as that descried in conjunction with FIG. 4A, and therefore is
omitted here.
[0075] Then, in step S4303, the relay device 410 includes the
determined timing in an acknowledgement message to transmit to the
remote device 420. In step S4403, the remote device 420 and the
relay device 410 start a timer (the time taken for signal
transmission may be ignored), an expiration time of which
corresponds to the timing determined by the relay device 410 to
transmit the next link maintenance message.
[0076] During the timer is started, the remote device 420 does not
transmit a link maintenance message, and the relay device 410 also
does not monitor the link maintenance message. When the timer
expires, the remote device 420 transmits the next link maintenance
message, as shown in step S4503. Then, steps S4203 to S4403 are
repeated.
[0077] FIG. 4D shows a fourth signaling flow of link maintenance
according to the third embodiment of the present disclosure. In the
embodiment, the relay device 410 and the remote device 420 store in
advance the same table for determining the transmission of the
timing, such as Table 1 and Table 2 described above. As shown in
FIG. 4D, in step S4104, the remote device 420 transmits a link
maintenance message to the relay device 410. The relay device 410
determines a level of a state of link by measuring the received
link maintenance message, and determines a timing at which the
remote device 420 transmits the next link maintenance message based
on the level of the state of link determined currently and the
levels of the historical states of link, as shown in step
S4204.
[0078] Then, in step S4304, the relay device 410 transmits an
acknowledgement message to the remote device 420. The
acknowledgement message does not include the timing determined by
the relay device 410. In step S4504, the relay device 410 starts a
timer, an expiration time of which corresponds to the determined
timing .
[0079] In another aspect, the remote device 420 determines a level
of a state of link by measuring the received acknowledgement
message, and determines a timing for transmitting the next link
maintenance message based on the level of the state of link
determined currently and the levels of the historical states of
link, as shown in step S4404. The levels of the historical states
of link are determined based on the acknowledgement message
received previously. Since the relay device 410 and the remote
device 420 use the same tables, it may be considered that the same
timing is determined by the relay device 410 and the remote device
420. Then, in step S4504, the remote device 420 starts a timer
corresponding to the determined timing. As described above, the
time taken for information processing by the relay device 410 and
the remote device 420 and the time taken for signal transmission
between the relay device 410 and the remote device 420 may be
ignored. Therefore, it may be considered that the relay device 410
and the remote device 420 start a timer at the same time in step
S4504.
[0080] When the timer expires, the remote device 420 transmits the
next link maintenance message to the relay device 410, as shown in
step S4604. Then, steps S4204 to 54504 are repeated.
[0081] According to the present embodiment, the remote device 420
may flexibly configure, based on the measured state of the link,
the time at which the relay device 410 transmits the next link
maintenance message. If the state of link is good, the timing for
transmitting the next link maintenance message may be postponed,
such that the frequency of signaling interaction can be reduced,
thereby reducing signaling overheads. Otherwise, if the state of
link is not good, the time for transmitting the next link
maintenance message may be advanced.
[0082] A fourth embodiment according to the present disclosure is
described below in conjunction with FIG. 5A to FIG. 5C. The fourth
embodiment is applicable to the architecture of the communication
system shown in FIG. 3A, that is, a unidirectional communication
may be performed between the relay device and the remote
device.
[0083] FIG. 5A shows a first signaling flow of link maintenance
according to the fourth embodiment of the present disclosure. As
shown in FIG. 5A, in step S5101, a remote device 520 transmits a
link maintenance message to a relay device 510. In step S5201, the
relay device 510 determines a level of a state of link by measuring
the received link maintenance message, and determines a timing at
which the remote device 520 transmits the next link maintenance
message based on the level of the state of link determined
currently and the levels of the historical states of link. The
manner for determining the timing is the same as that descried in
conjunction with FIG. 4A in the third embodiment (for example,
based on Table 1 and Table 2), and therefore is omitted here.
[0084] Then, in step S5301, the relay device 510 starts a timer
which is corresponding to the determined timing. In step S5401, the
relay device 510 transmits the determined timing to a base station
500. In step S5501, the base station 500 notifies the remote device
520 of the timing. In step S5601, the remote device 520 starts a
timer which is corresponding to the received timing. As described
above, the time taken for signal transmission between the device
and the base station may be ignored. Therefore, it may be
considered that the relay device 510 starts a timer in step S301
and the remote device 520 starts a timer in step S5601
substantially at the same time.
[0085] During the timer is started, the remote device 520 does not
transmit a link maintenance message, and the relay device 510 also
does not monitor a link maintenance message. When the timer
expires, the remote device 520 transmits the next link maintenance
message to the relay device 510, as shown in step S5701. Then,
steps S5201 to S5701 are repeated.
[0086] In the embodiment, since a unidirectional relay mode is
employed, the relay device 510 cannot directly notify the remote
device 520 of the timing determined by the relay device 510.
Therefore, it is required to notify, via the base station 500, the
remote device 520 of the timing determined by the relay device 510
to transmit the next link maintenance message.
[0087] FIG. 5B shows a second signaling flow of link maintenance
according to a fourth embodiment of the present disclosure. As
shown in FIG. 5B, in step S5102, the remote device 520 transmits a
link maintenance message to the relay device 510. The relay device
510 measures the received link maintenance message in step S5202,
and transmits the measurement result to the base station 500 in
step S5302.
[0088] In step S402, the base station 500 determines a level of a
state of link based on the received measurement result, and
determines a timing at which the remote device 520 transmits the
next link maintenance message based on the level of the state of
link determined currently and the levels of the historical states
of link determined previously in the same manner. The manner that
the base station 500 determines the timing is the same as that
descried in conjunction with FIG. 4A in the third embodiment, and
therefore is omitted here.
[0089] Then, in step S5502, the base station 500 notifies the relay
device 510 and the remote device 520 of the determined timing.
Then, in step S5602, the relay device 510 and the remote device 520
start a timer at the same time, an expiration time of which
corresponds to the timing notified by the base station 500.
[0090] When the timer expires, the remote device 520 transmits the
next link maintenance message to the relay device 510, as shown in
step S5702. Then, steps S5202 to S5702 may be repeated.
[0091] FIG. 5C shows a third signaling flow of link maintenance
according to the fourth embodiment of the present disclosure. In
the embodiment, the relay device 510 and the remote device 520
store in advance the same tables for determining the timing for
transmitting the link maintenance message, such as Table 1 and
Table 2 as described above.
[0092] As shown in FIG. 5C, in step S5103, the remote device 520
transmits a link maintenance message to the relay device 510. In
step S5203, the relay device 510 measures the received link
maintenance message. Then, the relay device 510 determines a timing
for transmitting the next link maintenance message by referring to
Table 1 and Table 2 based on the measurement result, and the relay
device 510 starts a timer corresponding to the determined timing,
as shown in step S5303. Furthermore, in step S5403, the relay
device 510 transmits the measurement result to the base station
500. It is to be noted that step S5403 and step S5303 may be
performed simultaneously.
[0093] Then, in step S5503, the base station 500 transmits the
measurement result to the remote device 520. The remote device 520
determines a timing for transmitting the next link maintenance
message (which is the same as the timing determined by the relay
device 510) by referring to the same tables based on the received
measurement result, and starts a timer corresponding to the
determined timing, as shown in step S5603. As described above, the
time taken for signal transmission between the devices is short
with respect to the duration of the timer, and therefore the time
taken for signal transmission may be ignored. In this case, it may
be considered that the remote device 520 and the relay device 510
start the timer at the same time.
[0094] When the timer expires, the remote device 520 transmits the
next link maintenance message to the relay device 510, as shown in
step S5703. Then, steps S5203 to 55703 may be repeated.
[0095] A fifth embodiment according to the present disclosure is
described below in conjunction with FIG. 6A to FIG. 6E. FIG. 6A
schematically shows an architecture of a communication system to
which a fifth embodiment is applicable. In the communication
system, a bidirectional relay mode is employed.
[0096] As shown in FIG. 6A, a base station 600 communicates with a
relay device 610, and the relay device 610 performs a bidirectional
communication with multiple remote devices 621 to 627. In this
case, for the relay device 610, one-to-one link maintenance process
between the relay device and remote devices requires a large amount
of signaling overheads and energy consumption. In view of the
problem, a scheme is provided according to a fifth embodiment of
the present disclosure, in which the multiple remote devices are
grouped into groups and a primary device is selected for each
group. Besides, the primary device performs link maintenance with
the relay device 610 on behalf of the group.
