KR20100061966A - Apparatus and method for managing rx buffer in wireless communication ststem - Google Patents

Abstract

PURPOSE: A reception buffer management device in a wireless communication system and a method thereof are provided to reduce a memory use amount of a received burst buffer by managing an ARQ block buffer effectively. CONSTITUTION: When the maximum BSN(Block Sequence Number) of an ARQ(Automatic Repeat reQuest) block is 2047 and an ARQ window size is 1024, an ARQ block buffer has a double spiral structure. Contacted cells each other has a same buffer address physically. One ARQ block size is decided through an MAC(Media Access Control) management message. It is defined as level 1 from the BSN 0 to the BSN 1023. It is defined as level 2 from the BSN 1024 to the BSN 2047. An ARQ buffer map stores status information of a spin buffer.

Description

Receiving buffer management device and method in wireless communication system {APPARATUS AND METHOD FOR MANAGING RX BUFFER IN WIRELESS COMMUNICATION STSTEM}

The present invention relates to an apparatus and method for managing a receiving buffer in a wireless communication system, and more particularly, to an apparatus and method for managing an automatic repeat request (ARQ) block buffer in a broadband wireless communication system.

Today, many wireless communication technologies have been proposed as candidates for high speed mobile communication. Among them, orthogonal frequency division multiplexing (OFDM) is recognized as the most powerful next generation wireless communication technology.

In general, in the case of wireless communication, an error may occur in specific data according to a channel state of a radio resource. Control and recovery techniques for such errors can be largely divided into Automatic Repeat ReQuest (ARQ) and Forward Error Correction (FEC). The ARQ is a technique for requesting retransmission for data lost at the receiving end, and the FEC is a technique for correcting an error for data lost at the receiving end.

In particular, in the ARQ scheme, an error checking result (eg, CRC result) for packets received at a receiving end should be transmitted to the transmitting end. First, when the transmitting end initially transmits the packet, the receiving end decodes the received packet and checks for an error. In this case, if an error does not occur, an ACK signal is transmitted to the transmitting end, and if an error occurs, the NACK signal is transmitted to the transmitting end. The transmitter retransmits the previous packet or transmits a new packet according to the feedback signal (ACK / NACK) from the receiver.

In a typical OFDM / OFDMA-based broadband wireless communication system, the physical layer packet unit is a burst. The receiver extracts a Media Access Control (MAC) Protocol Data Unit (PDU) from the received burst and extracts an ARQ block from each MAC PDU. That is, one burst may include at least one PDU, and one PDU may include at least one ARQ block. Each ARQ block is divided into a block sequence number (BSN), and is rounded from the maximum value to the minimum value to concatenate sequence numbers.

On the other hand, the service data unit (SDU) is made of a combination of at least one PDU. That is, one SDU may be generated from one PDU, or several PDUs may be collected to generate one SDU. The MAC Extended Subheader of each PDU contains a field (or flag) indicating whether the PDU is a single PDU, the first, last, or intermediate PDU of the SDU. Can be assembled.

Since the ARQ block can be retransmitted, the ARQ block is not received in the order of the BSN. Therefore, the receiving end must store the received ARQ blocks using a buffer until the SDU is assembled.

In the prior art, look at the method of assembling the SDU as follows.

First, there is a method of waiting the received ARQ blocks in the Rx Burst Buffer and configuring the SDU when assembly is possible. This method should store the ARQ block within the ARQ window and the maximum ARQ purge timer time. That is, since the received burst buffer cannot be released until all ARQs in the buffer are assembled into SDUs, a large amount of memory is used. In addition, there is a problem in that buffer management becomes complicated when there are ARQ blocks for several connections in one reception burst buffer or when there are many ARQ blocks that are not assembled.

Next, there is a method of copying the received ARQ blocks (or PDUs) once and storing them within the ARQ window and the purge timer time, and generating an SDU if assembly is possible. In this case, since there is a separate space for storing the PDU, the reception burst buffer can be released immediately. In other words, the number of receive burst buffers is not required. However, since the copy operation is performed once more, there is a problem that the processing speed is lowered.

