KR101430482B1 - Method of forming Protocol Data - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio access system, and relates to a method for constructing protocol data. A method of configuring a protocol data unit (PDU) comprises: a first step of negotiating a size of a block generated by dividing data transferred from an upper layer and a size of a block set composed of a predetermined block; A second step of constructing a block and a block set in which data is fragmented, a subheader for controlling an automatic retransmission scheme based on random-number linear coding, and a third step of constructing protocol data including the block or the block set . ≪ / RTI >

SDU, PDU, R-ARQ, RLC

Description

Method of forming protocol data [

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio access system, and relates to a method for constructing protocol data.

Hereinafter, a general Medium Access Control (MAC) header used in an Orthogonal Frequency Division Multiplexing Access (OFDMA) system will be briefly described.

1 shows an example of a MAC header format used in a wireless MAN mobile communication system based on the IEEE 802.16 system.

Referring to FIG. 1, a MAC PDU may include six subheaders in addition to a general MAC header. The PDU-specific subheader is inserted after the generic MAC header. In Fig. 1, the number in parentheses after each field name indicates the number of bits occupied by each field.

A description of each field included in a general MAC header will be described in detail below.

Table 1 below shows an example of the MAC header format.

Referring to Table 1, the HT field indicates a header type. For example, it indicates whether the MAC PDU is a generic MAC header including a payload after the header, or a signaling header for control such as a bandwidth request. The EC field indicates encryption control, and indicates whether or not the payload is encrypted. The Type field indicates the presence or absence of a subheader after the header and the type of the subheader. The ESF field indicates the presence or absence of an extended subheader after the header.

The CI field also indicates whether the CRC is attached after the payload. The EKS field indicates an encryption key sequence number used for encryption when the payload is encrypted. The LEN field indicates the length of the MAC PDU. A CID (Connection Identifier) field indicates a CID to which the MAC PDU is delivered. Connection is used as an identifier of the MAC layer for data and message transmission between the BS and the UE, and the CID identifies a specific UE or identifies a specific service between the BS and the UE. The HCS (Header Check Sequence) is used to detect errors in the header.

Table 2 below shows an example of the Type field format included in Table 1.

The Type field occupies an area of 6 bits in the MAC header. Referring to Table 2, the type of the MAC PDU can be confirmed according to each bit included in the Type field.

For example, the Type field is composed of 6 bits. The first bit (# 0, LSB) represents a FAST-FEEDBACK allocation subheader in the downlink and a grant management subheader Subheader.

The second bit # 1 represents a packing subheader, the third bit # 2 represents a fragmentation subheader, the fourth bit # 3 is an extended type, Indicates whether the packing or fragmentation subheader has been expanded. The fifth bit (# 4) represents the AQR feedback payload, and the sixth bit (# 5, MSB) represents the mesh subheader

The currently used PDU configuration method is significantly different from the method of constructing a MAC PDU for transmitting a coded block generated using Random Linear Coding (RLC). That is, it is difficult to transmit a code block using the RLC as a general PDU configuration method.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the related art, and it is an object of the present invention to provide a method of constructing an MAC PDU for efficient data transmission.

It is another object of the present invention to provide an efficient communication method by applying a random number linear coding (RLC) in the MAC PDU construction.

In order to solve the above technical problem, the present invention relates to a method for constructing protocol data.

In one aspect of the present invention, a method of configuring a protocol data unit (PDU) in a wireless access system includes negotiating a size of a block generated by dividing data transferred from an upper layer and a size of a block set composed of a predetermined block A second step of constructing the block and the block set in which the upper layer data is fragmented according to a result of the negotiation with the first step, a subheader for controlling an automatic retransmission scheme based on the random number linear encoding, And a third step of constructing protocol data including a set of blocks.

In the second step, the number of fragments in the fragmentation is equal to the number of block sets, and the number of block sets is determined in consideration of the size of the blocks and the number of blocks included in the block set. The number of block sets may be determined by dividing the upper layer data by a value obtained by multiplying the size of the block by the number of blocks included in the block set, and rounding up the result value.

If the size of the upper layer data is smaller than the size of the block set, the upper layer data is not fragmented, and the upper layer data is divided into the blocks and the PDU .

