U.S. patent application number 14/006081 was filed with the patent office on 2019-05-23 for method and apparatus for transmitting a buffer status report in a wireless communication system.
This patent application is currently assigned to Samsung Electronics Co., Ltd. The applicant listed for this patent is Jae Hyuk Jang, Soeng Hun Kim. Invention is credited to Jae Hyuk Jang, Soeng Hun Kim.
Application Number | 20190159235 14/006081 |
Document ID | / |
Family ID | 46879868 |
Filed Date | 2019-05-23 |
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United States Patent
Application |
20190159235 |
Kind Code |
A9 |
Jang; Jae Hyuk ; et
al. |
May 23, 2019 |
METHOD AND APPARATUS FOR TRANSMITTING A BUFFER STATUS REPORT IN A
WIRELESS COMMUNICATION SYSTEM
Abstract
The present disclosure proposes a method for transmitting a
buffer status report informing of the data to be transmit in
uplink. The method for transmitting buffer status report of a
terminal in a wireless communication system includes checking, when
allocating uplink resource for new data transmission, whether first
buffer status report triggered but not cancelled exists,
generating, when the first buffer status report exists, uplink data
including the buffer status report, checking whether second buffer
status report triggered but not cancelled exist except for the
buffers status report included in the uplink data, and determining
whether to cancel the second buffer status report depending on
whether the first buffer status report is a regular buffer status
report or periodic buffer status report. With the proposed method,
the terminal is capable of transmitting the padding BSR without
extra cancellation operation, resulting in reduction terminal's
operation complexity.
Inventors: |
Jang; Jae Hyuk; (Suwon-si,
KR) ; Kim; Soeng Hun; (Yongin-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Jang; Jae Hyuk
Kim; Soeng Hun |
Suwon-si
Yongin-si |
|
KR
KR |
|
|
Assignee: |
Samsung Electronics Co.,
Ltd
Gyeonggi-do
KR
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20150043352 A1 |
February 12, 2015 |
|
|
Family ID: |
46879868 |
Appl. No.: |
14/006081 |
Filed: |
March 19, 2012 |
PCT Filed: |
March 19, 2012 |
PCT NO: |
PCT/KR2012/001915 PCKC 00 |
371 Date: |
September 18, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61477339 |
Apr 20, 2011 |
|
|
|
61454110 |
Mar 18, 2011 |
|
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 24/10 20130101;
H04L 41/065 20130101; H04W 72/1284 20130101; H04L 43/065
20130101 |
International
Class: |
H04W 72/12 20060101
H04W072/12; H04W 24/10 20060101 H04W024/10; H04L 12/26 20060101
H04L012/26 |
Claims
1. A method for transmitting a buffer status report of a terminal
in a wireless communication system, the method comprising:
checking, when allocating uplink resource for new data
transmission, whether a first buffer status report has been
triggered but not cancelled; generating, in response to determining
that the first buffer status report has been triggered but not
cancelled, uplink data including the buffer status report; checking
whether a second buffer status report has been triggered but not
cancelled except for the buffers status report included in the
uplink data; and determining, whether to cancel the second buffer
status report depending on whether the first buffer status report
is a regular buffer status report or periodic buffer status
report.
2. The method of claim 1, wherein determining whether to cancel the
second buffer status report comprises cancelling, in response to
determining, that the first buffer status report is the regular
buffer status report or the periodic buffer status report, the
second buffer status report.
3. The method of claim 1, wherein determining whether to cancel the
second buffer status report comprises skipping, in response to
determining, that the first buffer status report is a padding
buffer status report, cancellation of the second buffer status
report.
4. The method of claim 3, wherein the padding buffer status report
is transmitted when padding bits for filling a space remained after
transmitting data on the uplink resource are equal to or greater
than a sum of a size of a buffer status report control element and
a subheader of the buffer status report control element.
5. The method of claim 1, further comprising starting, after the
generating of the uplink data, a timer for transmitting the buffer
status report periodically or retransmitting the buffer status
report.
6. The method of claim 1, further comprising transmitting the
uplink data to the base station.
7. The method of claim 1, wherein the buffer status report
comprises control information for reporting a buffered data amount
to be transmitted by the terminal to the base station per logical
channel group.
