U.S. patent number RE44,203 [Application Number 13/371,329] was granted by the patent office on 2013-05-07 for method of allocating radio resources in a wireless communication system.
This patent grant is currently assigned to LG Electronics Inc.. The grantee listed for this patent is Sung Duck Chun, Young Dae Lee, Sung Jun Park, Seung June Yi. Invention is credited to Sung Duck Chun, Young Dae Lee, Sung Jun Park, Seung June Yi.
United States Patent |
RE44,203 |
Chun , et al. |
May 7, 2013 |
Method of allocating radio resources in a wireless communication
system
Abstract
A method of allocating radio resources in a wireless
communication system is disclosed. A method of allocating radio
resources from a network of a wireless communication system in
accordance with a plurality of scheduling modes comprises
transmitting first scheduling information to a user equipment to
allocate radio resources to the user equipment in accordance with a
first scheduling mode, the first scheduling information including a
first user equipment identifier, and transmitting second scheduling
information to the user equipment to allocate radio resources to
the user equipment in accordance with a second scheduling mode, the
second scheduling information including a second user equipment
identifier.
Inventors: |
Chun; Sung Duck (Anyang-si,
KR), Lee; Young Dae (Anyang-si, KR), Park;
Sung Jun (Anyang-si, KR), Yi; Seung June
(Anyang-si, KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
Chun; Sung Duck
Lee; Young Dae
Park; Sung Jun
Yi; Seung June |
Anyang-si
Anyang-si
Anyang-si
Anyang-si |
N/A
N/A
N/A
N/A |
KR
KR
KR
KR |
|
|
Assignee: |
LG Electronics Inc. (Seoul,
KR)
|
Family
ID: |
43048793 |
Appl.
No.: |
13/371,329 |
Filed: |
August 22, 2008 |
PCT
Filed: |
August 22, 2008 |
PCT No.: |
PCT/KR2008/004915 |
371(c)(1),(2),(4) Date: |
April 20, 2010 |
PCT
Pub. No.: |
WO2009/025525 |
PCT
Pub. Date: |
February 26, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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60957450 |
Aug 22, 2007 |
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60976766 |
Oct 1, 2007 |
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60977366 |
Oct 3, 2007 |
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61018884 |
Jan 3, 2008 |
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61038470 |
Mar 21, 2008 |
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61039095 |
Mar 24, 2008 |
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61074998 |
Jun 23, 2008 |
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Reissue of: |
12667380 |
Apr 20, 2010 |
7996029 |
Aug 9, 2011 |
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Foreign Application Priority Data
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Aug 22, 2008 [KR] |
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10-2008-0082245 |
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Current U.S.
Class: |
455/509; 370/436;
455/450; 455/451; 455/453; 455/454; 370/395.4; 455/455;
370/431 |
Current CPC
Class: |
H04W
72/042 (20130101); H04W 72/04 (20130101) |
Current International
Class: |
H04B
7/00 (20060101) |
Field of
Search: |
;455/450-455 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1921683 |
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Feb 2007 |
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CN |
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2434281 |
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Jul 2007 |
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GB |
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10-2006-0052437 |
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May 2006 |
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KR |
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10-2007-0061329 |
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Jun 2006 |
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KR |
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10-2007-0061329 |
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Jun 2007 |
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KR |
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10-2007-0076374 |
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Jul 2007 |
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KR |
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10-2007-0076375 |
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Jul 2007 |
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KR |
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10-2009-0016412 |
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Feb 2009 |
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KR |
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2004102431 |
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Nov 2004 |
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WO |
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2007/078173 |
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Jul 2007 |
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WO |
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Other References
Nokia et al., "Stage 3 Aspects of Semi-Persistent Scheduling",
R2-072401, 3GPP TSG-RAN WG2 Meeting #58bis, Jun. 2007. cited by
applicant .
Philips et al., "Control of E-UTRAN UL Scheduling", R2-073394, 3GPP
TSG-RAN WG2#59, Aug. 2007. cited by applicant .
Philips et al., "Control signalling for dynamically- and
persistently-scheduled transmissions in E-UTRA", R1-073135, 3GPP
TSG RAN WG1 Meeting #49bis, Jun. 2007. cited by applicant .
