KR20100085362A - Method of buffer status reporting - Google Patents

Abstract

PURPOSE: A method for reporting a buffer state is provided to be unnecessary for assigning wireless resources in order to check the amount of buffer occupation of a terminal, thereby reducing the delay phenomenon of data transmission. CONSTITUTION: A UE(User Equipment) transmits a buffer state report according to the amount of data saved in a buffer. Wireless resources according to the buffer state report are assigned to the UE(S1605,S1607,S1610,S1612). The UE transmits uplink data saved in the buffer by using the wireless resources(S1606,S1608,S1611,S1613). The uplink data is MAC PDU. The UE indicates information about the buffer status changed according to the transmission of the MAC PDU in the MAC PDU and transmits the MAC PDU.

Description

How to report buffer status {METHOD OF BUFFER STATUS REPORTING}

The present invention relates to a wireless communication, and more particularly, to a method for reporting a buffer status for proper resource allocation in a wireless communication system.

3rd generation partnership project (3GPP) mobile communication systems based on wideband code division multiple access (WCDMA) wireless access technology are widely deployed around the world. High Speed Downlink Packet Access (HSDPA), which can be defined as the first evolution of WCDMA, provides 3GPP with a highly competitive wireless access technology in the mid-term future. However, as the demands and expectations of users and operators continue to increase, and the development of competing wireless access technologies continues to progress, new technological evolution in 3GPP is required to be competitive in the future. Reduced cost per bit, increased service availability, the use of flexible frequency bands, simple structure and open interface, and adequate power consumption of the terminal are demanding requirements.

When transmitting data in the uplink, the terminal transmits a buffer status report (BSR) to the base station in order to request radio resources for transmitting the uplink data. The BSR includes information on priority of uplink data to be transmitted and information on the amount of data occupying a buffer. The BSR may be transmitted by PHY (Physical) signaling or MAC (Media Access Control) signaling.

According to 3GPP TS 36.321 v8.1.0, the UE may be divided into three BSRs according to a condition for transmitting a BSR. That is, a regular BSR for transmitting BSR when the uplink data to be transmitted belongs to a logical channel having a high priority, and the number of padding bits of the allocated uplink radio resource is larger than the size of the BSR MAC control element. A padding BSR for transmitting BSRs and a periodic BSR for transmitting BSRs when the periodic BSR timer expires.

According to the related art, when the terminal transmits a regular BSR to the base station, the base station allocates a limited amount of radio resources to the terminal until the periodic BSR timer expires. When the periodic BSR timer expires, the terminal transmits a periodic BSR including a buffer occupancy (BO) of the terminal to the base station, and the base station allocates radio resources in consideration of the buffer status of the terminal.

However, despite the transmission of the BSR, there may be a difference between the actual buffer occupancy of the terminal and the estimated buffer occupancy of the terminal grasped by the base station. In this case, the base station unnecessarily allocates a radio resource, or even if it is necessary to allocate a radio resource, there is a problem such as delay of data due to not allocating a radio resource to the terminal.

In addition, if to solve this problem, if the allocated radio resource does not exist when the timer of the periodic BSR expires (triggering the SR (scheduling request)), even if the scheduler of the base station is normally scheduled for each terminal Frequent SRs can occur, which can cause confusion in scheduling. In particular, the SR due to the regular BSR and the periodic BSR cannot be distinguished, which may cause a problem in determining the priority of each scheduler / logical channel.

Alternatively, an additional timer can be associated with periodic BSR timer expiration to reduce the number of frequent SR triggerings. However, when using this method, there is a problem that complexity is increased by defining an additional timer in the currently defined BSR related definition.

According to an embodiment of the present invention, the method comprising: transmitting a buffer status report according to the amount of data stored in a buffer, receiving a radio resource according to the buffer status report, and using an radio resource, an uplink stored in the buffer Although transmitting data, the uplink data is a MAC PDU, and a buffer status reporting method is provided, which includes displaying and transmitting information on a buffer status changing according to transmission of the MAC PDU to the MAC PDU.

