KR101086045B1 - Method for Transmitting/Receiving of Data with ARQ in Mobile Communication System - Google Patents

Abstract

The present invention relates to a data transmission / reception method using an automatic retransmission request of a mobile communication system.

The present invention divides data to be transmitted in block units, transmits a data block located within a window range, receives an ACK or a NACK, updates the window range according to the number of received ACKs, and retransmits the data block. A data transmission method for receiving an ACK or a NACK for each data block within a retransmitted window range is provided. According to the present invention, when a data block is received, the data block within the window range is stored in the first data queue, and the data block outside the window range is stored in the second data queue and then ACKed to the data block stored in the first data queue. Alternatively, the present invention provides a data receiving method of generating and transmitting a NACK and moving a data block within the updated window range from the second data queue to the first data queue when the window range is updated.

According to the present invention, it is possible to maximize the use of the BSN, it is possible to reduce the latency of data, increase the throughput per unit time, increase the probability of reception.

ARQ, SDU, Retransmission, BSN, Selective ACK

Description

Method for transmitting and receiving data using automatic retransmission request of mobile communication system {Method for Transmitting / Receiving of Data with ARQ in Mobile Communication System}

The present invention relates to a data transmission / reception method using an automatic retransmission request of a mobile communication system. Particularly, in the present invention, when there are many service data units (SDUs) to be transmitted, an automatic repeat request (ARQ) in a mobile communication system for maximizing the use of blocks to improve performance is provided. The present invention relates to a method for transmitting and receiving data using

The present invention is derived from the research conducted as part of the information and communication standard development support project of the Ministry of Knowledge Economy and the Ministry of Information and Telecommunications Research and Development. Standardization technology research].

In communication systems, various methods are used to prevent the loss or loss of transmitted data. ARQ method is widely used as a representative method among a number of methods for preventing the loss and loss of data.

The ARQ method is a technology for informing the transmitter of unreceived or undecoded data so that the transmitter can retransmit data when the receiver does not receive or decode specific data transmitted by the transmitter.

Since the ARQ method only adds a code for error detection, it is possible to reduce wasted bits for error processing, and many studies have been conducted due to the advantage that the transmitter can perform the operation with only one buffer having a maximum block size. Many kinds of ARQ methods are used in various communication systems.

Meanwhile, in the communication system, various parameters are used to use the ARQ method.

1 is a table for explaining the ARQ parameters used in the portable Internet system.

In the portable Internet system, lost or lost data among transmitted data may be identified and retransmitted using various ARQ parameters illustrated in FIG. 1.

FIG. 2 is a diagram for describing a process of inserting an SDU into an ARQ block in a transmitter.

SDUs delivered from higher layers are divided into block units, and each block is assigned a unique number. The number assigned to each block in this way is referred to as a block sequence number (BSN).

Here, in allocating the BSN to each block, the BSN is sequentially assigned to the SDUs that arrive first. In this case, the first data block that is first allocated by the BSN and transmitted through data transmission is called a transmission start data block (ARQ_TX_WINDOW_START, hereinafter referred to as 'ARQ_TX_WINDOW_START'). Typically, the transmission start data block is set to block 0 at the first transmission.

At this time, if the number of blocks of the SDU to be transmitted is smaller than the number of transmission data blocks (ARQ_WINDOW_SIZE, hereinafter referred to as 'ARQ_WINDOW_SIZE'), the BSN is allocated to the blocks of all SDUs. Here, the number of transmission data blocks means the number of data blocks that are set in advance so that they can be transmitted through one data transmission.

When the allocation of the BSN is completed, a transmission unique number (ARQ_TX_NEXT_BSN, hereinafter referred to as 'ARQ_TX_NEXT_BSN') that designates a data block to be transmitted through the next transmission is set to 'last allocated BSN + 1'. Subsequently, the received SDU is allocated from the set value of ARQ_TX_NEXT_BSN. At this time, ARQ_TX_NEXT_BSN is updated every time the BSN is allocated.