Meanwhile, according to the prior art, even if the SDU is assembled, if the previously received ARQ block is not assembled into the SDU, the assembled SDU may not be delivered to a higher layer. For example, as shown in FIG. 1, since SDU3 is assembled but SDU1 and SDU2 are not assembled, SDU3 cannot be delivered and the fuzzy timers for SDU1 and SDU2 must be expired before SDU3 can be delivered to a higher layer. have.

In general, in the case of Voice over Internet Protocol (VoIP) packets in User Datagram Protocol (UDP) communication, a normal function can be performed only when the packet arrives within a predetermined time. However, as described above, when the ARQ purge timer is operated, the assembled SDU may not be delivered to the upper layer due to the purge timer of the previous ARQ block. As a result, a problem of failing to guarantee the real time of the corresponding service and degrading the service quality may occur.

Accordingly, an object of the present invention is to provide an apparatus and method for effectively managing a buffer for an ARQ block (or PDU) in a receiver of a wireless communication system.

Another object of the present invention is to provide an apparatus and method for reducing memory usage for an ARQ block in a receiver of a wireless communication system.

It is still another object of the present invention to provide an apparatus and method for simplifying processing of an ARQ block in a receiver of a wireless communication system.

It is still another object of the present invention to provide an apparatus and method for reducing an SDU propagation delay to satisfy a jitter tolerance of an application in a receiver of a wireless communication system.

Another object of the present invention is to provide an apparatus and method for efficiently assembling an ARQ block into an SDU in a receiver of a wireless communication system.

According to an aspect of the present invention for achieving the above object, in a method of operating a base station in a wireless communication system, at the time of connection creation, includes at least one of an ARQ (Automatic Repeat Request) block size, ARQ jitter control information Generating a message, and transmitting the generated message to a terminal.

According to another aspect of the present invention, in a method of operating a terminal in a wireless communication system, when a connection is generated, receiving a message including at least one of an Automatic Repeat Request (ARQ) block size and ARQ jitter control information. And setting a jitter reference value for controlling jitter of a corresponding connection according to the ARQ jitter control information, storing an ARQ block received through the connection in a buffer, and when the SDU is assembled, Checking whether there is an unreceived ARQ block from the SDU to the start of the ARQ window, and comparing the number of unreceived ARQ blocks with the jitter reference value, and delivering the assembled SDU to a higher layer when the jitter reference value is larger than the jitter reference value. Characterized in that.

According to still another aspect of the present invention, a terminal device in a wireless communication system, comprising: a receiving unit receiving a message including at least one of an Automatic Repeat Request (ARQ) block size and ARQ jitter control information when a connection is generated; And a controller configured to set a jitter reference value for controlling jitter of a corresponding connection according to the ARQ jitter control information.

Preferably, the controller allocates a spin buffer for buffering an ARQ block in consideration of the ARQ block size and allocates a buffer map for storing state information about the spin buffer.

Preferably, the spin buffer has a logical spiral structure, cells overlapping at the same location correspond to the same physical address, and the overlapping cells correspond to different block sequence numbers (BSNs) according to corresponding levels. It is characterized by.

Preferably, each field of the buffer map stores state information of a corresponding cell of the spin buffer, and the state information includes at least one of usage information, split state information of the corresponding ARQ block, and level information of the corresponding ARQ block. Characterized by including one.

Preferably, the control unit stores an ARQ block received through the connection in a corresponding cell of the spin buffer according to a BSN, updates the buffer map, and searches for the buffer map to assemble a service data unit (SDU). If it is determined whether or not the SDU is assembled, check whether there is an unreceived ARQ block from the assembled SDU to the start of the ARQ window, and if there is no unreceived ARQ block, deliver the assembled SDU to a higher layer, and the unreceived If there is an ARQ block, the number of unreceived ARQ blocks is counted, and the number of unreceived ARQ blocks is compared with the jitter reference value, and when the jitter reference value is larger, the assembled SDU is transferred to a higher layer, and the ARQ window is transferred. It is characterized by moving.

As described above, the present invention has an advantage that the memory usage of the received burst buffer can be reduced by effectively managing the ARQ block buffer in the receiver of the wireless communication system. In addition, by automatically sorting the received ARQ blocks, there is an advantage that can reduce the number of copies. In addition, it is possible to more easily determine whether the SDU assembly, there is an advantage that the SDU assembly can be performed more simply. In addition, by reducing the delivery delay of the assembled SDU, there is an advantage that can improve the quality of service. As such, the present invention can simplify the system and have the advantage of improving the overall performance.