In the present invention, the PDU may further include a header including a field indicating whether the sub-header is included. At this time, the subheader may further include an indicator for indicating the size of the block included in the PDU and the size of the block set. The subheader may further include an indicator indicating whether or not padding is required in the block. If the indicator indicates that padding is necessary, the subheader may further include a field for indicating the number of bits to be padded.

In the present invention, the PDU may further include an error detection code for error control. At this time, the error detection code may be inserted separately for each block included in the PDU.

The present invention has the following effects.

First, data communication can be efficiently performed by using the MAC PDU configuration method according to the present invention.

Secondly, in the construction of the MAC PDU according to the present invention, a code block generated using the RLC technique can be effectively transmitted between the transmitting side and the receiving side in the OFDMA system. This makes it possible to efficiently utilize the resources of the system.

The present invention relates to a communication method using a random number linear coding (RLC). In addition, the present invention relates to a method of configuring a MAC PDU using an RLC, and provides an efficient communication method even in an OFDMA system.

The following embodiments are a combination of elements and features of the present invention in a predetermined form. Each component or characteristic may be considered optional unless otherwise expressly stated. Each component or feature may be implemented in a form that is not combined with other components or features. In addition, some of the elements and / or features may be combined to form an embodiment of the present invention. The order of the operations described in the embodiments of the present invention may be changed. Some configurations or features of certain embodiments may be included in other embodiments, or may be replaced with corresponding configurations or features of other embodiments.

In the description of the drawings, there is no description of procedures or steps that may obscure the gist of the present invention, nor is any description of steps or steps that can be understood by those skilled in the art.

Herein, embodiments of the present invention have been described with reference to a data transmission / reception relationship between a base station and a terminal. Here, the BS has a meaning as a terminal node of a network that directly communicates with the MS. The particular operation described herein as performed by the base station may be performed by an upper node of the base station, as the case may be.

That is, it is apparent that various operations performed for communication with a terminal in a network composed of a plurality of network nodes including a base station can be performed by a network node other than the base station or the base station. A 'base station' may be replaced by terms such as a fixed station, a Node B, an eNode B (eNB), an access point, and the like. The term 'terminal' may be replaced with terms such as User Equipment (UE), Mobile Station (MS), and Mobile Subscriber Station (MSS).

Also, the transmitting end refers to a node that transmits data or voice service, and the receiving end refers to a node that receives data or voice service. Therefore, in the uplink, the terminal may be the transmitting end and the base station may be the receiving end. Similarly, in the downlink, the terminal may be the receiving end and the base station may be the transmitting end.

Meanwhile, the mobile terminal of the present invention may be a PDA (Personal Digital Assistant), a cellular phone, a PCS (Personal Communication Service) phone, a GSM (Global System for Mobile) phone, a WCDMA (Wideband CDMA) Etc. may be used.

Embodiments of the present invention may be implemented by various means. For example, embodiments of the present invention may be implemented by hardware, firmware, software, or a combination thereof.

For a hardware implementation, the method according to embodiments of the present invention may be implemented in one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs) , Field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, and the like.

In the case of an implementation by firmware or software, the method according to embodiments of the present invention may be implemented in the form of a module, a procedure or a function for performing the functions or operations described above. The software code can be stored in a memory unit and driven by the processor. The memory unit may be located inside or outside the processor, and may exchange data with the processor by various well-known means.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention, and are not intended to limit the scope of the invention.

2 shows a method of constructing a MAC PDU using a service data unit (SDU).

An MAC PDU can be configured using a service data unit (SDU) received from an upper layer. At this time, a fragmentation or packing technique can be used. Fragmentation refers to the operation of dividing a PDU, the basic exchange unit of an SDU or protocol, into several smaller units. The packing technique combines several small fields into one large field, which means combining two or more information units in one physical unit to save storage space.

Referring to FIG. 2, it can be seen that the upper layer data including the payload header suppression index (PHSI) and the packet PDU is fragmented, or the process of packing the SDUs divided from one or more upper layer data.

FIG. 3 shows a method of constructing a MAC PDU by fragmenting or packing an SDU, and applying an ARQ method thereto.

Referring to FIG. 3, two consecutive SDUs (SDU # 1 and SDU # 2) transmitted to the MAC layer for the same connection can be identified. SDU # 1 and SDU # 2 are composed of two fragments (Frag 0, Frag 1). In addition, SDU # 1 includes data blocks of 5 to 11, and SDU # 2 includes 12 to 16 data blocks.

