U.S. patent application number 14/452549 was filed with the patent office on 2014-11-20 for method for allocating an uplink resource in a wireless communication system and system thereof.
The applicant listed for this patent is HTC Corporation. Invention is credited to Chih-Hsiang Wu.
Application Number | 20140341173 14/452549 |
Document ID | / |
Family ID | 42262322 |
Filed Date | 2014-11-20 |
United States Patent
Application |
20140341173 |
Kind Code |
A1 |
Wu; Chih-Hsiang |
November 20, 2014 |
METHOD FOR ALLOCATING AN UPLINK RESOURCE IN A WIRELESS
COMMUNICATION SYSTEM AND SYSTEM THEREOF
Abstract
A method for data transmission in a wireless communication
system including a User Equipment (UE) and a radio access network
(RAN) includes: transmitting a Medium Access Control (MAC) protocol
data unit (PDU) to the UE, wherein the MAC PDU includes a downlink
Radio Link Control (RLC) data PDU including a polling request for
requesting the UE to transmit a RLC status PDU; receiving an
acknowledgement signal from the UE, in response to the MAC PDU
including the polling request; and allocating an uplink resource to
the UE in response to the acknowledgement signal wherein the uplink
resource is used for the UE transmitting the RLC status PDU.
Inventors: |
Wu; Chih-Hsiang; (Taoyuan
County, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HTC Corporation |
Taoyuan County |
|
TW |
|
|
Family ID: |
42262322 |
Appl. No.: |
14/452549 |
Filed: |
August 6, 2014 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
12485914 |
Jun 17, 2009 |
|
|
|
14452549 |
|
|
|
|
Current U.S.
Class: |
370/329 |
Current CPC
Class: |
H04L 1/1867 20130101;
H04L 1/1812 20130101; H04L 5/003 20130101; H04W 72/04 20130101;
H04W 28/04 20130101; H04L 5/0055 20130101 |
Class at
Publication: |
370/329 |
International
Class: |
H04L 5/00 20060101
H04L005/00 |
Claims
1. A method for data transmission in a wireless communication
system including a User Equipment (UE) and a radio access network
(RAN), the method utilized in the RAN and comprising: transmitting
a Medium Access Control (MAC) protocol data unit (PDU) to the UE,
wherein the MAC PDU includes a downlink Radio Link Control (RLC)
data PDU including a polling request for requesting the UE to
transmit a RLC status PDU; receiving an acknowledgement signal from
the UE, in response to the MAC PDU including the polling request;
and allocating an uplink resource to the UE in response to the
acknowledgement signal wherein the uplink resource is used for the
UE transmitting the RLC status PDU.
2. The method of claim 1, wherein the downlink RLC data PDU
including the polling request is the last downlink RLC data PDU of
a downlink session.
3. The method of claim 1, wherein the UE comprises a Radio Link
Control (RLC) layer and a Medium Access Control and Physical
(MAC/PHY) layer, and the RAN comprises a Radio Link Control (RLC)
layer and a Medium Access Control and Physical (MAC/PHY) layer; and
step of transmitting the MAC protocol data unit (PDU) to the UE
further comprises: transmitting the MAC protocol data unit (PDU)
from the MAC/PHY layer of the RAN to the MAC/PHY layer of the
UE.
4. The method of claim 1, wherein the wireless communication system
is an LTE system and the RAN is an Evolved Universal Terrestrial
Radio Access Network (E-UTRAN).
5. The method of claim 1, wherein the acknowledgement signal is a
Hybrid Automatic Repeat ReQuest (HARQ) Acknowledgement (ACK).
6. The method of claim 4, wherein the E-UTRAN includes a Node B for
implementing the steps of transmitting the MAC protocol data unit
(PDU) and the step of receiving the acknowledgement signal and
allocating the uplink resource.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation application of U.S. patent
application Ser. No. 12/485,914, filed on Jun. 17, 2009, the
contents of which are included herein for reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a method for allocating an
uplink resource, and more particularly, a method for allocating an
uplink resource in a wireless communication system and a system
thereof.
