KR101624937B1 - Apparatus and method for generating buffer status information of user equipment in wireless communication system - Google Patents

Abstract

A method for generating buffer status report information of a terminal in a wireless communication system of the present invention includes receiving a logical channel setting message including identifier information of a logical channel group to which a logical channel belongs from a base station, Determining whether or not the semi-persistent transmission resource is allocated, and setting the buffer status report information not to be generated when it is determined that the semi-persistent transmission resource is allocated. The logical channel setting message may further include indicator information indicating that the logical channel does not belong to the logical channel group when the semi-persistent transmission resource is allocated to the logical channel. According to the method and apparatus for generating buffer status reporting information of a terminal in a wireless communication system of the present invention, a terminal running a service in which data of a predetermined size periodically occurs, such as VoIP (Voice Over Internet Protocol) It is possible to prevent the terminal from being reduced due to the monitoring of the control channel, thereby extending the battery life of the terminal.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method and apparatus for generating buffer status report information of a UE in a wireless communication system,

The present invention relates to a method and apparatus for a terminal to report buffer status in a wireless communication system.

Generally, a wireless communication system has been developed for providing communication while ensuring user mobility. This wireless communication system has reached the stage of providing high-speed data communication service as well as voice communication due to the breakthrough of the technology.

Recently, as one of the next generation wireless communication systems, standard works for LTE (Long Term Evolution) systems are underway in 3GPP. LTE is a technology that realizes high-speed packet-based communication with a transfer rate of up to 100 Mbps, which is higher than the currently available data rate, with the aim of commercialization in 2010 or so. For example, there are discussions on how to reduce the number of nodes on the communication path by simplifying the structure of the network, and to make the wireless protocols as close as possible to the wireless channel.

Unlike the voice service, the data service determines the amount of data to be transmitted and the resources that can be allocated according to the channel status. Therefore, in the wireless communication system, the scheduler manages allocation of transmission resources in consideration of the amount of resources to be transmitted, the channel status, and the amount of data. This is also done in the LTE system, which is one of the next generation mobile communication systems, and the scheduler located in the base station manages and allocates wireless transmission resources.

In the wireless communication system, data transmission is divided into forward transmission and reverse transmission according to the data transmission direction. Forward transmission means a direction from a base station to a mobile station, and reverse transmission means a direction from a mobile station to a base station. In the forward direction, the amount of data to be transmitted by the base station can be accurately grasped. Therefore, the scheduler can smoothly perform the scheduling because it can accurately grasp the channel condition, the amount of resources, and the amount of data to be transmitted. However, there is a difficulty in the reverse transmission in that the allocation of the reverse wireless transmission resources may be performed in a state in which the scheduler can not accurately grasp the buffer status of the UE.

In the LTE system, the UE reports the buffer status to the BS using the buffer status report control information. Since the buffer status report control information is transmitted only when a specific condition is satisfied, the base station does not always accurately recognize the buffer status of the terminal. For example, when new data is generated in the buffer of the UE, the UE generates buffer status control information and transmits the buffer status control information to the BS when the priority of the newly generated data is higher than the priority of the previously stored data. If the generation condition of the buffer status reporting control information is directly applied to a service in which a certain amount of data such as Voice over Internet Protocol (VoIP) is periodically generated, the UE needs to monitor the forward control channel for a longer period than necessary It causes.

It is an object of the present invention to provide a method and apparatus for preventing a decrease in battery life due to unnecessary forward control channel monitoring of a terminal driving a service in which data of a predetermined size periodically occurs, such as Voice over Internet Protocol (VoIP) do.

According to an aspect of the present invention, there is provided a method for setting buffer status reporting information of a terminal in a wireless communication system, the method including receiving a logical channel setting message including identifier information of a logical channel group to which a logical channel belongs, Determining whether or not semi-persistent transmission resources are allocated to the logical channel; and setting the buffer status reporting information to be not generated when it is determined that the semi-persistent transmission resource is allocated. The logical channel setting message may further include indicator information indicating that the logical channel does not belong to the logical channel group when the semi-persistent transmission resource is allocated to the logical channel. And setting the logical channel group identifier of the logical channel to 'Null'.