SDU # 1 is fragmented to form PDU # 1. PDU # 1 may be configured as Frag 0 of SDU # 1. At this time, a fragmentation sub-header may be attached before the PDU # 1.

The PDU # 2 is configured using a packing method. That is, Frag 1 of SDU # 1 and Frag 0 of SDU # 2 are combined to form PDU # 2. Packet subheader may be used for PDU # 2. In PDU # 2, the packing subheader may be attached to the front portion of Frag 1 of SDU # 1 and the front portion of Frag 0 of SDU # 2.

However, if an error occurs in transmission in the PDU # 2, the transmitting end retransmits the packet in which the error occurred according to the ARQ scheme. Therefore, the transmitter can fragment PDU # 2 to construct PDU # 3, and reconfigure PDU # 4 and PDU # 5 using a packing method. The transmitting end can retransmit the reconfigured PDU # 3 to PDU # 5.

Table 3 below shows an example of the fragmented subheader format used in the present invention.

Syntax Size
( bit ) Notes Fragmentation Subheader () {    FC 2 Indicates the fragmentation state of the payload:
00 = No fragmentation
01 = Last fragment
10 = First fragment
11 = Continuing (middle) fragment    if (ARQ-enabled Connection)       BSN 11 Sequence number of the first block in the current SDU fragment.    else {       if (Type bit Extended Type)          FSN 11 Sequence number of the current SDU fragment.
This field increments by one (modulo 2048) for each fragment, including unfragmented SDUs.       else          FSN 3    } Reserved 3 Shall be set to zero. }

Referring to Table 3, the FC field indicates the fragmented state of the payload. For example, '00' indicates that fragmentation is not applied, '01' means the last fragment, and '10' means the first fragment. In addition, '11' means a fragment that continues as an intermediate fragment.

In Table 3, the BSN field indicates the sequence number of the first block of the current SDU fragment. The FSN field indicates the sequence number of the current SDU fragment. The FSN field is incremented by 1 for each fragment.

Table 4 below shows an example of a packing sub-header format used when applying the packing method.

Syntax Size
( bit ) Notes Packing Subheader () {    FC 2 Indicates the packing state of the payload:
00 = No packing
01 = Last packing
10 = First packing
11 = Continuing (middle) packing.    if (ARQ-enabled Connection)       BSN 11 Sequence number of first block in the current SDU packing.    else {       if (Type bit Extended Type)          FSN 11 Sequence number of the current SDU packing.
This field increments by one (modulo 2048) for each packing, including unpacked, SDUs.       else          FSN 3    } Length 11 Length of the SDU packing in bytes including the PSH. }

Referring to Table 4, the FC field indicates whether the payload is packed. For example, if the FC field is '00', it indicates that the packing is not used, '01' indicates the last packing, '10' indicates the first packing, and '11' indicates the middle packing.

The BSN represents the first sequence number of the current SDU packing. Also, the FSN represents the sequence number of the current SDU packing.

4 is a diagram illustrating a method of constructing a code block using a random-number linear encoding method according to an embodiment of the present invention.

One of the data processing methods that can be used in the embodiments of the present invention is Randomized Linear Coding (RLC). A method of processing data blocks using RLC is as follows.

The RLC is used in the data processing process of the transmission side communication system. The transmitting side divides the upper layer data into one or more data blocks. Generating a coefficient matrix for coding data blocks divided at the transmitting end, multiplying the divided data blocks by the coefficient matrix generated according to a predetermined rule, . The RLC is a data processing method like this.

As one embodiment of the present invention, one of the data processing methods is Randomized Linear Decoding (RLD). A method of processing a data block using a random number linear decoding method is as follows.

The RLD is used in the data processing of the receiver communication system. The receiving side receives coded data blocks from the transmitting side. Further, the receiving side receives the coefficient matrix necessary for decoding from the transmitting side. On the receiving side, the decoding process is performed using the coded data blocks and the inverse matrix of the coefficient matrix or by using various other calculation methods. RLD is such a data processing method.

The coefficient matrix used in the RLC and the RLD can be generated using a random number determined by a sender or a sender and a receiver within a certain range. The random number refers to a random number extracted from the number of the predetermined range (for example, 0 to 255) by negotiation between the transmitting side or the transmitting side and the receiving side. Also, the coefficient matrix may be generated using a seed value necessary for generating a coefficient.

