WO2009102166A2

WO2009102166A2 - Method and apparatus for transmitting data by using prioritized bit rate in mobile communication system

Info

Publication number: WO2009102166A2
Application number: PCT/KR2009/000711
Authority: WO
Inventors: Soeng-Hun Kim; Gert Jan Van Lieshout
Original assignee: Samsung Electronics Co., Ltd.
Priority date: 2008-02-13
Filing date: 2009-02-13
Publication date: 2009-08-20
Also published as: KR20090087779A; WO2009102166A3

Abstract

This invention relates to a method for transmitting control data in a mobile communication system. The invention is characterized by including the steps of: generating, according to the generation of control data for logical channels to which a temporary prioritized bit rate (PBR) is applied, a temporary PBR token which has the size corresponding to the control data and inserting the PBR token into a PBR token bucket of a correspondent logical channel; and determining the amount of the control data, which is supposed to be transmitted through allocated resources, according to the priorities of the logical channels that the temporary PBR token is able to use. The invention is characterized by further including the step of removing the temporary PBR token, which remains in the PBR token bucket, after transmitting the determined amount of the control data.

Description

【Specification】

[Name blue of invention]

Method and apparatus for transmitting day 9 using priority call bit rate in mobile communication system

[Detailed Description of the Invention]

Technical Field

The present invention relates to a method and apparatus for transmitting control data in a mobile communication system, and more particularly, to a method and apparatus for rapidly transmitting two-layer control data.

Background Art

The Universal Mobile Telecommunication Service (IMS) system is based on the European System for Mobile Communications (GSM) Global System for Mobile Communications (Genera I Packet Radio Services) GPRS *, and is a wideband code division multiple access (Code Division). 3GPP (3rd Generation Partnership Project), which is in charge of UMTS standardization, is the next generation mobile communication system of L TS system. Term Evolution (LTE) is a technology that implements high-speed packet-based communication with a transmission rate of up to 100 Mbps and aims to commercialize it in 2010. It is discussed, for example, by simplifying the structure of the network to reduce the number of nodes β on the communication path, There is a debate on how to get as close to the wireless channel as possible, etc. Fig. 1 illustrates one of the structures of the next generation mobile communication system as described above, and shows a system structure based on the UMTS system.

Referring to FIG. 1, as illustrated, a next-generation radio access network (hereinafter referred to as E-RAN) 110 and 112 may be referred to as a next-generation base station (evolved Node B, ENB or Node B) 120 122, 124, 126, 128, and the upper node (referred to as Access Gateway) 130, 132 is simplified to a two node structure. User Equipment (hereinafter referred to as UE) 101 is E-RAN (110,

Alternative Response (Article 26) 112 connects to the Internet Protocol (IP) network 114. The ENBs 120 to 128 correspond to existing Node Bs of the UMTS system and are connected to the UE 01 through a radio channel. However, the ENBs 120 to 128 play a more complicated role than the existing Node B. In LTE, all user traffic including real-time services such as V () IP (Voice over IP) over the Internet protocol is serviced through a shared channel, so a device for collecting and scheduling situation information of UEs is required. The ENB 120 to 128 is in charge of this. In order to realize a transmission rate of up to 100 Mbps, LTE uses orthogonal frequency division multiplexing (OFDM) as a radio access technology in a bandwidth of up to 20 MHz. In addition, a modulation ion scheme and an adaptive modulation < RTI ID = 0.0 > coding < / RTI >

2 is a diagram illustrating a radio protocol structure of the LTE system as described above.

Referring to FIG. 2, the wireless protocol of the LTE system is PDCP (Packet Data Convergence Protocol 205, 240), RLC (Radio Link Control 210, 235), MAC (Medium Access Control 215,230), PHY (PHYSICAL 220, 225). Is done.

The Packet Data Convergence Protocol (PDCP) 205 and 240 is responsible for operations such as IP header compression / restore, non-password / decryption, and lossless handover support. The lossless handover means that after the UE completes the handover between ENBs, a PDCP STATUS REPORT containing the serial number of the PDCP SDU that the PDCP layer has not received is transmitted to the other PDCP layer. This is accomplished by retransmitting the unreceived PDCP SDU.

The radio link control (hereinafter referred to as RLC) (210, 235) reconfigures a PDCP PDU (Packet Data Unit (hereinafter referred to as PDU of the protocol) as an appropriate size) by reconfiguring it to an appropriate size. ARQ operation and so on.

The MACs 215 and 230 are connected to several RLC devices configured in one terminal, and multiplex RLC PDUs to MAC PDUs, and demultiplex RLC PDUs from MAC PDUs.