According to another aspect of the present invention, there is provided a method of setting buffer status reporting information of a UE, the method comprising: setting a logical channel group identifier of the logical channel as the received identifier information when determining that the semi-persistent transmission resource is not allocated; The UE generates the buffer status report information when the data generated in the buffer status report has a higher priority than the currently stored data.

Also, in the wireless communication system of the present invention for solving the above problems, a terminal device receives a logical channel setting message including identifier information of a logical channel group to which a logical channel belongs, and transmits buffer status report information to the base station A control channel processor for determining whether semi-permanent transmission resources are allocated or released from the base station, and a buffer status report generator for generating buffer status report information when it is determined that the semi-permanent transmission resource is allocated, . And setting the logical channel group identifier of the logical channel to " Null ". The control channel processing unit may set the logical channel group identifier of the logical channel to 'Null' when it is determined that the semi-permanent transmission resource is allocated.

In the wireless communication system of the present invention, when it is determined that the semi-persistent transmission resource is not allocated to the terminal apparatus, the control channel processing unit sets the logical channel group identifier of the logical channel as the received identifier information, And the generator generates the buffer status report information when the data generated in the logical channel has a higher priority than the currently stored data.

According to the method and apparatus for generating buffer status report information of a terminal in the wireless communication system of the present invention, it is possible to prevent unnecessary forward control channel monitoring and extend the battery life of the terminal.

Brief Description of the Drawings Fig. 1 shows the structure of an LTE mobile communication system. Fig.
2 is a diagram illustrating a random access procedure in an LTE mobile communication system;
3 shows a structure of buffer status report information.
4 is a diagram illustrating an example of semi-persistent transmission resources, scheduling request transmission, and VoIP packet generation;
5 is a diagram illustrating a resource allocation method according to a first embodiment of the present invention.
6 is a flowchart of a process of generating buffer status report information according to the first embodiment of the present invention.
7 is a block diagram of a terminal device according to the first embodiment of the present invention;
FIG. 8 is a flowchart illustrating a process of generating buffer status report information according to a second embodiment of the present invention; FIG.
FIG. 9 is a flowchart illustrating a process of generating buffer status report information according to a third embodiment of the present invention; FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the same components are denoted by the same reference numerals as possible in the accompanying drawings. Further, the detailed description of well-known functions and constructions that may obscure the gist of the present invention will be omitted.

Also, the terms and words used in the present specification and claims should not be construed to be limited to ordinary or dictionary meanings, and the inventor is not limited to the concept of terms in order to describe his invention in the best way. It should be construed in accordance with the meaning and concept consistent with the technical idea of the present invention based on the principle that it can be properly defined.

Before describing the present invention in detail, the LTE system will be described in more detail with reference to FIG. 1 and FIG.

1 is a diagram showing the structure of an LTE system.

1, an Evolved Radio Access Network (hereinafter referred to as E-RAN) 110 and 112 is a next-generation base station (hereinafter, referred to as an ENB or Node B) 120 and 122 , 124, 126, and 128) and an upper node (referred to as an Access Gateway) 130 and 132, respectively. A User Equipment (UE) 101 accesses an Internet Protocol (IP) network by an E-RAN 110 or 112.

The ENBs 120-128 correspond to the existing Node B of the UMTS system. The ENB is connected to the UE 101 via a radio channel and plays a more complex role than the existing Node B. In LTE, all user traffic including real-time services such as Voice over IP (VoIP) through the Internet protocol is serviced through a shared channel. Therefore, a device for collecting and scheduling the situation information of the UEs is needed. 120 to 128). One ENB typically controls multiple cells. 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, Adaptive Modulation and Coding (AMC) scheme is used to determine a modulation scheme and a channel coding rate in accordance with a channel state of a UE.

2 is a diagram illustrating a random access procedure in an LTE mobile communication system.

2, a wireless protocol of the LTE system includes Packet Data Convergence Protocol (PDCP) layers 205 and 240, Radio Link Control (RLC) layers 210 and 235, a MAC (Medium Access Control) layer 215 , 230, and PHY (Physical) layers 220 and 225. Data to be input to a protocol entity based on transmission is referred to as an SDU (Service Data Unit), and output data is referred to as a PDU (Protocol Data Unit).