It is intended to reduce the phenomenon that data transmission delay occurs because the network does not know the buffer occupancy of the terminal.

In addition, the present invention provides a method for reporting a buffer occupancy amount of a terminal to a network without additional radio resource allocation.

According to an exemplary embodiment of the present invention, a phenomenon in which data transmission is delayed can be reduced.

In addition, according to an embodiment of the present invention, it is not necessary to additionally allocate radio resources in order to confirm the buffer occupancy amount of the terminal, thereby reducing the waste of radio resources to be allocated.

1 is a block diagram illustrating a wireless communication system. This may be a network structure of an Evolved-Universal Mobile Telecommunications System (E-UMTS). The E-UMTS system may be referred to as a Long Term Evolution (LTE) system. Wireless communication systems are widely deployed to provide various communication services such as voice, packet data, and the like.

Referring to FIG. 1, an Evolved-UMTS Terrestrial Radio Access Network (E-UTRAN) includes a base station (BS) 20 that provides a control plane and a user plane.

The UE 10 may be fixed or mobile and may be called by other terms such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a wireless device, and the like. The base station 20 generally refers to a fixed station communicating with the terminal 10, and may be referred to as other terms such as an evolved-NodeB (eNB), a base transceiver system (BTS), and an access point. have.

One or more cells may exist in one base station 20. An interface for transmitting user traffic or control traffic may be used between the base stations 20. Hereinafter, downlink means communication from the base station 20 to the terminal 10, and uplink means communication from the terminal 10 to the base station 20.

The base stations 20 may be connected to each other through an X2 interface. The base station 20 is connected to an Evolved Packet Core (EPC), more specifically, a Mobility Management Entity (MME) / Serving Gateway (S-GW) 30 through an S1 interface. The S1 interface supports a many-to-manyrelation between the base station 20 and the MME / SAE gateway 30.

2 is a block diagram illustrating a functional split between an E-UTRAN and an EPC.

Referring to FIG. 2, the hatched block represents a radio protocol layer and the empty block represents a functional entity of the control plane.

The base station performs the following functions. (1) Radio resource management such as radio bearer control, radio admission control, connection mobility control, and dynamic resource allocation to a terminal RRM), (2) Internet Protocol (IP) header compression and encryption of user data streams, (3) routing of user plane data to S-GW, and (4) paging messages. Scheduling and transmission, (5) scheduling and transmission of broadcast information, and (6) measurement and measurement report setup for mobility and scheduling.

The MME performs the following functions. (1) distribution of paging messages to base stations, (2) Security Control, (3) Idle State Mobility Control, (4) SAE Bearer Control, (5) NAS (Non-Access) Stratum) Ciphering and Integrity Protection of Signaling.

S-GW performs the following functions. (1) termination of user plane packets for paging, and (2) user plane switching to support terminal mobility.

3 is a block diagram illustrating elements of a terminal. The terminal 50 includes a processor 51, a memory 52, an RF unit 53, a display unit 54, and a user interface unit 55. .

The processor 51 is implemented with layers of the air interface protocol to provide a control plane and a user plane. The functions of each layer may be implemented through the processor 51.

The memory 52 is connected to the processor 51 to store a terminal driving system, an application, and a general file. The display unit 54 displays various information of the terminal, and may use well-known elements such as liquid crystal display (LCD) and organic light emitting diodes (OLED).

The user interface unit 55 may be a combination of a well-known user interface such as a keypad or a touch screen. The RF unit 53 is connected to a processor and transmits and / or receives a radio signal.

Hereinafter, a radio protocol architecture between a terminal and a network will be described.

Layers of the radio interface protocol between the terminal and the network are based on the lower three layers of the Open System Interconnection (OSI) model, which is well known in communication systems. (Second layer) and L3 (third layer).

Among them, the physical layer belonging to the first layer provides an information transfer service using a physical channel, and is a radio resource control (RRC) layer located in the third layer. The role of controlling the radio resources between the terminal and the network. To this end, the RRC layer exchanges RRC messages between the UE and the network.