[0097] For example, in FIG. 6A, remote devices 621, 622, and 623
are grouped into one group, which are encircled by a dotted line
circle, and the remote device 621 serves as a primary device for
the group. It is to be noted that, although one group is
schematically shown in FIG. 6A, remote devices 621 to 627 may
further include the other groups.
[0098] In the embodiment, the relay device 610 may group remote
devices into groups. Specifically, before grouping, the relay
device 610 receives a link maintenance message from each of remote
devices, and the relay device 610 measures the received link
maintenance messages. Therefore, the relay device 610 may group the
remote devices based on measurement results (such as the receiving
power). For example, multiple remote devices for which the
measurement results are within the same range are grouped into one
group. As a simple example, the remote devices for which
measurement results are greater than a specific threshold are
grouped into one group, and the remote devices for which
measurement results are less than a specific threshold are grouped
into another group. However, the number of groups is not limited to
two and there may be more groups. In addition to performing
grouping based on measurement results, the relay device 610 may
group the remote devices which satisfy one of the following
conditions into one group: the relay device 610 and the remote
device have a mutual trust relationship, and a connection between
the relay device 610 and the remote device has been maintained for
a long time period. Hereinafter, a link maintenance process in the
case that the relay device determines the grouping is described in
conjunction with FIG. 6B and FIG. 6C.
[0099] Instead of performing grouping by the relay device 610,
remote devices may be grouped by the base station or an entity at a
network side. In the case that the base station performs grouping,
the relay device 610 and the multiple remote device 621 to 627
periodically report their own position information to the base
station. Therefore, the base station may group remote devices close
to each other into one group based on the obtained position
information and notifies the relay device 610 of the grouping
information. In the case that the received position information is
changed, the base station may perform grouping again and notifies
the relay device 610 of the updated grouping information. The case
where the grouping is performed by the entity at the network side
(such as MME) is similar to the case where the grouping is
performed by the base station as described above, except that the
MME needs to obtain the position information from the relay device
and the remote devices via the base station and transmit the
grouping information to the relay device via the base station.
Hereinafter, a link maintenance process in the case that the base
station performs grouping is described in conjunction with FIG. 6D
and FIG. 6E.
[0100] After remote devices are grouped, a primary device for each
group may be determined in one of the following manners.
[0101] the primary device is determined based on a power level or
energy consumption for each of remote devices in the group. For
example, the relay device 610 may request each of remote devices to
report its power information and then select a remote device having
a higher power level as the primary device;
[0102] the primary device is selected in a predetermined order in
the group. That is, each remote device in the group alternately
serves as the primary device to perform link maintenance on behalf
of the group; and [0103] a remote device in the group is randomly
selected as the primary device.
[0104] FIG. 6B shows a first signaling flow of link maintenance
according to a fifth embodiment of the present disclosure. As shown
in FIG. 6B, the relay device 610 performs one-to-one link
maintenance with each of remote devices 621, 622 and 623 in initial
phase. In step S6101, the relay device 610 measures a link
maintenance message from each of remote devices and groups the
remote devices based on measurement results, and determines a
primary device for each group. For conciseness, it is assumed that
the remote devices 621, 622 and 623 are grouped into one group and
the remote device 621 is determined as a primary device of the
group.
[0105] Then, in step S6201, the relay device 610 transmits the
grouping information to remote devices 621, 622 and 623. The
grouping information may include, for example, an identification
(ID) of each remote device in the group, an ID of the primary
device, and a range of measurement results corresponding to the
group. The remote devices 621, 622, and 623 may determine which
group they belong to and which remote device serves as the primary
device, based on the received grouping information.
[0106] Then, in step S6301, the remote device 621 serving as the
primary device transmits a link maintenance message to the relay
device 610, and the other remote devices in the group do not
transmit the link maintenance message.
[0107] In step S6401, the relay device 610 measures the link
maintenance message from the primary device 621. In step S6501, the
relay device 610 transmits an acknowledgement message in response
to the link maintenance message to each remote device in the group,
that is, the remote devices 621, 622, and 623.
[0108] In this manner, the primary device 621 performs a link
maintenance process with the relay device 610 on behalf of a group
of remote devices, such that energy consumption of the relay device
610 and signaling overheads can be reduced.
[0109] Furthermore, in step S6401, the relay device 610 may also
re-determine a primary device for the group. As an example, the
relay device 610 may determine, based on the measurement result for
the link maintenance message from the primary device 621, whether
the measurement result is within a range of measurement results
corresponding to the group (for example, as described above, the
measurement results are greater than a specific threshold or less
than a specific threshold). If the measurement result is within the
range, the primary device is not changed. Otherwise, if the
measurement result is not within the range, it is required to
perform grouping again and determine a primary device. As another
example, in the case that a primary device is selected in a
predetermined order, the relay device 610 may select, in a
predetermined order, another remote device in the group, for
example the remote device 622, as a primary device.
[0110] In the case that the primary device is changed, the relay
device 610 may include an ID of the new primary device in an
acknowledgement message to transmit to each remote device in step
S6501. Then, as shown in FIG. 6B, the new primary device 622
transmits the next link maintenance message to the relay device 610
in step S6601, and other remote devices does not transmit the link
maintenance message. Then, steps S6401 to S6501 may be repeated.
Specifically, in the case that the primary device is selected in a
predetermined order as described above, the relay device 610 may
receive the link maintenance message from each remote device,
thereby determining the state of link between the relay device 610
and each remote device.
[0111] FIG. 6C shows a second signaling flow of link maintenance
according to the fifth embodiment of present disclosure. As shown
in FIG. 6C, the relay device 610 performs one-to-one link
maintenance with each of remote devices 621, 622 and 623 in initial
phase. In step S6102, the relay device 610 measures a link
maintenance message from each of the remote devices and groups the
remote devices based on measurement results and determines a
primary device for each group. Similar to FIG. 6B, it is still
assumed that the remote devices 621, 622 and 623 are grouped into
one group, and the remote device 621 is determined as the primary
device for the group.
[0112] In step S6202, the relay device 610 transmits the grouping
information to the remote devices 621, 622 and 623. The grouping
information may include, for example, an ID of each remote device
in the group, an ID of the primary device, and a range of
measurement results corresponding to the group. Then, the primary
device 621 transmits a link maintenance message to the relay device
610 in step S6302.
[0113] In this case, if the remote device 622 determines, after
measuring the grouping information from the relay device 610, that
the measurement result is not within a range of measurement results
corresponding to the group as indicated by the grouping
information, the remote device 622 may also transmits a link
maintenance message to the relay device 610 in step S6402.
[0114] In step S6502, the relay device 610 measures the link
maintenance message from the primary device 621 and the link
maintenance message from the remote device 622. In the case that
the measurement result for the remote device 622 is not within a
range of measurement results corresponding to the group, the relay
device 610 performs grouping again and determines a primary device
for each group.
[0115] Then, in step S6602, the relay device 610 transmits an
acknowledgement message in response to the link maintenance message
to the remote devices 621, 622 and 623. In step S6702, the relay
device 610 transmits the updated grouping information to the remote
devices 621, 622 and 623. Then, the primary device indicated by the
updated grouping information transmits the next link maintenance
message.
[0116] FIG. 6D shows a third signaling flow of link maintenance
according to the fifth embodiment of the present disclosure. As
shown in FIG. 6D, the relay device 610 performs one-to-one link
maintenance with each of the remote devices 621, 622 and 623 in
initial phase. In another aspect, in step S6103, the base station
600 groups remote devices close to each other into one group based
on the position information reported by each of remote devices and
transmits the grouping information to the relay device 610 in step
S6203.
[0117] The relay device 610 may determine the grouping case for the
remote devices 621, 622 and 623 based on the received grouping
information. For the sake of conciseness, it is still assumed that
the remote devices 621, 622 and 623 are grouped into one group.
Furthermore, in step S6303, the relay device 610 determines a
primary device for the group in the manner described above, and it
is assumed that the remote device 621 is determined as a primary
device. Then, the relay device 610 transmits the grouping
information to each of the remote devices 621, 622 and 623 in step
S6403. The grouping information may include an ID of each remote
device in the group and an ID of the primary device.
[0118] The remote devices receiving the grouping information may
determine which group they belong to and which remote device serves
as the primary device for the group. In this case, the remote
device 621 serving as the primary device may transmits a link
maintenance message to the relay device 610 in step S6503, and
other remote devices do not transmit the link maintenance
message.
[0119] In step S6603, the relay device 610 measures the received
link maintenance message, and the relay device 610 may determine
whether it is required to perform grouping again or change the
primary device based on the measurement result, or may select
another remote device in the group as a primary device in a
predetermined order, as described with reference to FIG. 6B. Then,
in step S6703, the relay device 610 transmits an acknowledgement
message in response to the link maintenance message from the remote
device 621, to each of the remote devices in the group.