The PDCP layers 205 and 240 perform operations such as IP header compression / decompression, and the RLC layers 210 and 235 reconfigure PDCP PDUs to an appropriate size to perform ARQ (Automatic Repeat Request) operations. The MAC layers 215 and 230 are connected to the devices of the plurality of RLC layers 210 and 235 configured in one terminal, multiplex RLC PDUs into MAC PDUs, and demultiplex RLC PDUs from MAC PDUs. In addition, the PHY layers 220 and 225 perform channel coding and modulation on the upper layer data and transmit them to a wireless channel by making OFDM symbols, or demodulate and channel-decode OFDM symbols received through a wireless channel, do.

Data for which similar quality of service is required is transmitted and received through one logical channel, and the logical channel is a PDCP apparatus and an RLC apparatus set to be able to provide the service quality in detail. Usually one logical channel is set for one service, and an appropriate priority per logical channel is set according to the required service quality of the service. The priority is an indicator of the importance of data generated in the logical channel, and plays a role in reporting the buffer status.

Any logical channel may belong to a logical channel group. The logical channel group is a unit of buffer status reporting in the buffer status report control information. A maximum of four logical channel groups can be set in one terminal, and one logical channel group can include a plurality of logical channels.

3 is a diagram showing a structure of buffer status report information.

Referring to FIG. 3, the size of the buffer status report (BSR) information is 1 byte or 3 bytes. The 1-byte buffer status report information is referred to as short buffer status report information, and is composed of 2-bit LCG (Logical Channel Group) identifier 305 and 6-bit buffer size information 310. The LCG identifier 305 contains the identifier of the LCG for which the buffer size information is reported. The buffer size information 310 stores information indicating a total sum of data stored in all logical channels included in the LCG.

The 3-byte buffer status report information is called long buffer status report information and consists of four 6-bit buffer size information (315, 320, 325, and 330). Information indicating the sum of data stored in all logical channels included in the LCG having the LCG identifier of 0 is stored in the first buffer size information 315 and information indicating the sum of data stored in the LCG having the LCG identifier of 1 is stored in the second buffer size information 320 Information indicating the sum of data stored in all the logical channels included in the LCG, and information indicating the sum of data stored in all logical channels included in the LCG having the LCG identifier of 2 in the third buffer size information 325 Information indicating the total sum of data stored in all logical channels included in the LCG having the LCG identifier of 3 is stored in the fourth buffer size information 330. [

If there is only one LCG to report buffer status, then short buffer status reporting information is used. If there is more than one LCG to report buffer status, long buffer status reporting information is used.

In the LTE system, Semi Persistent Scheduling (SPS) is used to efficiently provide services such as voice service in which small packets are regularly generated. In the SPS, a predetermined transmission resource is periodically given to the UE without transmission resource allocation information. The transmission period of the transmission resource and the size of the transmission resource are appropriately set according to the period and size of the VoIP packet.

4 is a diagram illustrating an example of semi-persistent transmission resources, scheduling request transmission, and VoIP packet generation.

Referring to FIG. 4, the BS can allocate semi-persistent transmission resources having a period of 20 msec to a terminal driving a VoIP service in which a voice packet occurs every 20 msec. For example, when the semi-persistent transmission resource is allocated as (x + 20) msec, (x + 40) msec, (x + 60) msec and so on, and the voice packet is allocated between semi-permanent transmission resource allocation points Lt; / RTI >

On the other hand, a logical channel for VoIP is generally given a high priority. Since the voice packet is transmitted by the semi-permanent transmission resource before the next voice packet is generated, there is a high possibility that no data is stored in the logical channel for VoIP at the time of generation of the voice packet. Therefore, the generation of the voice packet satisfies the condition of 'generation of the higher priority data than the data stored in the current terminal', so that there is a high possibility of generating the buffer status report information.