The RLC and the RLD are merely definitions of the data processing method exemplified in the present invention, and the terms indicating the above method may be variously modified.

Referring to FIG. 4, a service data unit (SDU) transmitted from an upper layer is processed into at least one protocol data unit (PDUs).

The PDUs are referred to herein as an original data block (blk). The SDU, which is the data transferred from the upper layer, is divided into small data blocks of size s (size), n of them are selected to form a data block set. This is called an original data block set. In addition, a data block created through the data processing method disclosed by the embodiment of the present invention is referred to as a coded data block or a coded block. However, the terms used to describe FIG. 4 have been used to describe one embodiment of the present invention and can be modified in other forms of the term.

The method of encoding the data block can be generalized by the following equation.

Referring to Equation 1, blk coded _ _j denotes a general formula of the block of code, C _ji is a representation of the formula of the coefficient matrix. blk _i represents the original data block. As a generalized equation, the random number linear encoding method proposed in the present specification can be expressed.

Thus, the coded matrix can be formed by the product of the coefficient matrix and the original data matrix, and each code block contains all of the information of the original data block set. Therefore, even when some code blocks are lost or errors can not be used for restoring original data, it is not necessary to transmit the same code blocks as the code blocks in which an error occurs, and other code blocks can be generated and transmitted to correct errors .

5 is a protocol layer configuration diagram used in the IEEE 802.16 system.

5, an upper layer (for example, IP layer, ATM, Ethernet, etc.) 501 on the transmitting side transmits data through a CS (Convergence Sublayer) SAP (Service Access Point) MAC) to the MAC CPS (Common Point Sublayer) 502 via the SAP.

The MAC CPS 502 processes the data transmitted in the SDU format into MAC PDUs using the RLC. The processed MAC PDU is transmitted to the physical layer (PHY) 504 through a PHY (physical) SAP after a security encryption is additionally added in a security sublayer (503). The physical layer 504 performs an operation for transmitting the processed PDU to the wireless or wired section.

The physical layer of the receiving side receives the MAC PDU transmitted from the transmitting side in the wireless or wired section and delivers it to the MAC CPS through the PHY SAP. The MAC CPS restores original information data through a data processing method proposed in an embodiment of the present invention. The restored data is transmitted to the upper layer through the MAC SAP. In addition, the receiving side carries out an ARQ operation according to the data reception state and transmits ACK / NACK (Acknowledgment / Non-Acknowledgment) to the transmitting side.

The area where the data processing method and the data retransmission method proposed in the embodiments of the present invention can be used is the MAC CPS 502. Data processing such as data encoding, decoding, and the like is performed in the MAC CPS 502. In addition, an ARQ (Automatic Repeat Request) operation is performed in the MAC CPS 502 as a data retransmission method. Embodiments of the data retransmission method among the embodiments proposed in the present invention may also be performed in the MAC CPS 502. [

However, as shown in the protocol stack, a 'header' or the like necessary for protocol processing is attached to the data. Even though data is transmitted through another layer in data processing, the header may indicate that communication is performed between the same layers. Therefore, even in the case where the data processing method and the data retransmission method are used in the MAC CPS of the transmitting side and the receiving side, the embodiments of the present invention will briefly describe the transmitting side and the receiving side.

The terms used in FIG. 5 are merely examples of the data processing method and the data retransmission method used in the present invention, and may be used in other terms. For example, in WCDMA (Wideband Code Division Multiplex Access), a data retransmission method is used in the RLC (Radio Link Layer) layer.

6 shows an example of a method for segmenting SDUs according to another embodiment of the present invention.

FIG. 6 shows a method of fragmenting the size of the negotiated block between the transmitting and receiving end and the number of blocks included in the block set in order to use the RLC.

The following equation (2) represents a method of fragmenting the SDU.

In Equation 2, the symbol &lt; &gt; signifies an integer by rounding off the result value to the decimal point. That is, <x> means the smallest integer not smaller than x. For example, if the number of fragmentation = &lt; 1.7 &gt;, the number of fragmentation is two. Here, 'SDU size' represents the size (bits) of the received SDU, and 'BLOCK size' represents the size of one block. Also, 'BLOCK SET size' is a positive integer indicating how many blocks are contained in one block set. At this time, the size of one fragment can be expressed as 'BLOCK size * BLOCK SET size'.

