US00788l236B2
`
`(12) United States Patent
`Park et al.
`
`(10) Patent No.:
`
`(45) Date of Patent:
`
`US 7,881,236 B2
`Feb. 1, 2011
`
`(54) DATA TRANSMISSION METHOD AND USER
`EQUIPMENT FOR THE SAME
`
`2007/'0ll587l Al
`
`5/2007 Zhang et a1.
`
`(75)
`
`Inventors: Sung Jun Park, Anyang-Si (KR); Seung
`June Yi, Anyang-Si (KR); Young Dae
`Lee, Anyang-Si (KR); Sung Duck
`Chun, Anyang-Si (KR)
`
`(73) Assigncc: LG Electronics Inc., Seoul (KR)
`
`( * ) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. l54(b) by 0 days.
`
`(21) Appl. No.: 12/538,514
`
`(22) Filed:
`
`Aug. 10, 2009
`
`(Continued)
`FOREIGN PATENT DOCUMENTS
`
`JP
`
`2008-103862 A
`
`5/2008
`
`(Continued)
`OTHER PUBLICATIONS
`
`LG Electronics, “Corrections to the random access response recep-
`tion,” 3GPP TSG-RAN WG2 #62, May 5-9, 2008, p. 3, paragraph
`5.1.4.
`
`(Continued)
`
`(65)
`
`Prior Publication Data
`
`US 2010/0035581A1
`
`Feb. 11,2010
`
`Primary Examiner—John Pezzlo
`(74) Attornq/, Agent, or Firm—Birch, Stewart, Kolasch &
`Birch, LLP
`
`Related U.S. Application Data
`
`(57)
`
`ABSTRACT
`
`(60) Provisional application No. 61/087,988, filed on Aug.
`11, 2008.
`
`(30)
`
`Foreign Application Priority Data
`
`Jun. 25, 2009
`
`(KR)
`
`.................... .. 10-2009-0057128
`
`(51)
`
`Int. Cl.
`(2006.01)
`H04L 12/56
`(2006.01)
`H04J 1/16
`(52) U.S. Cl.
`...................... .. 370/278; 370/329; 370/412
`(58) Field of Classification Search ............... .. 370/329,
`370/412, 278
`See application file for complete search history.
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`7,660,279 B2*
`2007/0042784 A1
`
`2/2010 Bruecketal.
`2/2007 Anderson
`
`............. .. 370/328
`
`A mobile communication technology, and, more particularly,
`a method for efficiently transmitting data stored in a message
`3 (Msg3) buffer and a user equipment for the same is dis-
`closed. The method of transmitting data by a user equipment
`in uplink includes receiving an uplink (UP) Grant signal from
`a base station on a specific message, determining whether
`there is data stored iii a message 3 (Msg3) buffer when receiv-
`ing the UL Grant signal on the specific message, determining
`whether the specific message is a random access response
`message, and transmitting the data stored in the Msg3 buffer
`to the base station using the UL Grant signal received on the
`specific message, if there is data stored in the Msg3 buffer
`when receiving the UL Grant signal on the specific message
`and the spccific message is the random access rcsponsc mes-
`sage.
`
`13 Claims, 10 Drawing Sheets
`
`aNB
`
` CR Timer
`
`M 3 Lransrnissl
`with ESR
`
`55043
`
`
`
`
`Duc lo the ignorance
`orunguillg Randnm
`Access Proudnwe
`
`
`
`starts
`CR Timer
`(SE04)
`Elplfl rgb
`
`CR Timer
`warts
`
`0
`,
`4
`
`UL Grant on PDCC S605
`M 3 transmlssdo sacs
`with ESE)
`
`
`
`U Failure
`®__ aflaception
`UL Grant on P!3CCH(SBfl7)
`
`
`
`
`mm
`
`APPLE 1001
`
`1
`
`APPLE 1001
`
`

`
`US 7,881,236 B2
`Page 2
`
`U.S. PATENT DOCUMENTS
`
`W0
`
`WO 2008/023932 A1
`
`2/2008
`
`2010/0034162 Al '5‘
`2010/0037113 Al*
`
`................ ..
`2/2010 Ouetal.
`2/Z010 Maheshwari el al.