When the buffer status report information is generated, the UE transmits 1-bit information, i.e., a scheduling request, to the BS and monitors the forward control channel until an uplink transmission resource is allocated. The scheduling request may be transmitted to the UE through a periodically-arriving transmission resource given in advance. If the temporal location of the scheduling request 430 is between the voice packet origination time 420 and the semi-persistent transmission resource allocation time 410, the UE receives the discontinuous reception until the semi-persistent transmission resource is allocated at the time of transmitting the scheduling request. reception (DRX) operation 435, which leads to unnecessary power wastage. For reference, the active time of the DRX operation means a period during which the mobile station should monitor the forward control channel, and the mobile station must keep the receiver turned on during the active time.

The above-described problem may be solved by defining that buffer status reporting control information is not generated for a service in which semi-persistent transmission resources are likely to be used because a packet of a certain size occurs at a constant period such as VoIP. However, in this case, another problem arises that it is difficult to switch from the silent period of VoIP to talkspurt. The talk spurt is a period in which a voice packet occurs at a cycle of 20 msec, which corresponds to a period spoken by the user. The silence period is a period that the user does not speak, and a packet much smaller than the voice packet occurs every 160 msec.

The base station normally allocates semi-persistent transmission resources only in the talk spurt period. When it recognizes that the VoIP session has been switched to the silent period, it releases the semi-persistent transmission resources and allocates transmission resources to the mobile stations assuming that small packets are generated every 160 msec . That is, a transmission resource capable of transmitting a packet having a predetermined size is allocated every 160 msec. The switch from silence to talk spurt can be done at any time. That is, voice packets may start to occur at intervals of 20 msec when the base station does not expect it. When switched to talk spurt, it is necessary for the base station to quickly recognize it and allocate a new semi-permanent transmission resource to the terminal. If the packet generated in the VoIP logical channel is set not to generate the buffer status report control information, the base station transmits the buffer status report control information to the talk spurt There is no way of recognizing the voice packet, and there arises a problem that the transmission delay of the voice packet increases.

In order to solve the above problem, in the present invention, a packet generated in a VoIP logical channel does not generate buffer status reporting control information while a terminal operates as a talk spurt, and packets generated in a VoIP logical channel during operation in a silencer A logical channel setting mode of the terminal for generating buffer status report control information is presented.

In the present invention, the base station controls the terminal to operate in the above-described logical channel setting mode using 1-bit indicator information in the process of setting an arbitrary logical channel. That is, the BS transmits an indicator including the logical channel setting mode information to the UE, and indicates whether the logical channel is included in an arbitrary logical channel group conditionally. The conditional inclusion of any logical channel in any logical channel group means that the logical channel is included in the logical channel group only if a predetermined condition is satisfied and the condition may be whether or not to set the semi-persistent transmission resource .

In order to efficiently use the semi-persistent transmission resource, the base station usually allocates semi-persistent transmission resources to the terminal only during talk spurt and releases semi- permanent transmission resources to the silence period. Therefore, whether or not the semi-permanent transmission resource is allocated can be used as a basis for determining whether the terminal is in the talk spurt period. The fact that any logical channel does not belong to a logical channel group is synonymous with the fact that the data of the logical channel has no effect on the buffer status report. Therefore, even if new data is generated in the logical channel, buffer status report information is not generated.

The terminal operates the logical channel with the 1-bit indicator set to '1' as being not belonging to any logical channel while the semi-persistent transmission resource is allocated, while the semi-persistent transmission resource is allocated to the logical channel .

While the semi-persistent transmission resource is allocated, the logical channel is not included in any logical channel group, so that buffer status reporting information is not generated due to the data even if data is periodically generated in the logical channel. Also, while the semi-persistent transmission resource is not allocated, the logical channel is included in a specific logical channel group so that buffer status report information is generated when data is generated in the logical channel and the data satisfies a certain condition. Transmission from the silencer to the talk spurt can be recognized by receiving the buffer status report information.

≪ Embodiment 1 >

5 is a diagram illustrating a resource allocation method according to the first embodiment of the present invention.

Referring to FIG. 5, in step 515, the base station 510 transmits a setup message for setting the logical channel X to the terminal 505. The setting message may include identifier information (LCG Y) of the logical channel group Y in which the logical channel X is to be included, and indicator information of 1 bit.