Ericsson, "MAC Stage 3 Text Proposal for Semi Persistent DL
Scheduling," R2-072702, TSG-RAN WG2 Meeting #58bis, Jun. 2007,
XP-050135489. cited by applicant .
Nokia et al., "Stage 3 Aspects of Semi-Persistent Scheduling,"
R2-073059, 3GPP TSG-RAN WG2 Meeting #59, Aug. 2007, XP-050135796.
cited by applicant .
LG Electronics Inc., "Discussion on Persistent Scheduling,"
R2-073510, 3GPP TSG-RAN WG2 #59, Aug. 2007, XP-05013621. cited by
applicant .
NTT DoCoMo Inc., "Issues Regarding RRC.sub.--Connected DRX
Operation," R2-073566, 3GPP TSG RAN WG2 #59, Aug. 2007,
XP-050136257. cited by applicant.
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Primary Examiner: Alam; Fayyaz
Attorney, Agent or Firm: Lee, Hong, Degerman, Kang &
Waimey
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is .Iadd.a reissue application of U.S. Pat. No.
7,996,029 B2, the entirety of which is incorporated herein by
reference, which is .Iaddend.a 371 U.S. national stage application
of international application PCT/KR2008/004915, filed on Aug. 22,
2008, which claims .[.priority to.]. .Iadd.the benefit of
.Iaddend.U.S. provisional applications 60/957,450, filed on Aug.
22, 2007, 60/976,766, filed on Oct. 1, 2007, 60/977,366, filed on
Oct. 3, 2007, 61/018,884, filed on Jan. 3, 2008, 61/038,470, filed
on Mar. 21, 2008, 61/039,095, filed on Mar. 24, 2008, and
61/074,998, filed on Jun. 23, 2008, and .Iadd.also claims the
benefit of earlier filing date and right of priority to
.Iaddend.Korean patent application 10-2008-0082245, filed on Aug.
22, 2008, the contents of which are .Iadd.all .Iaddend.hereby
incorporated by reference herein in their entirety.
Claims
The invention claimed is:
1. A method of radio resources allocation at a user equipment of a
wireless communication system, the method comprising: receiving
scheduling information from a network, wherein the scheduling
information comprises either a radio network temporary identifier
(C-RNTI) to indicate that the scheduling information is associated
with a dynamic scheduling mode or a Semi-Persistent Scheduling RNTI
(SPS-C-RNTI) to indicate that the scheduling information is
associated with a semi-persistent scheduling mode; if the
scheduling information comprises the C-RNTI, receiving downlink
data using the scheduling information during a corresponding
transmission interval only; and if the scheduling information
comprises the SPS-C-RNTI, receiving the downlink data using the
scheduling information periodically according to an allocation
period .[.included in the scheduling information.]..
2. The method of claim 1, wherein the C-RNTI and the SPS-C-RNTI are
allocated from the network before receiving the scheduling
information.
3. The method of claim 1, wherein the scheduling information is
received on a physical downlink control channel (PDCCH).
4. A method of radio resources allocation at a user equipment of a
wireless communication system, the method comprising: receiving
scheduling information from a network, wherein the scheduling
information comprises either a radio network temporary identifier
(C-RNTI) to indicate that the scheduling information is associated
with a dynamic scheduling mode or a Semi-Persistent Scheduling RNTI
(SPS-C-RNTI) to indicate that the scheduling information is
associated with a semi-persistent scheduling mode; if the
scheduling information comprises the C-RNTI, transmitting uplink
data using the scheduling information during a corresponding
transmission interval only; and if the scheduling information
comprises the SPS-C-RNTI, transmitting the uplink data using the
scheduling information periodically according to an allocation
period .[.included in the scheduling information.]..
5. The method of claim 4, wherein the C-RNTI and the SPS-C-RNTI are
allocated from the network before receiving the scheduling
information.
6. The method of claim 4, wherein the scheduling information is
received on a physical downlink control channel (PDCCH).