`
`370/329
`714/743
`
`FOREIGN PATENT DOCUMENTS
`
`KR
`KR
`KR
`
`10-2007-0055004 A
`10-2007-0107619 A
`10-2008-0030941 A
`
`5/2007
`ll/2007
`4/2008
`
`OTHER PUBLICATIONS
`3GPP TS 36.321 V8.2.0., 3”’ Generation Partnership Project; Tech-
`nical Specification Group Radio Access Network; Evolved Universal
`Terrestrial Radio Access (E-UTRA) Medium.-Access Control (MAC)
`protocol specification (Release 8), pp. 1-33, May 2008.
`3”’ Generation Partnership Project (3GPP), “Enforcing New Trans-
`mission After Flushing HARQ Process”, pp. 1-6, Feb. 9-13, 2009,
`Athens, Greece, XP050323002.
`
`* cited by examiner
`
`2
`
`

`
`U.S. Patent
`
`Feb. 1, 2011
`
`Sheet 1 of 10
`
`US 7,881,236 B2
`
`FIG. 1
`
`Core Network
`
`3
`
`

`
`U.S. Patent
`
`Feb. 1, 2011
`
`Sheet 2 of 10
`
`US 7,881,236 B2
`
`FIG. 2
`
`
`
`UE
`
`E—UTRAN
`
`FIG. 3
`
`
`
`4
`
`

`
`U.S. Patent
`
`Feb. 1, 2011
`
`Sheet 3 of 10
`
`US 7,881,236 B2
`
`FIG. 4
`
`RA Preamble assignment
`
`S401
`
`
`
`
`S402
`
`Random Access Preamble
`
`Random Access Response
`
`4
`
`S 03
`
`5
`
`

`
`U.S. Patent
`
`Feb. 1, 2011
`
`Sheet 4 of 10
`
`US 7,881,236 B2
`
`FIG. 5
`
`Random Access Preamble
`
`Random Access Response
`
`3502
`
`
`
`
`S503
`
`Scheduled Transmission
`
`.
`,
`Contentlon Resolutwn
`
`S504
`
`6
`
`

`
`U.S. Patent
`
`Feb. 1, 2011
`
`Sheet 5 of 10
`
`US 7,881,236 B2
`
`FIG. 6
`
`Data 1 on PUSCH Initial transmission
`
`S602)
`
`NACK on PH[CH(S603)
`
`Data 1 on PUSCH(Retransmission) (S604)
`
`____ _ ACi<._9£1__ EHiC_P!(§5_Q5l _ _ _ _ _ _ _
`
`_ _ _ _ _EP§CE LNl31:1l (_3§0§} _____ _ _
`
`Data 2 on PUSCH([nitia1 transmission) (S607)
`
`7
`
`

`
`U.S. Patent
`
`Feb. 1, 2011
`
`Sheet 6 of 10
`
`US 7,881,236 B2
`
`FIG. 7
`
`WNew anival
`U
`
`601
`
`UE RLC or
`
`PDCP Buffer
`
`T S6100
`
`S6200
`
`
`
`'
`Generanon an
`storing Msg3
`
`d
`
`M-3g3 Buffer
`(602)
`
`HARQ Buffer
`Corresponding
`to HARQ
`process #A
`(603)
`
`(602)
`
`HARQ Buffer
`Corresponding
`to HA RQ
`process #B
`(604)
`
`
`
`8
`
`

`
`U.S. Patent
`
`Feb. 1, 2011
`
`Sheet 7 of 10
`
`US 7,881,236 B2
`
`FIG. 8
`
`
`
`Triggered
`
` ENS
`
`I Randomjsccess Rtjgamble S801“ _
`:-,,R33d0n3_,Acc¢s§ Resp2§§e(§§9§L
`1....
`
`Msgs
`
`..
`
`M333 *«1‘finSmiSSi0fl(3303)
`(with BSRS
`
`
`
`%
`
`CR Tim‘?
`Starts
`
`CR Ti_fI‘13I‘
`9313173 ~—
`
`(S394)
`CR Tiffifif
`starts
`
`
`
`{Inc to the ignorance
`nl°cng1’1-ingR&nd0n1
`
`r\ccessPruced111'e
`
`
`
`UL Grant :39” 1#nccH(sao5)
`M33 t.ransmissi0n(SiB{i6)
`. .