6 shows one SDU divided into k fragments using Equation (2). At this time, the number of fragments is equal to the number of block sets. In this case, the total number of blocks included in the block set is n, which is a value obtained through negotiation between the transmitting and receiving ends in the initial connection.

Figure 7 shows another example of a method for segmenting an SDU, according to another embodiment of the present invention.

FIG. 7 shows a case where the size of an SDU received from an upper layer is smaller than 'BLOCK size * BLOCK SET size'. That is, in this case, SDU can be used without fragmentation. That is, there is one block set. However, the SDU can be divided into the size of the block set in the initial negotiation process.

이고 블록집합의 크기를 n이라 했을 때, k<n인 경우를 나타낸다. 이때, k 및 n은 양의 정수이다.Referring to FIG. 7, the value obtained by dividing the SDU by the size of the block is an integer. That is, the number of fragments calculated using Equation (2) is 1. In other words,

And the size of the block set is n, k < n. Here, k and n are positive integers.

8 shows another example of a method for fragmenting an SDU according to another embodiment of the present invention.

이고, 블록집합의 크기를 n이라 했을 때,i<n인 경우이다. 이때, i는 양의 실수이고, n은 양의 정수이다. 마지막 블록의 경우 블록의 크기를 맞추기 위해 블록크기만큼 다른 비트들을 채워(padding)줄 수 있다. 채워지는 비트들은 모드 '0' 또는 '1'로 채울 수 있다. 본 발명의 실시예들에서는 1로 채우는 것을 가정한다. 다만, 0으로 채울 수도 있다.FIG. 8 shows a case where the size of the SDU received from the upper layer is smaller than the size of 'BLOCK size * BLOCK SET size'. That is, the SDU is not fragmented. When dividing the SDU of FIG. 8 into one block size, the value is not divided by an integer value. E.g,

, And when the size of the block set is n, i < n. Where i is a positive real number and n is a positive integer. In the case of the last block, it is possible to padd different bits as much as the block size to match the size of the block. The bits to be filled can be filled with mode '0' or '1'. In the embodiments of the present invention, it is assumed that 1 is filled. However, it may be filled with zero.

9 shows another example of a method of fragmenting an SDU according to another embodiment of the present invention.

이고, 블록집합의 크기를 n이라 하는 경우, k>n이고, k<(단편 개수×n)인 경우이다. 이때, k 및 n은 양의 정수를 나타낸다.Referring to FIG. 9, since the size of the SDU received from the upper layer is larger than 'BLOCK size * BLOCK SET size', fragmentation is performed. That is, the number of block sets is one or more and two or less. 9, it is assumed that the value obtained by dividing the SDU by one block is an integer, and the number of fragments calculated using Equation (2) is greater than 1. E.g,

, And when the size of the block set is n, k > n and k < (number of fragments x n). Here, k and n represent positive integers.

보다 작은 경우에는, 마지막 블록집합에 포함된 블록들을 첫 번째 블록집합에 포함시켜 RLC를 적용하고, 블록집합의 크기(예를 들어, k = n+1)를 수신단에 알려줘야 한다. 마지막 블록집합의 크기가

보다 큰 경우에는 두 개의 블록집합으로 각각 RLC를 적용하고, 각 블록집합의 크기를 수신단에 알려준다.When SDU is fragmented, the size of the last block set is

, The RLC is applied by including the blocks included in the last block set in the first block set, and the size of the block set (for example, k = n + 1) should be informed to the receiver. The size of the last block set is

The RLC is applied to two sets of blocks, and the size of each block set is informed to the receiver.

보다 작은 경우로서, 마지막 단편에 포함된 블록들은 첫 번째 단편에 포함하여 부호화를 수행할 수 있다. 이 경우, 단편의 크기를 수신단에 알려줘야 한다.9 shows the number of blocks of the last fragment, i.e., the size of the block set

, The blocks included in the last segment may be included in the first segment and may be encoded. In this case, the size of the fragment should be reported to the receiving end.

라는 기준은 본 발명을 가장 적합하게 설명하기 위해 정한 기준 중 하나이고, 다른 기준 값을 정하여 단편화를 수행할 수 있다.9

Is one of the criteria defined in order to best explain the present invention, and fragmentation can be performed by setting another reference value.

