WO1998012843A1

WO1998012843A1 - Data receiver

Info

Publication number: WO1998012843A1
Application number: PCT/JP1996/002721
Authority: WO
Inventors: Junko Nakase; Yutaka Okada
Original assignee: Hitachi, Ltd.
Priority date: 1996-09-20
Filing date: 1996-09-20
Publication date: 1998-03-26
Also published as: TW337626B

Abstract

The assembling error of an intermediate data unit CPSC-PDU caused by the error of a cell header of an ATM cell which is received data is reduced. A data receiver comprises a data constituting section (2) which composes an intermediate data unit CPSC-PDU of received ATM cells, an error inspecting section (5) for error detecting code data CRC of the unit CPSC-PDU, a packet composing section (70) which composes a plurality of transfer packets TS and (20) of the units CPSC-PDU, and a count section which counts the received ATM cells until a received ATM cell becomes a boundary cell next. When the counted number of received ATM cells is smaller than the number of transmitted cells, and when an error of a cell header is detected, the unit CPSC-PDU composed by the data constituting section (2) is transferred to the packet composing section (70) and the sections (70) compose a plurality of transferring packets TS and (20).

Description

Description Data receiving device Technical field

The present invention relates to a data receiving apparatus of a data transmitting / receiving system for transmitting / receiving a stream in which data such as video and audio are multiplexed in an ATM (Asynchronous Transfer Mode) cell system, and particularly to an MPEG-2 ( Moving Picture Experts Group 2) It relates to a data receiving device that receives video and audio data multiplexed by TS (Transport Stream) specified by the system standard, and then divides the data into ATM cells and receives the data. Background art

To date, applications for transmitting and receiving digital video data, digital audio data, and the like over a communication line, such as digital CATV (Cable Television) and VOD (Video On Demand), have been increasing.

In such a case, during transmission, video and audio data are stored in units called buckets, respectively, and a plurality of buckets are multiplexed to form a multiplexed stream. Transmission is performed using a transmission method suitable for transmission. ATM is the most promising TS transmission system defined by the MPEG2 system standard for multiplexed streams. Hereinafter, each of T S and A T M will be briefly described.

First, TS, which is a transfer bucket, will be described. TS is a stream in which 188-byte fixed-length transport packets (TS packets) are multiplexed. The TS is capable of multiplexing the video and audio data of the program in the form of a TS packet. The program here refers to the channel used in TV broadcasting. .

As shown in Fig. 2, a 4-byte TS bucket header 201 is added to the beginning of the TS bucket 20 and an adaptation—field is added after the TS bucket header 201. There is a data storage section called ll'i 'and a field 202 and a pay field 203 (the adap contains a TS called discontinuity-indicator in the action-field 202). Information indicating the inconsistency of the time axis is stored, etc. The payload 203 stores encoded data of video and audio.

In the first byte of the TS bucket header 201, a specific pattern called a synchronization pattern for synchronizing the TS packet 201 (a hexadecimal number 0x47, where 0x is 1 means hexadecimal notation). The TS bucket header also contains PI Includes a 13-bit packet identification field 201, called D. When restoring a specific program in the TS, the TS bucket that stores the video and audio data of the program is extracted from the TS using the PID. Next, video and audio data are extracted from the payload in the TS packet, and decoded by the video decoder and audio decoder, respectively.

Next, transmission / reception data of the ATM system will be described. ATM is a method of transmitting and receiving data in units of 53 bytes called ATM cells. As shown in Fig. 3, the ATM divides the transmission data into 48-byte data strings 302, each of which is preceded by a 5-byte header 301 (hereinafter referred to as a cell header), for a total of 53 bytes of ATM. Construct cell 30.

On the receiving side, the cell header is removed from the received ATM cells and the original data string is restored. The fifth byte 30 15 of the cell header 301 is a CRC (Cyclic Redundancy Check) corresponding to the preceding four bytes, and is called HEC (Header Error Control). The receiving side can determine whether there is an error in the cell header by using HEC. More specifically, polynomial division is performed by using the 5-byte data string of the received cell header as the dividend and the generator polynomial used in generating the HEC as the divisor. Since the time of transmission attached HEC force ^s like the remainder of the division is 0, result of the division on the receiving side, if the remainder does not become zero, and that some error occurs in Serue' da to decide. Note that, in practice, the HEC is capable of detecting multiple bits of error or one-bit error correction in the cell header ^{. In} the following description, for simplicity, HEC is used only for error detection. The CRC check at the receiving side as described above is also used to synchronize ATM cells. In other words, the received data sequence is shifted to perform a CRC check, and when a bit position determined to be error-free as a result of the CRC check is periodically found at ATM cell intervals, the position is determined by the ATM. Let it be a cell separator.