`_ Nfvlézleption
`Failxwe
`
`:
`
`
`
`
`UL Grant on PBCCH{SBO'?)
`
`Stop CR Timer
`
`-S808
`
`9
`
`

`
`U.S. Patent
`
`Feb. 1, 2011
`
`Sheet 8 of 10
`
`US 7,881,236 B2
`
`FIG. 9
`
`S903
`
`S901
`
`identify the HARQ process
`
`S902
`
`UL Grant indicated?
`
`Check
`
`Non~Adaptive
`
`Retransmission
`
`N0
`
`YES
`
`S904
`
`
`
`Adaptive
`
`Check
`
`Retransmission
`
`
`
`RNTI/NDI/RAR
`
`
`
`S905
`
`S909
`
`S906
`
`Is there a MAC PDU
`
`
`in the Msg3 buffer?
`
`S907
`
`Was UL Grant received
`
`in a RAH‘?
`
`YES
`
`New Data Transmission
`
`Data in the M333
`Buffer Transmission
`
`S908
`
`10
`
`10
`
`

`
`U.S. Patent
`
`Feb. 1, 2011
`
`Sheet 9 of 10
`
`US 7,881,236 B2
`
`FIG. 10
`
` 2. Random Access Preamble
`
`3. Random Access Response
`
`CR Timer
`
`starts
`
`5. Msgfl transmission
`%
`
`CR Timer
`
`expirs
`
`
`
`
`6. UL Grant on PDCCH
`
`
`
`
`7’. Acquiring New MAC I5DU
`from Muitiplexing
`and Assembly Entiiy
`
`
`with the UES C—RNTI or SPS C-RNTI
`
`B. Ne_w MAC PDU transmisjsipn
`
`11
`
`11
`
`

`
`
`
`US 7,881,236 B2US 7,881,236 B2
`
`
`
` 3:1Exam 3:1Exam
`
`
`
`35$35$
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`12
`
`
`
`

`
`US 7,881,236 B2
`
`1
`DATA TRANSMISSION METHOD AND USER
`EQUIPMENT FOR THE SAME
`
`CROSS REFERENCE TO RELATED
`APPI .I(IATl()NS
`
`This application claims the benefit of U.S. Provisional
`Application No. 61/087,988, filed onAug. 11,2008, which is
`hereby incorporated by reference as if fully set forth herein.
`This application claims the benefit of Korean PatentAppli-
`cation No. 10-2009-0057128, filed on Jun. 25, 2009, which is
`hereby incorporated by reference as if fully set forth herein.
`
`BACKGROUND OF THE INVENTION
`
`1. Field of the Invention
`
`The present invention relates to a mobile communication
`technology, and more particularly, to a method for efficiently
`transmitting data stored in a message 3 (Msg3) buffer and a
`user equipment for the same.
`2. Discussion of the Related Art
`As an example of a mobile communication system to
`which the present invention is applicable, a 3”” Generation
`Partnership Project Long Term Evolution (3GPP LTE) com-
`munication system will be schematically described.
`FIG. 1 is a schematic View showing the network architec-
`ture of an Evolved Universal Mobile Telecommunication
`System (E-UMTS) as an example ofa mobile communication
`system.
`The E-UMTS is evolved from the existing UMTS and has
`been currently standardized in the 3GPP. Generally,
`the
`E-UMTS may be called an LTE system.
`An E-UMTS network may be largely divided into an
`Evolved UMTS Terrestrial Radio Access Network (E-UT-
`RAN) 101 and a Core Network (CN) 102. Tl1e E-UTRAN 101
`may include a User Equipment (UE) 103, a base station
`(hereinafter, referred to as an “eNode B” or “eNB”) 104, and
`an Access Gateway (AG) 105 positioned at the end of the
`network and connected to an external network. The AG 105
`
`may be divided into a portion for processing user tralfic and a
`portion for processing control traffic. At this time, an AG for
`processing new user trafiic and an AG for processing control
`traflic may communicate with each other using a new inter-
`face.
`
`One or more cells may exist in one eNode B. A plurality of
`eNode Bs may be connected by an interface for transmitting
`the user traffic or control trafiic. The CN 102 may include the
`AG 105 and a node for registering a user of the UE 103. An
`interface for distinguishing between the E-UTRAN 101 and
`the CN 102 may be used.