However, if there are more blocks of SDUs to send than ARQ_WINDOW_SIZE, only BQ is allocated for ARQ_WINDOW_SIZE. When the transmitter checks the ACK message transmitted from the receiver and updates ARQ_TX_WINDOW_START, the transmitter further allocates BSNs as much as the updated number.

As such, the blocks allocated with the BSN are transmitted to the receiver. At this time, the valid period (ARQ_BLOCK_LIFETIME, hereinafter referred to as' ARQ_BLOCK_LIFETIME ') and the elapsed retransmission time (ARQ_RETRY_TIMEOUT, hereinafter referred to as ARQ_RETRY_TIMEOUT') of the data block transmitted when the block is transmitted are set. In addition, when the BSN of the transmitted block is set to the same block as ARQ_TX_WINDOW_START, the sink loss elapsed time ARQ_SYNC_LOSS_TIMEOUT of the transmitted data block is also set.

The receiver identifies the correctly received and unreceived blocks and generates an ACK message to be sent to the transmitter. The receiver transmits the generated ACK message to the transmitter, and the transmitter checks the ACK message to identify a block requiring retransmission, sets ARQ_RETRY_TIMEOUT for the block requiring retransmission, and retransmits it.

In the data transmission process in such a transmitter, there are four types of ACK messages used: Selective ACK, Cumulative ACK, Cumulative with Selective ACK, and Cumulative ACK with Block Sequence ACK.

3A to 3C are diagrams illustrating an operation process of a selective ACK, a cumulative ACK, and a cumulative with selective ACK, and FIG. 3A is a diagram illustrating an operation process of a selective ACK.

The transmitter assigns a BSN to each SDU block to be transmitted, and then transmits the block to which the BSN is assigned to the receiver. The receiver generates an ACK for the received block, generates a NACK for the unreceived block, and transmits it to the transmitter.

The transmitter checks the received ACK / NACK, and retransmits the block in which the NACK is received and the block in which the ACK / NACK is not received within a preset ARQ_RETRY_TIMEOUT time.

ARQ_TX_WINDOW_START is updated when an ACK is received for a block with the same BSN as ARQ_TX_WINDOW_START, or when ARQ_BLOCK_LIFETIME of a block with the same BSN as ARQ_TX_WINDOW_START is exceeded. As shown in FIG. 3A, when block 0 receives a NACK, ARQ_TX_WINDOW_START is not updated.

According to this method, the transmitter and the receiver may identify lost or lost data with respect to the transmitted data by using the selective ACK, and may perform retransmission of the identified lost data or lost data.

3B is a diagram for describing an operation process of a cumulative ACK.

As described with reference to FIGS. 2 and 3A, the transmitter allocates a BSN to each SDU block to be transmitted, and transmits a block to which the BSN is assigned to the receiver.

The receiver generates an ACK and transmits the ACK only to the block (block 3 in FIG. 3B) before the first block not received (block 4 in FIG. 3B).

The transmitter checks the received ACK and retransmits all blocks after the ACK BSN.

Since ACK is received for a block having a BSN equal to ARQ_TX_WINDOW_START, ARQ_TX_WINDOW_START is updated to block 4, and the next block (blocks 10 to 13 in FIG. 3B) is transmitted by the number of updated blocks.

According to this method, the transmitter and the receiver may confirm lost or lost data about the transmitted data by using Cumulative ACK and perform retransmission of the identified lost data or lost data.

3C is a diagram for describing an operation process of cumulative with selective ACK.

As described with reference to FIGS. 2 and 3A, the transmitter allocates a BSN to each SDU block to be transmitted, and transmits a block to which the BSN is assigned to the receiver.

The receiver generates a Cumulative ACK from a block before the block (block 4 in FIG. 3C) that has not been received for the first time (block 3 in FIG. 3C), and generates an ACK / NACK from the next block according to the selective ACK scheme. Transmit to the transmitter.

The transmitter checks the received ACK / NACK, updates ARQ_TX_WINDOW_START to block 4 by Cumulative ACK, and transmits the next block (blocks 10 to 13 in FIG. 3C) as much as updated. Then, the NACK is received by the Selective ACK or a block is not transmitted within the ARQ_RETRY_TIMEOUT time.