7. A user equipment for use in a wireless communication system, the
user equipment comprising: a receiver configured to: receive
scheduling information from a network, wherein the scheduling
information comprises either a radio network temporary identifier
(C-RNTI) to indicate that the scheduling information is associated
with a dynamic scheduling mode or a Semi-Persistent Scheduling RNTI
(SPS-C-RNTI) to indicate that the scheduling information is
associated with a semi-persistent scheduling mode; receive downlink
data using the scheduling information during a corresponding
transmission interval only, if the scheduling information comprises
the C-RNTI; and receive the downlink data using the scheduling
information periodically according to an allocation period
.[.included in the scheduling information.]., if the scheduling
information comprises the SPS-C-RNTI; and a transmitter configured
to: transmit uplink data using the scheduling information during a
corresponding transmission interval only, if the scheduling
information comprises the C-RNTI; and transmit the uplink data
using the scheduling information periodically according to an
allocation period .[.included in the scheduling information.]., if
the scheduling information comprises the SPS-C-RNTI.
Description
TECHNICAL FIELD
The present invention relates to a wireless communication system,
and more particularly, to a method of allocating radio resources in
a wireless communication system.
BACKGROUND ART
In a wireless communication system which uses multiple carriers,
such as an orthogonal frequency division multiple access (OFDMA) or
a single carrier-frequency division multiple access (SC-FDMA),
radio resources are a set of continuous sub-carriers and are
defined by a time-frequency region on a two-dimensional sphere. A
time-frequency region is a rectangular form sectioned by time and
sub-carrier coordinates. In other words, one time-frequency region
could be a rectangular form sectioned by at least one symbol on a
time axis and a plurality of sub-carriers on a frequency axis. Such
a time-frequency region can be allocated to an uplink for a
specific user equipment (UE), or an eNode B can transmit the
time-frequency region to a specific user equipment in a downlink.
In order to define such a time-frequency region on the
two-dimensional sphere, the number of OFDM symbols and the number
of continuous sub-carriers starting from a point having an offset
from a reference point should be given.
An evolved universal mobile telecommunications system (E-UMTS)
which is currently being discussed uses 10 ms radio frame
comprising 10 sub-frames. Namely, one sub-frame includes two
continuous slots. One slot has a length of 0.5 ms. Also, one
sub-frame comprises a plurality of OFDM symbols, and a part (for
example, first symbol) of the plurality of OFDM symbols can be used
for transmission of L1/L2 control information.
FIG. 1 illustrates an example of a structure of physical channels
used in the E-UMTS. In FIG. 1, one sub-frame comprises an L1/L2
control information transmission region (hatching part) and a data
transmission region (non-hatching part).
FIG. 2 illustrates a general method of transmitting data in the
E-UMTS. In the E-UMTS, a hybrid auto repeat request (HARQ) scheme,
which is one of data retransmission schemes, is used to improve
throughput, thereby enabling desirable communication.
Referring to FIG. 2, the eNB transmits downlink scheduling
information (hereinafter, referred to as `DL scheduling
information`) through DL L1/L2 control channel, for example, a
physical downlink control channel (PDCCH), to transmit data to a
user equipment in accordance with the HARQ scheme. The DL
scheduling information includes user equipment identifier (UE ID)
or group identifier (group ID) of user equipments, location and
duration (resource assignment and duration of assignment)
information of radio resources allocated for transmission of
downlink data, modulation mode, payload size, transmission
parameters such as MIMO related information, HARQ process
information, redundancy version, and new data indicator.
In order to notify that DL scheduling information is transmitted
through the PDCCH for what user equipment, the user equipment
identifier (or group identifier), for example, a radio network
temporary identifier (RNTI) is transmitted. The RNTI can be
classified into a dedicated RNTI and a common RNTI. The dedicated
RNTI is used for data transmission and reception to and from a user
equipment of which information is registered with a eNB. The common
RNTI is used if communication is performed with user equipments,
which are not allocated with dedicated RNTI as their information is
not registered with the eNB. Alternatively, the common RNTI is used
for transmission and reception of information used commonly for a
plurality of user equipments, such as system information. For
example, examples of the common RNTI include RA-RNTI and T-C-RNTI,
which are used during a random access procedure through a random
access channel (RACH). The user equipment identifier or group
identifier can be transmitted in a type of CRC masking in DL
scheduling information transmitted through the PDCCH.
User equipments located in a specific cell monitor the PDCCH
through the L1/L2 control channel using their RNTI information, and
receive DL scheduling information through the corresponding PDCCH
if they successfully perform CRC decoding through their RNTI. The
user equipments receive downlink data transmitted thereto through a
physical downlink shared channel (PDSCH) indicated by the received
DL scheduling information.