The physical layer (PHYSICAL, hereinafter referred to as PHY) layer 220 and 225 channel-codes and modulates upper layer data, and then forms a 0FDM symbol to a wireless channel. It transmits or demodulates, decodes, and channel-decodes an OFDM symbol received through a wireless channel.

However, as described above, after the handover between the ENBs is completed, the terminal and the base station prevents data loss through the exchange of PDCP status reports. For this, refer to FIG. This will be described.

Referring to FIG. 3, the source ENB 315 commands a handover to the terminal 305 in step 320, and then delivers PDCP SDUs that have not been successfully transmitted to the destination ENB 310 in step 325. do. The terminal 305 that performed the handover from the source ENB 315 to the destination ENB 310 transmits a HANDOVER COMPLETE message in step 330 to indicate that the handover is successful to the destination ENB 310. Notify me. Accordingly, the target ENB 310 allocates the uplink transmission resource to the terminal 305 in step 335. Then, the terminal 305 transmits the PDCP status report containing the forward PDCP SDU reception status to the destination ENB 310 in step 340.

In step 345, the target ENB 310 detects unreceived PDCP SDUs by referring to the received PDCP status report, first transmits retransmission forward data of the detected PDCP SDU, and then transmits data of an initial transmission. Done.

As described above, since PDCP status report serves as an initiation of forward data transmission, it is desirable to transmit as soon as possible.

Of course, the destination ENB can resume forward data transmission without receiving a PDCP STATUS REPORT, but in this case it must retransmit the PDCP SDUs already sent by the source ENB without knowing whether the reception was successful. do. However, among the retransmitted PDCP SDUs, there may be PDCP SDUs already successfully received by the UE. Retransmitting the successfully received PDCP SDU is unnecessary in terms of efficiency since unnecessary redundant transmission is required.

Meanwhile, the PDCP status report is generated for each logical channel and processed according to the priority of the logical channel. In other words, the transmission time of PDCP STATUS REPORT generated in the low priority logical channel is after all the data E 의 of the high priority logical channel are transmitted. Accordingly, there is a problem in that forward data transmission may be delayed or redundantly transmitted in the low priority logical channel. [Content of invention]

Problem to be solved

Accordingly, an object of the present invention for solving the above problems is that the terminal does not delay transmission due to the low priority of important control data.

Another object of the present invention is to provide a method and apparatus for a terminal to more quickly transmit a PDCP status report after handover.

[Task solution]

According to one embodiment of the present invention as described above, in a method of transmitting control data in a mobile communication system, control data generation of logical channels to which a temporary prioritized bit rate (hereinafter referred to as PBR) is applied And generating a temporary PBR token of a size corresponding to the control data and injecting the temporary PBR token into a PBR token bucket of a corresponding logical channel, and the logic that the temporary PBR token can use. Determining the amount of control data to be transmitted through the allocated resource according to a predetermined priority of the channels; and, after transmitting the determined amount of control data, the temporary data remaining in the PBR token bucket. This includes removing the PBR token.

The present invention provides an apparatus for transmitting control data in a mobile communication system, comprising: a control unit for generating control data of logical channels to which a temporary prioritized bit rate (PBR) is to be applied; and a temporary PBR token having a size corresponding to the generated control data. (Token) is created and injected into the PBR token bucket of the logical channel, and after the control data is transmitted, the temporary PBR token remaining in the PBR token bucket is transferred. A temporary PBR token management unit to remove, a logical channel prioritization unit to determine an amount of control data to be transmitted through an allocated resource according to a predetermined priority of the logical channels available for the temporary PBR token OI; And a transmitter for transmitting the determined amount of control data through a wireless channel.

【effect】

The present invention has the advantage that it is possible to preferentially transmit important data such as PDCP STATUS REPORT to be transmitted quickly using the PBR token. [Brief Description of Drawings]

1 is a diagram illustrating the structure of an LTE mobile communication system.

2 is a diagram illustrating a radio protocol architecture of an LTE mobile communication system. 3 illustrates an example of lossless handover.

4 illustrates an example of a PBR token bucket operation.

5 is a diagram illustrating an operation of a terminal processing a PDCP status report using a temporary PBR token.

6 shows an example of PDCP STATUS REPORT.

7 is a diagram illustrating an operation of a terminal for processing second layer control data using a temporary PBR token.

8 shows a device of the invention.