8. The method of claim 1, wherein the buffer status report logs a
status of a buffer remaining after mapping data to be transmitted
to the uplink resource when the uplink resource for new data can
carry only one uplink data, and logs the status of the buffer
remained after the data to entire uplink resource at a same
subframe when the uplink resource for the new data may be used for
transmitting plural uplink data transmitted at the same
subframe.
9. A terminal for reporting buffer status in a wireless
communication system, the terminal comprising: a transceiver
configured to communicate signals with a base station; and a
controller configured to: check, when allocating uplink resource
for new data transmission, whether first buffer status report
triggered has been triggered but not cancelled, generate, in
response to determining that the first buffer status report has
been triggered but not cancelled, uplink data including the buffer
status report, check whether second buffer status report has been
triggered but not cancelled except for the buffers status report
included in the uplink data, and determine whether to cancel the
second buffer status report depending on whether the first buffer
status report is a regular buffer status report or periodic buffer
status report.
10. The terminal of claim 9, wherein the controller is configured
to control cancelling, in response to determining that the first
buffer status report is the regular buffer status report or the
periodic buffer status report, the second buffer status report.
11. The terminal of claim 9, wherein the controller is configured
to control skipping, in response to determining that the first
buffer status report is a padding buffer status report,
cancellation of the second buffer status report.
12. The terminal of claim 11, wherein the padding buffer status
report is transmitted when padding bits for filling a space
remained after transmitting data on the uplink resource are equal
to or greater than a sum of a size of a buffer status report
control element and a subheader of the buffer status report control
element.
13. The terminal of claim 9, wherein the controller is configured
to control starting, after the generating of the uplink data, a
timer for transmitting the buffer status report periodically or
retransmitting the buffer status report.
14. The terminal of claim 9, wherein the controller is configured
to control transmitting the uplink data to the base station.
15. The terminal of claim 9, wherein the buffer status report
comprises control information for reporting a buffered data amount
to be transmitted by the terminal to the base station per logical
channel group.
16. The terminal of claim 9, wherein buffer status report is
configured to log a status of a buffer remaining after mapping data
to be transmitted to the uplink resource when the uplink resource
for new data can carry only one uplink data, and log the status of
the buffer remained after the data to entire uplink resource at a
same subframe when the uplink resource for the new data may be used
for transmitting plural uplink data transmitted at the same
subframe.
17. A wireless communication system comprising: a base station; and
a terminal capable of communication with the base station and
configured to: check, when allocating uplink resource for new data
transmission, whether first buffer status report triggered has been
triggered but not cancelled, generate, in response to determining
that the first buffer status report has been triggered but not
cancelled, uplink data including a buffer status report, check
whether second buffer status report has been triggered but not
cancelled except for the buffers status report included in the
uplink data, and determine whether to cancel the second buffer
status report depending on whether the first buffer status report
is a regular buffer status report or periodic buffer status
report.
18. The wireless communication system of claim 17, wherein the
terminal is configured to cancel, in response to determining that
the first buffer status report is the regular buffer status report
or the periodic buffer status report, the second buffer status
report.
19. The wireless communication system of claim 17, wherein the
terminal is configured skip, in response to determining that the
first buffer status report is a padding buffer status report,
cancelation of the second buffer status report.
20. The wireless communication system of claim 19, wherein the
padding buffer status report is transmitted when padding bits for
filling a space remained after transmitting data on the uplink
resource are equal to or greater than a sum of a size of a buffer
status report control element and a subheader of the buffer status
report control element.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a wireless communication
system and, in particular, to a method for transmitting a buffer
status report informing of the data to be transmit in uplink.
BACKGROUND ART
[0002] In order to meet the rapid increase in demand for mobile
data, the wireless communication system has evolved over and over
again and current representative communication system is Long Term
Evolution (LTE) system.
[0003] In the LTE system, when it has data to be transmitted in
uplink buffer, the terminal notifies base station of the current
buffer state by transmitting a Buffer Status Report (BSR).
Meanwhile, there is a need of defining the operation to be
performed depending on whether the BSR is a normal BSR, periodic
BSR, or BSR transmitted using the padding resource remained after
base station's scheduling.
DISCLOSURE OF INVENTION
Technical Problem
[0004] The present disclosure has been conceived to solve the above
problem and aims to provide a method transmitting a padding BSR at
the terminal supporting normal or periodic BSR.
Solution to Problem
[0005] In order to solve the above problem, the terminal transmits,
when the resource is remained in transmitting uplink data, a
padding BSR and, although there is regular BSR or periodic BSR in
the uplink data, skips cancelling regular or periodic BSR
transmission.