4 is a block diagram illustrating a radio protocol architecture for a user plane. 5 is a block diagram illustrating a radio protocol structure for a control plane. This shows the structure of the air interface protocol between the terminal and the E-UTRAN. The data plane is a protocol stack for user data transmission, and the control plane is a protocol stack for control signal transmission.

4 and 5, a physical layer (PHY), which is a first layer, provides an information transfer service to a higher layer using a physical channel. The physical layer is connected to the upper Media Access Control (MAC) layer through a transport channel, and data between the MAC layer and the physical layer moves through this transport channel.

Data moves between physical layers between physical layers, that is, between physical layers of a transmitting side and a receiving side. The physical channel is modulated by an orthogonal frequency division multiplexing (OFDM) scheme, and may use time and frequency as radio resources.

The MAC layer of the second layer provides a service to a radio link control (RLC) layer, which is a higher layer, through a logical channel. The RLC layer of the second layer supports the transmission of reliable data. In the RLC layer, there are three operation modes according to a data transmission method: transparent mode (TM), unacknowledged mode (UM), and acknowledged mode (AM). The AM RLC provides a bidirectional data transmission service, and supports retransmission when an RLC Protocol Data Unit (PDU) fails to transmit.

The Packet Data Convergence Protocol (PDCP) layer of the second layer contains relatively large and unnecessary control information in order to efficiently transmit packets in a wireless bandwidth having a low bandwidth when transmitting an Internet Protocol (IP) packet such as IPv4 or IPv6. Perform header compression to reduce the IP packet header size.

The radio resource control (RRC) layer of the third layer is defined only in the control plane. The RRC layer is responsible for controlling logical channels, transport channels, and physical channels in connection with configuration, re-configuration, and release of radio bearers (RBs). RB means a service provided by the second layer for data transfer between the UE and the E-UTRAN. If there is an RRC connection (RRC Connection) between the RRC of the terminal and the RRC of the network, the terminal is in the RRC Connected Mode, otherwise it is in the RRC Idle Mode.

The non-access stratum (NAS) layer located above the RRC layer performs functions such as session management and mobility management.

As a downlink transport channel for transmitting data from a network to a terminal, a BCH (Broadcast Channel) for transmitting system information, a DL-SCH (Downlink-Shared Channel) for transmitting user traffic or a control message, etc. There is this. Traffic or control messages of the downlink broadcast service may be transmitted through the DL-SCH. An uplink transport channel for transmitting data from a terminal to a network includes a random access channel (RAC) for transmitting an initial control message and an uplink-shared channel (UL-SCH) for transmitting user traffic or a control message.

A downlink physical channel mapped to a downlink transport channel includes a physical broadcast channel (PBCH) for transmitting BCH information, a physical downlink shared channel (PDSCH) for transmitting PCH and DL-SCH information, and a downlink or uplink There is a Physical Downlink Control Channel (PDCCH) for transmitting control information provided by the first layer and the second layer, such as radio resource allocation information (DL / UL Scheduling Grant). The PDCCH is also called a downlink L1 / L2 control channel.

As an uplink physical channel mapped to an uplink transport channel, a physical uplink shared channel (PUSCH) for transmitting UL-SCH information, a physical random access channel (PRACH) for transmitting RACH information, a HARQ ACK / NACK signal, and scheduling There is a Physical Uplink Control Channel (PUCCH) for transmitting control information provided by the first layer and the second layer, such as a scheduling request signal and a channel quality indicator (CQI).

Hereinafter, the Buffer Status Report (BSR) will be described.

When the terminal intends to transmit data in the uplink, the terminal transmits a buffer status report (BSR) to the base station in order to request radio resources for transmitting the uplink data. The BSR includes information on the priority of data to be transmitted and information on the amount of data occupying the buffer. The BSR may be transmitted by PHY (Physical) signaling or MAC (Media Access Control) signaling.

The BSR can be divided into three types, a regular BSR, a padding BSR, and a periodic BSR depending on the triggered condition.