[Specific contents for implementation of the invention]

Hereinafter, the operation principle of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that a detailed description of a known function or configuration may unnecessarily flow the gist of the present invention, the detailed description thereof will be omitted. In addition, terms to be described below are terms defined in consideration of functions in the present invention, and may be changed according to intention or custom of a user or an operator. Therefore, the definition should be made based on the contents throughout the specification.

In addition, although the LTE system is used as an example in describing the present invention, the present invention can be applied to all mobile communication systems to which signal scheduling is applied without any significant addition or subtraction.

The mobile communication system according to an embodiment of the present invention, the PDCP status report (PDCP) generated to prevent the delay of important control data, such as PDCP STATUS REPORT corresponding to a low-priority logical channel A method and apparatus for injecting a PBR (PNor itized Bit Rate) token having a size corresponding to a STATUS REPORT into a PBR token bucket of a corresponding logical channel and transmitting the same are provided.

The PBR is a right to be preferentially transmitted regardless of the general priority of the logical channel in order to prevent continuous transmission of data of the lower priority logical channel. The PBR is assigned to a logical channel connected to a service that needs to periodically transmit data among logical channels of low priority. The PBR operates in the form of a token bucket, by creating FIG. Let's explain.

Referring to FIG. 4, a PBR-allowed logical channel includes a bucket 405 of a predetermined size, and a PBR token of a predetermined size is injected into the PBR bucket at predetermined cycles (410). The rate at which the size of the PBR token increases is set at the logical channel configuration. Data equal to the size of the PBR token transmitted on a PBR capable logical channel is transmitted at a higher priority than a general priority. PBR is not allowed for all logical channels, and PBR tokens are set to increase by a predetermined amount at predetermined intervals. In the present invention, a temporary PBR token is allocated to a logical channel in which reception success status information (PDCP status report) is generated so that reception success status information (PDCP status report) can be transmitted using the PBR. It is increased only by a predetermined size without increasing the temporary PBR token to the token, unlike the general periodic, when the reception success eu ^■ control information such as information indicating whether eu (PDCP STATUS REPORT) is generated. Therefore, when a predetermined event is detected, the temporary PBR token is generated and injected into the PBR bucket. The temporary PBR token is used for the transmission of data requiring a low priority but rapid transmission, such as PDCP STATUS REPORT in the future. Fig. 5 is a flowchart for explaining the operation of the terminal 0 in accordance with the embodiment of the present invention as described above.

Referring to FIG. 5, in step 505, the UE recognizes one or more logical channels to which the temporary PBR is to be applied and recognizes the size of the temporary PBR of each of the recognized logical channels. The temporary PBR may be used in a logical channel in which PDCP STATUS REPORT is likely to be generated, ie in a logical channel operating in RLC AM (Acknowledge Mode). Since the size of the temporary PBR is preferably determined according to the size of PDCP status report, the base station does not set the size of the temporary PBR separately, and when the terminal generates the PDCP status report in advance, The decision may be made according to In addition, step 505 may be performed in a call setup process, and the terminal performs forward data reception and reverse data transmission according to a conventional procedure when the call setup step is completed.

If the handover is started in step 510, the terminal performs the handover according to a conventional procedure. The handover is completed by the terminal transmitting a predetermined control message to the new target base station, and the terminal performs an operation necessary for resuming data transmission and reception at the new base station after completing the handover, for example, lossless handover in step 515. Generates PDCP STATUS REPORT of the required logical channels.

An example of the generated PDCP STATUS REPORT is shown in FIG. 6.

Referring to FIG. 6, the PDCP STATUS REPORT 605 includes a conventional PDCP header 610, a reference PDCP SN 615, and a bitmap 620. The reference PDCP SN 615 is a reference value for the PDCP SN to which each bit of the bitmap 620 corresponds. '0' of the bitmap 620 indicates that retransmission is not necessary and Ί indicates that retransmission is necessary. The size of the bitmap 620 is variable according to the distance between PDCP SDUs that require retransmission. The PDCP status report 605 may be generated immediately after the UE is instructed to handover or may be generated after completing the handover. Prior to transmission over the wireless channel, the PDCP STATUS REPORT 605 is attached with a header 625 of a lower layer, such as an RLC header.

Referring back to FIG. 5, in step 520, the UE generates a temporary PBR token of a size corresponding to the size of the generated PDCP status report and injects it into the PBR token bucket of the corresponding logical channel. The size of the temporary PBR token of any logical channel X is calculated as in Equation 1 below.

[Equation 1]

Size of temporary PBR token in logical channel X = (size of PDCP status report in logical channel X) + RLC header size + n

In Equation 1, _n indicates that the unexpected lower layer header is PDCP

To provide sufficient PBR token in case of addition to STATUS REPORT, it can have a small value of about 2 bytes. N may be preset in the call setup process.