[0006] In order to solve the above problem, a method for
transmitting buffer status report of a terminal in a wireless
communication system includes checking, when allocating uplink
resource for new data transmission, whether first buffer status
report triggered but not cancelled exists, generating, when the
first buffer status report exists, uplink data including the buffer
status report, checking whether second buffer status report
triggered but not cancelled exist except for the buffers status
report included in the uplink data, and determining whether to
cancel the second buffer status report depending on whether the
first buffer status report is a regular buffer status report or
periodic buffer status report.
[0007] A terminal for reporting buffer status in a wireless
communication system according to the present disclosure includes a
transceiver which communicating signals with a base station and a
controller which checks, when allocating uplink resource for new
data transmission, whether first buffer status report triggered but
not cancelled exists, generates, when the first buffer status
report exists, uplink data including the buffer status report,
checks whether second buffer status report triggered but not
cancelled exist except for the buffers status report included in
the uplink data, and determines whether to cancel the second buffer
status report depending on whether the first buffer status report
is a regular buffer status report or periodic buffer status
report.
Advantageous Effects of Invention
[0008] With the proposed method, the terminal is capable of
transmitting the padding BSR without extra cancellation operation,
resulting in reduction terminal's operation complexity.
BRIEF DESCRIPTION OF DRAWINGS
[0009] FIG. 1 is a diagram illustrating architecture of an LTE
system to which the present disclosure is applied;
[0010] FIG. 2 is a diagram illustrating a protocol stack of the LTE
system to which the present disclosure is applied;
[0011] FIG. 3 is a flowchart illustrating a UE operation procedure
according to the first embodiment of the present disclosure;
[0012] FIG. 4 is a flowchart illustrating a UE operation procedure
according to the second embodiment of the present disclosure;
and
[0013] FIG. 5 is a diagram illustrating a configuration of the UE
according to an embodiment of the present disclosure.
MODE FOR THE INVENTION
[0014] Detailed description of well-known functions and structures
incorporated herein may be omitted to avoid obscuring the subject
matter of the present disclosure. Exemplary embodiments of the
present disclosure are described with reference to the accompanying
drawings in detail.
[0015] Although the description is directed to the LTE system as a
cellular communication system for simplicity of explanation, the
present disclosure is also applicable to other well-known cellular
communication systems. In the following description, the LTE
terminal is referred to as User Equipment (UE) and the LTE base
station is referred to as evolved Node B (eNB).
[0016] FIG. 1 is a diagram illustrating architecture of an LTE
system to which the present disclosure is applied.
[0017] Referring to FIG. 1, the radio access network of the LTE
system includes evolved Node Bs (eNBs) 105, 110, 115, and 120, a
Mobility Management Entity (MME) 125, and a Serving-Gateway (S-GW)
130. The User Equipment (hereinafter, referred to as UE) 135
connects to an external network via eNBs 105, 110, 115, and 120 and
the S-GW 130.
[0018] FIG. 1, the eNBs 105, 110, 115, and 120 correspond to legacy
node Bs of Universal Mobile Communications System (UMTS). The eNBs
105, 110, 115, and 120 allow the UE establish a radio link and are
responsible for complicated functions as compared to the legacy
node B. In the LTE system, all the user traffic including real time
services such as Voice over Internet Protocol (VoIP) are provided
through a shared channel and thus there is a need of a device
located in the eNB to schedule data based on the state information
such as UE buffer conditions, power headroom state, and channel
state. In order to meet the data rate of up to 100 Mbps, the LTE
system adopts Orthogonal Frequency Division Multiplexing (OFDM) as
a radio access technology. Also, the LTE system adopts Adaptive
Modulation and Coding (AMC) to determine the modulation scheme and
channel coding rate in adaptation to the channel condition of the
UE. The AMC is a technique for determining the modulation scheme
and channel coding rate for the channel condition. The S-GW 130 is
an entity to provide data bearers and establishes and releases data
bearers under the control of the MME 125. MME 125 is responsible
for various control functions and connected to a plurality of eNBs
105, 110, 115, and 120.
[0019] FIG. 2 is a diagram illustrating a protocol stack of the LTE
system to which the present disclosure is applied.