Indicator information indicates whether the logical channel operates in the above-described logical channel setting mode. If the logical channel always belongs to a logical channel group (indicator information is '0'), or if a semi-permanent transmission resource is not allocated to the logical channel Quot; 1 " (indicating information is " 1 "). That is, whether or not a logical channel belongs to a logical channel group affects whether to generate buffer status report information.

For example, if a logical channel does not belong to a logical channel group, buffer status reporting information is not generated even if data is generated in the logical channel. Therefore, if the logical channel X does not belong to the logical channel group but semi-persistent transmission resource is allocated, even if data is generated in the logical channel X, the buffer status report information is not generated and the scheduling request is not transmitted.

In addition, when data is generated in the logical channel X in a state where semi-permanent transmission resources are not allocated, buffer status reporting information is generated when the condition that the data generated in the logical channel X has higher priority than the currently stored data is satisfied .

Subsequently, in step 520, the base station 510 allocates semi-persistent transmission resources to the terminal 505. Thereafter, in step 525, a data packet is generated on the logical channel X. [ Since the logical channel X does not belong to any logical channel group in the state in which the semi-persistent transmission resource is allocated, the newly generated data does not generate the buffer status report information.

In addition, in step 530, the UE 505 transmits data generated in the logical channel X to the base station 510 through the semi-persistent transmission resource. Thereafter, data generation and reverse transmission are repeated. In step 540, the BS 510 releases the semi-persistent transmission resource allocated to the UE 505. For example, if the base station detects that the VoIP session being served through the logical channel X has switched from talk spurt to silence, it can release the semi-persistent transmission resources.

Subsequently, in step 545, a data packet is generated on the logical channel X. [ In this case, since the semi-persistent transmission resource is not allocated, the logical channel X is included in the logical channel group Y, and the terminal determines that the data generated in the logical channel X has a higher priority than the currently stored data And determines whether to generate buffer status report information. If only the VoIP service is running in the terminal, data is not stored in the terminal at the time when the data newly occurs. Therefore, in step 550, the terminal 505 generates buffer status report information and transmits it to the base station.

6 is a flowchart showing an operation of a terminal according to the first embodiment of the present invention.

Referring to FIG. 6, in step 605, the terminal receives a logical channel setting message from the base station. The logical channel setting message includes the identifier information of the logical channel group to which the logical channel belongs and the indicator information indicating the logical channel setting mode. Indicator information indicating the above-described logical channel setting mode indicates whether the logical channel always belongs to the logical channel group or only when the semi-permanent transmission resource is not allocated.

In step 610, the terminal determines whether the indicator information is '1' or '0'. If the logical channel is a service in which packets of a relatively constant size such as VoIP periodically occur, the indicator is set to '1'.

On the other hand, if the indicator is '0', the UE sets the logical channel group identifier of the corresponding logical channel to the indicated value in step 615, and determines that the data generated in the logical channel has a higher priority than the currently stored data If the condition is satisfied, buffer status report information is generated.

If the indicator is '1', the MS sets the logical channel group identifier of the corresponding logical channel to the received value and waits until semi-permanent transmission resources are allocated in step 620. Before the semi-persistent transmission resource is allocated, since it is included in the logical channel group corresponding to the identifier of the logical channel group, if the condition that the data generated in the logical channel has higher priority than the currently stored data is satisfied, Generates status report information and transmits it to the base station.

If the semi-persistent transmission resource is allocated in step 625, the UE sets the logical channel group identifier of the logical channel to 'Null' in step 630. That is, the logical channel does not belong to any logical channel group and does not generate buffer status report information even if data is generated in the logical channel.

If the semi-persistent transmission resource is released as in step 635, the MS sets the logical channel group identifier of the logical channel to a value indicated in the setup message in step 640. [ If the logical channel group identifier of the logical channel is not 'Null', the UE generates and transmits buffer status report information if the data generated in the logical channel satisfies the above-mentioned condition. Also, the UE keeps the logical channel group identifier of the logical channel until the semi-persistent transmission resource is allocated.

7 is a block diagram of a terminal device according to an embodiment of the present invention. It should be noted that the upper hierarchical apparatus in the terminal device block diagram of FIG. 7 is not shown.