A scheduling mode can be classified into a dynamic scheduling mode
and a persistent or semi-persistent scheduling mode. The dynamic
scheduling mode is to transmit scheduling information to a specific
user equipment through the PDCCH whenever allocation of uplink or
downlink resources is required for the specific user equipment. The
persistent scheduling mode means that the eNB allocates downlink or
uplink scheduling information to the user equipment statically
during initial call establishment such as establishment of a radio
bearer.
In case of the persistent scheduling mode, the user equipment
transmits or receives data using scheduling information previously
allocated to the eNB without using DL scheduling information or UL
scheduling information allocated from the eNB. For example, if the
eNB previously sets a specific user equipment to allow the user
equipment to receive downlink data through RRC signal and a radio
resource "A" in accordance with a transport format "B" and a period
"C" during establishment of a radio bearer, the user equipment can
receive downlink data transmitted from the eNB using information
"A", "B" and "C". Likewise, even in case that the user equipment
transmits data to the eNB, the user equipment can transmit uplink
data using a previously defined radio resource in accordance with
previously allocated uplink scheduling information. The persistent
scheduling mode is a scheduling mode that can well be applied to a
service of which traffic is regular, such as voice
communication.
AMR codec used in voice communication, i.e., voice data generated
through voice codec has a special feature. Namely, voice data are
classified into a talk spurt and a silent period. The talk spurt
means a voice data period generated while a person is actually
talking, and the silent period means a voice data period generated
while a person does not talk. For example, voice packets, which
include voice data in the talk spurt, are generated per 20 ms, and
silent packets (SID), which include voice data in the silent
period, are generated per 160 ms.
If the persistent scheduling mode is used for voice communication,
the eNB will establish radio resources in accordance with the talk
spurt. Namely, the eNB will previously establish radio resources
for transmitting and receiving uplink or downlink data to and from
the user equipment at an interval of 20 ms during call
establishment using a feature that voice packets are generated per
20 ms. The user equipment receives downlink data or transmits
uplink data using radio resources, which are previously established
per 20 ms.
DISCLOSURE OF THE INVENTION
In the wireless communication system, communication can be
performed in such a manner that the dynamic scheduling mode and the
persistent scheduling mode are simultaneously applied to one user
equipment. For example, if voice communication according to a VoIP
service is performed in accordance with an HARQ scheme, the
persistent scheduling mode is applied to initial transmission
packets, and the dynamic scheduling mode is applied to
retransmission packets. Also, if the user equipment simultaneously
uses two or more services, the persistent scheduling mode can be
applied to one service and the dynamic scheduling mode can be
applied to the other service. In these cases, it is required that
the user equipment should definitely identify whether scheduling
information transmitted thereto depends on what scheduling mode, or
whether the scheduling information is for initial transmission
packets or retransmission packets, or whether the scheduling
information is for what service.
Accordingly, the present invention is directed to a method of
allocating radio resources in a wireless communication system,
which substantially obviates one or more problems due to
limitations and disadvantages of the related art.
An object of the present invention is to provide a method of
allocating radio resources in a wireless communication system, in
which radio resources can efficiently be used in the wireless
communication system.
Another object of the present invention is to provide a method of
allocating radio resources in a wireless communication system, in
which a user equipment can definitely identify scheduling
information according to each scheduling mode in a wireless
communication system which allocates radio resources in accordance
with a plurality of scheduling modes.
In one aspect of the present invention, a network of a wireless
communication system transmits first scheduling information to a
user equipment to allocate radio resources to the user equipment in
accordance with a first scheduling mode, the first scheduling
information including a first user equipment identifier, and
transmits second scheduling information to the user equipment to
allocate radio resources to the user equipment in accordance with a
second scheduling mode, the second scheduling information including
a second user equipment identifier.
In another aspect of the present invention, when a user equipment
receives scheduling information including a user equipment
identifier from a network, the user equipment transmits uplink data
or receives downlink data using radio resources allocated in
accordance with a first scheduling mode. When a second user
equipment identifier is included in the scheduling information, the
user equipment transmits uplink data or receives downlink data
using radio resources allocated in accordance with a second
scheduling mode.