According to this method, the transmitter and the receiver may confirm lost or lost data about the transmitted data by using Cumulative with Selective ACK, and may retransmit the identified lost data or lost data.

The currently executed ARQ method differs depending on the above three ACK types, but the size of the BSN that can be used simultaneously for all three ACK types is limited to ARQ_WINDOW_SIZE. In addition, when all ARQ_WINDOW_SIZE BSNs are in use, if ARQ_TX_WINDOW_START is not updated, a new block may not be transmitted.

Accordingly, the range of blocks that can be received by the receiver is limited to a reception start data block (ARQ_RX_WINDOW_START, hereinafter referred to as 'ARQ_RX_WINDOW_START') and ARQ_WINDOW_SIZE. Here, ARQ_RX_WINDOW_START represents the first data block received through data transmission.

The last data block received by the receiver is called a reception end data block (ARQ_RX_WINDOW_END, hereinafter referred to as 'ARQ_RX_WINDOW_END'), and ARQ_RX_WINDOW_END is set to 'ARQ_RX_WINDOW_START + ARQ_WINDOW_SIZE-1'.

When using Cumulative ACK, as the ARQ_TX_WINDOW_START is updated, a new BSN can be allocated to a new SDU block and transmitted to the receiver.In a situation where the SDU block to be transmitted is larger than ARQ_WINDOW_SIZE, the ARQ_WINDOW_SIZE BSN is always used. However, since the correctly received blocks must also be retransmitted for blocks after the block receiving the ACK, there is a problem in that resources are wasted.

Selective ACK improves the problem of retransmitting a correctly received block pointed out as a problem of Cumulative ACK, but has a problem that a new block cannot be transmitted unless ARQ_TX_WINDOW_START is updated.

In addition, even if an ACK for the block 0 is received as shown in FIG. 3A, ARQ_TX_WINDOW_START is updated only up to three. Accordingly, unlike the use of BSNs equal to ARQ_WINDOW_SIZE in the Cumulative ACK, two blocks for blocks 6 and 7 that receive the ACK are not used.

Cumulative with Selective ACK can not transmit a new block because ARQ_TX_WINDOW_START is not updated, but has a problem that can not reuse the block as the number of blocks receiving the ACK, such as Selective ACK.

As described above, according to the ACK type selection at the receiver, resource waste due to retransmission of a correctly received block can be solved, but a problem that a block cannot be reused as many as the number of blocks having received an ACK can be solved.

The technical problem to be solved by the present invention is to use ARQ blocks efficiently when there is a lot of data to be transmitted in a mobile communication system, ARQ to solve the problem of resource waste and inefficient use of blocks for retransmission generated in the ARQ transmission process To provide a way.

To this end, the data transmission method according to an embodiment of the present invention is a data transmission method using an automatic retransmission request, which comprises: (a) dividing data to be transmitted in block units and assigning a unique number to each other; Sending a block; (b) checking whether the received data block is received or not; (c) updating the window range and resending the data block within the updated window range according to the number of data blocks normally sent; And (d) confirming reception of each data block within the resent window range.

In addition, the data reception method according to an embodiment of the present invention is a data reception method using an automatic retransmission request, and (a) if a data block assigned a unique number is received, it is determined whether the data block is within a preset window range. step; (b) storing data blocks within a window range in a first data queue, and storing data blocks outside the window range in a second data queue; (c) generating and transmitting a response signal indicating whether the data block stored in the first data queue is received; And (d) when the window range is updated, moving a block of data within the updated window range from the second data queue to the first data queue, and repeating the process after step (c).

According to the present invention, when there are many SDU blocks to be transmitted in a mobile communication system, the number of blocks to be transmitted is always maintained by using a BSN such as ARQ_WINDOW_SIZE, thereby maximizing the use of the BSN and speeding up the update of ARQ_WINDOW_START. Can be. Accordingly, the effect of reducing the waiting delay of data, increasing throughput per unit time, and increasing reception probability can be expected.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise. In addition, the terms “… unit”, “… unit”, “module”, etc. described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. have.