Referring back to FIG. 5, after performing step 520, the terminal performs reverse data transmission fixation.

In step 525, the UE requests and allocates the uplink transmission resource to the base station. The terminal allocated with the uplink transmission resource proceeds to step 530 and performs logical channel prioritization. The logical channel prioritization channel (logical channel priority it) is determined in the data to be transmitted by using the allocated transmission resources, considering the priority of each logical channel and the amount of stored data E 저장된, This process ensures that the data of the high logical channel is transmitted as soon as possible. The terminal first determines the amount of data to be transmitted based on the priority of logical channels for which the temporary PBR token is available. The amount of data to be transmitted is the smaller of the amount of temporary PBR token, the amount of stored data and the amount of remaining space of the transmission resource. The remaining space of the transmission resource means a space excluding a space already occupied by the data in the size of data to be transmitted through the allocated transmission resource. If the remaining space of the transmission resource remains even after processing all the data corresponding to the temporary PBR, the terminal according to the priority of the logical channel in which the data to be transmitted, the amount of remaining space and the amount of data to be transmitted The process of selecting the data of the small amount of only comb is repeated until the remaining space of the transmission resource becomes 0 bytes. When the logical channel prioritization process as described above is completed, the UE transmits backward data using the uplink transmission resource according to the determined logical channel priority result in step 535.

In step 540, the UE checks whether the transmission of the PDCP status report is completed in the logical channel into which the temporary PBR token is injected. In step 540, if the transmission of the PDCP status report is completed, the terminal proceeds to step 545 and removes all the remaining temporary PBR tokens from the PBR token bucket of the corresponding logical channel. In step 525, the terminal waits until a reverse transmission resource is allocated. However, if there is no logical channel in which the transmission of the PDCP status report in step 540 is completed, the terminal immediately proceeds to step 525. The terminal repeats the process from step 525 to step 545 until PDCP status reports of all logical channels are transmitted. In the above description, the forward data transmission of the handover-completed terminal has been described as an example, but it can be applied to the method of using the PBR token of the present invention in all cases of transmitting important data generated in a low-priority logical channel.

In particular, the method may be applied to general two-layer control data processing. The two-layer control data is control data generated in a two-layer protocol device such as PDCP and RLC, and typical examples thereof include PDCP STATUS REPORT and RLC STATUS REPORT.

Next, referring to FIG. 7, an operation of a terminal for quickly transmitting layer 2 control data using a temporary PBR will be described.

Referring to FIG. 7, in step 705, the UE recognizes the type of control data to which the temporary PBR token is applied. For example, it may be set to apply a temporary PBR token to all two-layer control data, or it may be a specific two-layer control. The data may be set not to apply the temporary PBR token.

If predetermined control data configured to inject a temporary PBR token is generated in step 710, the UE injects a predetermined temporary PBR token into a PBR token bucket of a logical channel in which the control data has occurred in step 715. The size of the temporary PBR token may be a predetermined value added to the size of the generated control data, or may be a predetermined value at the call setup.

If the backward transmission resource is allocated in step 720, the UE performs logical channel prioritization (H channel) prior to step 725 and transmits backward data. In step 730, the terminal checks whether the transmission of the control data that caused the generation of the temporary PBR token is completed. If the transmission of the control data, which resulted in the generation of the test result ᅡ temporary PBR token of step 730, is not completed, the terminal returns to step 720. However, if the inspection result of step 730 and transmission of the control data that caused the generation of the temporary PBR token are completed, the terminal proceeds to step 735 to remove all the temporary PBR tokens remaining in the corresponding logical channel, and proceeds to step 720. Go back. The terminal repeats the process from step 720 to step 735 until all transmission of control data is completed.

8 illustrates a structure of a terminal device according to an embodiment of the present invention. In the following description, a terminal device for transmitting control data, which is PDCP STATUS REPORT or RLC STATUS REPORT, will be described as an example. However, it will be understood that other device configurations for transmitting important control data using a temporary PBR token are also possible.

The terminal apparatus may include a PDCP transmission process 805, a PDCP control unit 820, a PDCP reception process 835, an RLC transmission process 810, an RLC control unit 825, an RLC reception process 830, and a logical channel prioritization unit 815. ), A multiplexing and demultiplexing apparatus 840, a temporary PBR token management unit 845, and a transmission / reception apparatus 850.

