(19)
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`(12)
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`Europäisches Patentamt
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`European Patent Office
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`Office européen des brevets
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`*EP001599063A1*
`EP 1 599 063 A1
`
`(11)
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`EUROPEAN PATENT APPLICATION
`
`(43) Date of publication:
`23.11.2005 Bulletin 2005/47
`
`(21) Application number: 05010890.1
`
`(22) Date of filing: 19.05.2005
`
`(51) Int Cl.7: H04Q 7/38
`
`(84) Designated Contracting States:
`AT BE BG CH CY CZ DE DK EE ES FI FR GB GR
`HU IE IS IT LI LT LU MC NL PL PT RO SE SI SK TR
`Designated Extension States:
`AL BA HR LV MK YU
`
`(72) Inventors:
`• Kim, Soeng-Hun
`Yeongtong-gu Suwon-si Gyeonggi-do (KR)
`• Lee, Kook-Heul
`Yeongtong-gu Suwon-si Gyeonggi-do (KR)
`
`(30) Priority: 19.05.2004 KR 2004035729
`
`(71) Applicant: SAMSUNG ELECTRONICS CO., LTD.
`Suwon-si, Gyeonggi-do (KR)
`
`(74) Representative: Grünecker, Kinkeldey,
`Stockmair & Schwanhäusser Anwaltssozietät
`Maximilianstrasse 58
`80538 München (DE)
`
`(54) Method and apparatus for scheduling enhanced uplink dedicated channels in a mobile
`communication system
`
`(57)
`An apparatus and method are provided for per-
`forming scheduling in a Node B for data transmission of
`a user equipment (UE) in a mobile communication sys-
`tem supporting an enhanced uplink dedicated channel
`(E-DCH). The Node B receives, from a radio network
`controller (RNC), scheduling assistance information for
`
`an uplink service to be provided from the UE. The Node
`B estimates a data amount for the uplink service on the
`basis of the scheduling assistance information in each
`scheduling period. The Node B schedules data trans-
`mission for the uplink service according to the estimated
`data amount.
`
`Printed by Jouve, 75001 PARIS (FR)
`
`EP1 599 063A1
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`

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`EP 1 599 063 A1
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`Description
`
`BACKGROUND OF THE INVENTION
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`Field of the Invention:
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`[0001] The present invention relates generally to an asynchronous wideband code division multiple access (WCDMA)
`communication system. More particularly, the present invention relates to a scheduling method and apparatus for
`supporting an enhanced uplink dedicated channel (E-DCH).
`
`Description of the Related Art:
`
`[0002] A universal mobile telecommunication service (UMTS) system serving as the third generation mobile com-
`munication system uses wideband code division multiple access (WCDMA) based on a global system for mobile com-
`munications (GSM) serving as a European mobile communication system and general packet radio services (GPRS).
`The UMTS system performs packet-based transmission of text, digitized voice, video, and multimedia at data rates up
`to 2 megabits per second (Mbps) that offers a consistent set of services to mobile computer and phone users no matter
`where they are located in the world. In UMTS, a packet-switched connection using a packet protocol such as an Internet
`Protocol (IP) uses a virtual connection that is always available to any other end point in the network.
`[0003]
`In uplink (UL) communications from a user equipment (UE) to a Node B, the UMTS system uses an enhanced
`uplink dedicated channel (E-DCH) to improve the performance of packet transmission. The E-DCH supports technol-
`ogies such as adaptive modulation and coding (AMC), hybrid automatic retransmission request (HARQ), Node B control
`scheduling, and others in order to support stable high-speed data transmission.
`[0004] The AMC determines modulation and coding schemes of a data channel according to channel states between
`a Node-B and a UE, and improves resource use efficiency. A combination of the modulation and coding schemes is
`referred to as a modulation and coding scheme (MCS). Various MCS levels can be defined by supportable modulation
`and coding schemes. The AMC adaptively changes an MCS level according to channel states between a Node-B and
`a UE, and improves resource use efficiency.