`Layers of radio interface protocol between the UE and the
`network may be classified into a first layer L1, a second layer
`L2 and a third layer L3 based on three lower layers ofan Open
`System Interconnection (OSI) reference model that is widely
`known in the field of communication systems. A physical
`layer belonging to the first layer provides an information
`transfer service using a physical charmel. A Radio Resource
`Control (RRC) layer belonging to the third layer serves to
`control radio resources between the UE and the network. The
`
`UE and the network exchange an RRC mes sage via the RRC
`layer. The RRC layer may be distributed and located at net-
`work nodes ofthe eNode B 1 04 and theAG 1 05. Alternatively,
`the RRC layer may be located at only the eNode B 104 or the
`AG 105.
`
`FIGS. 2 and 3 show the structures of radio interface proto-
`cols between the UE and the UTRAN based on a 3GPP radio
`access network standard.
`
`10
`
`15
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`25
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`30
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`
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`65
`
`2
`
`The radio interface protocols of FIGS. 2 and 3 are horizon-
`tally formed of a physical layer, a data link layer and a net-
`work layer. The radio interface protocols are vertically
`formed of a user plane for transmitting data information and
`a control plane for transmitting control signals. In detail, 1" 1G.
`2 shows the layers of a radio protocol control plane and FIG.
`3 shows the layers ofa radio protocol user plane. The protocol
`layers of FIGS. 2 and 3 may be divided into a first layer (L1),
`a second layer (L2) and a third layer (L3) based on three lower
`layers of an OSI reference model that is widely known in the
`field of communication systems.
`Hereinafter, the layers of the control plane of the radio
`protocol of FIG. 2 and the user plane of the radio protocol of
`FIG. 3 will be described.
`
`A physical (PHY) layer ofthe first layer provides an infor-
`mation transfer service to an upper layer using a physical
`channel. The PHY layer is connected to an upper layer, such
`as a Medium Access Control (MAC) layer, via a transport
`channel. Data is transferred between the MAC layer and the
`PHY layer via the transport channel. At this time, the trans-
`port charmel is largely divided into a dedicated transport
`channel and a common transport charmel, depending on
`whether or not a channel is shared. Data is also transferred
`
`between different PHY layers, such as a physical layer of a
`transmitting side and a physical layer of a receiving side, via
`a physical channel using radio resources.
`Various layers exist in the second layer. First, the MAC
`layer serves to map various logical channels to various trans-
`port channels and serves to multiplex several logical charmels
`into one transport channel. The MAC layer is connected to a
`Radio Link Control (RLC) layer, which is an upper layer, by
`the logical channel. The logical channel may be largely
`divided into a control channel for transmitting information
`about the control plane and a traffic channel for transmitting
`information about the user plane according to the kinds of
`information transmitted.
`
`The RLC layer of the second layer serves to segment and
`concatenate data received from an upper layer so as to adjust
`data size such that a lower layer transmits data in a radio
`section. In addition, the RLC provides three modes, namely,
`a Transparent Mode (TM), an Unacknowledged Mode (UM)
`and an Acknowledged Mode (AM) in order to guarantee
`various Quality of Services (QoSs) requested by Radio Bear-
`ers (RBs). In particular, the AM RLC performs a retransmis-
`sion function using an Automatic Repeat and Request (ARQ)
`function for reliable data transmission.
`
`A Packet Data Convergence Protocol G’DCP) layer of the
`second layer performs a header compression function to
`reduce the size of an Intemet Protocol (IP) packet header that
`includes unnecessary control information and has a relatively
`large size, for effective transmission in a radio section having
`a relatively small bandwidth when transmitting an IP packet
`such as an IPv4 packet or an IPv6 packet. Therefore, only
`necessary information in a header portion of data is transmit-
`ted so as to improve transmission efficiency of the radio
`section. In the LTE system, the PDCP layer also performs a
`security function, which includes ciphering for preventing
`data from being intercepted by a third party and integrity
`protection for preventing data from being handled by a third
`Part)’-
`A Radio Resource Control (RRC) located at a highest
`portion of the third layer is defined only hi the control plane.