Specifically, in the case that the primary device is changed, the
relay device 610 may also include an ID of the new primary device
in the acknowledgement message to transmit to each of the remote
devices.
[0120] In addition, since the remote devices and the relay device
periodically report their position information to the base station
600, in the case that positions of the remote devices and the relay
device are changed, the base station 600 may perform regrouping
based on the changed positions and transmits the updated grouping
information to the relay device 610, as shown in steps S6803 to
56903. Then, the relay device 610 may perform step S6303 again
based on the received updated grouping information. It is to be
noted that, although FIG. 6D shows that steps S6803 to 56903 are
performed after step S6703, the performing order is not limited
thereto. The operation that the base station 600 updates and
transmits the grouping information may be performed at any time
between step S6203 and step S6703 shown in FIG. 6D.
[0121] FIG. 6E shows a fourth signaling flow of link maintenance
according to the fifth embodiment of the present disclosure. As
shown in FIG. 6E, the relay device 610 performs one-to-one link
maintenance with each of the remote devices 621, 622 and 623 in
initial phase. In another aspect, the base station 600 groups
remote devices close to each other into one group based on the
position information reported by each of remote devices in step
S6104 and transmits the grouping information to the relay device
610 in step S6204.
[0122] The relay device 610 determines the grouping case for the
remote devices 621, 622 and 623 based on the received grouping
information. It is still assumed that the remote devices 621, 622
and 623 are grouped into one group. Furthermore, in step S6304, the
relay device 610 determines a primary device for the group, and it
is assumed that the remote device 621 is determined as the primary
device. Then, in step S6404, the relay device 610 transmits the
grouping information to each of the remote devices 621, 622 and
623. The grouping information may include an ID of each remote
device in the group and an ID of the primary device.
[0123] Then, in step S6504, the remote device 621 serving as the
primary device transmits a link maintenance message to the relay
device 610. If the remote device 622 determines, after measuring
the grouping information from the relay device 610, that the
measurement result is lower than a specific threshold, the remote
device 622 may also transmits a link maintenance message to the
relay device 610, as shown in step S6504'.
[0124] In step S6604, the relay device 610 measures the link
maintenance message from the primary device 621 and the link
maintenance message from the remote device 622. In the case that
the measurement result for the remote device 622 is lower than a
specific threshold, the relay device 610 removes the remote device
622 from the group and then performs one-to-one link maintenance
with the remote device 622. Since the measurement result below the
specific threshold means that a state of the link between the relay
device 610 and the remote device 622 has got worse, one-to-one link
maintenance would be helpful for the relay device 610 to timely
determine the state of link or detect the disconnection of the
link.
[0125] In the case that the remote device 622 is removed from the
group, the relay device 610 transmits an acknowledgement message in
response to the link maintenance message from the primary device
621, only to the remote devices 621 and 623 in step S6704, while
the acknowledgement message is no longer transmitted to the remote
device 622.
[0126] Furthermore, similar to the example shown in FIG. 6D, in
steps S6804 and S6904, the base station 600 may perform grouping
again based on the change in positions of the remote devices and
transmit the updated grouping information to the relay device 610,
so that the relay device 610 may perform step S6304 again based on
the updated grouping information.
[0127] A sixth embodiment according to the present disclosure is
described below with reference to FIG. 7A to FIG. 7C. FIG. 7A
schematically shows an architecture of a communication system to
which the sixth embodiment is applicable. In the communication
system, a unidirectional relay mode is employed.
[0128] As shown in FIG. 7A, a base station 700 communicates with a
relay device 710, and the relay device 710 simultaneously
communicates with multiple remote devices 721 to 724. The
communication between the relay device 710 and the remote devices
is unidirectional (that is, from the remote devices to the relay
device). Similar to the fifth embodiment, the multiple remote
devices 721 to 724 are grouped in the embodiment, and a primary
device of each group performs link maintenance with the relay
device 710 on behalf of the group , thereby reducing signaling
overheads and energy consumption.
[0129] For example, in FIG. 7A, the remote devices 721, 722 are
grouped into one group, which is encircled by a dotted line circle,
and the remote device 721 is determined as a primary device for the
group. It is to be noted that, FIG. 7A schematically shows only one
case of grouping, and the remote devices 721 to 724 may also be
grouped in other manners.
[0130] In the embodiment, multiple remote devices may be grouped by
the relay device 710 based on a result of measuring a link
maintenance message, or may be grouped by the base station 700
based on positions of the remote devices, which is the same as that
described in the fifth embodiment and is omitted here.
[0131] FIG. 7B shows a first signaling flow of link maintenance
according to the sixth embodiment of the present disclosure. As
shown in FIG. 7B, the relay device 710 performs one-to-one link
maintenance with each of the remote devices 721, 722 in initial
phase. In step 57101, the relay device 710 groups the remote
devices by measuring a link maintenance message from each of remote
devices and determines a primary device for each group. For
conciseness and clarity, it is assumed that the remote devices 721,
722 are grouped into one group and the remote device 721 is
determined as a primary device for the group.
[0132] Then, in step S7201, the relay device 710 transmits the
grouping information to the base station 700. The grouping
information may include, for example, an ID of each remote device
in the group and an ID of the primary device. Then, in step S7301,
the base station 700 transmits the grouping information to the
remote devices 721 and 722.
[0133] The remote devices 721 and 722 may determine which group
they belong to and which remote device serves as the primary device
for the group, based on the received grouping information. Then,
the remote device 721 serving as the primary device transmits a
link maintenance message to the relay device 710 in step S7401,
while the remote device 722 does not transmit a link maintenance
message.
[0134] In step S7501, the relay device 710 measures the link
maintenance message from the primary device 721 and determines
whether the measurement result is within a range of measurement
results corresponding to the group (for example, a range that the
measurement results are greater than a specific threshold). If the
measurement result is within the range, it is unnecessary to change
the group and the primary device. Otherwise, if the measurement
result is not within the range, it is required to perform grouping
again and determine a primary device. Alternatively, in step S7501,
the relay device 710 may also select another remote device (such as
the remote device 722) as a primary device in a predetermined
order.
[0135] Then, the relay device 710 transmits the grouping
information determined in step S7501 to the base station 700, as
shown in step S7601. In step S7701, the base station 700 transmits
the new grouping information to the remote devices 721 and 722.
[0136] It is assumed that the relay device 710 determines the
remote device 722 as a primary device in step S7501, the remote
device 722 transmits a link maintenance message to the relay device
710 in step S7801. The relay device 710 may perform step S7501
again in response to the link maintenance message.
[0137] FIG. 7C shows a second signaling flow of link maintenance
according to the sixth embodiment of the present disclosure. As
shown in FIG. 7C, the relay device 710 performs one-to-one link
maintenance with each of the remote devices 721, 722 in initial
phase. In step 57102, the relay device 710 measures a link
maintenance message from each of the remote devices, and in step
S7202, the relay device 710 transmits measurement results to the
base station 700.
[0138] In step S7302, the base station 700 group the remote devices
721, 722 based on position information reported by each of the
remote devices and determines a primary device for each group. It
is still assumed that remote devices 721, 722 are grouped into one
group and the remote device 721 is determined as the primary device
for the group.
[0139] Then, in step S7402, the base station 700 transmits the
grouping information to the relay device 710 and remote devices 721
and 722. The grouping information may include, for example, an ID
of each remote device in the group and an ID of the primary
device.
[0140] Then, in step S7502, the remote device 721 serving as the
primary device transmits a link maintenance message to the relay
device 710. In step S7602, the relay device 710 measures the link
maintenance message. In step S7702, the relay device 710 reports
the measurement result to the base station 700. The base station
700 may perform step S7302 again based on the received measurement
result.
[0141] A seventh embodiment according to the present disclosure is
described below with reference to FIG. 8A and FIG. 8B. The seventh
embodiment is a variation of the fifth embodiment described with
reference to FIG. 6A to FIG. 6E, and therefore, the seventh
embodiment is applicable to the communication system shown in FIG.
6A. In this communication system, a base station communicates with
a relay device, and the relay device performs bidirectional
communication with multiple remote devices. The multiple remote
devices are grouped.
[0142] FIG. 8A shows a first signaling flow of link maintenance
according to the seventh embodiment of the present disclosure. As
shown in FIG. 8A, a relay device 810 performs one-to-one link
maintenance with each of remote devices 821, 822 and 823 in initial
phase. In step S8101, the relay device 810 groups the remote
devices by measuring a link maintenance message from each of the
remote devices and determines a primary device for each group. The
manner of grouping and determining a primary device is the same as
that described in the fifth embodiment and therefore is omitted
here. For the sake of conciseness, it is assumed that the remote
devices 821, 822 and 823 are grouped into one group, and the remote
device 821 is determined as the primary device for the group.