`[0005] The HARQ is a scheme for re-transmitting a packet to compensate for an erroneous packet when an error
`occurs in an initially transmitted data packet. The HARQ scheme is divided into a chase combining (CC) scheme for
`re-transmitting a packet with the same format as that of the initially transmitted data packet when an error occurs, and
`an incremental redundancy (IR) scheme for re-transmitting a packet with a format different from that of the initially
`transmitted data packet when an error occurs.
`[0006] According to the Node B control scheduling, a Node B determines uplink data transmission and an upper limit
`of a data rate when multiple UEs transmit data using the E-DCH, and sends information to the UEs through a scheduling
`command. The UEs refer to the scheduling command, and determine a data rate of an uplink E-DCH.
`[0007] FIG. 1 illustrates uplink packet transmission through the E-DCH in the conventional wireless communication
`system. In FIG. 1, reference numeral 100 denotes a Node B for supporting the E-DCH, and reference numerals 101,
`102, 103, and 104 denote UEs using the E-DCH. As illustrated in FIG. 1, the UEs 101 to 104 transmit data to the Node
`B 100 through E-DCHs 111, 112, 113, and 114, respectively.
`[0008] Using a data buffer status, requested data rate, or channel status information of the UEs 101 to 104, the Node
`B 100 provides each UE with information indicating if E-DCH data transmission is possible, or performs a scheduling
`operation for controlling an E-DCH data rate. To improve the overall performance of the system, the scheduling oper-
`ation assigns relatively low data rates to the UEs 103 and 104 that are far away from the Node B 100 such that a noise
`rise value measured by the Node B 100 does not exceed a target value. However, the scheduling operation assigns
`relatively high data rates to the UEs 101 and 102 close to the Node B 100.
`[0009] FIG. 2 is a call flow diagram illustrating a transmission and reception procedure through the conventional
`E-DCH.
`[0010] Referring to FIG. 2, the Node B and the UE establish the E-DCH in step 202. Step 202 includes a process
`for sending messages through a dedicated channel. When the E-DCH has been established, the UE notifies the Node
`B of scheduling information in step 204. The scheduling information includes UE transmission power information for
`an uplink channel, remaining UE transmission power information, information about an amount of transmission data
`accumulated in a buffer of the UE, and others.
`[0011] When receiving the scheduling information from a plurality ofUEs currently performing communication, the
`Node B monitors scheduling information of the UEs to schedule data transmission of the UEs in step 206. In step 208,
`the Node B determines whether to allow the UE to transmit an uplink packet, and sends a scheduling assignment
`command to the UE. The scheduling assignment command includes information about an allowed data rate and allowed
`transmission timing, and others. In step 210, the UE determines the amount of radio resources to be assigned to the
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`E-DCH using the scheduling assignment command. In steps 212 and 214, the UE transmits uplink (UL) packet data
`through the E-DCH and simultaneously sends, to the Node B, radio resource assignment information including a trans-
`port format resource indicator (TFRI) necessary to demodulate the E-DCH. In step 214, the UE selects an MCS level
`by considering radio resources assigned by the Node B and a channel state, and transmits the UL packet data using
`the MCS level.
`[0012]
`In step 216, the Node B determines if an error is present in the TFRI and/or the packet data. In step 218, the
`Node B sends non-acknowledge (NACK) information to the UE through an NACK channel when an error is present,
`and sends acknowledge (ACK) information to the UE through an ACK channel when no error is present. When the
`ACK information is sent, the packet data transmission is completed, and the UE transmits new user data through the
`E-DCH. However, when the NACK information is sent, the UE re-transmits the same packet data through the E-DCH.
`[0013] Representative services capable of being provided through the E-DCH are a streaming service, interactive
`service, and background service. The streaming service is a quasi-realtime service sensitive to delay, and corresponds
`to, for example, video streaming. In this streaming service, data is generated regularly, but the utility value of the data
`is lost when the data is delayed for a predetermined time. The interactive service is not sensitive to delay, but a user
`is inconvenienced when data transmission or reception is delayed for a relatively long time. For example, a web brows-
`ing service corresponds to the interactive service. In this interactive service, data is irregularly generated, and the utility
`value of the data is not lost due to delay. The background service is not sensitive to delay as in a file transfer protocol
`(FTP), and does not have a serious problem even though data transmission or reception is delayed for a relatively long
`time. In this background service, data is irregularly generated, but the utility value of the data is not lost due to delay.