`The RRC layer handles logical channels, transport charmels
`and physical channels for the configuration, re-configuration
`and release of RBS. Here, the RBS refer to logical paths
`provided by the first and second layers of the radio protocol,
`for data transfer between the U13 and the UTRAN, and the
`
`13
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`13
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`

`
`US 7,881,236 B2
`
`3
`configuration of the RBs refers to a process of defining the
`characteristics of the radio protocol layer and channel neces-
`sary for providing a specific service, and setting detailed
`parameters and operation methods. Each of the RBs is
`divided into a signaling RB and a data RI}. The SRB is used
`as apath for transmitting an RRC message in the control plane
`(C-plane), and the DRB is used as a path for transmitting user
`data in the user plane (U-plane).
`Downlink transport channels for transmitting data from a
`network to a UE may include a Broadcast Channel (BCH) for
`transmitting system information and a downlink Shared
`Channel (SCI I) for transmitting user traffic or a control mes-
`sage. The traffic or the control message of a downlink multi-
`cast or broadcast service may be transmitted via the downlink
`SCH or via a separate Downlink Multicast Channel (MCH).
`Uplink transport channels for transmitting data from a UE to
`a network may include a Random Access Channel (RACH)
`for transmitting an initial control message and an uplink SCH
`for transmitting user traffic or a control message.
`Downlink physical channels for transmitting information
`transferred via the downlink transport channels in a radio
`section between a network and a UE may include a Physical
`Broadcast Channel (PBCH) for transmitting information
`about a BCH, a Physical Multicast Channel (PMCH) for
`transmitting infomiation about an MCH, a Physical Down-
`link Shared Channel (PDSCH) for transmitting information
`about a PCH and a downlink SCH, and a Physical Downlink
`Control Channel (PDCCH) (also referred to as a DL L1/L2
`control channel) for transmitting control information pro-
`vided by the first layer and the second layer, such as downlink
`(DL) or uplink (UL) scheduling grant information. Uplink
`physical channels for transmitting information transferred via
`the uplink transport channels in a radio section between a
`network and a UE may include a Physical Uplink Shared.
`Channel (PUSCH) for transmitting information about an
`uplink SCH, a Physical Random Access Channel (PRACH)
`for transmitting information about an RACH, and a Physical
`Uplink Control Charmel (PUCCH) for transmitting control
`information provided by the first layer and the second layer,
`such as a HARQ ACK or NACK, a Scheduling Request (SR),
`a Channel Quality Indicator (CQI) report.
`Hereinafter, a random access procedure provided by an
`LTE system will be schematically described based on the
`above description.
`First, a UE performs the random access procedure in the
`following cases.
`when the UE performs initial access because there is no
`RRC Connection with an eNode B,
`when the UII‘. initially accesses a target cell in a handover
`procedure,
`when the random access procedure is requested by a com-
`mand of an eNode B,
`when there is uplink data transmission in a situation where
`uplink time synchronization is not aligned or where a
`specific radio resource used for requesting radio
`resources is not allocated, and
`when a recovery procedure is performed in case of radio
`link failure or handover failure.
`
`In the LTE system, there are provided two procedures in
`selecting a random access preamble: one is a contention
`based random access procedure in which the UE randomly
`selects one preamble within a specific group for use, and
`another is a non-contention based random access procedure
`i11 which the UE uses a random access preamble allocated
`only to a specific UE by the eNode B. The non-contention
`based random access procedure may be used only in the
`
`5
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`
`handover procedure or when it is requested by the command
`of the base station, as described above.
`A random access procedure of a UE with a specific eNode
`B may largely include (1) a step of, at the UE, transmitting a
`random access preamble to the eNode B (hereinafter, referred
`to as a “message 1” transmitting step if such use will not lead
`to confusion),
`(2) a step of receiving a random access
`response from the eNode B in correspondence with the trans-
`mitted random access preamble (hereinafter, referred to as a
`“message 2” receiving step if such use will not lead to con-
`fusion), (3) a step oftransmitting an uplink mes sage using the
`information received by the random access response message
`(hereinafter, referred to as a “message 3” transmitting step if
`such use will not lead to confusion), and (4) a step ofreceiving
`a message corresponding to the uplink message from the
`eNode B (hereinafter, referred to as a “message 4” receiving
`step if such use will not lead to confusion).