Hereinafter, the operating principle of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intentions or customs of the user, the operator, and the like. Therefore, the definition should be made based on the contents throughout the specification.

Hereinafter, a method for efficiently managing an ARQ block buffer in a receiver of a wireless communication system will be described.

Hereinafter, an OFDM / OFDMA based broadband wireless communication system will be described as an example, but the present invention can be easily applied to other communication systems.

2 illustrates a buffer structure for storing an ARQ block in a receiver according to an embodiment of the present invention.

As shown, the ARQ block buffer according to the present invention has a helical structure. For example, when the maximum block sequence number (BSN) of the ARQ block is 2047 and the ARQ window size (1/2 or less of the maximum BSN) is 1024, the ARQ block buffer may have a double spiral structure as shown in FIG. have. Cells that are in contact with each other have a physically identical buffer address. For example, a cell of BSN 0 and a cell of BSN 1024 have a physically identical buffer address. Hereinafter, such a buffer structure will be defined as a "spin buffer".

One ARQ block size may be determined (or negotiated) through a Media Access Control (MAC) management message. For example, it may be determined through a Dynamic Service Addition (DSA) message or a Dynamic Service Change (DSC) message. In addition, since the ARQ block size is constant according to the connection, the spin buffer corresponding to one connection may be represented as a uniform set of cells as shown in FIG. 2.

In the spin buffer as shown in FIG. 2, BSN 0 to BSN 1023 are defined as level 1, and BSN 1024 to BSN 2047 are defined as level 2. Since the BSN is modulated based on 2048, the BSN is cycled from '1023' to '1024' and from '2047' to '0' according to the arrow direction.

The ARQ buffer map shown in FIG. 2 stores state information of the spin buffer. The number of cells of the ARQ buffer map is equal to the number of physical cells of the spin buffer (1024). That is, the ARQ buffer map is generated when the spin buffer is allocated, and the spin buffer may be released by initializing the ARQ buffer map.

For example, each cell of the ARQ buffer map may consist of 4 bits. The number of bits used by each cell of the ARQ buffer map may be extended, but when considering alignment, it is preferable to take a value of two's complement, such as 4 bits or 8 bits. In the case of Fig. 2, since the 4-bit information is 1024 pieces, the total size of the ARQ buffer map is 512 bytes. Table 1 below shows an example of state information stored in each cell of the ARQ buffer map.

Used bit bit [0] 0: Not Used
1: Used Fragment State bit [1: 2] 00: No Fragment
01: Last
01: First
11: Continue Level Bit [3] 0: Level 0 (BSN 0 ~ BSN 1023)
1: Level 1 (BSN 1024 ~ BSN 2047)

Referring to Table 1, the first bit Bit [0] of each cell indicates whether the cell is used, and the second and third bits Bit [1: 2] are divided states for the corresponding ARQ block. (fragment state), and the fourth bit Bit [3] is information for determining the BSN of the corresponding ARQ block.

The spin buffer may be configured in various ways according to the ARQ window size. FIG. 2 is a double spiral configuration of a spin buffer on the assumption that the ARQ window size is 1/2 of Max BSN. However, when the ARQ window size is smaller than 1/2 of the BSN, the number of physical storage areas (cells) can be reduced. In general, if the ARQ block size is increased, the transmission time is increased, thereby reducing the ARQ window size. In such a case, the spin buffer may consist of four overlaps or eight overlaps.

(A) of FIG. 3 consists of a double superimposition of the spin buffer, and (b) is comprised of four superpositions. That is, when the ARQ block size is increased, the number of physical cells (or window size) can be reduced, and when the ARQ block size is reduced, the number of physical cells can be increased.

4 illustrates a signaling procedure for creating an ARQ connection in a wireless communication system according to an embodiment of the present invention.

Referring to FIG. 4, when a connection creation (or service flow generation) is required, the terminal 10 may provide information on the type of the connection (eg, BE, UGS, rt-PS, nrt-PS, etc.) in step 401. A service generation request message (eg, a DSA-REQ message) including the generated message is transmitted to the base station 20.