According to the present invention, the wireless communication
system can efficiently use radio resources. Also, in the wireless
communication system which allocates radio resources in accordance
with a plurality of scheduling modes, a user equipment can
definitely identify scheduling information according to each
scheduling mode.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram illustrating an example of a structure of a
physical channel used in an E-UMTS (Evolved-Universal Mobile
Telecommunications System);
FIG. 2 is a diagram illustrating a general method of transmitting
data in an E-UMTS;
FIG. 3 is a diagram illustrating a network structure of an
E-UMTS;
FIG. 4 is a schematic view illustrating an E-UTRAN (Evolved
Universal Terrestrial Radio Access Network);
FIG. 5A and FIG. 5B are diagrams illustrating a structure of a
radio interface protocol between a user equipment (UE) and E-UTRAN,
in which FIG. 5A is a schematic view of a control plane protocol
and FIG. 5B is a schematic view of a user plane protocol; and
FIG. 6 is a flow chart illustrating a procedure of a method of
transmitting data in accordance with one embodiment of the present
invention.
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, structures, operations, and other features of the
present invention will be understood readily by the preferred
embodiments of the present invention, examples of which are
illustrated in the accompanying drawings. Embodiments described
later are examples in which technical features of the present
invention are applied to an E-UMTS (Evolved Universal Mobile
Telecommunications System).
FIG. 3 illustrates a network structure of an E-UMTS. An E-UMTS is a
system evolving from the conventional WCDMA UMTS and its basic
standardization is currently handled by the 3GPP (3.sup.rd
Generation Partnership Project). The E-UMTS can also be called an
LTE (Long Term Evolution) system.
Referring to FIG. 3, an E-UTRAN includes eNode Bs (hereinafter,
referred to as `eNode B` or `eNB`), wherein respective eNBs are
connected with each other through X2 interface. Also, each of eNBs
is connected with a user equipment (UE) through a radio interface
and connected with EPC (Evolved Packet Core) through S1 interface.
The EPC includes a mobility management entity/system architecture
evolution (MME/SAE) gateway.
Layers of a radio interface protocol between a UE and a network can
be classified into a first layer L1, a second layer L2 and a third
layer L3 based on three lower layers of OSI (open system
interconnection) standard model widely known in communication
systems. A physical layer belonging to the first layer L1 provides
an information transfer service using a physical channel. A radio
resource control (hereinafter, abbreviated as `RRC`) located at the
third layer plays a role in controlling radio resources between the
UE and the network. For this, the RRC layer enables RRC messages to
be exchanged between the UE and the network. The RRC layer can be
distributively located at network nodes including Node B, an AG and
the like or can be independently located at either the Node B or
the AG.
FIG. 4 is a schematic view illustrating an E-UTRAN (UMTS
terrestrial radio access network). In FIG. 4, a hatching part
represents functional entities of a user plane, and a non-hatching
part represents functional entities of a control plane.
FIG. 5A and FIG. 5B illustrate a structure of a radio interface
protocol between the UE and the E-UTRAN, in which FIG. 5A is a
schematic view of a control plane protocol and FIG. 5B is a
schematic view of a user plane protocol. Referring to FIG. 5A and
FIG. 5B, a radio interface protocol horizontally includes a
physical layer, a data link layer, and a network layer, and
vertically includes a user plane for data information transfer and
a control plane for signaling transfer. The protocol layers in FIG.
5A and FIG. 5B can be classified into L1 (first layer), L2 (second
layer), and L3 (third layer) based on three lower layers of the
open system interconnection (OSI) standard model widely known in
the communications systems.
The physical layer as the first layer provides an information
transfer service to an upper layer using physical channels. The
physical layer (PHY) is connected to a medium access control
(hereinafter, abbreviated as `MAC`) layer above the physical layer
via transport channels. Data are transferred between the medium
access control layer and the physical layer via the transport
channels. Moreover, data are transferred between different physical
layers, and more particularly, between one physical layer of a
transmitting side and the other physical layer of a receiving side
via the physical channels. The physical channel of the E-UMTS is
modulated in accordance with an orthogonal frequency division
multiplexing (OFDM) scheme, and time and frequency are used as
radio resources.