7, a terminal according to embodiments of the present invention includes a multiplexing and demultiplexing apparatus 705, an HARQ processor 710, a buffer status report generating unit 715, a control channel processing unit 720, And a transmission / reception unit 725.

The buffer status report generator 715 determines which logical channel group the logical channels set in the UE belong to and monitors the buffer status of the logical channels belonging to the logical channel group. If new data is generated in the logical channel belonging to the logical channel group and the priority of the logical channel in which the data is generated is higher than the priority of the logical channels in which data was previously stored, buffer status report information is generated, And transmits the scheduling request information.

Also, the buffer status report generator 715 determines whether to generate the buffer status report information in connection with the semi-persistent transmission resource allocation, especially for the logical channel whose indicator information is set to '1'. More specifically, when a semi-persistent transmission resource is allocated from a base station, the logical channel does not belong to the logical channel group, so that even if data is generated in the logical channel, the buffer status report information is not generated. If the semi-persistent transmission resource is not allocated from the base station, since the logical channel belongs to the logical channel group, it is determined whether the data generated in the logical channel is data having higher priority than the currently stored data, .

The control channel processing unit 720 processes the forward and reverse control channels. For example, by analyzing the forward control information and determining whether or not to perform scheduling. In particular, since the semi-persistent transmission resource is allocated through the forward control channel, the control channel processor notifies the buffer status report generator when the semi-persistent transmission resource is allocated or released. The terminal transceiver 725 is a device that transmits / receives an MAC PDU over a wireless channel or transmits / receives control information. And receives an H-ARQ packet. An H-ARQ (Hybrid-Automatic Repeat Request) processor 710 is a set of soft buffers configured to perform H-ARQ operations, and is identified by an H-ARQ process identifier. The multiplexing and demultiplexing apparatus constructs a MAC PDU by concatenating the data transferred from the plurality of logical channels.

≪ Embodiment 2 >

FIG. 8 is a flowchart showing the operation of the terminal according to the second embodiment of the present invention.

In the second embodiment of the present invention, a method and apparatus for controlling whether or not a regular BSR of a specific logical channel is generated according to the semi-persistent transmission resource allocation is proposed.

The BSR is subdivided into the following three types according to the cause of occurrence.

Normal BSR: A BSR that is triggered when data of a higher priority than the data currently stored by the UE occurs, or when a predetermined timer expires. The timer is a timer for preparing for an error condition in which the BS does not recognize that the UE has data to be transmitted, and is a timer different from a timer for controlling the periodic BSR described below as a BSR retransmission timer. When the regular BSR is triggered, a status report (SR) is also triggered.

Periodic BSR: A BSR that is triggered when a given timer expires. Even if the periodic BSR is triggered, the SR is not triggered.

Padding BSR: A BSR inserted in place of padding when there is extra space in the transmitting MAC PDU. Even if the padding BSR is triggered, the SR is not triggered.

SR is triggered only by the normal BSR, so that it is possible to consider not to trigger the normal BSR in the logical channel corresponding to the VoIP service in order to solve the problem of preventing SR and BSR from being triggered every time a VoIP packet is generated .

In setting the logical channel corresponding to the VoIP service, the base station sets the indicator to a predetermined value in the logical channel in the second embodiment of the present invention. If the indicator is set to a predetermined value and the terminal is allocated with a semi-persistent transmission resource in the reverse direction, data is generated in the logical channel, and the data is data having a higher priority than other data stored in the terminal at that time , It does not trigger the normal BSR.

Referring to FIG. 8, in step 805, the terminal receives a logical channel setup message from the base station. The logical channel setup message includes indicator information indicating whether or not the normal BSR is allowed. Indicator information indicating whether or not the regular BSR is permitted indicates whether the data generated in the corresponding logical channel always triggers the normal BSR when the predetermined condition is satisfied or only when the predetermined condition is satisfied and the semi-persistent reverse transmission resource is not allocated, Is triggered.

In step 810, the terminal determines whether the indicator information is '1' or '0'. If the logical channel is a service in which packets of a relatively constant size such as VoIP periodically occur, the indicator is set to '1'.