In step 403, the base station 20 performs connection admission control using information of the service generation request message. If the call is accepted, the base station 20 generates a service generation response message (eg, a DSA-RSP message) including the QoS parameter information and transmits it to the terminal 20 in step 405. In this case, the service generation response message may include ARQ block size information, jitter enable information, jitter reference value (JITTER_SENSITIVE_THRESHOLD) information, and the like. Here, the ARQ jitter related information (jitter enable information and jitter reference value information) is a newly defined parameter according to the present invention. When the ARQ jitter function is enabled, the UE may configure the SDU even when the purge timer of the previous ARQ block is running. Can be passed to higher layers. A detailed embodiment of the ARQ jitter related information will be described in detail later.

In step 407, the terminal 10 acquires necessary information from the service generation response message and generates a connection (or service flow) using the obtained information. In this case, the terminal 10 allocates a spin buffer and a buffer map using the ARQ block size obtained from the service generation response message. That is, the number of overlapping spin buffers is determined based on the size of the ARQ block, and the memory as many as the number of physical cells is secured. The ARQ buffer map is generated in correspondence with the allocated spin buffer. In addition, the terminal 10 sets ARQ jitter related information obtained from the service generation response message corresponding to the connection.

The above-described embodiment of FIG. 4 assumes a case where the terminal 10 initiates call setup. If the base station 20 initiates call setup, the base station 20 may transmit a service generation request message to the terminal 10 and the terminal 10 may respond with a service generation response message.

On the other hand, ARQ-related parameters (ARQ block size, jitter enable information, jitter reference value information, etc.) according to the present invention is a service generation-related messages (eg, DSA-REQ, DSA-RSP, DSC-REQ, DSC-RSP, etc.) ), Registration related messages (eg, REG-REQ, REG-RSP, etc.) and capability negotiation related messages (eg, SBC-REQ, SBC-RSP, etc.). That is, the ARQ jitter related information according to the present invention may be included in a previously defined message in the form of TLV (Type / Length / Value) or may be included in a newly defined message.

Table 2 below shows the ARQ Jitter Enable TLV.

Type Length Value Scope [145/146] .XXX One 0: ARQ Jitter Not Requested / Accepted
1: ARQ Jitter Requested / Accepted DSA-REQ, DSA-RSP
REG-REQ, REG-RSP

Referring to Table 2, when creating an ARQ connection through a MAC management message (eg, DSA), if the ARQ jitter enable TLV value in the message is '1', the ARQ jitter function is used. Decide not to use the jitter function. In addition, when the ARQ jitter enable TLV value is '1', the terminal checks the jitter reference value through the ARQ jitter reference value (JITTER_SENSITIVE_THRESHOLD) TLV. In this case, when the jitter reference value is '0', the arbitrary reference value set in the terminal may be used as the jitter reference value, and when the jitter reference value is not '0', the jitter reference value set in the message may be used.

Table 3 below shows the ARQ jitter reference value (JITTER_SENSITIVE_THRESHOLD) TLV.

Type Length Value Scope [145/146] .XXX 2 JITTER_SENSITIVE_THRESHOLD
0: Set the jitter reference value as the reference value of the terminal
1-1024: Jitter Reference Value Dropped from Base Station
DSA-REQ, DSA-RSP
REG-REQ, REG-RSP

Hereinafter, when the ARQ jitter function is enabled, the operation method of the receiver will be briefly described. First, the receiver buffers the received ARQ block into a pin buffer and assembles the buffered ARQ block into an SDU. At this time, if any SDU is assembled, the receiver checks how many ARQ blocks have not been received from the assembled SDU to the start of the ARQ window. In general, when the purge timer of a specific ARQ block expires, the ARQ window starts to move to the next ARQ block in which the current purge timer is running.

Referring to FIG. 5, there are a total of nine ARQ blocks from the assembled SDU to the start of the ARQ window, of which three ARQ blocks are in an unreceived state. At this time, the Missed ARQ Block count (m) value is '3'. The receiver compares the m value with a set jitter sensitive threshold. If the m value is greater than the jitter reference value, it is determined that a purge timer for an unreceived ARQ block is likely to time out (or expires). Thus, the receiver delivers the assembled SDU to a higher layer and moves an ARQ window. On the other hand, if the value of m is smaller than the jitter reference value, the unreceived ARQ blocks are waited without delivering the assembled SDU to the upper layer. As described above, when the assembled packet SDU is delivered to a higher layer (application), the present invention can reduce delay of packet delivery by the fuzzy timer.