[0143] Then, in step S8201, the relay device 810 transmits the
grouping information to the remote devices 821, 822 and 823. The
grouping information may include, for example, an ID of each device
in the group and an ID of the primary device. The remote devices
821, 822 and 823 may determine, based on the received grouping
information, which group they belong to and which remote device
serves as the primary device for the group.
[0144] Then, the remote device 821 serving as the primary device
transmits a link maintenance message to the relay device 810 in
step S8301, while other remote devices in the group do not transmit
the link maintenance message.
[0145] In step S8401, the relay device 810 measures the link
maintenance message from the primary device 821 and determines
whether it is required to perform grouping again or change the
primary device, based on the measurement result, which is similar
to step S6401 described in the fifth embodiment. The embodiment
differs from the fifth embodiment in that, in step S8401, the relay
device 810 determines a timing at which the primary device
transmits the next link maintenance message further based on a
result of measuring the link maintenance message from the primary
device 821. Specifically, the relay device 810 may determine a
level of a state of link by referring to Table 1 as described
above, based on the measurement result and a predetermined
threshold. Then, the relay device 810 determines a timing for
transmitting the next link maintenance message by referring to
Table 2 as described above, based on the level of the state of link
determined currently and the levels of the historical states of
link determined previously.
[0146] Then, in step S8501, the relay device 810 transmits an
acknowledgement message in response to the link maintenance message
from the primary device 821, to each of the remote devices in the
group, that is, the remote devices 821, 822 and 823. Specifically,
the acknowledgement message includes an ID of the primary device
(which is assumed to be the remote device 822) determined by the
relay device 810 in step S8401 and the timing for transmitting the
next link maintenance message.
[0147] The remote devices 821, 822 and 823 start a timer based on
the received acknowledgement message, an expiration time of which
corresponds to the timing determined by the relay device 810 to
transmit the next link maintenance message, as shown in step
S8601.
[0148] During the timer is started, the new primary device 822 does
not transmit the link maintenance message, and the relay device 810
also does not monitor the link maintenance message. When the timer
expires, the primary device 822 transmits the next link maintenance
message, as shown in step S8701. Then, the relay device 810 may
perform step S8401 again.
[0149] FIG. 8B shows a second signaling flow of link maintenance
according to the seventh embodiment of the present disclosure. As
shown in FIG. 8B, the relay device 810 performs one-to-one link
maintenance with each of the remote devices 821, 822 and 823 in
initial phase. In another aspect, in step S8102, the base station
800 groups remote devices close to each other into one group based
on the position information reported by each of the remote devices
and transmits the grouping information to the relay device 810 in
step S8202.
[0150] The relay device 810 may determine the grouping case for the
remote devices 821,822 and 823 based on the received grouping
information. For the sake of conciseness, it is assumed that the
remote devices 821, 822 and 823 are grouped into one group.
Furthermore, the relay device 810 determines a primary device for
the group in step S8302, for example, the remote device 821. Then,
in step S8402, the relay device 810 transmits the grouping
information to each of the remote devices 821, 822 and 823. The
grouping information may include an ID of each member in the group
and an ID of the primary device.
[0151] Then, the remote device 821 serving as the primary device
may transmit a link maintenance message to the relay device 810 in
step S8502, while the other remote devices do not transmit the link
maintenance message.
[0152] In step S8602, the relay device 810 measures the received
link maintenance message and determines whether it is required to
performing grouping again or change the primary device, or
alternatively, the relay device 810 may select another remote
device in the group as a primary device in a predetermined order,
as described above. In addition, the relay device 810 further
determines a timing at which the primary device transmits the next
link maintenance message by referring to Table 1 and Table 2 based
on the measurement result.
[0153] Then, in step S8702, the relay device 810 transmits an
acknowledgement message in response to the link maintenance message
from the primary device 821, to each of the remote devices in the
group. The acknowledgement message includes the ID of the primary
device determined by the relay device 810 in step S8602 and the
timing for transmitting the next link maintenance message. Thus,
the primary device indicated by the ID of the primary device will
transmit the next link maintenance message to the relay device 810
at the timing.
[0154] In another aspect, the base station 800 may group, based on
position information reported periodically by the remote devices
and the relay device, the remote devices again in the case that
positions of the remote devices and the relay device are changed,
and transmits the updated grouping information to the relay device
810, as shown in steps S8802 to 58902. Then, the relay device 810
may perform step S8302 again based on the received updated grouping
information. It is to be noted that, the time for performing steps
S8802 to 58902 is not limited to that shown in FIG. 8B. The
operation that the base station 800 updates and transmits the
grouping information may be performed at any time between step
S8202 and step S8702 shown in FIG. 8B.
[0155] In the embodiment, for the bidirectional relay mode, a
scheme for grouping remote devices is applied in conjunction with a
scheme for determining a timing for transmitting the next link
maintenance message based on a state of a link. Therefore, effects
of reducing the frequency of signaling interaction (for example, in
the case that the state of link is good), reducing signaling
overheads and reducing energy consumption can be achieved.
[0156] An eighth embodiment according to the present disclosure is
described below with reference to FIG. 9A and FIG. 9B. The eighth
embodiment is a variation of the sixth embodiment described with
reference to FIG. 7A to FIG. 7C, and therefore, the eighth
embodiment is applicable to the communication system shown in FIG.
7A. In this communication system, a base station communicates with
a relay device, and the relay device performs unidirectional
communication with multiple remote devices. The multiple remote
devices are grouped.
[0157] FIG. 9A shows a first signaling flow of link maintenance
according to the eighth embodiment of the present disclosure. As
shown in FIG. 9A, a relay device 910 performs one-to-one link
maintenance with each of remote devices 921, 922 in initial phase.
In step S9101, the relay device 910 measures a link maintenance
messages from each of the remote devices, groups the remote devices
based on measurement results and determines a primary device for
each group. The manner for performing grouping and determining a
primary device is the same as that described above and therefore is
omitted here. For the sake of conciseness, it is assumed that the
remote devices 921, 922 are grouped into one group, and the remote
device 921 is determined as the primary device for the group.
[0158] Then, in step S9201, the relay device 910 transmits the
grouping information to the base station 900. The grouping
information may include, for example, an ID of each remote device
in the group and an ID of the primary device. In step S9301, the
base station 900 transmits the grouping information to the remote
devices 921 and 922.
[0159] The remote devices 921 and 922 may determine, based on the
received grouping information, which group they belong to and which
remote device serves as the primary device for the group. Then, the
remote device 921 serving as the primary device transmits a link
maintenance message to the relay device 910 in step S9401, while
the remote device 922 does not transmit the link maintenance
message.
[0160] In step S9501, the relay device 910 measures the link
maintenance message from the primary device 921 and determines
whether it is required to perform grouping again or change the
primary device based on the measurement result, or selects a new
primary device in a predetermined order, which is similar to step
S7501 described in the sixth embodiment. The embodiment differs
from the sixth embodiment in that, in step S9501, the relay device
910 determines, further based on a result of measuring the link
maintenance message from the primary device 921, a timing at which
the primary device transmits the next link maintenance message.
Specifically, the relay device 910 may determine a level of a state
of link by referring to Table 1 as described above, based on the
measurement result and a predetermined threshold. Then, the relay
device 910 determines a timing for transmitting the next link
maintenance message by referring to Table 2 as described above,
based on the level of the state of link determined currently and
the levels of the historical states of link determined
previously.
[0161] Then, in step S9601, the relay device 910 transmits the
determined ID of the primary device (which is assumed to be the
remote device 922) and the timing for transmitting the next link
maintenance message, to the base station 900. Then, in step S9701,
the base station 900 transmits the received information to the
remote devices 921 and 922.
[0162] In step S9801, the remote devices 921 and 922 start a timer
corresponding to the timing notified by the base station 900. When
the timer expires, a new primary device 922 transmits the next link
maintenance message to the relay device 910, as shown in step
S9901. In response to receiving the next link maintenance message,
the relay device 910 may perform step S9501 again.
[0163] FIG. 9B shows a second signaling flow of link maintenance
according to the eighth embodiment of the present disclosure. As
shown in FIG. 9B, the relay device 910 performs one-to-one link
maintenance with each of the remote devices 921, 922 in initial
phase. In step S9102, the relay device 910 measures a link
maintenance messages from each of the remote devices, and in step
S9202, the relay device 910 transmits measurement results to the
base station 900.