[0004] 2. Description of the Prior Art
[0005] As today's applications for electronic systems grow at
ever-increasing rates, the demand for better communications
performance is never ceasing. Standards for various technologies
such as the 3rd Generation Partnership Project (3GPP) High-Speed
Packet Access (HSPA) and Long Term Evolution (LTE) work towards
creating more efficient communication systems. For example, dynamic
resource allocation for uplink transmissions has been introduced in
the 3GPP TS 36.321 standard, for communicating between a user
equipment (UE) such as a mobile station or a mobile handset, and an
Evolved Universal Terrestrial Radio Access Network (E-UTRAN) base
station. Dynamic resource allocation utilizes radio resources more
efficiently, where radio resources are allocated only when the UE
has data to transmit. But a drawback becomes clear when
insufficient radio resources are allocated by the E-UTRAN: the UE
must request for resources to be allocated and wait for the uplink
resource allocation, and this causes a delay before its data can be
transmitted, slowing down the overall communication between the UE
and the E-UTRAN. Fast allocation of uplink resources may be
required when the UE and E-UTRAN are in an active downlink session
but there is a need to transmit uplink data. Fast allocation of
uplink resources may also be required when uplink data has been
unsuccessfully received and needs to be retransmitted. The E-UTRAN
informs the UE of the status of received data packets via Status
PDUs, which contain positive and/or negative acknowledgements of
RLC PDUs. The status PDU can be sent in response to a polling
request from the UE, as disclosed in RLC protocol specification
3GPP TS 36.322 v8.2.0: "The receiving side of an AM RLC entity
shall trigger a STATUS report when it receives a RLC data PDU with
the P field set to "1" and the HARQ reordering of the corresponding
RLC data PDU is completed".
[0006] Long Term Evolution (LTE) is being developed by the 3rd
Generation Partnership Project (3GPP) and moving towards creating
more efficient communication systems. In 3GPP TS 36.321
specification for LTE MAC protocol, dynamic resource allocation for
uplink transmissions has been introduced for improving the
efficient utilization of the radio resources between a user
equipment (UE) and a Node B, i.e. a base station in an Evolved
Universal Terrestrial Radio Access Network (E-UTRAN) . With the
dynamic resource allocation, the radio resources are allocated only
when the UE has data to transmit so that the radio resources for
data transmission can be saved.
[0007] In an LTE system, an uplink scheduler assigns transmission
resources (resource blocks) to mobile terminals in that cell. In
order to perform these tasks, the scheduler needs information at
least about the terminals' current buffer state: that is, if and
how much data the terminal buffers have in its priority queues. The
3GPP TS 36.321 standard specifies certain behaviors in sections
5.4.4 (Scheduling Request) and 5.4.5 (Buffer Status Reporting). The
Scheduling Request is for requesting uplink resources: when a
Scheduling Request is triggered and no uplink resources are
allocated for the UE, the E-UTRAN will initiate a procedure to
grant uplink resources. The Buffer Status reporting procedure, on
the other hand, provides the E-UTRAN with information about the
amount of data remaining in the uplink buffers of the UE. A Buffer
Status report shall be triggered if (as one of several possible
conditions) a Buffer Status report is determined to be pending and
the UE has uplink resources allocated; if uplink resources are not
already allocated, a Scheduling Request shall be triggered.
[0008] FIG. 1 shows an exemplary signaling diagram 1000
illustrating an uplink data transmission from a User Equipment (UE)
1100 to an Evolved Universal Terrestrial Radio Access Network
(E-UTRAN) 1200 in an LTE system, according to the current
convention. The UE 1100 comprises a Radio Link Control (RLC) layer
1110 and a Medium Access Control and Physical (MAC/PHY) layer 1120.