The regular BSR is triggered when the uplink data reaching the buffer of the UE belongs to a logical channel having a higher priority than the uplink data already present in the buffer of the UE or when the serving cell is changed. . The padding BSR is triggered when the number of padding bits of the uplink radio resource allocated from the base station is larger than the size of the BSR MAC control element. Periodic BSR is triggered when the periodic BSR timer expires.

6 is a diagram illustrating an example of a MAC PDU.

First, the MAC PDU will be described, and then the MAC PDU subheader will be described.

The MAC PDU (or Transport Block (TB)) includes a MAC header, a MAC SDU, the MAC control element described above, and padding. The size of the MAC PDU may be defined in units of bytes. MAC header and MAC SDU have a variable size.

The MAC header includes at least one MAC PDU subheader, and each sub header corresponds to one MAC SDU or one MAC control element or padding. The MAC control element, MAC SDU and padding together are also referred to as MAC payload.

7 through 9 illustrate various examples of MAC PDU subheaders.

The MAC PDU subheaders shown in FIG. 7 and FIG. 8 have six fields of R, R, E, LCID, F, L, except for the last subheader of the MAC PDU and a fixed size MAC control element. Include.

The L field is a length field and indicates the size of a corresponding MAC SDU or MAC control element in bytes. There is one L field per MAC PDU subheader, except for the subheader corresponding to the last subheader and the MAC control element with a fixed size. The size of the L field is indicated by the F field.

The F field is a format field and indicates the size of the L field. There is one F field per MAC PDU subheader, except for the subheader corresponding to the last subheader and the MAC control element with a fixed size. The size of the F field is 1 bit. If the size of the MAC SDU or MAC control element is less than 128 bytes, the terminal sets the value of the F field to 0, otherwise set to 1.

The E field is an extension field and is a flag indicating whether there are more fields in the MAC header. If the E field is 1, this indicates that there is at least one more field of R / R / E / LCID. If the E field is 0, it indicates that the next byte starts with a MAC SDU, a MAC control element, or padding. The R field means reserved bits.

The LCID field is a logical channel ID field and identifies a logical channel instance of a corresponding MAC SDU or a type of a corresponding MAC control element or panning. There is one LCID field for each MAC SDU, MAC control element or padding included in the MAC PDU. The size of the LCID field is 5 bits.

The last subheader of the MAC PDU shown in FIG. 9 and the MAC control element of fixed size include four fields: R, R, E, and LCID. The LCID field is a field for identifying a logical channel corresponding to the MAC SDU. That is, the LCID field is mapped to the RLC entity on the logical channel. There is one LCID per MAC SDU included in the MAC PDU.

10 through 12 illustrate MAC PDU subheaders transmitted according to an embodiment of the present invention.

Any one of the R fields may be used as the M field. The M field indicates whether there is any uplink data remaining in the buffer of the UE. That is, in the buffer status reporting method according to the embodiment of the present invention, the MAC PDU including the M field is transmitted to complement the existing buffer status reporting method. Herein, the M field indicates a buffer status field as a field indicating whether or not the buffer of the UE is empty.

The base station may determine whether to allocate radio resources to the terminal by checking the information on the buffer status shown in the buffer status field. If the buffer status field indicates that uplink data that has not yet been transmitted remains in the buffer, the base station additionally allocates radio resources to the terminal. On the other hand, when the buffer status field indicates that uplink data that has not yet been transmitted remains in the buffer, the base station does not allocate any radio resources to the terminal.

The information about the buffer status displayed through the buffer status field may be 1-bit information indicating whether the buffer occupancy amount of the terminal is 0 or whether there is no remaining uplink data. If more than one bit is used to indicate information about the buffer status, the amount of uplink data remaining in the buffer may also be indicated.

13 is a flowchart illustrating a regular buffer status report and a data transmission process accordingly.

Uplink data is input to the RLC of the terminal (S1301). This triggers a regular buffer status report (S1302). However, the terminal has not been allocated radio resources for uplink transmission. The terminal transmits a scheduling request (SR) to the network through the PUCCH (S1303). The radio resource is allocated from the network through the PDCCH (S1304).