[0020] Referring to FIG. 2, the protocol stack of the LTE system
includes Packet Data Convergence Protocol (PDCP) 205 and 240, Radio
Link Control (RLC) 210 and 235, Medium Access Control (MAC) 215 and
230, and Physical (PHY) 220 and 225. The PDCP 205 and 240 is
responsible for IP header compression/decompression. The RLC 210
and 235 is responsible for segmenting the PDCP Protocol Data Unit
(PDU) into segments in appropriate size for Automatic Repeat
Request (ARQ) operation. The MAC 215 and 230 is responsible for
establishing connection to a plurality of RLC entities so as to
multiplex the RLC PDUs into MAC PDUs and demultiplex the MAC PDUs
into RLC PDUs. The MAC PDUs are delivered to the PHY 220 and 225.
The MAC 215 and 230 demultiplexes the MAC PDUs from the PHY 220 and
225 into RLC PDUs and delivers the RLC PDUs to corresponding RLC
entities. The PHY 220 and 225 performs channel coding and
modulation on the higher layer data to transmit the modulation
result through a radio channel in the form of OFDM symbols and
demodulation and channel decoding on the OFDM symbols received
through the radio channel to deliver the decoded data to the higher
layer.
[0021] In the case that heterogeneous devices coexist in the UE,
the normal measurement and report method is not a good method for
solve such interference problem. Although the inter-device
interference, which occurs sporadically, causes the problem of data
transmission failure for the interference occurrence time, the
influence of such interference is averaged for long time so as not
to be reflected. Typically, the services provided to the user have
respective Quality of Service (QoS) requirements including Block
Error Rate (BLER). This is a value of average transmission failure
probability of packets and indicates how much actual data have
transmitted successfully.
[0022] FIG. 3 is a flowchart illustrating a UE operation procedure
according to the first embodiment of the present disclosure.
[0023] The UE starts communication with the eNB at operation 301
and is allocated uplink resource from the eNB for new data
transmission at operation 303.
[0024] Next, the UE determines whether there is any BSR which has
been triggered but not cancelled at operation 305. Here, BSR is the
information of reporting data amount accumulated (or stored) in the
UE's buffer per Logical Channel Group (LCG). Up to 4 LCGs may be
configured, and LCG is a set of logical channels having similar QoS
requirements. The LCG is configured by eNB per UE.
[0025] If there is any BSR which has not been canceled, the UE
includes the BSR in a MAC PDU (i.e. uplink data) at operation 307.
The buffer status is contained in the BSR according to the
following rules. [0026] If the uplink resource for new data is
available for transmitting only one MAC PDU, the UE includes the
data in the corresponding MAC PDU and logs the buffer state in the
BSR. [0027] If the uplink resource for the new data is available
for transmitting plural MAC PDUs at the same subframe (i.e. large
amount of resource is allocated), the UE includes all MAC PDUs in
the same subframe and logs the buffer station in the BSR. [0028]
BSR is the control information reporting buffer status per LCB.
[0029] The UE generates a BSR MAC control element including the BSR
content and includes the BSR MAC control element in the MAC PDU
and, if the BSR is not a truncated BSR, (re)starts a
periodicBSR-Timer and retxBSR-Timer at operation 309. The truncated
BSR is the BSR including partial buffer status other than entire
buffer status, the periodicBSR-Timer is the timer for periodic BSR
transmission, and retxBSR-Timer is the timer for BSR retransmission
when uplink resource is not allocated for BSR.
[0030] There are several types of BSRs as follows. [0031] First
type: Regular BSR [0032] BSR transmitted after expiry of the
retxBSR-Timer when the UE has data that can be transmitted for a
certain logical channel belonging to the LCG. [0033] BSR
transmitted when data occurs from a higher layer (RLC or PDCP
layer) for the logical channel belonging to the LCG and the data
has the priority higher than any of the logical channel belonging
to the LCG. [0034] BSR transmitted when data to be transmitted
occurs from a higher layer (RLC or PDCP layer) for the logical
channel belonging to the LCG and there is no other data with the
exception of the corresponding data in any LCG. [0035] Second type:
Periodic BSR [0036] BSR transmitted when the periodicBSR-Timer
expires. [0037] Third type: Padding BSR [0038] BSR when uplink
resource is allocated and the padding bits filling the space
remained after transmitting the data is equal to or greater than
the sum of the size of BSR MAC Control Element and the size of the
sub-header of the BSR MAC Control Element.