When transmitting the above-mentioned TS by ATM, it is considered that a method called AAL (ATM Adaptation Layer) 5 is used (see The ATM Forum: “Audiovisual Multimedia Services: Video on Demand Specification 1.0”). . The AAL is a layer that determines how the upper data sequence (here, TS) is allocated to the lower ATM cells.

Figure 4 shows the procedure for storing a TS bucket in an ATM cell on the transmitting side using this AAL5 method. First, two TS buckets as two transfer buckets are grouped (concentrated), followed by an 8-byte trailer and 384 bytes (= 1 8 8 bytes X 2 + 8) Byte) CPSC—Constitutes one intermediate data unit called PDU (Common Part Convergence Sublayer-Protcol Data Unit). The CPSC—PDU trailer contains the TS bucket data in the CPSC—PDU. It contains information on the byte length (188 bytes X 2 = 376 bytes) and 4-byte CRC data as error detection code data for checking errors in the CP SC-PDU.

Next, the above CPS C—PDU is divided into 8 parts of 48 bytes, each of which is preceded by a 5-byte cell header, and the c-cell header that constitutes the transmission data consisting of 8 ATM cells is It contains information that distinguishes whether the ATM cell is the last ATM cell among the eight ATM cells that make up the CPSC-PDU. This last ATM cell identification is called the ATM layer user-to-user indication. In the following description, the display is simply between users. The indication between users is 1 in the last ATM cell of the CP SC—PDU, and 0 in other ATM cells. Disclosure of the invention

As described above, it has been clarified by the study of the present inventors that when the TS stored in the ATM cell is decoded by the AAL5, an ATM receiving apparatus as shown in FIG. 5 is required. That is, the ATM receiving device to which eight ATM cells, which are received data, are input, the ATM-TS conversion unit 91 that extracts TS from the ATM cell, and decodes video and audio of a desired program using TS as input. And a TS decoding unit 92 for outputting.

FIG. 6 shows the configuration of the ATM-TS converter 91 shown in FIG. In the ATM-TS conversion section 91, first, cell synchronization is performed in the cell synchronization section 911, and a partition of the ATM cell is detected. After the detection of the ATM cell division, the ATM cell is input to the CP SC-PDU assembly unit 912 and the inter-user display inspection unit 914. The inter-user display inspection unit 914 checks the inter-user display in the cell header and sends the result to the CPSC-PDU assembly unit 912. 〇? 5 (: ?? 011 In the assembling section 912, when the information indicating that the display between users is 1 is sent from the inter-user display inspection section 914, the ATM cell corresponding to the information and the immediately preceding 7-cell total 8 Configure the CPSC-PDU in the cell.

On the other hand, the CRC check unit 915 performs a CRC check on the CPSC-PDU assembled by the CPSC-PDU assembly unit 912. CP SC—A CRC check on the PDU is the same as the CRC check on the cell header described above? Divide the 384 bytes of 5 (: —? 01] as the dividend and the given generator polynomial as the divisor. As a result of this division, when the remainder is 0, it is determined that there is no error in the CP SC—PDU, If it is not 0, it is determined that there is an error in the CPSC-1 PDU.

Therefore, in the TS bucket filter unit 917, of the CPSC-PDU assembled by the CP SC-PDU assembling unit 912, eight bytes from the CP SC-PDU determined to be error-prone by the CRC checking unit 915. The data of the TS bucket excluding the trailer is output as TS. On the other hand, the CRC checker 9 The specified CP SC—PDU is discarded.

FIG. 7 shows a configuration example of the TS decoding section 92 shown in FIG. The TS decoder 92 receives the TS extracted by the ATM-TS converter 91, separates the video and audio of the desired program from the TS by the TS separator 921, and sends them to the video decoder 922 and the audio decoder 923, respectively. The video decoder 922 and the audio decoder 923 decode and output the encoded video and audio data, respectively.

Prior to the present invention, the inventor of the present application has examined the above-described data receiving apparatus, and as a result, has found that it has the following problems.