If the indicator is '0', the UE generates new data in the corresponding logical channel in step 815 and if the priority of the newly generated data is higher than the priority of data already stored, or if the BSR retransmission timer expires, Lt; / RTI >

Also, if the indicator is '1', the UE checks in step 820 whether or not to allocate backward semi-persistent transmission resources. If the reverse semi-persistent transmission resource is allocated, the BS proceeds to step 825 to prevent the normal BSR from being generated depending on the data generated in the corresponding logical channel. That is, even if the new data is generated in the logical channel in which the indicator is set to 1 and the priority of the data is higher than the priority of other data already stored, it does not trigger the normal BSR. At this time, even if the indicator is '1', if the BSR retransmission timer expires, the normal BSR is triggered.

If the reverse semi- permanent transmission resource is not allocated, the BS proceeds to step 830 to generate the normal BSR according to the data generated in the logical channel. That is, if new data is generated in the logical channel in which the indicator is set to 1 and the priority of the data is higher than the priority of other data already stored, the normal BSR is triggered.

The terminal repeats the above operation until the logical channel is released.

≪ Third Embodiment >

9 is a flowchart of a buffer status report information generation process according to the third embodiment of the present invention.

In the third embodiment of the present invention, a method and apparatus for considering only logical channels other than a logical channel for processing traffic having a special attribute such as VoIP when the terminal triggers the normal BSR are proposed.

Currently, a parameter called logicalchannel-SRmask is defined in 3GPP standard 36.321. The parameter is set differently according to the logical channel. Even if the normal BSR is triggered by the data generated in the logical channel in which the parameter is set to 'true', SR is not triggered in the state where semi-permanent transmission resources are allocated. The reason for introducing the parameter is to minimize the power consumption of the UE by preventing the SR from being frequently triggered. For reference, SR is 1-bit information indicating that the UE has generated data to be transmitted to the BS, and is transmitted through a transmission resource dedicated to the UE. The transmission resource for transmitting the SR is allocated in advance to the UE, and the transmission resource has a preset periodicity. For example, the UE has an opportunity to transmit the SR at the period of x msec. Upon receiving the SR transmitted by the UE, the Node B recognizes that the UE has received a normal BSR and allocates transmission resources so that the UE can transmit the BSR.

The parameter is set to 'true' for a logical channel that handles traffic in which priority is high and data of small size frequently occurs, such as VoIP. However, even if the normal BSR is triggered, when the data is generated in the logical channel on which the SR is not triggered and the BSR is triggered, the normal BSR is not triggered even if new data is generated in the logical channel of lower priority than the logical channel . the BSR triggered by the logical channel with logicalchannel-SRmask of 'true' does not trigger the SR, so that the SR is not triggered even if data is generated in the logical channel with lower priority than the logical channel. There may be a logical channel that has a priority lower than that of the logical channel having the logical channel-SRmask of 'true' but still transmits and receives important traffic, and a situation where the base station does not recognize data generated from the data of the logical channel needs to be improved.

In the third embodiment of the present invention, in order to improve the above situation, when new data is generated in an arbitrary logical channel, it is determined whether or not a normal BSR is generated. In the case where logical channels- SRmask is 'true' We consider how to consider only the presence of data.

Referring to FIG. 9, in step 905, the terminal receives a control message indicating a logical channel setting. In the control message, the logical channel-SRmask of each logical channel is set to 'true' or 'false'.

In step 910, reverse data that can be transmitted in any one of the logical channels of the terminal is generated. This means that data is newly generated in the RLC entity or the PDCP entity of the logical channel and the generated data is transmittable data. For reference, transmission may not be possible depending on the window operation of the RLC entity even if data is generated.

The buffer status report information generation process proceeds to step 915 to determine whether a regular BSR for the newly generated uplink data can be generated. According to the current standard, even if data exists in the logical channel to which the newly generated data belongs, the logical channel triggers the normal BSR only if it has a higher priority than other logical channels in which data to be transmitted exists. However, if data already exists in the logical channel of the newly generated data and the logical channel has the highest priority among the logical channels having the data to be transmitted, the data already existing in the logical channel of the newly generated data It is very likely that the normal BSR has already been triggered and the base station is already aware of the fact that data exists on the logical channel of the terminal. Therefore, triggering the normal BSR results in unnecessarily triggering the SR, even though there is already data available to transmit on the new logical channel. In step 915 of the present invention, the terminal determines whether data that can be transmitted to the logical channel in which the transmittable reverse data is generated already exists.