`[0014] Because data generation is irregular and not predicted in the case of the interactive or background service,
`a method for reporting a buffer status to the Node B is useful whenever data is generated. However, because data is
`regularly generated in the streaming service, the method for reporting a buffer status to the Node B whenever data is
`generated is inefficient.
`[0015] For example, in the case of a service in which video is coded according to the H.263 standard which is incor-
`porated herein by reference, 128 75-byte packets are generated per second. Alternatively, in the case of a service in
`which voice is coded at a 12.2 kbps adaptive multi-rate, 50 32-byte packets are generated per second. In the case
`where data is generated regularly, an operation for reporting a buffer state whenever data is generated is an important
`factor causing radio resources to be wasted.
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`SUMMARY OF THE INVENTION
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`[0016]
`It is, therefore, an aspect of the present invention to prevent the inefficient use of radio resources due to buffer
`status reporting by suitably selecting buffer state reporting according to a type of service in a user equipment (UE).
`[0017]
`It is another aspect of the present invention to exactly estimate uplink data generation without buffer status
`reporting of a user equipment (UE) by providing advance information about regularly generated data from a radio
`network controller (RNC) to a Node B scheduler.
`[0018]
`It is yet another aspect of the present invention to efficiently provide a service sensitive to delay by sending
`a scheduling assignment command before the utility value of data is lost.
`[0019] The above and other aspects of the present invention can be achieved by a method for performing scheduling
`in a Node B for data transmission of a user equipment (UE) in a mobile communication system supporting an enhanced
`uplink dedicated channel (E-DCH). The method comprises the steps of receiving, from a radio network controller (RNC),
`scheduling assistance information for an uplink service to be provided from the UE; estimating a data amount for the
`uplink service on a basis of the scheduling assistance information in each scheduling period; and scheduling data
`transmission for the uplink service according to the estimated data amount.
`[0020] The above and other aspects of the present invention can also be achieved by an apparatus for performing
`scheduling in a Node B for data transmission of a user equipment (UE) in a mobile communication system supporting
`an enhanced uplink dedicated channel (E-DCH). The apparatus comprises a Node B scheduler for receiving, from a
`radio network controller (RNC), scheduling assistance information for an uplink service to be provided from the UE,
`estimating a data amount for the uplink service on a basis of the scheduling assistance information in each scheduling
`period, and scheduling data transmission for the uplink service using the estimated data amount; and an E-DCH proc-
`essor.
`[0021] The above and other aspects of the present invention can also be achieved by a scheduling method for
`transmitting data according to a scheduling operation of a Node B in a mobile communication system supporting an
`enhanced uplink dedicated channel (E-DCH). The scheduling method comprises the steps of receiving a radio bearer
`setup message from a radio network controller (RNC) and establishing radio bearers for the E-DCH according to
`configuration information included in the radio bearer setup message; examining indication information associated with
`a buffer status report for at least one uplink service included in the configuration information; and limiting buffer status
`reporting for an uplink service not requiring the buffer status report, and performing buffer status reporting for an uplink
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`service requiring the buffer status report according to a result of the examination.