The medium access control (hereinafter, abbreviated as `MAC`) layer
of the second layer provides a service to a radio link control
(hereinafter, abbreviated as `RLC`) layer above the MAC layer via
logical channels. The RLC layer of the second layer supports
reliable data transfer. In order to effectively transmit data using
IP packets (e.g., IPv4 or IPv6) within a radio-communication period
having a narrow bandwidth, a PDCP layer of the second layer (L2)
performs header compression to reduce the size of unnecessary
control information.
A radio resource control (hereinafter, abbreviated as `RRC`) layer
located on a lowest part of the third layer is defined in the
control plane only and is associated with configuration,
reconfiguration and release of radio bearers (hereinafter,
abbreviated as `RB s`) to be in charge of controlling the logical,
transport and physical channels. In this case, the RB means a
service provided by the second layer for the data transfer between
the UE and the UTRAN.
As downlink transport channels carrying data from the network to
the UEs, there are provided a broadcast channel (BCH) carrying
system information, a paging channel (PCH) carrying paging message,
and a downlink shared channel (SCH) carrying user traffic or
control messages. The traffic or control messages of a downlink
multicast or broadcast service can be transmitted via the downlink
SCH or an additional downlink multicast channel (MCH). Meanwhile,
as uplink transport channels carrying data from the UEs to the
network, there are provided a random access channel (RACH) carrying
an initial control message and an uplink shared channel (UL-SCH)
carrying user traffic or control message.
As logical channels located above the transport channels and mapped
with the transport channels, there are provided a broadcast control
channel (BCCH), a paging control channel (PCCH), a common control
channel (CCCH), a multicast control channel (MCCH), and a multicast
traffic channel (MTCH).
In the E-UMTS system, an OFDM is used on the downlink and a single
carrier frequency division multiple access (SC-FDMA) on the uplink.
The OFDM scheme using multiple carriers allocates resources by unit
of multiple sub-carriers including a group of carriers and utilizes
an orthogonal frequency division multiple access (OFDMA) as an
access scheme.
FIG. 6 is a flow chart illustrating a procedure of a method of
transmitting data in accordance with one embodiment of the present
invention. According to the embodiment of FIG. 6, the user
equipment (UE) receives SRB packets in accordance with a dynamic
scheduling mode while receiving voice data (VoIP packets) in
accordance with a persistent scheduling mode. Hereinafter,
description will be made only if necessary for understanding of the
embodiment of the present invention, and description of a general
procedure required for communication between a network and a UE
will be omitted.
Referring to FIG. 6, the eNode-B (eNB) allocates two UE identifiers
to the UE [S61]. Examples of the two UE identifiers include a
C-RNTI and an SPS-C-RNTI (Semi-Persistent Scheduling RNTI).
However, the two UE identifiers will not be limited to the above
examples. For example, temporary C-RNTI and RA-RNTI may be used as
the two UE identifiers. The two UE identifiers can be allocated to
the UE by the network during random access procedure, call
establishment procedure, or radio bearer (RB) establishment
procedure, etc. Also, the two UE identifiers may be allocated
simultaneously or individually.
The eNB transmits first scheduling information to the UE to
allocate radio resources for transmission and reception of voice
data [S62]. The first scheduling information can include uplink
scheduling information and downlink scheduling information. The
first scheduling information includes the SPS-C-RNTI to indicate
that the scheduling information is allocated in accordance with the
persistent scheduling mode. The SPS-C-RNTI can be included in the
first scheduling information in a type of CRC (Cyclic Redundancy
Check) masking in at least part of the first scheduling
information. The first scheduling information is set to have a
format (first format) different from that of scheduling information
according to the dynamic scheduling mode. The UE decodes the first
scheduling information in accordance with the first format, and if
the SPS-C-RNTI is included in the first scheduling information, the
UE recognizes that the first scheduling information is scheduling
information according to the persistent scheduling mode. The first
scheduling information includes information associated with a
location of radio resources allocated to the UE, an allocation
period, and an allocation interval, etc. The UE transmits uplink
data or receives downlink data using the radio resources allocated
at an allocation period for an allocation interval in accordance
with the first scheduling information.