Here, in the practice of the present invention, the problem of Cumulative ACK can be solved by using the Selective ACK or Cumulative with Selective ACK, the present invention is not used in Cumulative ACK, the following description to Selective ACK and Cumulative with Selective ACK I will explain only.

4 is a configuration diagram schematically showing the structure of a transmitter and a receiver according to an embodiment of the present invention.

The transmitter 400 according to an embodiment of the present invention includes a reception ACK management module 410, a transmitter timer management module 420, and an ARQ transmission module 430, and the ARQ transmission module 430 includes a transmission control module 432. And transmit unique number processing module 434.

The reception ACK management module 410 performs a function of processing, storing, and managing ACKs and NACKs received from the receiver 440, and updates ARQ_TX_WINDOW_START by calculating the number of blocks that have received the ACK.

The transmitter timer management module 420 performs a timer function of checking a preset time limit for checking whether the ACK / NACK is received.

The transmission control module 432 processes data transmission and reception with the receiver 440 through a mobile communication network. The transmission control module 432 transmits a plurality of SDU blocks to which the BSN is assigned to the receiver 440, and transmits an ACK / It performs the function of checking NACK. Then, the ACK is transmitted to the receiving ACK management module 410 according to the confirmation result of the ACK / NACK, or retransmits the block in which the NACK is received. In addition, according to the update of ARQ_TX_WINDOW_START, the transmission control module 432 allocates as many BSNs as the number of blocks that receive the ACK to the new SDU block.

In addition, the transmission control module 432 according to the embodiment of the present invention, if it is confirmed that the ACK / NACK received from the receiver 440 is an ACK / NACK for a block outside the range ARQ_TX_WINDOW_START and ARQ_TX_WINDOW_END, '(2 * ARQ_WINDOW_SIZE-2 + ARQ_TX_WINDOW_START) Check whether it is included in the range of mod (2 * ARQ_WINDOW_SIZE) ', and accept ACK / NACK for blocks included in the range. Where mod is the operator to get the rest of the values. In addition, it is determined whether a block receiving the ACK / NACK is a block transmitted to the receiver 440. If an ACK / NACK is received for a block not transmitted, the receiver 440 determines that an incorrect block is received. It performs a function of correcting an error by performing a RESET operation.

The transmit unique number processing module (hereinafter referred to as an 'ARQ_TX_NEXT_BSN processing module') 434 is a part for storing and managing a BSN allocated to an SDU block to be transmitted later.

The receiver 440 includes an ARQ reception module 450, a transmission ACK management module 460, a data queue 470 that falls within the Window range, a data queue 480 that does not fall within the Window range, and a receiver timer management module 490. The ARQ receiving module 450 includes a receiving control module 452 and a receiving unique number processing module 454.

The reception control module 452 processes data transmission and reception with the transmitter 400, receives an SDU block transmitted from the transmitter 400, and transmits an ACK / NACK signal generated by the transmission ACK management module 460. Serves to transmit to 400.

A reception unique number processing module (hereinafter referred to as an 'ARQ_RX_HIGHEST_BSN processing module') 454 is a part that processes the BSN according to the SDU block received from the transmitter 400. The ARQ_RX_HIGHEST_BSN processing module 454 stores the value obtained by adding 1 as the BSN of the SDU block having the highest BSN among the SDU blocks received from the transmitter 400.

The transmission ACK management module 460 generates an ACK / NACK according to whether the SDU block is received from the transmitter 400, and transmits the generated ACK / NACK to the transmitter 400 through the reception control module 452. .

The data queue 470 that belongs to the window range is a part that stores the data blocks within the reception range ARQ_RX_WINDOW_START + ARQ_WINDOW_SIZE among the received data blocks, and the data queue 480 that does not belong to the window range includes the received data blocks. This part stores data blocks outside the reception range (ARQ_RX_WINDOW_START + ARQ_WINDOW_SIZE).