`[0022] The above and other aspects of the present invention can also be achieved by an apparatus for performing
`scheduling in a user equipment (UE) for transmitting data according to a scheduling operation of a Node B in a mobile
`communication system supporting an enhanced uplink dedicated channel (E-DCH). The apparatus comprises a service
`discriminator for detecting and outputting data according to uplink services to be used by a user; a buffer for storing
`service data output from the service discriminator; a buffer manager for determining if a buffer status report must be
`sent according to a buffer status and types of the uplink services, sending the buffer status report according to a result
`of the determination, and receiving a scheduling assignment command; and an E-DCH processor for transmitting data
`stored in the buffer to the Node B through the E-DCH in response to the scheduling assignment command.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`[0023] The above and other aspects and advantages of the present invention will be more clearly understood from
`the following detailed description taken in conjunction with the accompanying drawings, in which:
`
`FIG. 1 illustrates uplink packet transmission in a conventional mobile communication system;
`FIG. 2 is a call flow diagram illustrating a transmission and reception procedure through a conventional enhanced
`uplink dedicated channel (E-DCH);
`FIG. 3 is a block diagram illustrating the operation between a Node B and a user equipment (UE) in accordance
`with an embodiment of the present invention;
`FIG. 4 is a call flow diagram illustrating control signal flows between a Node B and a UE in accordance with an
`embodiment of the present invention;
`FIG. 5 is a flow chart illustrating the operation of the UE in accordance with an embodiment of the present invention;
`and
`FIG. 6 is a flow chart illustrating the operation of the Node B in accordance with an embodiment of the present
`invention.
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`[0024] Throughout the drawings, the same or similar elements are denoted by the same reference numerals.
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`DETAILED DESCRIPTION OF EXEMPLARY PREFERRED EMBODIMENTS
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`[0025] Embodiments of the present invention will now be described in detail herein below with reference to the ac-
`companying drawings. In the following description, a detailed description of known functions and configurations incor-
`porated herein will be omitted for conciseness. It is to be understood that the phraseology and terminology used herein
`are for the purpose of description and should not be regarded as limiting.
`[0026] First, interfaces between a user equipment (UE) and a Node B in a wideband code division multiple access
`(WCDMA) system to which the present invention is applied will be described.
`[0027] An interface between the UE and a wireless communication network is referred to as a Uu interface. The Uu
`interface is divided into a control plane used to exchange a control signal and a user plane used to transmit data.
`[0028] The control plane comprises a radio resource control (RRC) layer, a radio link control (RLC) layer, a media
`access control (MAC) layer, and a physical (PHY) layer. The user plane comprises a packet data convergence protocol
`(PDCP) layer, a broadcast/multicast control (BMC) layer, an RLC layer, a MAC layer, and a PHY layer. The PHY layer
`is located in each Node B or cell, and the MAC layer, the RRC layer, and others are located in a radio network controller
`(RNC).
`[0029] The PHY layer provides an information transmission service using the radio transfer technology, and corre-
`sponds to the first layer of an open system interconnection (OSI) model. Transport channels are connected between
`the PHY and MAC layers. The transport channels are defined by a scheme for processing specific data in the PHY
`layer. The transport format of the transport channels is referred to as TF. The transport format of a PHY layer mapped
`to a plurality of transport channels is indicated by a TFC indicator (TFCI) indicating one of transport format combinations
`(TFCs).
`[0030] The MAC and RLC layer are connected through logical channels. The MAC layer receives data through a
`logical channel from the RLC layer, and delivers the received data to the PHY layer through a suitable transport channel.
`Moreover, the MAC layer receives data through a transport channel from the PHY layer, and delivers the received data
`to the RLC layer through a suitable logical channel. Moreover, the MAC layer inserts additional information into data
`delivered through a logical or transport channel, or interprets inserted information to take a suitable operation and
`controls a random access operation. In the MAC layer, an entity relating to a dedicated service is referred to as a MAC-
`d entity, and an entity relating to a common service is referred to as a MAC-c entity. In relation to an embodiment of
`the present invention, an entity responsible for controlling the E-DCH and transmitting data through the E-DCH is
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`referred to as a MAC-e entity.
`[0031] The RLC layer is responsible for establishing and releasing a logical channel. The RLC layer can operate in
`one of three operating modes an acknowledged mode (AM), unacknowledged mode (UM), and transparent mode (TM).
`These three operating modes provide different functions. Conventionally, the RLC layer is responsible for dividing or
`assembling a service data unit (SDU) received from a higher layer to a suitable size, and an error correction function.
`[0032] The PDCP layer is located in a higher level of the RLC layer on the user plane. The PDCP layer is responsible
`for compressing or decompressing a header of Internet protocol (IP) packet data, and a lossless transfer function in a
`state in which a RNC providing a service to a specific UE is changed.