[0164] In step S9302, the base station 900 groups the remote
devices 921, 922 based on position information reported by each of
the remote devices and determines a primary device for each group,
which are similar to step S7302 described in the sixth embodiment.
It is still assumed that remote devices 921 and 922 are grouped
into one group, and the remote device 921 serves as a primary
device for the group. The embodiment differs from the sixth
embodiment in that, in step S9302, the base station 900 determines,
further based on the measurement result received from the relay
device 910, a timing at which the primary device transmits the next
link maintenance message. For example, the base station 900 may
determine, based on the level of the current state of the link and
the levels of the historical states of the link, a timing for
transmitting the next link maintenance message by referring to
Table 1 and Table 2 as described above.
[0165] Then, in step S9402, the base station 900 transmits the
determined grouping information and the timing information to the
relay device 910 and remote devices 921 and 922. The determined
grouping information may include, for example, an ID of each remote
device in the group and an ID of the primary device.
[0166] Then, in step S9502, the relay device 910 and remote devices
921 and 922 start a timer corresponding to the timing notified by
the base station 900. When the timer expires, the remote device 921
serving as the primary device transmits a link maintenance message
to the relay device 910 in step S9602. The relay device 910
measures the received link maintenance message in step S9702, and
reports the measurement result to the base station 900 in step
59802. The base station 900 performs step S9302 again based on the
received measurement result.
[0167] In the embodiment, for a unidirectional relay mode, a scheme
for grouping remote devices is applied in conjunction with another
scheme for determining a timing for transmitting the next link
maintenance message based on a state of a link. Therefore, effects
of reducing the frequency of signaling interaction (for example, in
the case that the state of link is good), reducing signaling
overheads and reducing energy consumption can be achieved.
[0168] A ninth embodiment according to the present disclosure is
described below with reference to FIG. 10. The ninth embodiment is
another variation of the fifth embodiment, and therefore, the ninth
embodiment is applicable to the communication system shown in FIG.
6A. In this communication system, a base station communicates with
a relay device, and the relay device performs bidirectional
communication with multiple remote devices. The multiple remote
devices are grouped.
[0169] In the embodiment, the remote devices satisfying one of the
following conditions are grouped into one group: the relay device
and the remote device have a mutual trust relationship, and a
connection between the relay device and the remote device has been
maintained for a long time period. Satisfying one of the above
conditions generally means that there is a stable connection
between the relay device and the remote device. Therefore, a link
maintenance process in which an acknowledgement message is omitted
may be performed, as described in the first embodiment according to
the present disclosure. That is, in the embodiment, the remote
devices capable of performing the link maintenance process in which
an acknowledgement message is omitted with the relay device are
grouped into one group.
[0170] FIG. 10 shows a signaling flow of link maintenance according
to the ninth embodiment of the present disclosure. As shown in FIG.
10, a relay device 1010 performs one-to-one link maintenance with
each of remote devices 1021, 1022 and 1023 in initial phase. In
step S1010, the relay device 1010 determines a state of each link
by measuring a link maintenance message from each of the remote
devices. Furthermore, in step S1010, the relay device 1010 groups
the remote devices 1021, 1022 and 1023 further based on whether one
of the above conditions is satisfied. For the sake of conciseness,
it is assumed that each of the remote devices 1021, 1022 and 1023
satisfy one of the above conditions and are grouped into one group.
In step S1020, the relay device 1010 transmits the grouping
information to each of the remote devices 1021, 1022 and 1023.
[0171] Then, in step S1030 the relay device 1010 transmits a link
maintenance message to each of the remote devices in a multicast
way. Specifically, in the case that the relay device performs
one-to-one link maintenance with the remote devices, the relay
device needs to transmit a link maintenance message to each of the
remote devices in a unicast way. Compared with this case,
transmitting a link maintenance message in a multicast way can
reduce signaling overheads or energy consumption of the relay
device.
[0172] As described above, the remote devices 1021, 1022, 1023 and
the relay device 1010 perform link maintenance for which an
acknowledgement message is omitted. Therefore, the remote devices
1021, 1022 and 1023 do not transmit an acknowledgement message in
response to the link maintenance message to the relay device
1010.
[0173] In the way as described above, the relay device 1010 may
periodically multicast link maintenance message to the remote
devices 1021, 1022 and 1023. For example, in step S1040, the relay
device 1010 multicasts the next link maintenance message.
Similarly, the remote devices 1021, 1022 and 1023 may not feedback
an acknowledgement message.
[0174] A tenth embodiment according to the present disclosure is
described below with reference to FIG. 11A to FIG. 11C. The tenth
embodiment relates to releasing a link between a relay device and a
remote device.
[0175] FIG. 11A shows a first signaling flow of link release
according to the tenth embodiment of the present disclosure. In the
embodiment, it is assumed that the relay device and the remote
device perform a link maintenance process in which an
acknowledgement message is omitted. As shown in FIG. 11A, in step
S1111, a relay device 1110 transmits a link maintenance message to
a remote device 1120, and in step S1121, the remote device 1120
measures the link maintenance message. In the case that the
measurement result indicates that a state of link is normal (for
example, the measurement result is greater than a predetermined
threshold), the remote device 1120 does not feedback an
acknowledgement message. After a certain time period, the relay
device 1110 transmits the next link maintenance message to the
remote device 1120 in step S1131, and the remote device 1120
measures the next link maintenance message in step S1141. It is
assumed that the measurement result in this case is less than a
predetermined threshold, it means that the state of link has
deteriorated and it is difficult to maintain communication.
Therefore, the remote device 1120 transmits a link release message
to the relay device 1110 in step S1151 to request for releasing the
link. In response to receiving the link release message, the relay
device 1110 transmits a release accept message in step S1161, such
that the link between the relay device 1110 and the remote device
1120 is disconnected.
[0176] FIG. 11B shows a second signaling flow of link release
according to the tenth of the present disclosure. In the
embodiment, it is still assumed that the relay device and the
remote device perform the link maintenance process in which an
acknowledgement message is omitted.
[0177] As shown in FIG. 11B, in step S1112, the relay device 1110
transmits a link maintenance message to the remote device 1120. It
is assumed that the remote device 1120 is suddenly disconnected
with the relay device 1110 for some reasons (for example, battery
runs out, device failure). In this case, the relay device 1110
cannot receive a link release message from the remote device 1120,
that is, the relay device 1110 cannot obtain the notification that
the link is disconnected from the remote device 1120. Furthermore,
since link maintenance for which an acknowledgement message is
omitted, the relay device 1110 cannot determine whether the link is
disconnected based on an acknowledgement message.
[0178] Since the remote device 1120 periodically transmits a
tracking area update (TAU) message to an entity at the network side
(such as MME) in normal operation, in case that the remote device
1120 is suddenly disconnected, the MME will no longer receive TAU
message from the remote device 1120. In this case, in step S1132,
the MME may notify a base station 1100 of a fact that the TAU
message is not received from the remote device 1120. In step S1142,
the base station 1100 notifies the relay device 1100 of this. After
receiving the notification from the base station 1100, the relay
device 1110 may determine that the remote device 1120 has been
disconnected and then the link is released in step S1152.
[0179] FIG. 11C shows a third signaling flow of link release
according to the tenth embodiment of the present disclosure. In the
embodiment, it is still assumed that a relay device and a remote
device perform a link maintenance process in which the
acknowledgement message is omitted.
[0180] As shown in FIG. 11C, in step S1113, the relay device 1110
transmits a link maintenance message to the remote device 1120. It
is assumed that the remote device 1120 has established a connection
with other relay devices, or the remote device 1120 has directly
established a connection with the base station 1100, as shown in
step S1123. Since the relay device 1110 and the remote device 1120
performs the link maintenance in which the acknowledgement message
is omitted, the relay device 1110 cannot determine whether the link
is disconnected based on the acknowledgement message.
[0181] In the case that the remote device 1120 establishes a
connection with other devices, the network side entity (such as
MME) for storing connection information modifies the previously
registered connection information related to the remote device
1120, as shown in step S1133. In step S1143, MME notifies the base
station 1100 that the connection target of the remote device 1120
has changed, and then the base station 1100 notifies the relay
device 1110 of this fact in step S1153. After receiving the
notification from the base station 1100, the relay device 1110 may
release the link between the relay device 1110 and the remote
device 1120 in step S1163.