The reception control module 452 according to an embodiment of the present invention determines whether the received SDU block is a data block within a reception range or a data block belonging to a window range, so that the data block belonging to a window range includes data belonging to a window range. The data block is stored in the queue 470, and data blocks not included in the window range are stored in the data queue 480 not included in the window range. At this time, if the received data block is a block outside the reception block range and is identified as a data block that is later than the acceptable number of blocks, the data block is determined to be an invalid block and discarded.

The receiver timer management module 490 performs a timer function of checking a preset time limit in order to check whether the SDU block transmitted from the transmitter 400 is received.

5 is a diagram illustrating a signal and an SDU block transmitted and received between a transmitter and a receiver in order to explain the selective ACK according to an embodiment of the present invention.

As described above, a signal between the transmitter 400 and the receiver 440, the SDU block of the transmitter 400, and the SDU block of the receiver may be described, and thus a data transmission / reception process using the selective ACK type may be described.

6 is a flowchart illustrating a data transmission and reception method using a selective ACK type according to an embodiment of the present invention.

Since the number of SDU blocks is larger than ARQ_WINDOW_SIZE, the transmitter 400 allocates BSNs corresponding to ARQ_WINDOW_SIZE to each block. At this time, ARQ_TX_NEXT_BSN becomes 'the last allocated BSN + 1', and becomes block 10 in FIG. 5 (S602).

As such, when the BSN is allocated to each SDU block, an SDU block between ARQ_TX_WINDOW_START and a transmission end data block (ARQ_TX_WINDOW_END, hereinafter referred to as ARQ_TX_WINDOW_END) is transmitted to the receiver 440. Here, ARQ_TX_WINDOW_START is the first data block to which the BSN is allocated, is set to block 0, and ARQ_TX_WINDOW_END is block 9 to be the last data block to which the BSN is allocated. Here, ARQ_TX_WINDOW_END may be calculated as 'ARQ_TX_WINDOW_START + ARQ_WINDOW_SIZE-1'. That is, the transmitter 400 transmits blocks 0 to 9 to the receiver 440 (S604).

The receiver 440 checks the SDU block received from the transmitter 400 (S606). As shown in FIG. 5, the receiver 440 has received block 1, block 2, block 3, block 6, block 7 and block 9, block 0, block 4, and block 5 If block and block 8 are not received, the receiver 440 generates an ACK for the received blocks (block 1, block 2, block 3, block 6, block 7 and block 9). In operation S608, a NACK is generated for the unreceived blocks (blocks 0, 4, 5, and 8) (S610), and the generated ACK / NACK is transmitted to the transmitter 400 (S610). S612).

At this time, the transmitter 400 receives ACKs for blocks 1, 2, 3, 6, and 7, and receives NACKs for blocks 0, 4, and 5, respectively. In one case, the transmitter 400 retransmits the blocks (blocks 0, 4, and 5) where the NACK is received. In addition, the transmitter 400 performs retransmission for blocks (blocks 8 and 9) for which ACK or NACK is not received within a preset ARQ_RETRY_TIMEOUT.

In addition, the transmitter 400 stores the received ACK in the reception ACK management module 410 and then uses it to update ARQ_TX_WINDOW_START.

The transmitter 440 calculates the number of blocks that have received the ACK, allocates BSNs equal to the calculated number of blocks to a new SDU block (S614), and updates ARQ_TX_NEXT_BSN (S616).

In FIG. 5, the number of blocks that receive the ACK is 5, and accordingly, ARQ_TX_NEXT_BSN is updated to block 15. FIG.

Accordingly, blocks 11 to 14 are allocated with a new BSN and are enclosed and transmitted when a block in which NACK is received or a block in which no ACK or NACK is received within ARQ_RETRY_TIMEOUT is retransmitted. At this time, ARQ_RETRY_TIMEOUT and ARQ_BLOCK_LIFETIME are set in blocks 11 to 14 transmitted first (S618).

The receiver 440 receives the retransmitted blocks (blocks 0, 4, 5, 8, and 9) and the first transmitted blocks (blocks 11 to 14). And, ARQ_RX_HIGHEST_BSN is set to 'last received BSN + 1'. In FIG. 5, block 15 is set in ARQ_RX_HIGHEST_BSN.