The eNB transmits an initial transmission VoIP packet V1 to the UE
on the PDSCH in accordance with the first scheduling information
[S63]. The initial transmission VoIP packet V1 means a voice packet
which is not a retransmission packet, when the HARQ scheme is used.
If the UE fails to successfully receive the initial transmission
VoIP packet V1, i.e., if the UE fails to decode the initial
transmission VoIP packet V1, the UE transmits NACK to the eNB on a
physical uplink control channel (PUCCH) [S64]. The UE receives the
initial transmission VoIP packet V1 or transmits NACK (or ACK)
using the first scheduling information.
When the UE receives the initial transmission VoIP packet V1 or
transmits NACK (or ACK), the persistent scheduling mode is used.
However, the dynamic scheduling mode is used for transmission of a
retransmission VoIP packet by the eNB. Accordingly, after
transmitting the NACK to the eNB, the UE should first receive
scheduling information to receive the retransmission packet. To
this end, the UE monitors the PDCCH of the L1/L2 control
channel.
In FIG. 6, the eNB transmits second scheduling information to the
UE on the PDCCH [S65]. The second scheduling information is to
allocate uplink and downlink channel resources in accordance with
the dynamic scheduling mode, and can include downlink (DL)
scheduling information and uplink (UL) scheduling information. The
second scheduling information includes the C-RNTI to indicate that
the second scheduling information is allocated in accordance with
the dynamic scheduling mode. The C-RNTI can be included in the
second scheduling information in a type of CRC(Cyclic Redundancy
Check) masking in at least part of the second scheduling
information. The second scheduling information is set to have a
format (second format) different from that of the scheduling
information according to the persistent scheduling mode, i.e., the
first scheduling information. The UE decodes the second scheduling
information in accordance with the second format, and if the C-RNTI
is included in the second scheduling information, the UE recognizes
that the second scheduling information is scheduling information
according to the dynamic scheduling mode. The second scheduling
information includes a HARQ process identifier.
The eNB transmits an initial transmission SRB packet S1 to the UE
in accordance with the second scheduling information [S66]. The
initial transmission SRB packet S1 means SRB packet which is not a
retransmission packet, when the HARQ scheme is used. If the UE
fails to successfully receive the initial transmission SRB packet
S1, i.e., if the UE fails to decode the initial transmission SRB
packet S1, the UE transmits NACK to the eNB on the PUCCH [S67]. The
UE receives the initial transmission SRB packet S1 or transmits the
NACK (or ACK) using the second scheduling information.
The eNB transmits third scheduling information to the UE on PDCCH
to transmit a retransmission packet V2 for the initial transmission
VoIP packet V1, wherein the third scheduling information includes
the SPS-C-RNTI [S68]. If the UE receives the third scheduling
information which includes the SPS-C-RNTI, the UE receives the
retransmission VoIP packet V2, which is transmitted from the eNB,
using the third scheduling information [S69]. The UE combines the
received retransmission VoIP packet V2 with the initial
transmission VoIP packet V1 in accordance with the HARQ scheme to
recover a VoIP packet [S70]. If the UE successfully recovers the
VoIP packet, the UE transmits ACK to the eNB [S71]. The VoIP packet
means a data packet intended to be transmitted from the eNB to the
UE. The VoIP packet is divided into the initial transmission VoIP
packet V1 and the retransmission VoIP packet V2 based on the VoIP
packet and then transmitted to the UE in accordance with the HARQ
scheme.
The third scheduling information can include information related to
a transmission timing point when the eNB transmits the initial
transmission VoIP packet V1. For example, the third scheduling
information can include information indicating a transport time
interval (TTI) where the initial transmission VoIP packet V1 is
transmitted. The UE can easily recognize that the retransmission
VoIP packet V2 is a retransmission packet for the initial
transmission VoIP packet, in accordance with the information
related to the timing point when the eNB transmits the initial
transmission VoIP packet V1 included in the third scheduling
information.