`[0033] Characteristics of a transport channel connected between PHY and higher layers are defined by the TF pre-
`scribing processing schemes such as convolutional channel encoding, interleaving, and service-specific rate matching.
`[0034] As described above, the E-DCH used for a WCDMA communication system supports adaptive modulation
`and coding (AMC), hybrid automatic retransmission request (HARQ), Node B control scheduling, and others. UEs
`send, to the Node B, scheduling information such as a UE buffer status, a UE power status, and the like such that all
`available resources of the Node B are assigned to selected optimal terminals at each time interval, and Node B control
`scheduling is efficiently performed.
`[0035] The UEs for providing a plurality of services through the E-DCHs configure a plurality of priority queues (PQs)
`therefor, and temporarily store service data in the PQs. Then, the UEs report, to the Node B, an amount of data stored
`in each PQ. The Node B performs scheduling on the basis of reporting of the UEs.
`[0036] FIG. 3 illustrates the operation between the Node B and the UE in accordance with an embodiment of the
`present invention.
`[0037] UE-1 305 transmits streaming service data 310 and background service data 315 detected and output by a
`service discriminator 307 using an E-DCH processor 335. The streaming service data 310 is stored in PQ-1 320 within
`a buffer 327 before being transmitted through the E-DCH, and the background service data 315 is stored in PQ-2 325
`within the buffer 327. A buffer manager 330 monitors the statuses of PQ-1 320 and PQ-2 325. Because the streaming
`service data 310 is regularly input to PQ-1 320, the buffer manager 330 does not report the buffer status for PQ-1 320.
`[0038] The buffer manager 330 determines that service data not requiring buffer status reporting is stored in PQ-1
`320. Even when the buffer status for PQ-1 320 is varied, the buffer manager 330 does not send a buffer status report
`350. Alternatively, the buffer manager 330 determines that service data requiring buffer status reporting is stored in
`PQ-2 325. When the buffer status for PQ-2 325 is varied, the buffer manager 330 sends a buffer status report 355.
`[0039] For example, the buffer manager 330 sends the buffer status report 355 when new data is stored in PQ-2
`325 or a data amount of PQ-2 325 exceeds a threshold value.
`[0040] Similarly, a Node B scheduler 345 receives buffer status reporting 365 from other UEs.
`[0041] The Node B scheduler 345 assigns radio resources to the UEs on the basis of the buffer status reports 355
`and 365 received from the UEs including the UE 305, and scheduling assistance information 375 for a streaming
`service. Information about the assigned radio resources is sent to corresponding UEs through scheduling assignment
`commands 360 and 370.
`[0042] Specifically, the Node B scheduler 345 receives, from a radio network controller (RNC) (not illustrated), the
`scheduling assistance information 375 comprising information about regular data generation in PQ-1 320 of LTE-1 305
`and information about how to schedule data of PQ-1 320. For example, when data of an amount value E is generated
`from PQ-1 320 of UE-1 305 in a period D, the scheduling assistance information may include information indicating
`that transmission resources capable of transmitting the data of the amount value E in the period D must be assigned
`for PQ-1 320. Accordingly, the scheduler 345 estimates a data amount of PQ-1 320 through the scheduling assistance
`information 375.
`[0043] The scheduler 345 determines basic radio resources to be assigned to transmit data of PQ-1 320 using the
`estimated data amount of PQ-1 320, and determines radio resources to be assigned to transmit data stored in PQ-2
`325 on the basis of the buffer state report 350 sent from UE-1 305. The scheduling assignment command 360 to be
`sent to UE-1 305 comprises information about a sum of radio resources determined for PQ-1 320 and PQ-2 325.
`[0044] The UE 305 to which the radio resources are assigned through the scheduling assignment command 360
`sends data stored in the PQs 320 and 325 to the E-DCH processor 335. The E-DCH processor 335 transmits data
`through the E-DCH. An E-DCH processor 340 of the Node B delivers the data received through the E-DCH to the RNC.