[0039] Although the BSR may have been triggered several times, only
one BSR is included in on MAC PDU. The UE determines, at operation
311, whether there is any BSR triggered but not cancelled at
previous operation in addition to the BSR included in the MAC PDU.
If such BSR exists, the UE checks, at operation 313, the type of
the BSR included in the MAC PDU at previous operation.
[0040] If type 1 or type 2 BSR has been included in the MAC PDU,
the UE cancels the remained BSRs at operation 315.
[0041] Otherwise, if type 3 BSR has been included in the MAC PDU,
the UE does not cancel the remained BSRs at operation 317.
[0042] Afterward, the UE transmits the generated MAC PDU at
operation 319 and ends the procedure at operation 321.
[0043] FIG. 4 is a flowchart illustrating a UE operation procedure
according to the second embodiment of the present disclosure.
[0044] The UE starts communication with the eNB at operation 401
and is allocated uplink resource from the eNB for new data
transmission at operation 403.
[0045] Next, the UE determines whether there is any BSR which has
been triggered but not cancelled at operation 305. Here, BSR is the
information of reporting data amount accumulated (or stored) in the
UE's buffer per Logical Channel Group (LCG). Up to 4 LCGs may be
configured, and LCG is a set of logical channels having similar QoS
requirements. The LCG is configured by eNB per UE.
[0046] If there is any BSR which has not been canceled, the UE
includes the BSR in the MAC PDU at operation 407. The buffer status
is contained in the BSR according to the following rules. [0047] If
the uplink resource for new data is available for transmitting only
one MAC PDU, the UE includes the data in the corresponding MAC PDU
and logs the buffer state in the BSR. [0048] If the uplink resource
for the new data is available for transmitting plural MAC PDUs at
the same subframe (i.e. large amount of resource is allocated), the
UE includes all MAC PDUs in the same subframe and logs the buffer
station in the BSR.
[0049] The UE generates a BSR MAC control element including the BSR
content and includes the BSR MAC control element in the MAC PDU
and, if the BSR is not a truncated BSR, (re)starts a
periodicBSR-Timer and retxBSR-Timer at operation 309. The truncated
BSR is the BSR including partial buffer status other than entire
buffer status, the periodic BSR-Timer is the timer for periodic BSR
transmission, and retxBSR-Timer is the timer for BSR retransmission
when uplink resource is not allocated for BSR. [0050] BSR is the
control information reporting buffer status per LCG.
[0051] There are several types of BSRs as follows. [0052] First
type: Regular BSR [0053] BSR transmitted after expiry of the
retxBSR-Timer when the UE has data that can be transmitted for a
certain logical channel belonging to the LCG. [0054] BSR
transmitted when data occurs from a higher layer (RLC or PDCP
layer) for the logical channel belonging to the LCG and the data
has the priority higher than any of the logical channel belonging
to the LCG. [0055] BSR transmitted when data to be transmitted
occurs from a higher layer (RLC or PDCP layer) for the logical
channel belonging to the LCG and there is no other data with the
exception of the corresponding data in any LCG. [0056] Second type:
Periodic BSR [0057] BSR transmitted when the periodicBSR-Timer
expires. [0058] Third type: Padding BSR [0059] BSR when uplink
resource is allocated and the padding bits filling the space
remained after transmitting the data is equal to or greater than
the sum of the size of BSR MAC Control Element and the size of the
sub-header of the BSR MAC Control Element.
[0060] Although the BSR may have been triggered several times, only
one BSR is included in on MAC PDU. The UE determines, at operation
411, whether there is any BSR triggered but not cancelled at
previous operation in addition to the BSR included in the MAC PDU.
If such BSR exists, the UE checks, at operation 413, the type of
the BSR included in the MAC PDU at previous operation.
[0061] If the type 1 or type 2 BSR has been included in the MAC PDU
(i.e. no type 3 BSR has not been included in the MAC PDU), the UE
cancels the remained BSRs at operation 415. Typically, the type 3
BSR is not triggered in advance but whether to trigger the type 3
BSR is determined when a specific MAC PDU is generated.
Accordingly, although the above operation is triggered when the
type 1 or type 2 BSR is transmitted, this has the same meaning that
another non-cancelled type 1 or type 2 BSR is cancelled. Or,
although the type 3 BSR is included in the MAC PDU, this has the
same meaning that type 1 or type 2 BSR triggered but not cancelled
yet cannot be cancelled.