[0182] Each of the above embodiments according to the present
disclosure can be implemented at a Non-Access Stratum (NAS) and a
Access Stratum (AS). Specifically, in the case that the embodiment
is implemented at the NAS layer, the above link maintenance message
may be a "Direct_Communication_Keepalive" message. In the case that
the embodiment is implemented at the AS layer, the above link
maintenance message may be a " PC5_Discovery_Solicitation"
message.
[0183] The present disclosure can be applied to various products.
For example, the network side device or the base station in the
above-described embodiments may include any type of new generation
node (such as gNB), and evolved node B (eNB), such as a macro eNB
and a small eNB. The small eNB may be an eNB such as pico eNB,
micro eNB and home (femto) eNB that covers a cell smaller than a
macro cell. Alternatively, the network side device or the base
station may further include any other type of base station, such as
an NodeB and a base transceiver station (BTS). The base station may
include: a main body (which is also referred to as a base station
device) configured to control wireless communication; and one or
more remote radio heads (RRH) located at positions different from
the main body. In addition, various types of terminal devices may
function as a base station by performing the function of the base
station temporarily or semi-permanently.
[0184] In another aspect, the terminal device or the user equipment
in the above-described embodiments may be implemented as a
communication terminal device (such as a smart phone, a panel
personal computer (PC), a notebook PC, a portable game terminal, a
portable/dongle mobile router and a digital camera) or an
in-vehicle terminal device (such as a car navigation device). The
terminal device or the user equipment may also be implemented as a
terminal device for performing machine to machine (M2M)
communication, which is also referred to as a machine-type
communication (MTC) terminal device. Furthermore, the terminal
device or the user equipment may be a wireless communication module
(such as an integrated circuit module including a single chip)
mounted on each of the above terminals.
[0185] The implementation of the relay device or the remote device
is described below by taking a smart phone as an example in
conjunction with FIG. 12.
[0186] FIG. 12 shows a block diagram of a schematic configuration
of a smart phone. As shown in FIG. 12, a smart phone 2500 includes
a processor 2501, a memory 2502, a storage device 2503, an external
connection interface 2504, a camera 2506, a sensor 2507, a
microphone 2508, an input apparatus 2509, a display apparatus 2510,
a loudspeaker 2511, a wireless communication interface 2512, one or
more antenna switches 2515, one or more antennas 2516, a bus 2517,
a battery 2518 and an auxiliary controller 2519.
[0187] The processor 2501 may be, for example, a CPU or a System On
Chip (SoC), and controls functions of an application layer and
other layers of the smart phone 2500. The memory 2502 includes an
RAM and an ROM, and stores a program that is executed by the
processor 2501, and data. The storage device 2503 may include a
storage medium such as a semiconductor memory and a hard disk. The
external connection interface 2504 is an interface for connecting
an external device (such as a memory card and a universal serial
bus (USB) device) to the smart phone 2500.
[0188] The camera 2506 includes an image sensor (such as a charge
coupled device (CCD) and a complementary metal oxide semiconductor
(CMOS)), and generates a captured image.
[0189] The sensor 2507 may include a set of sensors such as
measurement sensor, gyro sensor, geomagnetic sensor, and
acceleration sensor. The microphone 2508 converts sounds that are
input to the smart phone 2500 into audio signals. The input device
2509 includes, for example, a touch sensor configured to detect
touch on a screen of the display device 2510, a keypad, a keyboard,
a button, or a switch, and receives an operation or information
input from a user. The display device 2510 includes a screen (such
as a liquid crystal display (LCD) and an organic light-emitting
diode (OLED) display), and displays an output image of the smart
phone 2500. The loudspeaker 2511 converts audio signals that are
output from the smartphone 2500 into sounds.
[0190] The wireless communication interface 2512 supports any
cellular communication scheme (such as LET and LTE-Advanced), and
performs wireless communication. The wireless communication
interface 2512 may typically include, for example, a baseband (BB)
processor 2513 and a radio frequency (RF) circuit 2514. The BB
processor 2513 may perform for example coding/decoding,
modulation/demodulation and multiplexing/de-multiplexing, and
perform various types of signal processes for wireless
communication. In addition, the RF circuit 2514 also may include,
for example, a mixer, a filter and an amplifier, and transmits and
receives wireless signals via an antenna 2516. The wireless
communication interface 2512 may be a chip module with the BB
processor 2513 and the RF circuit 2514 integrated therein. As shown
in FIG. 12, the wireless communication interface 2512 may include
multiple BB processors 2513 and multiple RF circuits 2514. However,
the wireless communication interface 2512 may also include a single
BB processor 2513 or a single RF circuit 2514.
[0191] Furthermore, in addition to the cellular communication
schemes, the wireless communication interface 2512 may support
another type of wireless communication scheme such as short-range
wireless communication scheme, near field communication scheme, and
wireless local area network (LAN) scheme. In this case, the
wireless communication interface 2512 may include the BB processor
2513 and the RF circuit 2514 for each wireless communication
scheme.
[0192] Each of the antenna switches 2515 switches connection
destinations for the antennas 2516 among multiple circuits (such as
circuits for different wireless communication schemes) included in
the wireless communication interface 2512.
[0193] Each of the antennas 2516 includes a single antenna element
or multiple antenna elements (such as multiple antenna elements
included in an MIMO antenna), and is used for the wireless
communication interface 2512 to transmit and receive wireless
signals. As shown in FIG. 12, the smart phone 2500 may include the
multiple antennas 2516. However, the smart phone 2500 may include a
single antenna 2516.
[0194] Furthermore, the smart phone 2500 may include the antenna
2516 used for each wireless communication scheme. In this case, the
antenna switch 2515 may be omitted in the configuration of the
smart phone 2500.
[0195] The bus 2517 connects the processor 2501, the memory 2502,
the storage device 2503, the external connection interface 2504,
the camera 2506, the sensor 2507, the microphone 2508, the input
device 2509, the display device 2510, the loudspeaker 2511, the
wireless communication interface 2512, and the auxiliary controller
2519 to each other. The battery 2518 supplies power to respective
components of the smart phone 2500 via feeders which are partially
shown with dashed lines in FIG. 12. The auxiliary controller 2519,
for example, performs the minimum function necessary for the smart
phone 2500 in a sleep mode.
[0196] In the smart phone 2500 as shown in FIG. 12, a transceiving
device of the terminal device may be implemented with the wireless
communication interface 2512. At least a part of the functions of
respective functional units of the terminal device may also be
implemented with the processor 2501 or the auxiliary controller
2519. For example, a part of functions of the processor 2501 may be
performed by the auxiliary controller 2519 to reduce the
consumption of power of the battery 2518 is reduced. Furthermore,
the processor 2501 or the auxiliary controller 2519 may perform at
least a part of the functions of respective functional units of the
terminal device by executing programs stored in the memory 2502 or
the storage 2503.
[0197] The implementation of the based station is described below
by taking eNB as an example in conjunction with FIG. 13.
[0198] FIG. 13 shows a block diagram of a schematic configuration
of an eNB. As shown in FIG. 13, an eNB 2300 includes one or more
antennas 2310 and a base station device 2320. The base station
device 2320 and each antenna 2310 may be connected with each other
via a radio frequency (RF) cable.
[0199] Each of the antennas 2310 includes a single antenna element
or multiple antenna elements (such as multiple antenna elements
included in the multiple-input multiple-output (MIMO) antenna), and
is used for the base station device 2320 to transmit and receive
wireless signals. As show in FIG. 13, the eNB 2300 may include
multiple antennas 2310. For example, the multiple antennas 2310 may
be compatible with multiple frequency bands used by the eNB 2300.
Although FIG. 13 shows an example in which the eNB 2300 includes
multiple antennas 2310, the eNB 2300 may include a single antenna
2310.
[0200] The base station device 2320 includes a controller 2321, a
memory 2322, a network interface 2323 and a wireless communication
interface 2325.
[0201] The controller 2321 may be for example a CPU or a DSP, and
may perform various functions of higher layers of the base station
device 2320. For example, the controller 2321 generates data
packets based on the data in the signal processed by the wireless
communication interface 2325, and transfers the generated packets
via the network interface 2323. The controller 2321 may bundle data
from multiple baseband processors to generate bundled packets, and
transfer the generated bundled packets. The controller 2321 may
have logic functions for performing the following control: radio
resource control, radio carrying control, mobility management,
admission control and schedule. The control may be performed in
conjunction with an adjacent eNB or a core network node. The memory
2322 includes RAM and ROM, and stores a program that is executed by
the controller 2321, and various types of control data (such as
terminal list, transmission power data, and scheduling data).