Similarly, the E-UTRAN 1200 comprises an RLC layer 1210 and a
MAC/PHY layer 1220. In the mentioned figure and example, the RLC
1110 of the UE 1100 initiates a transmission of RLC data PDUs 1-5
(indicated at 1300), and sends a data transmission request to the
MAC/PHY layer 1120 (indicated at 1310). The MAC/PHY layer 1120
notes that an uplink resource is already allocated (indicated at
1320) for the UE 1100, and thus sends a confirmation signal to the
RLC 1110 so as to confirm that data transmission may begin
(indicated at 1330). Following this, the RLC 1110 respectively
sends the five RLC data PDUs, i.e. RLC data PDUs 1, 2, 3, 4 and 5,
(indicated at 1340a-e) to the MAC/PHY 1120. After receiving the
five RLC data PDUs, the MAC/PHY 1120 converts them as MAC PDUs and
then sends them to the MAC/PHY layer 1220 of the E-UTRAN 1200
respectively. In addition, the MAC/PHY 1120 packages a Buffer
Status Report (BSR), which indicates the UE transmission buffer is
now empty, into the MAC PDU 5 so as to inform the E-UTRAN 1200 that
the information to be sent has been sent. Upon receiving the empty
buffer information, the MAC/PHY 1220 closes the uplink resource
(indicated at 1360), and the final RLC data PDU 5 is received by
the RLC 1210 of the E-UTRAN 1200 (indicated at 1350e).
[0009] From the standpoint of E-UTRAN 1200, the RLC data PDUs 1, 2,
and 5 are received successfully (indicated at 1350a, 1350b, and
1350e), but the RLC data PDUs 3 and 4 are not received by the
MAC/PHY 1220 (indicated at 1350c and 1350d). Therefore, the RLC
1210 needs to transmit an RLC status (control) PDU (indicated at
1400) to relay the acknowledgement ("received") of the RLC data
PDUs 1, 2, and 5 and the negative acknowledgement ("not received")
of the RLC data PDUs 3 and 4. The RLC status (control) PDU is sent
(indicated at 1410a) and received by the RLC 1110 (indicated at
1420a).
[0010] After receiving the RLC status (control) PDU, the RLC 1110
needs to retransmit the RLC data PDUs 3 and 4 (indicated at 1500),
and makes a data transmission request to the MAC/PHY 1120
(indicated at 1510). Because the uplink resource was stopped
previously in step 1360, the MAC/PHY 1120 does not have sufficient
uplink resources allocated for the data retransmission (indicated
at 1520) . Between the MAC/PHY 1120 of the UE 1100 and the MAC/PHY
1220 of the E-UTRAN 1200, steps 1530 through 1540 involve a
Scheduling Request from the MAC/PHY 1120 to the MAC/PHY 1220
(indicated at 1530), to which the response is an uplink resource
allocated by the MAC/PHY 1220 (indicated at 1540). Alternatively,
the MAC/PHY 1220 may allocate the uplink resource in response to a
Buffer Status Report (indicated at 1550 and 1560). When the MAC/PHY
1120 notes that the uplink resource has been allocated (indicated
at 1600), it will send a confirmation signal to the RLC 1110 to
confirm that data retransmission for RLC data PDUs 3 and 4 may
begin (indicated at 1610).
[0011] During the time consumed by sending Scheduling Request and
Buffer Status Report by the MAC/PHY 1120 and waiting for uplink
resource allocation from the MAC/PHY 1220 (indicated at 1530
through 1560), the RLC 1110 must wait for the data transmission
confirmation (indicated at 1610) before it may begin retransmitting
the RLC data PDUs 3 and 4 (indicated at 1620a-b) to the RLC 1210 of
the E-UTRAN 1200 (indicated at 1630a-b).
[0012] FIG. 3 shows an exemplary signaling diagram 3000
illustrating a downlink data transmission from an Evolved Universal
Terrestrial Radio Access Network (E-UTRAN) to a User Equipment (UE)
in an LTE system, according to the current convention. Using
substantially the same UE 1100 and E-UTRAN 1200 (and their
components) as originally introduced in FIG. 1, the downlink data
transmission interaction of FIG. 3 begins with the RLC 1210 of the
E-UTRAN 1200 transmitting RLC data PDUs 1-5 (indicated at 3330).
The RLC 1210 sends the RLC data PDUs 1-5 (indicated at 3310a-e)
through the MAC/PHY 1220, the MAC/PHY 1120 to the RLC 1110. In this
example, the RLC data PDUs 1, 3, 4, and 5 are received successfully
(indicated at 3320a, 3320c, 3320d and 3320e), but the RLC data PDU
2 is not received by the RLC 1110 (indicated at 3310b). The RLC
data PDU 5 also includes polling, signifying the end of transmitted
data (indicated at 3320e).