If the ARQ jitter function is not used, the receiver may store the assembled SDUs in the waiting queue, check the order of the SDUs stored in the waiting queue, and deliver them to the upper layer in order.

6 illustrates an operation procedure of a receiver in a wireless communication system according to an embodiment of the present invention. Here, in a relative concept, the receiver may be a terminal in downlink communication and a base station in uplink communication. Hereinafter, a case of the terminal will be described.

Referring to FIG. 6, the terminal first checks whether connection creation is required in step 601. In this case, the connection generation may be initiated by the terminal (MS_init) or the base station (BS_init).

When the connection generation is required, the terminal negotiates QoS parameters in step 603. That is, according to the present invention, the terminal negotiates with the base station an ARQ block size to be applied to the connection, whether to enable ARQ jitter and a jitter reference value. For example, the terminal may negotiate the QoS parameters through a dynamic service addition (DSA) procedure.

In this manner, after negotiating QoS parameters for the connection, the terminal proceeds to step 605 to determine an ARQ window size using the ARQ block size and allocate a spin buffer and a buffer map according to the ARQ window size. . Here, the terminal determines the number of superimposition of the spin buffer and the number of physical cells according to the ARQ window size, and sequentially allocates the number of cells having the ARQ block size by the determined number to allocate the spin buffer. The terminal generates a buffer map corresponding to the allocated spin buffer.

In step 607, the terminal checks whether the ARQ jitter function is enabled for the corresponding connection. That is, it is checked whether the ARQ jitter enable field in the negotiation message received from the base station is set to a specific value. When the ARQ jitter function is enabled, the terminal proceeds to step 609 to set a jitter threshold (TH) to be applied to the connection. In this case, the terminal may set the value designated by the base station or an arbitrary value determined by the base station as the jitter reference value.

In this manner, after establishing the connection, the terminal checks whether an ARQ block is received through the connection in step 611. When the ARQ block is received, the terminal proceeds to step 613 to store the received ARQ block in the assigned spin buffer, and records the stored ARQ block information in the buffer map.

Specifically, the terminal calculates a storage location by modulating the BSN of the received ARQ block by the number of physical cells. For example, when the BSN of the corresponding ARQ block is 1026, when 1026 is modulated by the physical number of cells (for example, 1024), the number becomes 2, and thus the corresponding ARQ block may be stored in the third cell. The terminal checks the information of the buffer map to check whether the third cell of the spin buffer is currently in use. If not, the terminal draws the corresponding ARQ block from the receiving buffer and stores it in the cell of the spin buffer. If the third cell of the spin buffer is already in use, the terminal checks its level to determine whether it is the same BSN. If it is the same BSN, the same ARQ block is received again, in which case it can be skipped or overwritten. If there is an ARQ block having another BSN in the corresponding cell of the spin buffer while the BSN is in the ARQ window, the terminal stores the received ARQ block in another separate memory. This case does not occur in double overlapping, but may occur in case of more than four overlapping. If this situation occurs more than a certain number of times, the terminal may readjust the number of cells of the spin buffer.

As described above, after the received ARQ block is stored in the spin buffer, the terminal proceeds to step 615 to determine whether to assemble the SDU based on the stored ARQ block. Specifically, the terminal determines whether to assemble the SDU based on the information of the buffer map. For example, if the fragment state of the stored ARQ block is “First”, the terminal searches for “Last” in the direction in which the BSN is increased. At this time, if an unused cell is detected, the search is stopped. If the partition state of the stored ARQ block is "last", the UE searches for "first" in the direction of decreasing BSN, and stops searching if an unused cell is detected during the search. If the division state of the stored ARQ block is “Continue”, the UE first searches for “last” in a direction in which the BSN is increased, and then searches for “first” in a direction in which the BSN is decreased. If an unused cell is detected during the search, the search is stopped. Here, the reason for searching for the "last" first is to prevent unnecessary reverse search since ARQ blocks are generally received sequentially.