Then, the UE transmits a regular buffer status report to the PUSCH (S1305). Radio resources are allocated again through the PDCCH (S1306), and uplink data is transmitted to the network through the PUSCH (S1307).

14 is a flowchart illustrating a periodic buffer status report and a data transmission process accordingly.

First, the terminal is allocated a radio resource through the PDCCH from the network (S1401). The terminal transmits uplink data to the network through the PUSCH using the allocated radio resource (S1402). The periodic buffer status report timer of the terminal expires (S1403).

The terminal receives radio resources from the network through the PDCCH (S1404). The terminal transmits a periodic buffer status report to the network through the PUSCH to the allocated radio resource (S1405). According to the buffer status report, the terminal is again allocated radio resources (S1406).

The terminal transmits uplink data through the PUSCH to the allocated radio resource (S1407). The radio resources are allocated again (S1408) and the process of transmitting uplink data is repeated (S1409).

At this time, the periodic buffer status report timer expires again (S1410), and the terminal is not receiving a new radio resource from the network (S1411). Therefore, the terminal cannot transmit the buffer status report because there is no radio resource, and the buffer status report remains pending (S1412). Thereafter, if the UE is allocated radio resources through the PDCCH (S1413), the UE transmits a periodic buffer status report through the PUSCH (S1414).

15 is a flowchart illustrating a conventional buffer status report and a data transmission process according thereto.

First, the periodic buffer status report timer of the terminal of the MAC layer of the terminal expires (S1501). In this case, it is assumed that the initial buffer occupancy amount of the terminal is 3000 bytes. The UE receives radio resources from the network through the PDCCH (S1502).

The terminal reports that the buffer occupancy is 3000Byte through the periodic buffer status report (S1503). If the terminal generates the uplink transmission data again (S1504), the buffer occupancy is increased to 4000 bytes. Nevertheless, the network recognizes that the buffer occupancy of the terminal is 2000 bytes. In other words, the estimated buffer occupancy amount of the terminal evaluated by the network is 2000 bytes.

The terminal is further allocated radio resources from the network (S1505). The terminal transmits uplink data to the allocated radio resource (S1506).

The terminal and the network repeat radio resource allocation and uplink data transmission once more (S1507 and S1508). Due to two uplink data transmissions, the actual buffer occupancy is 2000 bytes, whereas the estimated buffer occupancy of the terminal recognized by the network is 1000 bytes.

At this time, the periodic buffer status report timer of the terminal expires (S1509). Thereafter, the terminal allocated the radio resource from the network transmits uplink data of 990 bytes to the network along with the periodic buffer status report (S1510 and S1511). Accordingly, the buffer occupancy of the terminal becomes 1010Byte, and the network also evaluates the buffer occupancy of the terminal to 1010Byte.

Thereafter, uplink data of 1500 bytes is further generated in the RLC layer of the UE (S1512). Therefore, the buffer occupancy amount of the terminal is 2510 bytes. However, since the estimated buffer occupancy of the terminal from the network point of view is 1010 bytes, only the radio resource of 1010 bytes is allocated (S1513). The terminal transmits only 1010 bytes of data among the buffered uplink data (S1514).

As a result, even though the actual buffer occupancy of the terminal is 2500 bytes, the estimated buffer occupancy becomes 0 bytes, and the network no longer allocates radio resources to the terminal (S1515). In this case, the network does not allocate radio resources for transmitting uplink data to the terminal until the SR is received from the terminal.

Therefore, even if the periodic buffer status report timer of the terminal expires (S1516 and S1519) and there is more uplink data to be transmitted (S1517 and S1518), the terminal cannot transmit the buffer status report or transmit the uplink data. Therefore, uplink data of the terminal is delayed.

16 is a flowchart illustrating a buffer status report and a data transmission process according to an embodiment of the present invention.

Initial buffer occupancy of the terminal (initial BO) is 3000 bytes. In the MAC layer of the terminal, the periodic buffer status report timer expires (S1601). The terminal receives a radio resource from the network (S1602). The terminal transmits a periodic buffer status report to the network (S1603).