[0013] Because of the missing RLC data PDU 2, the RLC 1110
initiates a transmission of an RLC status (control) PDU (indicated
at 3400) and sends a data transmission request to the MAC/PHY 1120
(indicated at 3410). After receiving the data transmission request,
the MAC/PHY 1120 notes that there is no sufficient uplink resource
allocated for transmitting the RLC status (control) PDU (indicated
at 3420) and thus sends a Scheduling Request (SR) to the MAC/PHY
1220 of the E-UTRAN 1200 (indicated at 3430). In response to the
Scheduling Request, the MAC/PHY 1220 allocates an uplink resource
to the MAC/PHY 1120 (indicated at 3440). Alternatively, the MAC/PHY
1220 may allocate the uplink resource in response to a Buffer
Status Report sent by the MAC/PHY 1120 (indicated at 3450 and 3460)
. Once the uplink resource is allocated (indicated at 3500), the
MAC/PHY 1120 confirms that data transmission is ready to the RLC
1110 (indicated at 3510) so that the RLC 1110 begins sending the
RLC status PDU (indicated at 3520) through the MAC/PHY 1120, the
MAC/PHY 1220 to the RLC 1210 of the E-UTRAN 1200 (indicated at
3530). In response to the RLC status PDU, the RLC 1210 retransmits
the originally missing RLC data PDU 2 to the RLC 1110 of the UE
1100 (indicated at 3540 to 3560).
[0014] Once more, the time is consumed by sending Scheduling
Request and Buffer Status Report by the MAC/PHY 1120 and waiting
for uplink resource allocation from the MAC/PHY 1220 (indicated at
3430 through 3460), and the RLC 1110 of UE 1100 must wait for
confirmation to send its RLC status PDU to the E-UTRAN 1200.
[0015] As illustrated in FIG. 1 and FIG. 3, it is understood that
the dynamic resource allocation has the drawback that UE has to
request for transmission resources and wait for the uplink resource
allocation if no sufficient radio resources are allocated by
E-UTRAN, and this causes a delay before its data can be
transmitted, slowing down the overall communication between the UE
and the E-UTRAN.
SUMMARY OF THE INVENTION
[0016] It is therefore an objective of the present invention to
solve the aforementioned problems, and to provide a method for
transmitting data on a wireless network, allocating an uplink
resource before the E-UTRAN receives a UE Radio Link Control (RLC)
data transmission request.
[0017] These and other problems are generally solved or
circumvented, and technical advantages are generally achieved, by
advantageous embodiments of the present invention, which includes a
method for data transmission in a wireless communication system
comprising a User Equipment (UE) and a radio access network (RAN).
The method comprises: transmitting a Medium Access Control (MAC)
protocol data unit (PDU) to the UE, wherein the MAC PDU includes a
downlink Radio Link Control (RLC) data PDU including a polling
request for requesting the UE to transmit a RLC status PDU;
receiving an acknowledgement signal from the UE, in response to the
MAC PDU including the polling request; and allocating an uplink
resource to the UE in response to the acknowledgement signal
wherein the uplink resource is used for the UE transmitting the RLC
status PDU.
[0018] A system embodiment of the present invention comprises a
User Equipment (UE) device and an Evolved Universal Terrestrial
Radio Access Network (E-UTRAN) wherein, when expecting a data
transmission from a UE device to the E-UTRAN, the E-UTRAN is for
allocating an uplink resource before the E-UTRAN receives a UE
Radio Link Control (RLC) data transmission request from the UE
device, and transmitting data between the E-UTRAN and the UE device
via the uplink resource.
[0019] The foregoing has outlined rather broadly the features and
technical advantages of the present invention in order that the
detailed description of the invention that follows may be better
understood. Additional features and descriptions of the present
invention will be described hereinafter which form the subject of
the claims of the present invention. It should be appreciated by
those skilled in the art that the conception and specific
embodiments disclosed may be readily utilized as a basis for
modifying or designing other structures or processes for carrying
out the same purposes of the present invention. It should also be
realized by those skilled in the art that such equivalent
constructions do not depart from the spirit and scope of the
invention as set forth in the appended claims.