The eNB transmits fourth scheduling information to the UE on PDCCH
to transmit a retransmission packet S2 for the initial transmission
SRB packet S1, wherein the fourth scheduling information includes
the C-RNTI [S72]. If the UE receives the fourth scheduling
information which includes the C-RNTI, the UE receives the
retransmission SRB packet S2, which is transmitted from the eNB,
using the fourth scheduling information [S73]. The UE combines the
received retransmission SRB packet S2 with the initial transmission
SRB packet S1 in accordance with the HARQ scheme to recover an SRB
packet [S74]. If the UE successfully recovers the SRB packet, the
UE transmits ACK to the eNB [S75]. The SRB packet means a data
packet intended to be transmitted from the eNB to the UE. The SRB
packet is divided into the initial transmission SRB packet S1 and
the retransmission SRB packet S2 based on the SRB packet and then
transmitted to the UE in accordance with the HARQ scheme. The
fourth scheduling information includes the same HARQ process
identifier as that included in the second scheduling
information.
In the embodiment of FIG. 6, the first scheduling information to
the fourth scheduling information can further include
identification information that can identify whether the data
packet transmitted from the eNB to the UE in accordance with the
first scheduling information to the fourth scheduling information
is the initial transmission packet or the retransmission packet.
The identification information can be included in the first
scheduling information to the fourth scheduling information in such
a manner that a specific field of the first scheduling information
to the fourth scheduling information is set to a value which is a
previously determined. For example, a first retransmission packet,
a second retransmission packet, and a third retransmission packet
can be identified in such a manner that specific values such as 1,
2 and 3 are set in a redundancy version (RV) field included in the
first scheduling information to the fourth scheduling information.
In addition to the RV field, other field included in the first
scheduling information to the fourth scheduling information, for
example, at least one of HARQ process ID field, format field, MCS
field, NDI (New data indicator) field, TPC field, "Cyclic shift for
DMRS" field, "TX antenna" field, and CQI request field is set to a
specific value, whereby the set value can be used as the
identification information.
The aforementioned embodiments are achieved by combination of
structural elements and features of the present invention in a
predetermined type. Each of the structural elements or features
should be considered selectively unless specified separately. Each
of the structural elements or features may be carried out without
being combined with other structural elements or features. Also,
some structural elements and/or features may be combined with one
another to constitute the embodiments of the present invention. The
order of operations described in the embodiments of the present
invention may be changed. Some structural elements or features of
one embodiment may be included in another embodiment, or may be
replaced with corresponding structural elements or features of
another embodiment. Moreover, it will be apparent that some claims
referring to specific claims may be combined with another claims
referring to the other claims other than the specific claims to
constitute the embodiment or add new claims by means of amendment
after the application is filed.
The embodiments of the present invention have been described based
on data transmission and reception between an eNB and a UE. A
specific operation which has been described as being performed by
the eNB may be performed by an upper node of the eNB as the case
may be. In other words, it will be apparent that various operations
performed for communication with the UE in the network which
includes a plurality of network nodes along with the cNB may be
performed by the eNB or network nodes other than the eNB. The eNB
may be replaced with terms such as a fixed station, base station,
Node B, eNode B, and access point. Also, the UE may be replaced
with terms such as mobile station (MS) and mobile subscriber
station (MSS).
The embodiments according to the present invention may be
implemented by various means, for example, hardware, firmware,
software, or their combination. If the embodiment according to the
present invention is implemented by hardware, the embodiment of the
present invention may be implemented by one or more application
specific integrated circuits (ASICs), digital signal processors
(DSPs), digital signal processing devices (DSPDs), programmable
logic devices (PLDs), field programmable gate arrays (FPGAs),
processors, controllers, microcontrollers, microprocessors,
etc.
If the embodiment according to the present invention is implemented
by firmware or software, the method of transmitting and receiving
data in the wireless communication system according to the
embodiment of the present invention may be implemented by a type of
a module, a procedure, or a function, which performs functions or
operations described as above. A software code may be stored in a
memory unit and then may be driven by a processor. The memory unit
may be located inside or outside the processor to transmit and
receive data to and from the processor through various means which
are well known.
It will be apparent to those skilled in the art that the present
invention can be embodied in other specific forms without departing
from the spirit and essential characteristics of the invention.
Thus, the above embodiments are to be considered in all respects as
illustrative and not restrictive. The scope of the invention should
be determined by reasonable interpretation of the appended claims
and all change which comes within the equivalent scope of the
invention are included in the scope of the invention.
INDUSTRIAL APPLICABILITY
The present invention can be used in a wireless communication
system such as a mobile communication system or a wireless Internet
system.
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