In addition, the receiver 440 checks whether the received data block is a data block located in the reception range ARQ_RX_WINDOW_START + ARQ_WINDOW_SIZE (S620), and stores the data block within the reception range in the DATA queue 470 belonging to the window range. In operation S626, data blocks outside the reception range among the received data blocks are stored in the data queue 480 not belonging to the window range (S628). Here, the range outside the reception range ARQ_RX_WINDOW_START + ARQ_WINDOW_SIZE means 'ARQ_RX_WINDOW_END + 1' to 'ARQ_RX_WINDOW_END + ARQ_WINDOW_SIZE-1'.

Here, when the data block received in step S620 is confirmed as a data block outside the reception range, the data block located within the range of the number of acceptable data blocks may be stored in the DATA queue 480 not belonging to the window range.

At this time, in accommodating the data blocks outside the reception range into the DATA queue 480 that does not belong to the Window range, the number of data blocks in the DATA queue 470 belonging to the Window range cannot be exceeded. You must accept the data blocks sequentially. That is, in the situation where two data blocks outside the reception range can be received, the block 'ARQ_RX_WINDOW_END + 1' and the blocks 'ARQ_RX_WINDOW_END + 2' and 'ARQ_RX_WINDOW_END + 3' cannot be received.

For example, assuming that the current reception range is 0 to 4, the number of data blocks received in this range is 2, and the range outside the reception range is 5 to 8, the data blocks that can be received in the range outside the reception range are 5 Although a total of four data blocks can be received from the first data block to the eighth data block, since two data blocks are received in the reception range, only two data blocks are received in the range outside the reception range. In addition, only the 5th data block and the 6th data block can be received, the 5th data block is not received, and the 6th data block and the 7th data block cannot be received (S622).

The data block outside the reception range satisfying the above condition is stored in the DATA queue 480 not belonging to the window range, and the data block not satisfying the condition is determined as an incorrectly received data block and discarded (S624).

The receiver 440 receiving the retransmitted block and the first transmitted block transmits an ACK / NACK to the transmitter 400 (S630).

At this time, the receiver 440 according to the present invention is configured not to transmit ACK / NACK for blocks stored in the data queue 480 that does not belong to the window range. That is, ACK / NACK is transmitted only for blocks within the range of ARQ_RX_WINDOW_START to ARQ_RX_WINDOW_END, and ACK / NACK is not transmitted for blocks outside the range. In addition, if ACK / NACK is transmitted for a block belonging to the window range, and ARQ_RX_WINDOW_START is updated, the data blocks belonging to the updated window range among the blocks stored in the data queue 480 not belonging to the window range are the DATA queue belonging to the window range. After moving to 470, and transmits the ACK / NACK for the data block.

This is because if ACK / NACK is transmitted for data blocks out of range, it may overlap with ARQ_RX_WINDOW_START beyond ARQ_BSN_MODULUS. In addition, when the transmitter 400 does not receive the ACK / NACK generated for the data block belonging to the window range before the update, the transmitter 400 receives the ACK / NACK generated for the data block in the updated window range to receive the ACK / NACK. You can correct errors due to non-receipt.

The receiver 440 is newly received from the DATA queue 480 that does not belong to the window range when ARQ_RX_WINDOW_START is updated due to the reception of block 0 or the data block erase time (ARQ_PURGE_TIMEOUT, hereinafter referred to as 'ARQ_PURGE_TIMEOUT') (S632). Check whether there is a block having a BSN included between the updated ARQ_RX_WINDOW_START and ARQ_RX_WINDOW_END (S634), and move from the DATA queue 480 not in the Window range to the DATA queue 470 in the Window range (S636). . At this time, ARQ_PURGE_TIMEOUT is set, and an ACK / NACK for blocks stored in the DATA queue 470 belonging to the window range is generated (S638) and transmitted to the transmitter 400 (S640).