[0020] These and other objectives of the present invention will no
doubt become obvious to those of ordinary skill in the art after
reading the following detailed description of the preferred
embodiment that is illustrated in the various figures and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] For a more complete understanding of the present invention,
and the advantages thereof, reference is now made to the following
descriptions taken in conjunction with the accompanying drawings,
in which:
[0022] FIG. 1 shows a signaling diagram illustrating an uplink data
transmission from a User Equipment (UE) to an Evolved Universal
Terrestrial Radio Access Network (E-UTRAN) in an LTE system,
according to the current convention.
[0023] FIG. 2 shows a signaling diagram illustrating an uplink data
transmission from a User Equipment (UE) to an Evolved Universal
Terrestrial Radio Access Network (E-UTRAN) in an LTE system,
according to an embodiment of the present invention.
[0024] FIG. 3 shows a signaling diagram illustrating a downlink
data transmission from an Evolved Universal Terrestrial Radio
Access Network (E-UTRAN) to a User Equipment (UE) in an LTE system,
according to the current convention.
[0025] FIG. 4 shows a signaling diagram illustrating a downlink
data transmission from an Evolved Universal Terrestrial Radio
Access Network (E-UTRAN) to a User Equipment (UE) in an LTE system,
according to another embodiment of the present invention.
[0026] FIG. 5 shows a flowchart illustrating a method for
transmitting data between a User Equipment (UE) and an Evolved
Universal Terrestrial Radio Access Network (E-UTRAN) in an LTE
system, according to an embodiment of the present invention.
[0027] FIG. 6 shows a flowchart illustrating a method for
transmitting data between a User Equipment (UE) and an Evolved
Universal Terrestrial Radio Access Network (E-UTRAN) in a LTE
system, according to another embodiment of the present
invention.
[0028] FIG. 7 is a diagram of a User Equipment (UE) and an Evolved
Universal Terrestrial Radio Access Network (E-UTRAN) as a
communication system, according to an embodiment of the present
invention.
[0029] Corresponding numerals and symbols in the different figures
generally refer to corresponding parts unless otherwise indicated.
The figures are drawn to clearly illustrate the relevant aspects of
the preferred embodiments and are not necessarily drawn to
scale.
DETAILED DESCRIPTION
[0030] Certain terms are used throughout the following description
and claims to refer to particular system components. As one skilled
in the art will appreciate, manufacturers may refer to a component
by different names. This document does not intend to distinguish
between components that differ in name but not function. In the
following discussion and in the claims, the terms "including" and
"comprising" are used in an open-ended fashion, and thus should be
interpreted to mean "including, but not limited to . . . ".
[0031] Referring now to FIG. 2, the signaling diagram 2000
illustrates an uplink data transmission from a User Equipment (UE)
2100 to an Evolved Universal Terrestrial Radio Access Network
(E-UTRAN) 2200 in an LTE system. The UE 2100 comprises a Radio Link
Control (RLC) layer 2110 and a Medium Access Control and Physical
(MAC/PHY) layer 2120. The E-UTRAN 2200 comprises an RLC layer 2210
and a MAC/PHY layer 2220. In this embodiment, the UE 2100
respectively sends five RLC data PDUs 1, 2, 3, 4 and 5 to the
E-UTRAN 2200 and the RLC data PDUs 3 and 4 are not received
successfully by the PHY/MAC 2220 of the E-UTRAN 2200. The
procedures, e.g. the data transmission request and confirmation,
the conversion from the RLC data PDU to MAC PDU and the stop of
uplink resource allocation due to BSR (buffer=0), proceeded prior
to the RLC 2210 sending a RLC status (control) PDU are identical to
those illustrated in FIG. 1 and thus not illustrated in detail.
[0032] From the standpoint of E-UTRAN 2200, the RLC data PDUs 1, 2,
and 5 are received successfully, but the RLC data PDUs 3 and 4 are
not received by the MAC/PHY 2220. Therefore, the RLC 2210 of the
E-UTRAN 2200 sends an RLC status (control) PDU, which includes the
acknowledgement ("received") of the RLC data PDUs 1, 2, and 5 and
the negative acknowledgement ("not received") of the RLC data PDUs
3 and 4, to the RLC 2110 of the UE 2100 (indicated at 2410, 2420
and 2430). In the transmission procedure, the RLC status (control)
PDU is received and converted to a MAC PDU 1 by the PHY/MAC 2220
and then transmitted to the PHY/MAC 2120 of the UE 2100 (indicated
at 2420). When receiving the MAC PDU 1, the PHY/MAC 2120 converts
it back to the RLC status (control) PDU and sends it to the RLC
2110 (indicated at 2430).