Uplink data of 1000 bytes is input to the RLC of the terminal (S1604). Accordingly, the actual buffer occupancy amount of the terminal is 4000 bytes. The terminal receives a radio resource of 1000 bytes from the network (S1605). The uplink data of 1000 bytes is transmitted first (S1606). Further, 1000 bytes of radio resources are further allocated from the network (S1607), and uplink data of 1000 bytes is further transmitted (S1608). As a result, the actual buffer occupancy of the terminal is 2000 bytes, and the estimated buffer occupancy estimated by the network is 1000 bytes.

The periodic buffer status report timer of the terminal expires (S1609). The terminal is allocated a radio resource of 1000 bytes from the network (S1610). Then, the UE transmits a periodic buffer status report while transmitting uplink data of 990Byte, and notifies the network through the periodic buffer status report that the buffer occupancy amount is 1010Byte (S1611).

According to the periodic buffer status report of the terminal in step S1611, the network recognizes the estimated buffer occupancy amount of the terminal as 1010 bytes. Therefore, the network allocates 1010 bytes of radio resources to the terminal (S1612). The terminal transmits all remaining uplink data of 1010Byte (S1613). As a result, the buffer occupancy of the terminal and the estimated buffer occupancy of the terminal recognized by the network are 0 bytes.

However, in this situation, the network may not know whether more uplink data is generated in the terminal (S1614). Therefore, it is not possible to determine whether to allocate additional radio resources, additionally allocate radio resources to the terminal (S1615). However, the UE still has no additional uplink data. That is, according to the prior art, even though there is no data in the buffer, the terminal does not inform the network that the buffer is empty, resulting in the network assigning unnecessary radio resources to the terminal.

The terminal informs that the current buffer occupancy is 0 bytes by transmitting the padding buffer status report to the network (S1616). That is, according to the embodiment described with reference to FIG. 16, the network may know that uplink data no longer exists by allocating unnecessary radio resources to the terminal and receiving a padding buffer status report.

17 is a flowchart illustrating a buffer status report and a data transmission process according to an embodiment of the present invention.

First, the periodic buffer status report timer of the terminal expires (S1701). At this time, the initial buffer occupancy amount of the terminal is 3000 bytes. The terminal is allocated a radio resource from the network (S1702), and thus the terminal transmits a periodic buffer status report (S1703).

When uplink data is input to the RLC of the terminal (S1704), the actual buffer occupancy of the terminal becomes 4000 bytes, while the network recognizes that the buffer occupancy of the terminal is still 3000 bytes.

The network allocates a radio resource of 1000 bytes to the terminal (S1705, S1707). The process of transmitting only uplink data of 1000 Bytes is repeated twice (S1706, S1708). As a result, the buffer occupancy of the terminal is 2000 bytes, and the estimated buffer occupancy amount by the network is 1000 bytes.

When the periodic buffer status report timer of the terminal expires again (S1709), the terminal receives radio resources from the network (S1710), and transmits a periodic buffer status report reporting the current buffer occupancy amount to 1010 bytes to the network (S1711). Then, the network allocates 1010 bytes of radio resources to the terminal (S1712).

The terminal transmits 1010 bytes of uplink data to the network. In this case, it indicates that there is no longer uplink data to be transmitted in the M field of the MAC PDU (S1713). After transmitting the uplink data, the UE may inform whether the buffer to be transmitted to the RLC / PDCP remains using the reserved bit which is not used in the existing MAC PDU header format.

Therefore, the network no longer needs to allocate radio resources for uplink data transmission to the UE by checking the M field, and it is possible to prevent unnecessary waste of radio resources by allocating radio resources (S1714).

The problem with the conventional buffer status reporting method is that, when the base station allocates radio resources to the terminal according to the reported buffer status, the base station cannot determine whether outstanding uplink data still remains in the terminal. When the base station receives the buffer status report from the terminal, the base station cannot know whether additional uplink data has occurred between the terminals when the actual radio resource is allocated, and thus additionally allocates radio resources for receiving the buffer status report from the terminal. Inevitably had to do inefficient operation.