Fig. 10 shows another example of a method for fragmenting an SDU according to another embodiment of the present invention.

이고, 블록집합의 크기를 n이라 했을 때, i>n이고, i<(단편의 개수×n)이다. 이때, i는 양의 실수이고, n은 양의 정수이다. FIG. 10 shows a case where the size of an SDU received from an upper layer is larger than 'BLOCK size * BLOCK SET size'. In other words, two or more block sets are generated. 10, it is assumed that the value obtained by dividing the SDU by one block is not an integer value, and the number of block sets is two or more. E.g,

, And when the size of the block set is n, i > n and i < (number of fragments x n). Where i is a positive real number and n is a positive integer.

보다 작은 경우에는 마지막 블록집합에 해당하는 블록들을 이전 블록집합에 포함시키고, 이전 블록집합의 크기를 수신단에 알려준다. 마지막 블록집합의 크기가

보다 큰 경우에는, 각 단편을 독립 블록집합으로 구성하고 마지막 블록집합의 크기를 수신단에 알려준다. 마지막 블록의 경우에는 블록의 크기를 동일하게 하기 위해 블록 크기만큼 비트를 채워(padding)준다. When performing a fragment, the size of the last block set is

The blocks corresponding to the last block set are included in the previous block set and the size of the previous block set is informed to the receiving end. The size of the last block set is

If it is larger, each fragment is composed of a set of independent blocks and the size of the last block set is informed to the receiving end. In the case of the last block, the bits are padded by the block size to make the blocks the same size.

보다 큰 경우이며, 마지막 블록의 크기가 다른 블록보다 작은 경우이다. 따라서, 마지막 블록에 다른 비트들을 채워 블록의 크기를 동일하게 할 수 있다. 이때, 송신단은 수신단에 각 블록집합의 크기를 알려줘야 한다.10 shows a case where the number of blocks included in the last fragment is

And the size of the last block is smaller than that of the other blocks. Therefore, the size of the block can be made the same by filling other bits in the last block. At this time, the transmitting end must inform the receiving end of the size of each block set.

11 shows an example of a MAC header format for R-ARQ control according to another embodiment of the present invention.

11 is a diagram illustrating a generic MAC header format for informing whether an R-ARQ control sub-header for R-ARQ control (R-ARQ Control Sub-header) Fig. In this case, R-ARQ means an ARQ scheme using RLC.

When the bit of the R-Ind field in the MAC header is set to R-Ind = 1, it indicates that the R-ARQ control subheader is included in the MAC PDU. If R-Ind = 0, it indicates that the R-ARQ control subheader is not included.

12 shows an example of a method of configuring a MAC PDU considering R-ARQ as another embodiment of the present invention.

ARQ control sub-header in consideration of R-ARQ when the MAC PDU is configured in the transmitter. Referring to FIG. 12, when the R-Ind field included in the MAC header is 1, the R-ARQ control subheader is included in the MAC PDU. A MAC SDU is included in the payload of the MAC PDU. Here, the MAC SDU represents a part of a block set constructed using fragmentation of FIGS. In addition, a CRC is appended to the MAC PDU for error control.

Table 5 below shows an example of an R-ARQ control subheader that can be used in embodiments of the present invention.

Syntax Size (bit) Notes R-ARQ Control Subheader () {   FC 2 Indicates the fragmentation or packing state of the payload:
00 = Last fragment (no fragment)
01 = Middle fragment
10 = Packing
11 = Reserved   Fragmentation # 8 Fragmentation # = Block set #    Alignment indicator One     If (Alignment indicator)      # of Blocks 8    Padding indicator One     if (Padding indicator)      # of Padding bits 8 }

Table 5 is an example of an R-based Automatic Repeat reQuest (R-ARQ) control subheader used for indicating a fragment (i.e., a block set) in a communication using RLC. The FC field indicates whether the payload following the R-ARQ control subheader is a last fragment (or a no fragment (FC = 00) or an intermediate fragment (FC = 01) Or a packed fragment (FC = 10). When the FC is set as the last fragment, if the SDU is divided into two or more fragments, it indicates that the corresponding PDU contains the last fragment. Even if the sender is 'No fragment', it is treated the same as the last fragment, so it can be informed to the receiver that it is the last fragment.