If so, the buffer status report information generation process proceeds to step 925 to end the process without triggering the normal BSR. If there is no data that can be transmitted to the logical channel in which the transmittable reverse data is generated, the buffer status report information generating process proceeds to step 920. In step 920, the terminal checks whether the logical channel in which the transmittable reverse data is generated satisfies both of the following two conditions.

The logical channel is mapped to any LCG. Here, the mapping relationship between the logical channel and the LCG is indicated by the BS when the logical channel is set, and the fact that any logical channel is not mapped to the LCG means that BSR or SR is inactivated for the data of the logical channel.

- The priority of the logical channel is higher than the priority of the logical channels having the transferable data among the logical channels whose logical channel-SRmask is set to 'false'.

If both of the above conditions are satisfied, the buffer status report information generation process proceeds to step 930 and the UE triggers the normal BSR. If at least one of the two conditions is not satisfied, the buffer state reporting information generation process proceeds to step 925 and the UE does not trigger the normal BSR.

It should be noted that the embodiments of the present invention disclosed in the present specification and drawings are only illustrative examples of the present invention and are not intended to limit the scope of the present invention in order to facilitate understanding of the present invention. It is to be understood by those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

Claims (12)

Receiving a logical channel setup message including identifier information of a logical channel group to which a logical channel belongs from a base station;
Determining whether a semi-persistent transmission resource is allocated to the logical channel from the base station; And
And setting up to not generate buffer status report information when it is determined that the semi-persistent transmission resource is allocated to the UE in the wireless communication system. 2. The method of claim 1, wherein the logical channel setup message
Further comprising indicator information indicating that the logical channel does not belong to the logical channel group when the semi-persistent transmission resource is allocated to the logical channel. The method of claim 1, wherein the setting comprises:
And setting a logical channel group identifier of the logical channel to 'Null'. The method according to claim 1,
Setting a logical channel group identifier of the logical channel as the received identifier information when it is determined that the semi-permanent transmission resource is not allocated;
And generating buffer status report information when the data generated in the logical channel has a higher priority than data currently stored in the buffer. Way. The method according to claim 1,
Wherein the step of determining whether the semi-persistent transmission resource is allocated to the logical channel from the base station,
And determining whether or not a reverse semi-persistent transmission resource is allocated to the logical channel from the base station in the reverse communication period. 6. The method of claim 5,
Wherein the step of setting not to generate the buffer status report information when determining that the semi-permanent transmission resource is allocated,
And setting up to not generate normal buffer status report information when it is determined that the reverse semi-persistent transmission resource is allocated to the UE. A transmitting and receiving unit for receiving a logical channel setting message including identifier information of a logical channel group to which a logical channel belongs from the base station and transmitting buffer status reporting information to the base station;
A control channel processing unit for determining whether semi-permanent transmission resources are allocated or released from the base station; And
And a buffer status report generator for generating buffer status report information when it is determined that the semi-permanent transmission resource is allocated. 8. The method of claim 7, wherein the logical channel setup message
And indicator information indicating that the logical channel does not belong to the logical channel group when the semi-persistent transmission resource is allocated to the logical channel. 8. The apparatus of claim 7, wherein the control channel processing unit
Wherein the logical channel group identifier of the logical channel is set to " Null " when it is determined that the semi-permanent transmission resource is allocated. 8. The method of claim 7, wherein if it is determined that the semi-permanent transmission resource is not allocated
The control channel processing unit sets the logical channel group identifier of the logical channel as the received identifier information,
Wherein the buffer status report generator generates buffer status report information when data generated in the logical channel has a higher priority than data currently stored in the buffer. 8. The method of claim 7,
Wherein the control channel processing unit determines whether or not a backward semi-persistent transmission resource is allocated to the logical channel from the base station. 12. The method of claim 11,
Wherein the buffer status reporting information generator does not generate the normal buffer status report information when determining that the reverse semi-persistent transmission resource is allocated.

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