[0033] Following the transmission of the RLC status (control) PDU,
the MAC/PHY 2120 returns a Level 1 (L1) Hybrid Automatic Repeat
ReQuest (HARQ) Acknowledgement (ACK), in response to the MAC PDU 1
transmitted by the MAC/PHY 2220, to the MAC/PHY 2220 (indicated at
2510).
[0034] However, in this stage of the communication, the RLC 2210 of
the E-UTRAN 2200 is expecting a retransmission from the UE 2100 for
the missing RLC data PDUs 3 and 4, which are not successfully
received by the E-UTRAN 2200. Therefore, when the MAC/PHY 2220 of
the E-UTRAN 2200 receives the HARQ ACK from the UE 2100 according
to the present invention, it will allocate uplink resource(s) for
the UE 2100 to retransmit the expected data, i.e. the RLC data PDUs
3 and 4. In this scenario, the uplink resource is allocated by the
E-UTRAN 2200 according to the HARQ ACK from the MAC/PHY 2120. In
other embodiment, the uplink resource can be allocated further
according to the RLC data PDU 5, which contains the BSR trigger.
Meanwhile, the RLC 2110 initiates a retransmission of the RLC data
PDUs 3 and 4 (indicated at 2500), and sends a data transmission
request to the MAC/PHY 2120 (indicated at 2530). Due to the
pre-emptive nature of this embodiment of the present invention, the
uplink resource has already been allocated by the E-UTRAN 2200 so
that the RLC data PDUs 3 and 4 can be retransmitted from the RLC
2110 to the RLC 2210 (indicated at 2540a-b and 2550a-b) with a much
shorter delay than previously done in prior art as illustrated in
FIG. 1.
[0035] FIG. 4 shows a signaling diagram 4000 illustrating a
downlink data transmission from an Evolved Universal Terrestrial
Radio Access Network (E-UTRAN) 2200 to a User Equipment (UE) 2100
in an LTE system, according to another embodiment of the present
invention. In this embodiment, the E-UTRAN 2200 respectively sends
five RLC data PDUs 1, 2, 3, 4 and 5 to the UE 2100 and the RLC data
PDU 2 is not received successfully by the PHY/MAC 2120 of the UE
2100. In the transmission procedure, the five RLC data PDUs 1, 2,
3, 4 and 5 are received and respectively converted to MAC PDUs 1,
2, 3, 4 and 5 by the PHY/MAC 2220 and then transmitted to the
PHY/MAC 2120 of the UE 2100. When receiving the MAC PDUs 1, 3, 4
and 5 (MAC PDU 2 misses) , the PHY/MAC 2120 converts them back to
the RLC data PDUs 1, 3, 4 and 5 and sends them to the RLC 2110
respectively. The RLC data PDU 5 also includes polling, signifying
the end of transmitted data.
[0036] Following the successful transmission of the RLC data PDUs
1, 3, 4 and 5, the MAC/PHY 2120 returns a Level 1 (L1) Hybrid
Automatic Repeat ReQuest (HARQ) Acknowledgement (ACK), in response
to the MAC PDU 5 (with polling), to the MAC/PHY 2220 (indicated at
4410). When the MAC/PHY 2220 of the E-UTRAN 2200 receives the HARQ
ACK from the UE 2100 according to the present invention, it will
allocate uplink resource(s) for the UE 2100 to transmit the
expected data. Meanwhile, the RLC 2110 initiates the transmission
of a RLC status PDU (indicated at 4400) , which includes the
negative acknowledgement ("not received") of the RLC data PDU 2,
and sends a data transmission request to the MAC/PHY 2120
(indicated at 4430). Due to the pre-emptive nature of this
embodiment of the present invention, the uplink resource has
already been allocated by the E-UTRAN 2200 so that the RLC status
PDU can be transmitted from the RLC 2110 to the RLC 2210 (indicated
at 2560a-b) with a much shorter delay than previously done in prior
art as illustrated in FIG. 3. After receiving the RLC status PDU,
the RLC 2210 of the E-UTRAN 2200 retransmits the RLC data PDU 2 to
the RLC 2110 of the UE 2100 (indicated at 2570a-b).