[0062] The type 3 BSR is classified into one of two subtypes. One
is to reflecting the current buffer status correctly, the other is
to reflect the currently buffer state partially (reflects only
true). Particularly, the latter case is referred to as truncated
BSR, and although the padding space is permitted only based on the
buffer space of one LCU, the UE is triggered when one or more LCG
buffers have data. That is, the type 3 BSR fulfilling the following
conditions is the truncated BSR. [0063] condition 1: when the
padding bits filling the space remained after transmitting data is
equal to or greater than the sum of the short BSR size and its
sub-header size and less than the sum of the long BSR size and the
sub-header size and when data exist in two or more LCG at the
subframe carrying the BSR. In this case, the UE reports only the
buffer status of the LCG including the logical channel having the
highest priority.
[0064] By taking notice of the propriety of the type 3 BSR having
two subtypes, since the first subtype BSR reflects the UE's buffer
status comedy, if the BSR is transmitted, there is no need to
transmit the other BSRs. Accordingly, in spite of the type 3 BSR,
there is no need of transmitting the rest type 1 or type 2 BSRs
triggered but not cancelled. Since the second subtype BSR reflects
the UE's buffer state partially, if the transmission of the type 1
or type 2 BSR. triggered but not cancelled yet is cancelled, it is
delayed for the UE to report the correct UE's buffer state to the
eNB. Thus, the present disclosure may be modified as follows.
[0065] Although the BSR fulfilling the condition 1 among the type 3
BSRs is contained in the MAC PDU, the UE does not cancel the type 1
or type 2 BSR triggered but not cancelled.
[0066] If the remained BSRs are not cancelled through above
operations, the UE generates the next MAC PDU including the
remained BSR at operation 417.
[0067] Finally, the UE transmits the generated MAC PDU at operation
419 and ends the procedure at operation 421.
[0068] FIG. 5 is a diagram illustrating a configuration of the UE
according to an embodiment of the present disclosure.
[0069] The UE transmits and receives data with higher layer device
505 and control messages through the control message processing
unit 507 and, in transmission mode, the multiplexer/demultiplexer
503 multiplexes transmission signals and transmits the multiplexed
signal through the transceiver 501 and, in reception, the
multiplexer/demultiplexer 503 demultiplexes the received signal and
deliver the message information to the higher layer device 505 or
control message processor 507.
[0070] In the present disclosure, the BSR manager 511 checks
whether there is new data from the higher layer device 505 and
whether there is non-cancelled BSR. If there is any, the BSR
manager 511 controls the multiplexer/demultiplexer 503 to include
the BSR in the MAC PDU. If it is determined that there is
additional BSR, the BSR manager 511 checks the type of the BSR and,
if it is padding BSR, does not cancel the legacy BSR.
[0071] Although the description is directed to the case where the
UE includes plural blocks responsible for different functions, the
present disclosure is not limited thereto. for example, the
function of the BSR manager 511 may be performed by the controller
509 itself.
[0072] In this case, the controller 509 checks the presence/absence
of first type buffer status report which has been triggered in
allocation uplink resource for new data transmission but not
cancelled. If the first buffer status report exists, the controller
509 checks whether there is second type buffer status report
triggered but not cancelled in addition to the buffer status report
included in the uplink data and, if the second type buffer status
report exists, determines whether to cancel the second type buffer
status report depending on the first type buffer status report is
the regular buffer state report or periodic buffer status
report.
[0073] In more detail, if the first buffer status report is the
regular buffer status report or periodic buffer status report, the
controller 509 cancels the second buffer status report. Otherwise
if the first buffer status report is the padding buffer status
report, the controller 509 does not cancel the second buffer status
report.
[0074] According to an embodiment of the present disclosure, the
controller 509 generates the uplink data and controls to start a
timer for transmitting the buffer status report periodically or
retransmitting the buffer status report.
[0075] With the proposed method, it is possible to perform
measurement efficiently based on the current interference status or
potential interference factors and notifies the measurement result
to the eNB to make a handover decision to the cell capable of
reducing interference so as to avoid interference to the
interference communication technology and facilitate
communication.
[0076] Although the description has been made with reference to
particular embodiments, the present disclosure can be implemented
with various modification without departing from the scope of the
present disclosure. Thus, the present disclosure is not limited to
the particular embodiments disclosed but will include the following
claims and their equivalents.
* * * * *