The fragmentation # parameter may indicate the number of the fragment included in the corresponding PDU. It may also indicate the number of fragments included in the PDU.

The transmitting end can use an alignment indicator to inform the number of blocks included in the fragment. If the transmitter sets the alignment indicator to '1', it can inform the number of blocks using '# of block' field. If the alignment indicator is set to '0', it indicates that the SDU is not fragmented.

Also, in the case of the last fragment (a last fragment or a no fragment), padding may occur. Accordingly, the R-ARQ control subheader includes a padding indicator field for informing the R-ARQ control sub-header. At this time, if the padding indicator field is set to '1', the transmitting end can indicate the number of bits padded using the '# of padding bits' field. Even if the packing is used, alignment and padding may occur.

13 shows another example of a method of configuring a MAC PDU considering R-ARQ as another embodiment of the present invention.

FIG. 13 shows a case where there are two or more sets of blocks inserted into a MAC payload among methods of constructing a MAC PDU including an R-ARQ control subheader in consideration of R-ARQ. That is, if the number of fragments is two or more, a method of constructing the MAC PDU is shown. The number of fragments can be performed as many as the number of block sets.

Referring to FIG. 13, the transmitting end segments the SDU into two fragments (Frag 0 and Frag 1). At this time, Frag 0 and Frag 1 may constitute MAC PDUs that are separate from each other in MAC PDU configuration. The components included in each MAC PDU are similar to those in Fig.

FIG. 14 shows another example of a method for constructing a MAC PDU considering R-ARQ according to another embodiment of the present invention.

FIG. 14 shows a method of constructing a MAC PDU by packing two or more MAC PDUs among methods of constructing a MAC PDU configured by including an R-ARQ control subheader in consideration of R-ARQ.

In FIG. 14, when packed MAC SDUs are divided into block sizes, they are not divided into integers. The last block is padded to match the block size. The number of the block set can be sequentially increased from one to one in the case of a fragmented unit or packed when each of the MAC SDUs is segmented until the end of the connection, starting from '0' after the first connection is established. It increases in the defined range, but it can start from 0 again when it reaches the maximum value.

Referring to FIG. 14, one or more MAC SDUs may be packed in the MAC PDU configuration. That is, the MAC PDU in this case includes one MAC header including 'R-Ind = 1', an R-ARQ control subheader and a MAC SDU # 0. In addition, it further includes an R-ARQ control subheader and a MAC SDU # 1 for controlling a MAC SDU. Of course, it may include a CRC for error detection and correction of the MAC PDU.

15 is a diagram showing a method of assigning numbers of block sets according to still another embodiment of the present invention.

The number of the block set can be sequentially increased from one to one in the case of a fragmented unit or packed when each of the MAC SDUs is segmented until the end of the connection, starting from '0' after the first connection is established. It increases in the defined range, but it can start from 0 again when it reaches the maximum value.

For example, if the number of a block set is 1 byte (1 byte), use 0 to 255 and increase by one. If you use up to 255, the next block set number becomes 0. 12, 13 and 14 are sequentially transmitted, that is, SDU # 0 in FIG. 12, SDU # 1 in FIG. 13, SDU # 1 in FIG. 13, SDU # 2 and SDU # 3 in FIG. , It has numbers of block sets as shown in FIG.

16 illustrates a method of adding an error detection code to each block when one or more MAC PDUs are generated by dividing an SDU according to another embodiment of the present invention.

This is a method for determining whether or not each block has an error with respect to information transmitted in a block unit when the MAC PDU is constructed. This is to prevent the MPDU created in the above method from discarding all the blocks included in the MPDU when the CRC checker extracts the error.

Referring to FIG. 16, the error detection code (CRC) can perform error detection on the immediately preceding block. For example, if n blocks are included in 'frag 0', then n error detection codes (CRC) are required. CRC can be used for error detection, and CRC-8 is used as a basis here. However, it may use more error detection information (eg, CRC-16 or CRC-32) depending on the size of the block

17 is a diagram illustrating a method of configuring a MAC PDU when fragment size and block size are identical, according to another embodiment of the present invention.