FIG. 8 (a) shows a case in which the split state of the received ARQ block is the first (F), but the BSN is searched in an increasing direction but the unreceived ARQ block is found and stopped. 8 (b) shows that the split state of the ARQ block received this time is continuous (C). First, the last (L) is searched in the direction in which the BSN is increased, and then the first (F) in the direction in which the BSN is decreased. ), But it stops because it finds an unreceived ARQ block. 8 (c) shows a case in which the partition state of the received ARQ block is the last (L), and the SDU is assembled after finding the first (F) by searching in the direction of decreasing BSN.

If the SDU assembly fails as shown in (a) and (b) of FIG. 8, the terminal returns to step 611 to continue receiving the ARQ block. On the other hand, if the SDU is assembled as shown in FIG. If there is no unreceived ARQ block, the flow proceeds to step 623 to transfer the assembled SDU to a higher layer and to move the ARQ window.

If there is no received ARQ block, the terminal proceeds to step 619 and counts the number of unreceived ARQ blocks. In step 621, the terminal compares the counted m value with the jitter reference value TH. At this time, if the m value is less than or equal to the jitter reference value TH, the terminal returns to step 611 to continue receiving the ARQ block. On the other hand, if the m value is greater than the jitter reference value, the terminal proceeds to step 623 and delivers the assembled SDU to a higher layer, and moves back to step 611 after moving the ARQ window.

7 shows the configuration of a station in a wireless communication system according to an embodiment of the present invention. Here, the station may be a relative concept, and may be a terminal in downlink communication and a base station in uplink communication. Hereinafter, a description will be given on the assumption that the terminal.

As shown, the terminal includes a duplexer 700, an RF receiver 702, an OFDM demodulator 704, a demodulator 706, a decoder 708, an encoder 710, a modulator 712, an OFDM modulator. 714, an RF transmitter 716, a MAC PDU decoder 718, a MAC PDU encoder 720, a controller 722, a spin buffer 724, and a buffer map 726.

Referring to FIG. 7, the duplexer 700 provides the received signal from the antenna to the RF receiver 702 and the transmit signal from the RF transmitter 702 to the antenna according to the duplexing scheme. The RF receiver 702 converts an RF band signal from the duplexer 700 into a baseband signal, and converts the baseband analog signal into baseband sample data. The OFDM demodulator 704 converts the sample data from the RF receiver 702 into data in the frequency domain by performing a fast fourier transform (FFT) operation, and outputs the data in the frequency domain in burst units.

The demodulator 706 demodulates and outputs the burst data from the OFDM demodulator 704. The decoder 708 channel decodes the data from the demodulator 706 and delivers the received burst information data to the MAC layer.

The MAC PDU encoder 720 encodes ARQ blocks from the control unit 722 into MAC PDUs, and encodes signaling information from the control unit 722 into a MAC management message. Meanwhile, the MAC PDU encoder 720 configures at least one MAC PDU as a burst and delivers the burst to the physical layer.

The encoder 710 channel encodes and outputs burst data transmitted from the MAC layer. For example, the encoder 710 may perform channel coding using a convolutional code (CC), a convolutional turbo code (CTC), a low density parity check (LDPC) code, and the like. The modulator 712 modulates and outputs the channel coded data from the encoder 710. For example, the modulator 712 may perform modulation using QPSK, 16QAM, 32QAM, and the like.

The OFDM modulator 714 converts the modulated data from the modulator 712 into Inverse Fast Fourier Transform (IFFT) to sample data, and adds a guard interval to the sample data to generate an OFDM symbol. The RF transmitter 716 converts an OFDM symbol from the OFDM modulator 714 into an analog signal, and converts a baseband analog signal into an RF band signal to provide the duplexer 700.

The MAC PDU decoder 718 detects at least one MAC PDU from the burst data transmitted from the physical layer, and performs a header and error check on each detected MAC PDU. In this case, if it is determined that no error occurs, the MAC PDU decoder 718 checks the subheader of the MAC PDU to confirm the BSN, and extracts at least one ARQ block following the subheader. Here, the identified BSN is a sequence number corresponding to the first ARQ block among the extracted ARQ blocks, and subsequent ARQ blocks are automatically assigned a series of sequence numbers (BSN) from the BSN. As such, the MAC PDU provides the controller 722 with ARQ blocks extracted from the MAC PDU and various information extracted from the MAC header and the MAC subheader.