[0037] From the improvements made by the present invention over the
prior arts, the delay time experienced by the RLC 2110 of the UE
2100 is greatly reduced, further heightening the efficiency of the
communications in the LTE system.
[0038] Yet another embodiment of the present invention defines the
Buffer Status reporting from the 3GPP TS 36.321 description
presented earlier to include information about negatively
acknowledged data: the specification does not explicitly state
whether negatively acknowledged data should be counted in the
buffer status report (BSR) . As such, this embodiment comprises
receiving a BSR for a UE transmission buffer from the UE, at which
time the E-UTRAN expects the RLC data PDU retransmission and
allocates an uplink resource appropriately. In yet another
embodiment, the E-UTRAN expects an RLC data PDU retransmission and
allocates an uplink resource appropriately after receiving a BSR
for a UE transmission buffer from the UE, where the BSR contains
both a UE transmission buffer and a UE retransmission buffer.
[0039] In another embodiment, please referring to FIG. 2 and FIG.
4, if the E-UTRAN 2200 does not allocate an uplink resource to the
UE 2100 in response to the HARQ ACK within a predetermined time,
the MAC/PHY 2120 of the UE 2100 may automatically transmit a
scheduling request (SR) to the E-UTRAN 2200 for requesting the
uplink resource allocation from the E-UTRAN 2200 after the
predetermined time. The predetermined time may be implemented
differently according to design and requirements. In this
embodiment, the predetermined time can be set and begin counting
when the MAC/PHY 2120 transmits the HARQ ACK to the E-UTRAN 2200.
In other embodiment according to the present invention, the
predetermined time may be set and begin when the UE 2100 receives a
MAC PDU, which includes a RLC status PDU or a negative
acknowledgement ("not received") of at least one RLC data PDU. And
there is no limitation in the present invention that this
predetermined time must be set by a specific device: it can be
configured by either the E-UTRAN 2200 or the UE 2100, as needed by
the designer's specs.
[0040] It should be noted that although the above embodiments
specifically refer to a User Equipment (UE) and an Evolved
Universal Terrestrial Radio Access Network (E-UTRAN) in the
signaling diagrams and examples, this should in no way be construed
to be a limitation of the present invention: they are intended for
illustrative purposes only. In addition, while specifications from
the 3GPP TS 36.231 standard have been mentioned, they are pointed
to only as an example of a situation where an implementation of the
specification would benefit greatly from methods of the present
invention. Thus, the present invention can be applied to any
wireless communications system which experiences a delay such as
the examples provided, and such applications and embodiments also
obey the spirit of and should be considered with the scope of the
present invention.
[0041] FIG. 5 shows a basic flowchart 500 illustrating a method for
transmitting data between an UE and an E-UTRAN in an LTE system,
according to an embodiment of the present invention. In this
embodiment, the UE can be any portable hand-held devices, e.g.
mobile phones or PDA phones, with wireless communication functions.
Provided that substantially the same result is achieved, the steps
of the process flowchart need not be in the exact order shown and
need not be contiguous; that is, other steps can be intermediate.
Please refer to FIGS. 2, 4 and 5; this embodiment of the method
according to the present invention includes the following
steps:
[0042] Step 510: The MAC/PHY 2220 of the E-UTRAN 2200 transmits a
MAC protocol data unit (PDU) to the MAC/PHY 2120 of the UE 2100.
The MAC protocol data unit (PDU) may be the MAC PDU 1 including a
negative acknowledgement ("not received") of at least one RLC data
PDU sent by the UE 2100 as shown in FIG. 2, or the MAC PDU 5
converted from the RLC data PDU 5 (polling) as shown in FIG. 4.
[0043] Step 520: The MAC/PHY 2120 of the UE 2100 returns an
acknowledgement signal in response to the MAC PDU. The
acknowledgement signal may be the HARQ ACK shown in FIG. 2 and FIG.
4.
[0044] Step 530: The MAC/PHY 2220 of the E-UTRAN 2200 receives the
acknowledgement signal and allocates an uplink resource (indicated
at 2520 in FIG. 2 and at 4420 in FIG. 4) in response to the
acknowledgement signal.