`In the random access procedure, the UE stores data to be
`transmitted via the message 3 in a message 3 (Msg3) buffer
`and transmits the data stored. in the msg3 buller in correspon-
`dence with the reception of an Uplink (UL) Grant signal. The
`UL Grant signal indicates information about uplink radio
`resources which may be used when the UE transmits a signal
`to the eNode B, and is received on a random access response
`message received on a PDCCH or a PUSCH in the LTE
`system. According to the current LTE system standard, it is
`defined that, if the UI. Grant signal is received in a state in
`which data is stored in the Msg3 buifer, the data stored in the
`Msg3 buffer is transmitted regardless of the reception mode
`ofthe UL Grant signal. As described above, ifthe data stored
`in the Msg3 buffer is transmitted in correspondence with the
`reception of all UL Grant signals, problems may occur.
`Accordingly, there is a need for research to solve such prob-
`lems.
`
`SUMMARY OF THE INVENTION
`
`Accordingly, the present invention is directed to a data
`transmission method and a user equipment for the same that
`substantially obviate one or more problems due to limitations
`and disadvantages of the related art.
`An object of the present invention is to provide a data
`transmission method and a user equipment for the same,
`which is capable of solving a problem which may occur when
`data stored in a message 3 (Msg3) buffer is transmitted
`according to a reception mode of an Uplink (UL) Grant sig-
`nal.
`
`Additional advantages, objects, and features of the inven-
`tion will be set forth in part in the description which follows
`and in part will become apparent to those having ordinary
`skill in the art upon examination of the following or may be
`learned from practice of the invention. The objectives and
`other advantages of the invention may be realized and
`attained by the structure particularly pointed out in the written
`description and claims hereof as well as the appended draw-
`ings.
`To achieve these obj ects and other advantages and in accor-
`dance with the purpose of the invention, as embodied and
`broadly described herein, a method of transmitting data by a
`user equipment through an uplink includes receiving an
`uplink grant (UL Grant) signal from a base station on a
`specific mes sage, detennining whether there is data stored m
`a message 3 (Msg3) buffer when receiving the UL Grant
`signal on the specific message, determining whether the spe-
`cific message is a random access response message, and
`transmitting the data stored in the Msg3 bufifer to the base
`station using the UL Grant signal received on the specific
`
`14
`
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`

`
`US 7,881,236 B2
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`5
`message, if there is data stored in the Msg3 buffer when
`receiving the UL Grant signal on the specific message and the
`specific message is the random access response message.
`Ifthere is no data stored in the Msg3 buffer when receiving
`the UL Grant signal on the specilic message or the specilic
`message is not the random access response message, new data
`may be transmitted to the base station in correspondence with
`the UL Grant signal received on the specific message.
`The UL Grant signal received on the specific message may
`be a UL Grant signal received on a Physical Downlink Con-
`trol Channel (PDCCH). In this case, the user equipment may
`transmit. new data in correspondence with the UL Grant signal
`received on the PDCCH.
`
`The UL Grant signal received on the specific message may
`be a UL Grant signal received on a random access response
`message received on Physical Downlink Shared Charmel
`(PDSCH). In this case, if there is data stored in the Msg3
`buffer when receiving the UL Grant signal on the random
`access response message, the user equipment may transmit
`the data stored in the buffer iii the Msg3 buffer using the UL
`Grant signal received on the random access response mes-
`sage.
`The data stored in the Msg3 buffer may be a Medium
`Access Control Protocol Data Unit (MAC PDU) including a
`user equipment identifier, and the data stored in the Msg3
`buffer further include information about a buffer status report
`(BSR) if the user equipment starts the random access proce-
`dure for the BSR.
`
`In another aspect ofthe present invention, a user equipment
`includes a reception module receiving an uplink grant (UL
`Grant) signal from a base station on a specific message, a
`transmission module transmitting data to the base station
`using the UL Grant signal received on the specific message, a
`message 3 (Msg3) buller storing UL data to be transmitted i11
`a random access procedure, and a Hybrid Automatic Repeat
`Request (HARQ) entity determining whether there is data
`stored in the Msg3 buffer when the reception module receives
`the UL Grant signal and the specific message is a random
`access response message, acquiring the data stored in the
`Msg3 buffer ifthere is data stored in the Msg3 buffer when the
`reception module receives the UI. Grant signal and the spe-
`cific message is the random access response message, and
`controlling the transmission module to transmit the data
`stored in the Msg3 buffer to the base station using the UL
`Grant signal received by the reception module on the specific
`message.