The PDCP transmission process 805 is responsible for compressing and secreting headers of higher layer packets, and the PDCP receiving process 835 reverses the RLC SDUs delivered by the RLC receiving process 830 and restores the headers. Is in charge of the operation. PDCP receiving process 835 is also responsible for storing PDCP SDUs out of order due to unreceived PDCP SDUs during handover.

The PDCP control unit 820 generates a PDCP STATUS REPORT by checking the serial numbers of PDCP SDUs stored in the reception packet of the PDCP reception process 835 after the handover is completed and the black handover is completed. The RLC transmission process 810 performs framing on the PDCP PDUs, that is, concatenates or divides the PDCP PDUs, configures them into appropriately sized RLC PDUs, and retransmits the transmitted RLC PDUs until an RLC ACK is received. Save it. The RLC receiving process 830 stores the RLC PDUs received from the demultiplexing device 840 in a receiving packet, assembles the assembleable RLC PDUs into PDCP PDUs, and delivers them to the PDCP receiving process 835. . The RLC control unit 825 examines the serial numbers of the RLC PDUs stored in the receiving bay I 'of the RLC receiving process 830, and generates an RLC STATUS REPORT requesting retransmission of unreceived RLC PDUs at an appropriate time.

One PDCP process, one RLC process, one PDCP control unit, and one RLC control unit are provided per logical channel.

The logical channel prioritizer 815 determines the size of data to be transmitted in each logical channel according to a predetermined method in consideration of the PBR token status, priority of the logical channel, the amount of stored data, and the remaining space of the data to be transmitted. Do this. The temporary PBR token manager 845 injects or removes the temporary PBR token into the PBR token bucket of each logical channel when necessary. The multiplexing and demultiplexing apparatus 840 is an apparatus for multiplexing RLC PDUs generated in multiple logical channels into one MAC PDU or demultiplexing RLC PDUs from a MAC PDU. The transceiver 850 is a device that transmits or receives a MAC PDU through a wireless channel because it is a predetermined procedure i CC '.

Claims

[Patent Claims]

[Claim 1]

In a method of transmitting control data in a mobile communication system, the control data generation of logical channels to which a temporary PBR (PNoritized Bit Rate) is to be applied is generated, and a temporary PBR token having a size corresponding to the control data is generated to generate a corresponding logic. Injecting into the channel's PBR token bucket

A fixed value for determining an amount of control data E 'to be transmitted through an allocated resource according to a predetermined priority of logical channels for which the temporary PBR token is available; and after the transmission of the determined amount of control data is completed, the PBR token A method of transmitting control data, characterized in that it includes a fixation that removes the temporary PBR token remaining in the bucket.

[Claim 2]

The method of claim 1, wherein the control data is

PDCP STATUS REPORT or RLC STATUS REPORT, characterized in that the control data transmission method.

[Claim 3]

The method of claim 2, wherein the size of the temporary PBR token of any logical channel is calculated by Equation 2 below.

[Equation 2]

Size of temporary PBR token of logical channel X 二 (size of PDCP STATUS REPORT of logical channel X) + RLC header size + n

In Equation 2, n is the number of bits of arbitrary size.

[Claim 4]

The method of claim 1, wherein the amount of control data to be transmitted is

The amount of data to be transmitted is a control data transmission method, characterized in that the smaller of the amount of the temporary PBR token, the amount of stored control data and the remaining space of the allocated resources.

[Claim 5]

A device for transmitting control data in a mobile communication system, the control of logical channels to apply a temporary PBR (Prioritized Bit Rate) A control unit for generating data;

Create a temporary PBR token of a size corresponding to the generated control data and inject it into the PBR token bucket of the logical channel, and after the transmission of the control data is completed, remove the temporary PBR token remaining in the PBR token bucket Token management department,

A logical channel prioritization unit for determining an amount of control data to be transmitted through allocated resources according to predetermined priorities of logical channels available for the temporary PBR token;

And a transmitter for transmitting the determined amount of control data through a wireless channel.

[Claim 6]

The method of claim 5, wherein the control data

PDCP STATUS REPORT or RLC STATUS REPORT, characterized in that the control data transmission device.

[Claim 7]

The method of claim 6, wherein the temporary PBR token management unit

A control data transmission device characterized in that the size of the temporary PBR token of the logical channel is calculated by the following equation (3).

[Equation 3]

In Equation 2, n is the number of bits of arbitrary size.

[Claim 8]

The method of claim 5, wherein the logical channel prioritization unit

The amount of control data to be transmitted is a smaller value of the amount of the temporary PBR token, the amount of stored control data and the remaining space of the allocated resources.