[0202] The network interface 2323 is a communication interface for
connecting the base station device 2320 to a core network 2324. The
controller 2321 may communicate with the core network node or
another eNB via the network interface 2323. In this case, the eNB
2300 and the core network node or the other eNB may be connected
with each other via a logic interface (such as S1 interface and X2
interface). The network interface 2323 may be a wired communication
interface or a wireless communication interface for a wireless
backhaul line. If the network interface 2323 is the wireless
communication interface, the network interface 2323 may use a
higher frequency band for wireless communication than that used by
the wireless communication interface 2325.
[0203] The wireless communication interface 2325 supports any
cellular communication schemes (such as long term evolution (LTE)
and LTE-Advanced), and provides a wireless connection to a terminal
located in the cell of the eNB 2300 via the antenna 2310. The
wireless communication interface 2325 may generally include for
example the BB processor 2326 and the RF circuit 2327. The BB
processor 2326 may perform for example coding/decoding,
modulation/demodulation and multiplexing/de-multiplexing, and may
perform various signal processing for the layers (for example, L1
layer, media access control (MAC) layer, radio link control (RLC)
layer and packet data convergence protocol (PDCP) layer). Instead
of the controller 2321, the BB processor 2326 may have a part or
all of the above logic functions. The BB processor 2326 may be a
memory storing communication control programs, or a module
including a processor and a related circuit which are configured to
execute programs. Updating the program may change the functions of
the BB processor 2326. The module may be a card or a blade inserted
into the slot of the base station device 2320. Alternatively, the
module may be a chip installed on the card or the blade. In
addition, the RF circuit 2327 may also include, for example, a
mixer, a filter and an amplifier, and transmits and receives
wireless signals via the antenna 2310.
[0204] As shown in FIG. 13, the wireless communication interface
2325 may include multiple BB processors 2326. For example, the
multiple BB processors 2326 may be compatible with multiple
frequency bands used by the eNB 2300. As shown in FIG. 13, the
wireless communication interface 2325 may include multiple RF
circuits 2327. For example, the multiple RF circuits 2327 may be
compatible with multiple antenna elements. Although FIG. 13 shows
an example in which the wireless communication interface 2325
includes multiple BB processors 2326 and multiple RF circuits 2327,
the wireless communication interface 2325 may include a single BB
processor 2326 and a single RF circuit 2327.
[0205] In the eNB 2300 shown in FIG. 13, a transceiving device of
the base station device may be implemented with the wireless
communication interface 2325. At least a part of the functions of
respective units may be performed by the controller 2321. For
example, the controller 2321 may perform at least a part of the
functions of respective units by executing programs stored in the
memory 2322.
[0206] The various processes described in the above-described
embodiments may be implemented with software, hardware or a
combination of software and hardware. Programs included in the
software may be stored in advance in a storage medium provided
inside or outside each device. As an example, when being executed,
the programs are written into a random-access memory (RAM) and
executed by a processor (such as CPU), so as to perform the various
processes described herein.
[0207] FIG. 14 is a block diagram showing an example configuration
of computer hardware that executes the schemes of the present
disclosure based on a program.
[0208] In a computer 1400, a central processing unit (CPU) 1401, a
read only memory (ROM) 1402, and a random access memory (RAM) 1403
are connected with each other via a bus 1404.
[0209] An input/output interface 1405 is further connected to the
bus 1404. The following components are connected to the
input/output interface 1405: an input unit 1406 including keyboard,
mouse, microphone and the like; an output unit 1407 including
display, loudspeaker and the like; a storage unit 1408 including
hard disk, non-volatile memory and the like; a communication unit
1409 including a network interface card (such as Local area network
(LAN) card and modem and the like); and a driver 1410 for driving a
removable medium 1411 such as magnetic disk, optical disk, magnetic
optical disk or semiconductor memory.
[0210] In the computer having the above configuration, the CPU 1401
loads the program stored in the storage unit 1408 into the RAM 1403
via the input/output interface 1405 and the bus 1404 and executes
the program, to perform the above processes.
[0211] A program to be executed by a computer (the CPU 1401) may be
recorded in the removable medium 1411 which is a package medium
including for example magnetic disk (including floppy disk),
optical disk (including compact disk-read only memory (CD-ROM),
digital versatile disk (DVD) and the like), magneto-optical disk or
semiconductor memory. Furthermore, the program to be executed by
the computer (the CPU 1401) may also be provided via a wired
transmission medium or a wireless transmission medium such as local
area network, the Internet or digital satellite broadcast.
[0212] In the case that the removable medium 1411 is mounted in the
drive 1410, the program may be installed in the storage unit 1408
via the input/output interface 1405. In addition, the program may
be received by the communication unit 1409 via a wired transmission
medium or a wireless transmission medium, and then the program may
be installed in the storage unit 1408. Alternatively, the program
may be installed in advance in the ROM 1402 or the storage unit
1408.
[0213] The programs to be executed by the computer may be programs
for executing processes in the order described in the
specification, or may be programs for executing processes in
parallel or executing processes as required (such as when being
invoked).
[0214] The various devices or units described herein are only
logical and do not strictly correspond to physical devices or
entities. For example, the functionality of each unit described
herein may be implemented by multiple physical entities or the
functionality of multiple units described herein may be implemented
by a single physical entity. Furthermore, it is to be noted that
features, components, elements or steps, and the like described in
one embodiment are not limited to the embodiment, but may also be
applied to other embodiments. For example, the features,
components, elements or steps, and the like described in one
embodiment may substitute for specific features, components,
elements, or steps, and the like in other embodiments or may be
combined with them.
[0215] The embodiments and the technical effects of the present
disclosure have been described above in detail in conjunction with
the drawings, but the scope of the present disclosure is not
limited thereto. It should be understood by those skill in the art
that various modifications or changes can be made to the
embodiments discussed herein without departing from the principle
and spirit of the present disclosure, depending on design
requirements and other factors. The scope of the present disclosure
is defined by the appended claims or their equivalents.
[0216] In addition, the present disclosure may also be configured
as follows.
[0217] An electronic device performing communication with a
counterpart communication device, including a processing circuit
configured to: when the electronic device and the counterpart
communication device satisfy a predetermined condition, determine a
state of a link between the electronic device and the counterpart
communication device by measuring a link maintenance message
transmitted by the counterpart communication device, without
transmitting a feedback message in response to the link maintenance
message, wherein the link maintenance message is used for
confirmation on link maintenance between the electronic device and
the counterpart communication device.
[0218] In an embodiment, the predetermined condition includes at
least one of the followings: the electronic device and the
counterpart communication device have a mutual trust relationship,
and a duration for which the electronic device and the counterpart
communication device are connected with each other is greater than
a predetermined value.
[0219] In an embodiment, the link maintenance message includes
information for indicating, based on whether or not the
predetermined condition is satisfied, whether or not the feedback
message needs to be transmitted.
[0220] The processing circuit is further configured to: when a
measurement result is lower than a threshold, generate a message
for releasing the link, which message is to be transmitted to the
counterpart communication device.
[0221] In an embodiment, the counterpart communication device
determines disconnection of the link between the electronic device
and the counterpart communication device based on a message from a
base station.
[0222] In an embodiment, the electronic device is a remote device,
and the counterpart communication device is a relay device.
[0223] In an embodiment, the electronic device includes multiple
electronic devices, and wherein when each of multiple electronic
devices and the counterpart communication device satisfy the
predetermined condition, the multiple electronic devices form a
group, and each electronic device in the group measures the link
maintenance message multicast by the counterpart communication
device, without transmitting the feedback message in response to
the link maintenance message.
[0224] In an embodiment, the link maintenance message is any one of
a link maintenance message of a Non-Access Stratum and a link
maintenance message of an Access Stratum.
[0225] An electronic device performing communication with a
counterpart communication device, including a processing circuit
configured to: when the electronic device and the counterpart
communication device satisfy a predetermined condition, measure a
link maintenance message transmitted by the counterpart
communication device, without transmitting a feedback message in
response to the link maintenance message; and notify a base station
of a measurement result, wherein the link maintenance message is
used for confirmation on link maintenance between the electronic
device and the counterpart communication device.
[0226] The processing circuit is further configured to determine a
state of the link based on the measurement result; and notify the
base station of the determined state of the link.
[0227] In an embodiment, the predetermined condition includes at
least one of the followings: the electronic device and the
counterpart communication device have a mutual trust relationship,
and a duration for which the electronic device and the counterpart
communication device are connected with each other is greater than
a predetermined value.
[0228] In an embodiment, the link maintenance message includes
information for indicating, based on whether or not the
predetermined condition is satisfied, whether or not the feedback
message needs to be transmitted.
[0229] In an embodiment, the electronic device is a relay device,
and the counterpart communication device is a remote device.