Referring to FIG. 17, an SDU transmitted from an upper layer is divided into n blocks. Each block corresponds to one fragment, and each fragment is used to construct one MAC PDU. Accordingly, the MAC PDU may include a MAC header including an R-Ind, an R-ARQ control subheader, a MAC payload configured with Frag 0, and a CRC. That is, when performing a fragment, only one block can be transmitted to the MPDU.

The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the above description should not be construed in a limiting sense in all respects and should be considered illustrative. The scope of the present invention should be determined by rational interpretation of the appended claims, and all changes within the scope of equivalents of the present invention are included in the scope of the present invention. In addition, claims that do not have an explicit citation in the claims may be combined to form an embodiment or included in a new claim by amendment after the application.

1 shows an example of a MAC header format used in a wireless MAN mobile communication system based on the IEEE 802.16 system.

2 shows a method of constructing a MAC PDU using a service data unit (SDU).

FIG. 3 shows a method of constructing a MAC PDU by fragmenting or packing an SDU, and applying an ARQ method thereto.

4 is a diagram illustrating a method of constructing a code block using a random-number linear encoding method according to an embodiment of the present invention.

5 is a protocol layer configuration diagram used in the IEEE 802.16 system.

6 shows an example of a method for segmenting SDUs according to another embodiment of the present invention.

Figure 7 shows another example of a method for segmenting an SDU, according to another embodiment of the present invention.

8 shows another example of a method for fragmenting an SDU according to another embodiment of the present invention.

9 shows another example of a method of fragmenting an SDU according to another embodiment of the present invention.

Fig. 10 shows another example of a method for fragmenting an SDU according to another embodiment of the present invention.

11 shows an example of a MAC header format for R-ARQ control according to another embodiment of the present invention.

12 shows an example of a method of configuring a MAC PDU considering R-ARQ as another embodiment of the present invention.

13 shows another example of a method of configuring a MAC PDU considering R-ARQ as another embodiment of the present invention.

FIG. 14 shows another example of a method for constructing a MAC PDU considering R-ARQ according to another embodiment of the present invention.

15 is a diagram showing a method of assigning numbers of block sets according to still another embodiment of the present invention.

16 illustrates a method of adding an error detection code to each block when one or more MAC PDUs are generated by dividing an SDU according to another embodiment of the present invention.

17 is a diagram illustrating a method of configuring a MAC PDU when fragment size and block size are identical, according to another embodiment of the present invention.

Claims (12)

A method for configuring a protocol data unit (PDU) in a wireless access system, A first step of negotiating a size of a block generated by dividing data transferred from an upper layer and a size of a block set composed of a predetermined block; A second step of constructing the block and the block set in which the upper layer data is fragmented according to the negotiated result; And A subheader for controlling an automatic retransmission scheme based on a random number linear encoding, and a third step of configuring protocol data including the block or the block set, In the second step, Wherein the number of fragments in the fragmentation is equal to the number of block sets, Wherein the number of block sets is determined in consideration of the size of the block and the number of blocks included in the block set. delete The method according to claim 1, Wherein the number of block sets is a number Dividing the higher layer data by a value obtained by multiplying the size of the block by a number of blocks included in the block set, and determining the resultant value as a number obtained by rounding up the result value. The method according to claim 1, In the second step, In the case of constructing the block set, Wherein when the size of the upper layer data is smaller than the size of the block set, the upper layer data is not fragmented and the upper layer data is divided into the blocks to configure the PDU. 5. The method of claim 4, If the upper layer data is not divided by the size of the block, a predetermined bit is filled in the last block to form one block. The method according to claim 1, In the second step, In the case of constructing the block set, Wherein if the size of the upper layer data is larger than the size of the block set, the upper layer data is fragmented and the PDU is configured using the fragmented data. The method according to claim 6, If the upper layer data is not divided by the size of the block, a predetermined bit is filled in the last block to form one block. The method according to claim 1, Wherein the PDU further comprises a header including a field indicating whether the subheader is included. The method according to claim 1, The sub- Further comprising an indicator for indicating a size of the block included in the PDU and a size of the block set. 10. The method of claim 9, The sub- Further comprising an indicator indicating whether the padding is required in the block, and indicating a number of bits to be padded if the indicator indicates that padding is required. The method according to claim 1, Wherein the PDU further comprises an error detection code for error control. 12. The method of claim 11, Wherein the error- Wherein the PDU is inserted separately for each block included in the PDU.

Images