`
`The user equipment may further include a multiplexing
`and assembly entity used for transmission ofnew data. In this
`case, the HARQ entity may acquire the new data to be trans-
`mitted from the multiplexing and assembly entity if there is
`no data stored in the Msg3 buffer when the reception module
`receives the UL Grant signal on the specific message or the
`received mes sage is not the random access response message,
`and control the transmission module to transmit the new data
`acquired from the multiplexing and assembly entity using the
`UL Grant signal received by the reception module on the
`specific message.
`The user equipment may further include one or more
`HARQ processes, and HARQ buffers respectively corre-
`sponding to the one or more HARQ processes. In this case,
`the HARQ entity may transfer the data acquired from the
`multiplexing and assembly entity or the Msg3 buffer to a
`specific IIARQ process ofthe one or more IIARQ processes
`and control the specific HARQ process to transmit the data
`acquired from the multiplexing and assembly entity or the
`Msg3 buffer through the transmission module.
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`When the specific HARQ process transmits the data stored
`in the Msg3 buffer through the transmission module, the data
`stored in the Msg3 buffer may be controlled to be copied into
`a specific HARQ buffer corresponding to the specific HARQ
`process, and the data copied into the specific I IARQ buffer
`may be controlled to be transmitted through the transmission
`module.
`The UL Grant signal received by the reception module on
`the specific message may be a UL Grant signal received on a
`Physical Downlink Control Channel (PDCCH). In this case,
`the HARQ entity may control new data to be transmitted in
`correspondence with the received UL Grant signal received
`on the PDCCH.
`The UL Grant signal received by the reception module on
`the specific message may be a UL Grant signal received on a
`random access response message received on Physical
`Downlink Shared Charmel (PDSCH), and the HARQ entity
`may control the data stored in the Msg3 buffer to be transmit-
`ted using the UL Grant signal received on the random access
`response message if there is data stored in the Msg3 buffer
`when the reception module receives the UL Grant signal on
`the random access response message.
`According to the above-described embodiments of the
`present invention, it is possible to transmit data stored in a
`Msg3 buffer according to a reception mode of a UL Grant
`signal, without confusion.
`It is to be understood that both the foregoing general
`description and the following detailed description of the
`present invention are exemplary and explanatory and are
`intended to provide further explanation of the invention as
`claimed.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The accompanying drawings, which are included to pro-
`vide a fiirther understanding of the invention and are incor-
`porated in and constitute a part of this application, illustrate
`embodiment(s) ofthe invention and together with the descrip-
`tion serve to explain the principle of the invention. In the
`drawings:
`FIG. 1 is a schematic View showing the network architec-
`ture of an Evolved Universal Mobile Telecommunication
`
`System (E-UMTS) as anexample ofa mobile communication
`system;
`FIGS. 2 and 3 are views showing the structures of radio
`interface protocols between a user equipment (UE) and a
`UMTS Terrestrial Radio Access Network (UTRAN) based on
`a 3'5 Generation Partnership Project (3GPP) radio access
`network standard;
`FIG. 4 is a View illustrating an operating procedure ofa UE
`and a base station (eNode B) in a non-contention based ran-
`dom access procedure;
`FIG. 5 is a View illustrating an operating procedure ofa UE
`and an eNode B in a contention based random access proce-
`dure;
`FIG. 6 is a View illustrating an uplink Hybrid Automatic
`Repeat Request (I IARQ) scheme;
`FIG. 7 is a View illustrating a method of transmitting a
`message 3 in a random access procedure when uplink radio
`resources are requested;
`FIG. 8 is a View illustrating a problem which may occur
`when data stored in a message 3 bufl'er is transmitted by an
`Uplink (UL) Grant signal received on a message other than a
`random access response message;
`FIG. 9 is a flowchart illustrating a method of transmitting
`uplink data by a UE according to a preferred embodiment of
`the present invention;
`
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`
`US 7,881,236 B2
`
`7
`FIG. 10 is a View illustrating a method of transmitting
`uplink data when a Buffer status Report (BSR) is triggered in
`a UE, according to an embodiment of the present invention;
`and
`
`FIG. 11 is a schematic view showing the configuration of a
`UE according to an embodiment of the present invention.