[0230] In an embodiment, the link maintenance message is any one of
a link maintenance message of a Non-Access Stratum and a link
maintenance message of an Access Stratum.
[0231] An electronic device performing communication with a
counterpart communication device, including a processing circuit
configured to: determine a state of a link between the electronic
device and the counterpart communication device by measuring a link
maintenance message transmitted by the counterpart communication
device, wherein the link maintenance message is used for
confirmation on link maintenance between the electronic device and
the counterpart communication device; and determine, based on the
state of the link, a timing at which the counterpart communication
device transmits a next link maintenance message.
[0232] The processing circuit is further configured to determine
the timing further based on historical states of the link, wherein
the historical states of the link are determined by measuring link
maintenance messages previously transmitted by the counterpart
communication device.
[0233] The processing circuit is further configured to generate a
feedback message including the determined timing, which message is
to be transmitted to the counterpart communication device.
[0234] In an embodiment, the feedback message is generated and
transmitted to the counterpart communication device, such that the
counterpart communication device can determine the timing for
transmitting the next link maintenance message by measuring the
feedback message.
[0235] In an embodiment, the electronic device is one of a remote
device and a relay device, and the counterpart communication device
is the other of the remote device and the relay device.
[0236] In an embodiment, the electronic device is a relay device,
and the counterpart communication device includes multiple remote
devices, wherein the processing circuit is further configured to
determine a primary remote device among the multiple remote
devices; measure a link maintenance message transmitted by the
primary remote device; and determine, based on a measurement
result, a timing at which the primary remote device transmits a
next link maintenance message.
[0237] The processing circuit is further configured to generate a
feedback message including the timing determined for the primary
remote device, which message is to be transmitted to multiple
remote devices.
[0238] The processing circuit is further configured to determine
the primary remote device in one of the manners of: determining the
primary remote device based on available energy and/or energy
consumption of multiple remote devices; randomly selecting one of
multiple remote devices as the primary remote device; and selecting
the primary remote device in a predetermined order among multiple
remote devices.
[0239] In an embodiment, the link maintenance message is any one of
a link maintenance message of a Non-Access Stratum and a link
maintenance message of an Access Stratum.
[0240] An electronic device performing communication with a
counterpart communication device, including a processing circuit
configured to determine a state of a link between the electronic
device and the counterpart communication device by measuring a link
maintenance message transmitted by the counterpart communication
device, wherein the link maintenance message is used for
confirmation on link maintenance between the electronic device and
the counterpart communication device; determine, based on the state
of the link, a timing at which the counterpart communication device
transmits next link maintenance message; and notify a base station
of the determined timing.
[0241] The processing circuit is further configured to receive the
next link maintenance message from the counterpart communication
device according to the determined timing, wherein the next link
maintenance message is transmitted by the counterpart communication
device according to the timing acquired from the base station.
[0242] In an embodiment, the electronic device is a relay device,
and the counterpart communication device includes multiple remote
devices, wherein the processing circuit is further configured to
determine a primary remote device among multiple remote devices;
measure a link maintenance message transmitted by the primary
remote device; determine, based on a measurement result, a timing
at which the primary remote device transmits a next link
maintenance message; and notify the base station of the determined
timing.
[0243] The processing circuit is further configured to receive the
next link maintenance message is from the primary remote device
according to the timing determined for the primary remote device,
wherein the next link maintenance message is transmitted by the
primary remote device according to the timing acquired from the
base station.
[0244] An electronic device performing communication with a
counterpart communication device, including a processing circuit
configured to: measure a link maintenance message transmitted by
the counterpart communication device, wherein the link maintenance
message is used for confirmation on link maintenance between the
electronic device and the counterpart communication device; notify
a base station of a measurement result; and receive a next link
maintenance message from the counterpart communication device
according to a timing notified by the base station, wherein the
timing is determined by the base station based on the measurement
result.
[0245] In an embodiment, the next link maintenance message is
transmitted by the counterpart communication device according to
the timing acquired from the base station.
[0246] In an embodiment, the electronic device is a relay device,
and the counterpart communication device includes multiple remote
devices, wherein the processing circuit is further configured to:
determine a primary remote device among multiple remote devices
according to a message from the base station; measure a link
maintenance message transmitted by the primary remote device; and
notify the base station of a measurement result, such that the base
station determines a timing at which the primary remote device
transmits a next link maintenance message based on the measurement
result.
[0247] In an embodiment, the link maintenance message is any one of
a link maintenance message of a Non-Access Stratum and a link
maintenance message of an Access Stratum.
[0248] An electronic device performing communication with multiple
communication devices, wherein multiple communication devices are
divided into one or more groups, the electronic device including a
processing circuit configured to: determine, for each group, a
primary communication device of the group; measure a link
maintenance message transmitted by the primary communication device
of each group; and generate a first feedback message based on a
measurement result, which message is to be fed back to each
communication device in the group.
[0249] The processing circuit is further configured to determine
the primary communication device of each group in one of the
manners of: determining the primary communication device based on
available energy and/or energy consumption of each communication
device in the group; randomly selecting one communication device in
the group as the primary communication device; and selecting the
primary communication device in a predetermined order in the
group.
[0250] The processing circuit is further configured to: measure the
link maintenance messages transmitted by the multiple communication
devices respectively, and divide multiple communication devices
into the one or more groups based on a measurement result; or
divide the multiple communication devices into the one or more
groups based on grouping information acquired from a base station,
wherein the base station generates the grouping information based
on positions of multiple communication devices.
[0251] The processing circuit is further configured to: after
determining the primary communication device for each group,
generate a second feedback message which is to be transmitted to
each of the plurality of communication devices, wherein the second
feedback message includes information identifying the determined
primary communication device.
[0252] The processing circuit is further configured to regroup
multiple communication devices, upon receipt of link maintenance
messages transmitted by another communication device in the group
in addition to receipt of the link maintenance message transmitted
by the primary communication device, wherein the another
communication device transmits the link maintenance messages to the
electronic device based on a result of measuring the second
feedback message.
[0253] The processing circuit is further configured to: determine,
based on a result of measuring the link maintenance message
transmitted by the primary communication device of each group, a
timing at which the primary communication device transmits next
link maintenance message; and include the determined timing in the
first feedback message.
[0254] In an embodiment, the electronic device is a relay device,
and the multiple communication devices are multiple remote
devices.
[0255] In an embodiment, the link maintenance message is any one of
a link maintenance message of a Non-Access Stratum and a link
maintenance message of an Access Stratum.
[0256] An electronic device performing communication with multiple
communication devices, wherein the multiple communication devices
are divided into one or more groups, the electronic device
including a processing circuit configured to: determine, for each
group, a primary communication device of the group; measure a link
maintenance message transmitted by the primary communication device
of each group; and generate a first feedback message for the group
based on a measurement result, which message is to be transmitted
to a base station, wherein the base station transmits the first
feedback message to each communication device in the group.
[0257] The processing circuit is further configured to measure the
link maintenance messages transmitted by the multiple communication
devices respectively, and divide the multiple communication devices
into the one or more groups based on a measurement result.
[0258] The processing circuit is further configured to determine
the primary communication device for each group in one of the
manners of: determining the primary communication device based on
available energy and/or energy consumption of each communication
device in the group; randomly selecting one communication device in
the group as the primary communication device; and selecting the
primary communication device in a predetermined order in the
group.
[0259] The processing circuit is further configured to: after
determining the primary communication device for each group,
generate a second feedback message which is to be transmitted to
the base station, wherein the second feedback message includes
information identifying the determined primary communication
device, and the base station transmits the second feedback message
to each communication device in the group.
[0260] The processing circuit is further configured to determine,
based on a result of measuring the link maintenance message
transmitted by the primary communication device of each group, a
timing at which the primary communication device transmits a next
link maintenance message; and include the determined timing in the
first feedback message.
[0261] An electronic device performing communication with multiple
communication devices, including a processing circuit configured
to: based on grouping information acquired from a base station,
group the multiple communication devices and determine a primary
communication device for each group, wherein the base station
generates the grouping information based on positions of the
multiple communication devices; measure a link maintenance message
transmitted by the primary communication device of each group; and
transmit a measurement result to the base station.
[0262] In an embodiment, the base station determines, based on the
measurement result, a timing at which the primary communication
device transmits a next link maintenance message.
[0263] In an embodiment, the electronic device is a relay device,
and the multiple communication devices are multiple remote
devices.
[0264] In an embodiment, the link maintenance message is any one of
a link maintenance message of a Non-Access Stratum and a link
maintenance message of an Access Stratum.
* * * * *