To solve this problem, if you do not want to modify or change the definition of the currently defined buffer status report or add a timer to increase complexity, modify 1 bit of the MAC PDU header format to see if the buffer is empty. (buffer empty) can be reported.

In particular, since the embodiment of the present invention uses an R (reserved) field which is not used in the existing MAC PDU format, the problem can be alleviated without consuming additional radio resources.

The base station may also determine whether the uplink data should be scheduled immediately after receiving the uplink data, whether to continue scheduling the transmission of the uplink data or whether further scheduling is unnecessary.

All the above-described methods may be performed by a processor such as a microprocessor, a controller, a microcontroller, an application specific integrated circuit (ASIC), or the like according to software or program code coded to perform the method, or a processor of a terminal shown in FIG. 3. have. The design, development and implementation of the code will be apparent to those skilled in the art based on the description of the present invention.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention. You will understand. Therefore, the present invention is not limited to the above-described embodiment, and the present invention will include all embodiments within the scope of the following claims.

1 is a block diagram illustrating a wireless communication system.

2 is a block diagram illustrating a functional split between an E-UTRAN and an EPC.

3 is a block diagram illustrating elements of a terminal.

4 is a block diagram illustrating a radio protocol architecture for the user plane.

5 is a block diagram illustrating a radio protocol structure for a control plane.

6 illustrates an example of a MAC PDU.

7-9 illustrate various examples of MAC PDU subheaders.

10 and 12 illustrate a MAC PDU subheader transmitted according to an embodiment of the present invention.

13 is a flowchart illustrating a regular buffer status report and a data transmission process accordingly.

14 is a flowchart illustrating a periodic buffer status report and a data transmission process accordingly.

15 is a flowchart illustrating a conventional buffer status report and a data transmission process according thereto.

16 is a flowchart illustrating a buffer status reporting and data transmission process according to an embodiment of the present invention.

17 is a flowchart illustrating a buffer status report and a data transmission process according to an embodiment of the present invention.

Claims (13)

Sending a buffer status report according to the amount of data stored in the buffer; Receiving a radio resource according to the buffer status report; Transmitting uplink data stored in the buffer by using the radio resource, wherein the uplink data is a MAC PDU, and displays information on the buffer state changed according to transmission of the MAC PDU to the MAC PDU. Buffer status reporting method comprising the steps. The method of claim 1, The MAC PDU includes a MAC PDU header, and the MAC PDU header includes one or more subheaders. The method of claim 2, And wherein the subheader includes one or more buffer status fields indicating information regarding the buffer status. The method of claim 1, And the information about the buffer status indicates whether the buffer occupancy is zero or greater than zero. The method of claim 1, And the information on the buffer state indicates whether the uplink data remains in the buffer. The method of claim 1, And wherein the information about the buffer status is one bit of information representing either the capacity of the data remaining in the buffer or the buffer occupancy amount. The method of claim 1, And the buffer status report is periodically transmitted. The method of claim 1, The MAC PDU is buffer status reporting method characterized in that the transmission via the PUSCH. Receiving a buffer status report from the terminal Allocating radio resources to the terminal according to the buffer status report; Receiving a MAC PDU including information on a buffer state of the terminal from the terminal; And determining whether to additionally allocate radio resources to the terminal according to the state of the buffer indicated in the MAC PDU. 10. The method of claim 9, The MAC PDU received from the terminal includes a MAC PDU header, and the MAC PDU header includes one or more subheaders. The method of claim 10, The sub-header includes one or more buffer status fields indicating information on the buffer status, and determines whether to additionally allocate radio resources to the terminal by checking the buffer status field. 10. The method of claim 9, The method according to the information on the buffer state, if the buffer occupancy is not allocated to the additional radio resources, if the buffer occupancy is greater than zero further comprising the step of additionally assigning radio resources. 10. The method of claim 9, According to the information on the buffer state, if there is no uplink data remaining in the buffer, the radio resources are not additionally allocated, and if there is uplink data remaining in the buffer, the method further includes allocating radio resources. How to receive buffer status

Images