The controller 722 is responsible for the overall processing of the MAC layer. When creating a connection, the controller 722 exchanges a necessary MAC management message with a base station and allocates a spin buffer 724 and a buffer map 726 according to information negotiated with the base station. That is, the control unit 722 determines the ARQ window size using the negotiated ARQ block size, determines the number of superimposition of the spin buffer and the number of physical cells according to the ARQ window size, and the cells between the ARQ blocks. The spin buffer 724 and the buffer map 726 are allocated by sequentially assigning the determined number. In addition, when the ARQ jitter function is enabled through the negotiation, the controller 722 sets the jitter reference value corresponding to the connection.

Then, when the ARQ block is received, the controller 722 determines the storage cell by checking the BSN of the ARQ block from the MAC PDU decoder 718, and assigns the ARQ block to the corresponding cell of the spin buffer 724. The state information of the stored ARQ block is recorded in the buffer map 726. The controller 722 searches the information of the buffer map 722 to determine whether to assemble the SDU. If the SDU is assembled, the controller 722 checks whether there is an unreceived ARQ block from the assembled SDU to the start of the ARQ window. If there is no unreceived ARQ block, that is, when the start of the ARQ window corresponds to the assembled SDU, the controller 722 transmits the assembled SDU to a higher layer. If there is an unreceived ARQ block, the controller 722 checks the number of unreceived ARQ blocks (m), compares the m value with the jitter reference value, and if the m value is large, the assembled SDU is higher layer. After passing in, the ARQ window is moved. On the other hand, if the m value is less than the jitter reference value, the controller 722 continues to receive an unreceived ARQ block.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the scope of the following claims, but also by the equivalents of the claims.

1 is a view showing an example SDU assembly according to the prior art.

FIG. 2 is a diagram illustrating a pin buffer structure for storing an ARQ block according to an exemplary embodiment of the present invention. FIG.

3 shows examples of spin buffers in accordance with an embodiment of the present invention.

4 is a diagram illustrating a signaling procedure for creating an ARQ connection in a wireless communication system according to an embodiment of the present invention.

5 is a diagram illustrating an example of operating a jitter reference value according to the present invention.

6 is a diagram illustrating an operation procedure of a receiver in a wireless communication system according to an embodiment of the present invention.

7 illustrates a configuration of a station in a wireless communication system according to an embodiment of the present invention.

8 is a view showing an example SDU assembly according to the present invention.

Claims (24)