`The E-DCH processors 335 and 340 are associated with PHY layer implementation, and are not directly associated
`with the present invention. Accordingly, a detailed description of these E-DCH processors 335 and 340 is omitted.
`[0045] For the above-described streaming service, the Node B estimates an amount of streaming service data from
`scheduling assistance information. The RNC determines the scheduling assistance information on the basis of quality
`of service (QoS) parameters of radio bearers (RBs) for providing the streaming service. The scheduling assistance
`information is assistance information necessary to perform scheduling such that the utility value of generated data is
`not lost as a data generation status is reported to the scheduler in the streaming service. For example, the scheduling
`assistance information includes information about a data amount (hereinafter, referred to as Data_Amount) and a
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`repetition period (hereinafter, referred to as Repetition_Period).
`[0046] Data_Amount indicates an amount of streaming data generated for Repetition_Period. Repetition_Period is
`a period for maintaining the utility value of the streaming data.
`[0047]
`If the Node B has received, from the UE, the scheduling assistance information for an E-DCH service, it
`assigns, to the UE, transmission resources capable of transmitting data of Data_Amount in Repetition_Period.
`[0048] Data_Amount depends upon a guaranteed bit rate (GBR) and Repetition_Period as in the following.
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`Data_Amount = [GBR + retransmission margin] * Repetition_Period
`
`[0049] Here, the GBR indicates a bandwidth to be provided at any time for the streaming service or interactive service.
`[0050] The retransmission margin indicates an amount of data according to retransmission of the RLC. For example,
`because one RLC packet data unit (PDU) out of 100 RLC packet data units (PDUs) is retransmitted when a block error
`rate (BER) of the PHY layer is 0.01, the retransmission margin becomes 0.01. The GBR indicates a bandwidth to be
`always guaranteed for a corresponding service, and is defined in the form of bits per second (bps).
`[0051] Repetition_Period is determined by a transfer delay. The transfer delay is a parameter determined by delay
`sensitivity of a corresponding service. Repetition_Period is a maximum delay value for a service data unit (SDU) input
`to a corresponding RB endurable within a Universal Mobile Telecommunications Service (UMTS) Terrestrial Radio
`Access Network (UTRAN), and is given in milliseconds. In other words, when data does not reach a destination within
`an allowed transfer delay time, the utility value of the data is lost. In this case, a transmitting side releases the data
`transmission. The transfer delay and the GBR are defined only for the streaming service.
`[0052] Repetition_Period indicates a time interval until the utility value of data is lost after one packet reaches a PQ.
`That is, because the packet must be transmitted within Repetition_Period, the Node B scheduler schedules the packet
`within Repetition_Period. However, the Node B scheduler cannot track all individual packet generation statuses. In
`other words, the UE reports packet arrival whenever a packet arrives at a PQ, but it is almost impossible for the Node
`B scheduler to schedule all packets within Repetition_Period on the basis of the packet arrival report. When it is taken
`into account that data is regularly generated in the streaming service, the Node B scheduler can approximate an amount
`of data generated in each Repetition_Period. The GBR indicates an amount of data per second in the streaming service,
`and the amount of data generated in each Repetition_Period is a value obtained by multiplying the GBR with
`Repeition_Period. When the obtained value is added to an amount of retransmission data, Data_Amount to be trans-
`mitted in the streaming service is computed. That is, data of Data_Amount is generated in Repetition_Period for the
`streaming service, and the Node B scheduler determines that Data_Amount must be scheduled in each
`Repetition_Period.
`[0053] Repetition_Period is affected by operating mode of the RLC layer. If the streaming service does not support
`retransmission in the RLC layer, Repetition_Period has a value close to a transfer delay. Alternatively, if the streaming
`service supports two retransmissions, Repetition_Period is a half of the transfer delay.
`[0054] FIG. 4 is a ladder diagram illustrating control signal flow between a Node B and a UE in accordance with an
`embodiment of the present invention.
`[0055]
`In step 405, the RNC determines whether to establish two RBs of RB x and RB y with the UE using the E-DCH.