[0045] Step 540: The data can be transmitted from the UE 2100 to
the E-UTRAN 2200 via the allocated uplink resource. The data may be
the RLC data PDUs 3 and 4 shown in FIG. 2 and the RLC status PDU
shown in FIG. 4 transmitted from the UE 2100 to the E-UTRAN
2200.
[0046] FIG. 6 shows a basic flowchart 600 illustrating a method for
transmitting data between an UE and an E-UTRAN in an LTE system,
according to another embodiment of the present invention. Please
refer to FIGS. 2, 4 and 6; this embodiment of the method according
to the present invention includes the following steps:
[0047] Step 610: The MAC/PHY 2220 of the E-UTRAN 2200 transmits a
MAC protocol data unit (PDU) to the MAC/PHY 2120 of the UE 2100.
The MAC protocol data unit (PDU) may be the MAC PDU 1 including a
negative acknowledgement ("not received") of at least one RLC data
PDU sent by the UE 2100 as shown in FIG. 2, or the MAC PDU 5
converted from the RLC data PDU 5 (polling) as shown in FIG. 4.
[0048] Step 620: The MAC/PHY 2120 of the UE 2100 receives the MAC
PDU and begins counting a predetermined time.
[0049] Step 630: The MAC/PHY 2120 of the UE 2100 sends a scheduling
request (SR) to the MAC/PHY 2220 of the E-UTRAN 2200 after the
predetermined time (not shown in FIG. 2 and FIG. 4).
[0050] Step 640: The MAC/PHY 2220 of the E-UTRAN 2200 receives the
scheduling request (SR) and allocates an uplink resource in
response to the scheduling request (SR).
[0051] Step 650: The data can be transmitted from the UE 2100 to
the E-UTRAN 2200 via the allocated uplink resource. The data may be
the RLC data PDUs 3 and 4 shown in FIG. 2 and the RLC status PDU
shown in FIG. 4 transmitted from the UE 2100 to the E-UTRAN
2200.
[0052] It should be noted that the E-UTRAN 2200 according the
present invention may include a Node B, i.e. abase station, for
implementing all the functions implemented by the E-UTRAN as
described in the above-mentioned embodiments of FIG. 2 and FIG.
4.
[0053] FIG. 7 is a diagram of a User Equipment (UE) and an Evolved
Universal Terrestrial Radio Access Network (E-UTRAN) as a wireless
communication system 6000, according to an embodiment of the
present invention. As shown, the wireless communication system 6000
comprises a User Equipment (UE) 6100 and an Evolved Universal
Terrestrial Radio Access Network (E-UTRAN) 6200. The UE 6100
comprises a Radio Link Control (RLC) layer 6110 and a Medium Access
Control and Physical (MAC/PHY) layer 6120, and the E-UTRAN 6200
comprises an RLC layer 6210 and a MAC/PHY layer 6220. As the
methods described above, in their various embodiments, have already
covered the functionalities and utilizations of the UE 6100, RLC
6110, MAC/PHY 6220, E-UTRAN 6200, RLC 6210, and MAC/PHY 6220,
further description is omitted.
[0054] Also, although the present invention and its advantages have
been described in detail, it should be understood that various
changes, substitutions and alterations can be made herein without
departing from the spirit and scope of the invention as defined by
the appended claims. For example, many of the processes discussed
above can be implemented in different methodologies and replaced by
other processes, or a combination thereof.
[0055] Moreover, the scope of the present application is not
intended to be limited to the particular embodiments of the
systems, methods and steps described in the specification. As one
of ordinary skill in the art will readily appreciate from the
disclosure of the present invention, systems, methods, or steps,
presently existing or later to be developed, that perform
substantially the same function or achieve substantially the same
result as the corresponding embodiments described herein may be
utilized according to the present invention. Accordingly, the
appended claims are intended to include within their scope such
systems, methods, or steps.
[0056] Those skilled in the art will readily observe that numerous
modifications and alterations of the device and method may be made
while retaining the teachings of the invention. Accordingly, the
above disclosure should be construed as limited only by the metes
and bounds of the appended claims.
* * * * *