In the method of operation of a base station in a wireless communication system, Generating a message including at least one of an Automatic Repeat Request (ARQ) block size and ARQ jitter control information when a connection is created; And transmitting the generated message to the terminal. The method of claim 1, The ARQ jitter control information includes at least one of an ARQ jitter function on / off set value and an ARQ jitter reference value. The method of claim 1, The message may be one of a Dynamic Service Addition (DSA) negotiation message, a Dynamic Service Change (DSC) negotiation message, a Registration (REG) negotiation message, and an SS Basic Capability (SBC) negotiation message. The method of claim 2, If the ARQ jitter function is set to on, the terminal determines whether the upper layer delivery of the assembled SDU using the jitter reference value. In the method of operation of a terminal in a wireless communication system, Receiving a message including at least one of an Automatic Repeat Request (ARQ) block size and ARQ jitter control information when a connection is created; And setting a jitter reference value for controlling jitter of a corresponding connection according to the ARQ jitter control information. The method of claim 5, The ARQ jitter control information includes at least one of an ARQ jitter function on / off set value and an ARQ jitter reference value. The method of claim 5, The jitter reference value is one of a value set in the message and a value determined by the terminal. The method of claim 5, Allocating a spin buffer for buffering an ARQ block in consideration of the ARQ block size; And allocating a buffer map for storing state information about the spin buffer. The method of claim 8, wherein the spin buffer allocation process, Determining an ARQ window size in consideration of the ARQ block size; Determining the number of logical overlaps and the number of physical cells in the spin buffer in consideration of the ARQ window size; Generating the spin buffer by continuously allocating the cells having the ARQ block size by the number of the determined cells; The spin buffer has a logical spiral structure, and cells overlapped at the same location correspond to the same physical address, and the overlapped cells correspond to different block sequence numbers (BSNs) according to corresponding levels. Way. The method of claim 8, Each field of the buffer map stores state information of a corresponding cell of the spin buffer, and the state information includes at least one of usage information, split state information of a corresponding ARQ block, and level information of a corresponding ARQ block. Characterized in that the method. The method of claim 8, Storing the ARQ block received through the connection in a corresponding cell of the spin buffer according to a BSN, and updating the buffer map; Determining whether to assemble a service data unit (SDU) by searching the buffer map; When the SDU is assembled, checking whether there is an unreceived ARQ block from the assembled SDU to the start of an ARQ window; If there is no received ARQ block, the method comprising the step of delivering the assembled SDU to a higher layer. The method of claim 11, Counting the number of unreceived ARQ blocks if there is the unreceived ARQ blocks; And comparing the number of unreceived ARQ blocks with the jitter reference value and transferring the assembled SDU to an upper layer when the jitter reference value is larger than the jitter reference value, and moving the ARQ window. The method of claim 12, And if the number of unreceived ARQ blocks is less than or equal to the jitter reference value, receiving the unreceived ARQ blocks. The method of claim 5, Storing the ARQ block received through the connection in a buffer; When the SDU is assembled, checking whether there is an unreceived ARQ block from the assembled SDU to the start of an ARQ window; Counting the number of unreceived ARQ blocks if there is the unreceived ARQ blocks; And comparing the number of unreceived ARQ blocks with the jitter reference value and transferring the assembled SDU to an upper layer when the jitter reference value is larger than the jitter reference value, and moving the ARQ window. A terminal device in a wireless communication system, A receiver configured to receive a message including at least one of an Automatic Repeat Request (ARQ) block size and ARQ jitter control information when a connection is created; And a controller configured to set a jitter reference value for controlling jitter of a corresponding connection according to the ARQ jitter control information. The method of claim 15, And the ARQ jitter control information comprises at least one of an ARQ jitter function on / off set value and an ARQ jitter reference value. The method of claim 15, And the jitter reference value is one of a value set in the message and a value determined by the terminal. The method of claim 15, wherein the control unit, And allocating a spin buffer for buffering an ARQ block in consideration of the ARQ block size, and allocating a buffer map for storing state information about the spin buffer. The method of claim 18, The spin buffer has a logical spiral structure, and cells overlapped at the same location correspond to the same physical address, and the overlapped cells correspond to different block sequence numbers (BSNs) according to corresponding levels. Device. The method of claim 18, Each field of the buffer map stores state information of a corresponding cell of the spin buffer, and the state information includes at least one of usage information, split state information of a corresponding ARQ block, and level information of a corresponding ARQ block. Device characterized in that. The method of claim 18, wherein the control unit, The ARQ block received through the connection is stored in a corresponding cell of the spin buffer according to a BSN, the buffer map is updated, the buffer map is searched to determine whether a service data unit (SDU) is assembled, and the SDU is When assembled, the apparatus comprises the step of checking whether there is an unreceived ARQ block from the assembled SDU to the start of the ARQ window, and if there is no unreceived ARQ block, delivering the assembled SDU to a higher layer. The method of claim 21, wherein the control unit, When there is the unreceived ARQ block, the number of unreceived ARQ blocks is counted, and the number of unreceived ARQ blocks is compared with the jitter reference value. And move the window. The method of claim 22, wherein the control unit, And when the number of unreceived ARQ blocks is less than or equal to the jitter reference value, waits to receive the unreceived ARQ blocks. The method of claim 15, wherein the control unit, The ARQ block received through the connection is stored in a buffer, and when the SDU is assembled, it is checked whether there is an unreceived ARQ block from the assembled SDU to the start of an ARQ window, and if there is an unreceived ARQ block, Counting the number, and comparing the number of the unreceived ARQ block and the jitter reference value, if greater than the jitter reference value, delivers the assembled SDU to a higher layer, characterized in that for moving the ARQ window.

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