`The RBs are established to provide a specific service. The RBs comprise a packet data convergence protocol (PDCP)
`entity and a radio link control (RLC) entity configured suitably to provide the service. The streaming service is provided
`through RB x, and the background or interactive service is provided through RB y. The RNC sets PQs for RB x and
`RB y. For example, PQ z is set for RB x, and PQ w is set for RB y. Conventionally, because the streaming service and
`the background service are assigned different priorities, different PQs are assigned for RB x and RB y. Upon determining
`scheduling assignment information to be applied to PQ z mapped to the streaming service on the basis of a GBR and
`transfer delay of the streaming service, the RNC sends an E-DCH setup message to the Node B in step 410. The
`message includes E-DCH configuration information for RB x and RB y, and PQ z and PQ w configuration information,
`and further includes scheduling assignment information.
`[0056]
`In step 415, the RNC sends, to the UE, a message comprising the configuration information of the E-DCH
`for RB x and RB y. The message may be, for example, a RB setup message. The RB setup message comprises
`indication information (RB x : BRR = off) for limiting buffer status reporting for RB x of the streaming service, and
`indication information (RB y : BRR = on) for enabling buffer status reporting for RB y of the background or interactive
`service.
`[0057] That is, buffer status reporting required (BRR) for RB x is set to 'off', and a BRR for RB y is set to 'on'. The
`RB setup message comprises mapping information (RB x : PQ z and RB y : PQ w) between RBs and PQs. The RB
`setup message may comprise GBR information in place of BRR information. For example, the RB setup message may
`comprise GBR information as indication information (RB x) for limiting buffer status reporting for RB x of the streaming
`service, and may not comprise GBR information as indication information (RB y : GBR = y kbps) for enabling buffer
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`status reporting for RB y of the background or interactive service.
`[0058] When the GBR is used in indication information for enabling buffer status reporting, the UE can determine
`buffer status reporting according to a predetermined condition. For example, if an amount of generated RB data included
`in the GBR information is less than the GBR, the buffer status is not reported. Otherwise, a difference between the
`GBR and generated buffer data may be reported.
`[0059] The present invention supports both a BRR signaling method and a GBR signaling method to control the
`above-described buffer status reporting, but only the BRR signaling method will be described for convenience.
`[0060] Scheduling assistance information for the streaming service is sent to the Node B, and the UE is notified of
`the presence of the buffer status reporting. When an E-DCH is established between the Node B and the UE, they
`initiate E-DCH communication. Even when the UE generates data for a RB not requiring buffer status reporting as in
`the streaming service, it does not notify the Node B of the data generation. The Node B estimates the buffer status for
`PQ z by taking into account data generation corresponding to Data_Amount in each Repetition_Period in the UE
`according to the scheduling assistance information received from the RNC. When buffer state reporting is not received
`from the UE, the Node B assigns, to the UE, radio resources associated with the estimated Data_Amount in step 420.
`[0061]
`In step 425, when the UE generates data of an amount 'a' for RB y requiring a buffer status report as in the
`interactive or background service, the data is stored in PQ w, and reports the buffer status for PQ w.
`[0062]
`In step 430, the Node B assigns, to the UE, transmission resources capable of transmitting all data based on
`the estimated Data_Amount for PQ z and the data amount 'a' reported for PQ w.
`[0063] Similarly, in step 435, when the UE sends a buffer status report of 'PQ w = b', the Node B assigns, to the UE,
`transmission resources capable of transmitting all data based on the estimated Data_Amount and the data amount 'b'
`reported for PQ w in step 440.
`[0064] FIG. 5 is a flow chart illustrating the operation of the UE in accordance with an embodiment of the present
`invention.
`[0065]
`In step 505, the UE receives an RB setup message. The message comprises RB configuration information
`(RLC configuration information, BRR information, and others) and E-DCH configuration information.
`[0066]
`In step 510, the UE establishes RBs according to the configuration information. In this case, two layer entities
`such as PDCP and RLC are established, and a suitable transport channel is connected. In an embodiment of the
`present invention, the transport channel is an E-DCH. The UE establishes the E-DCH according to the setup message.
`In this case, an E-DCH processor is established,