When the transmitter 400 receives an ACK / NACK for blocks outside the range of ARQ_TX_WINDOW_START to ARQ_TX_WINDOW_END, it checks whether the transmitter 400 falls within the range of '(2 * ARQ_WINDOW_SIZE-2 + ARQ_TX_WINDOW_START) mod (2 * ARQ_WINDOW_SIZE)'. Accept ACK / NACK for the included block (S642). In addition, it is determined whether the block receiving the ACK / NACK is the block transmitted to the receiver 440 (S644). When the ACK / NACK is received for the untransmitted block, the receiver 440 receives the wrong block. In operation S645, the controller 130 determines that the error is corrected by performing a reset operation.

For ACK / NACK for a block within the range, retransmission of a block in which NACK is received or a block in which no ACK or NACK is received within ARQ_RETRY_TIMEOUT is performed, and a new BSN is allocated to a new SDU block as many as the number of blocks in which ACK is received. Repeat the process to perform (S648).

FIG. 7 is a diagram illustrating signals and SDU blocks transmitted and received between a transmitter and a receiver in order to explain Cumulative with Selective ACK according to an embodiment of the present invention.

The operation of using Cumulative with Selective ACK according to an embodiment of the present invention is the same as the operation process when using the selective ACK described with reference to FIGS. 5 and 6.

However, after updating ARQ_TX_WINDOW_START for Cumulative ACK, allocating a new BSN to a new SDU block as much as the updated block, there is a difference in performing a selective ACK according to an embodiment of the present invention.

8 is a wrong block in a transmitter when a data block having a BSN overlapped by a transmitter that does not receive an ACK transmitted by a receiver in a data transmission / reception method using a selective ACK type according to an embodiment of the present invention It is a figure for demonstrating the determination method.

9 is a wrong block in a receiver when a data block having a BSN overlapped by a transmitter that does not receive an ACK transmitted by a receiver in a data transmission / reception method using a selective ACK type according to an embodiment of the present invention It is a figure for demonstrating the determination method.

As described above, when the number of SDU blocks to be transmitted is larger than ARQ_WINDOW_SIZE, the number of SDU blocks involved in transmission can be maintained at all times according to the use of a BSN equal to ARQ_WINDOW_SIZE. In addition, the error which may occur in a transmitter and a receiver can be corrected and solved.

The embodiments of the present invention described above are not only implemented by the apparatus and method but may be implemented through a program for realizing the function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded, The embodiments can be easily implemented by those skilled in the art from the description of the embodiments described above.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

1 is a table for explaining the ARQ parameters used in the portable Internet system,

2 is a diagram for explaining a process of assigning an SDU to an ARQ block in a transmitter;

3A to 3C are views illustrating an operation process of a selective ACK, a cumulative ACK, and a cumulative with selective ACK;

4 is a schematic view showing the structure of a transmitter and a receiver according to an embodiment of the present invention;

5 is a view illustrating a signal and an SDU block transmitted and received between a transmitter and a receiver in order to explain the selective ACK according to an embodiment of the present invention;

6 is a flowchart illustrating a data transmission and reception method using a selective ACK type according to an embodiment of the present invention;

7 is a view illustrating a signal and an SDU block transmitted and received between a transmitter and a receiver in order to explain Cumulative with Selective ACK according to an embodiment of the present invention;

8 is a wrong block in a transmitter when a data block having a BSN overlapped by a transmitter that does not receive an ACK transmitted by a receiver in a data transmission / reception method using a selective ACK type according to an embodiment of the present invention Drawings for explaining how to judge,

9 is a wrong block in a receiver when a data block having a BSN overlapped by a transmitter that does not receive an ACK transmitted by a receiver in a data transmission / reception method using a selective ACK type according to an embodiment of the present invention It is a figure for demonstrating the determination method.

Claims (11)

delete delete delete delete delete delete delete In a data receiving method using an automatic retransmission request, (a) when a data block assigned a unique number is received, checking whether the data block is within a preset window range, wherein the window range is a data block section transmitted and received through one data transmission; (b) storing data blocks within the window range in a first data queue, and storing data blocks outside the window range in a second data queue; (c) generating and transmitting a response signal indicating whether the data block stored in the first data queue is received; And (d) if the window range is updated, moving a block of data within the updated window range from a second data queue to a first data queue, and repeating the process after step (c) Data receiving method comprising a. delete delete delete

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