`
`DETAILED DESCRIPTION OF THE INVENTION
`
`the preferred embodiments of the present
`Hereinafter,
`invention will be described with reference to the accompany-
`ing drawings. It is to be understood that the detailed descrip-
`tion which will be disclosed along with the accompanying
`drawings is intended to describe the exemplary embodiments
`of the present invention, and is not intended to describe a
`unique embodiment which the present invention can be car-
`ried out. Hereinafter,
`the detailed description includes
`detailed matters to provide full understanding of the present
`invention. However, it will be apparent to those skilled in the
`art that the present invention can be carried out without the
`detailed matters. For example, the following description will
`be made on the assumption that a mobile communication
`system is a 3"’ Generation Partnership Project Long Term
`Evolution (3GPP LTE) system, but the present invention is
`applicable to other mobile communication systems excluding
`the 3GPP LTE system.
`In some instances, well-known structures and devices are
`omitted in order to avoid obscuring the concepts of the
`present invention and the important fimctions of the struc-
`tures and devices are shown in block diagram form. The same
`reference numbers will be used throughout the drawings to
`refer to the same or like parts.
`In the following description, it is assumed that a terminal
`includes a mobile or fixed user end device such as a user
`
`equipment (UE) and a mobile station (MS), and a base station
`includes a node of a network end communicating with a
`terminal, such as a Node-B, an eNode B, and a base station.
`As described above, in the following description, a prob-
`lem which may occur when data stored in a message 3 (Msg3)
`bufler is transmitted according to a reception mode of an
`Uplink (UL) Grant signal will be described in detail and a
`method of solving the problem will be described. Transmis-
`sion and reception of a signal using a random access proce-
`dure and a Hybrid Automatic Repeat Request (HARQ)
`scheme will be described in detail.
`
`FIG. 4 is a view illustrating an operating procedure of a
`terminal (UE) and a base station (eNode B) in a non-conten-
`tion based random access procedure.
`(1) Random Access Preamble Assignment
`As described above, a non-contention based random access
`procedure may be performed (1) in a handover procedure and
`(2) when the random access procedure is requested by a
`command of an eNode B. Even in these cases, a contention
`based random access procedure may be performed.
`First, it is important that a specific random access preamble
`without the possibility ofcollision is received from the eNode
`B, for the non-contention based random access procedure.
`Methods of receiving the random access preamble may
`include a method using a handover command and a method
`using a Physical Downlink Control Charmel (PDCCH) com-
`mand. The UE receives an assigned random access preamble
`(S401).
`(2) Message 1 Transmission
`The UE transmits the preamble to the eNode B after receiv-
`ing the assigned random access preamble from the eNode B
`as described above (S402).
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`(3) Message 2 Transmission
`The UE attempts to receive a random access response
`within a random access response reception window indicated
`by the eNode B through a handover command or system
`information after transmitting the random access preamble in
`step S402 (S403). More specifically,
`the random access
`response information may be transmitted in the form of a
`MediumAccess Control (MAC) Packet Data Unit (PDU), and
`the MAC PDU may be transferred via a Physical Downlink
`Shared Channel (PDSCH). In addition, the UE preferably
`monitors the PDCCH in order to enable to the UE to properly
`receive the information transferred via the PDSCH. That is,
`the PDCCH may preferably include information about a UE
`that should receive the PDSCH, frequency and time informa-
`tion ofradio resources ofthe PDSCH, a transfer format ofthe
`PDSCH, and the like. Here, if the PDCCH has been success-
`fully received, the UE may appropriately receive the random
`access response transmitted on the PDSCH according to
`information ofthe PDCCH. The random access response may
`include a random access preamble identifier (e.g. Randem
`Access-Radio Network Temporary Identifier (RA-RNTI)),
`an UL Grant indicating uplink radio resources, a temporary
`C-RNTI, a Time Advance Command (TAC), and the like.
`As described above, the reason why the random access
`response includes the random access preamble identifier is
`because a single random access response may include ran-
`dom access response information ofat least one UE and thus
`it is reported to which UE the UL Grant, the Temporary
`C-RNTI and the TAC are valid. In this step, it is assumed that
`the UE selects a random access preamble identifier matched
`to t