The first problem is due to a misassembly of the CPS C-PDU. As described above, AAL5 recognizes the final ATM cell that constitutes the CPSC-PDU by indicating between users in the cell header, while ATM cell synchronization is controlled based on the result of the CRC check as described above. You. Once the ATM is synchronized, it is generally not determined that the cell has been synchronized unless a cell with an erroneous cell header is repeated a predetermined number of times for synchronization protection. As a result, an ATM cell having an error in the cell header is also treated as a valid cell. However, the display between users in the erroneous cell header may be incorrect.

That is, there is a possibility that the cell-to-user indication of a cell that is originally in the middle of the CPSC-PDU is 1 or conversely that the cell-to-user indication of the last ATM cell of the CPSC-PDU is 0. In such a case, the data receiving device cannot correctly assemble one intermediate packet CP SC-PDU from the eight ATM cells that are the received data, and consequently is a transfer bucket. The data in the TS bucket may be destroyed.

A basic object of the present invention is to provide a data receiving apparatus capable of reducing an error in assembling one intermediate data unit CPSC-PDU due to an error in a cell header of an ATM cell as received data. It is in.

Next, the second problem will be described. Intermediate data unit CP SC—Error in the PDU ⁵ 'If detected, the cause may be that there is an error in the CPSC-PDU or that the ATM cells constituting the CP SC-PDU are lost. Is received. Here, the cell loss means that a cell that should be received does not reach the receiving side. The causes of cell loss include incorrect delivery destinations due to errors in cell headers of ATM cells, and buffer overflows due to congestion. An example of the buffer overflow due to this congestion is discarding information of low importance when the amount of transmission is large.

However, even if the cells that make up the CPSC—PDU are lost, the two TS buckets originally included in the CPSC—PDU may depend on the location and number of lost cells. In some cases, the data of one T s packet may be correctly received.

However, in the past, since data was discarded in units of one intermediate data unit CPS C—PDU, there was a possibility that even the correct TS bucket data was discarded. It is understood that it is desirable to avoid data destruction as much as possible, as it causes a decrease in data quality.

Accordingly, a secondary object of the present invention is to provide a data receiving apparatus capable of extracting data of a TS bucket, which is a correct transfer bucket included in one intermediate data unit CPSC-PDU, and reducing the amount of data discard. Is to provide. Next, the third problem of the present invention will be described. The data quality is degraded due to data discard, and the output image quality and sound quality are lost. In particular, in hierarchical coding such as MPEG 1 video and MPEG 2 video, it can be understood that the output quality is significantly reduced when high-order coded data is lost. Also, in the adaptation-field of the TS packet, the time information serving as the time reference, such as the decoding / output of the TS, is stored. If data discarding occurs, the time information becomes discontinuous, which hinders decoding. However, it can be understood that as a result, the quality of the output may be deteriorated. Another secondary object of the present invention is to provide a data receiving apparatus capable of minimizing deterioration of program data such as video and audio due to data discard as described above.

The outline of a typical embodiment of the invention disclosed in the present application is as follows.

On the transmitting side, one intermediate data unit (CPC) to which error detection code data (CRC) is added from a plurality of transfer buckets (TS, 20) including a packet header (201) and encoded data (203). S-PDU) and a plurality of cell data (30) including a cell header (301) and a data system IJ (302) by dividing the one intermediate data unit (CPC S-PDU). , An ATM cell), and the cell header (301) of each of the plurality of cell data (30, ATM cells) has a corresponding cell data composed of the one intermediate data unit (CPCS-PDU). Boundary cell identification information indicating whether the cell is a boundary cell of one of the first cell data and the last cell data of the plurality of cell data,

A data receiving device for receiving the transmitted plurality of cell data (30, ATM cells),

A data configuration unit that forms one intermediate data unit (CPC S-PDU) to which error detection code data (CRC) is added from the plurality of received cell data (30, ATM cells) (2) When,

An error checking unit (5) for checking an error from the error detection code data (CRC) added to the one intermediate data unit (CPCS-PDU) configured by the data configuration unit (2); O 9 1

6

A plurality of transfer buckets (TS, 20) including a bucket header (201) and coded data (203) are formed from the one intermediate data unit (CPC S-PDU) by the above-mentioned reception 'structure. The packet composition part (70)

In response to the boundary cell identification information of the plurality of reception cell data (30, ATM cell), after the boundary cell identification information indicates that the reception cell data is the boundary cell, the subsequent reception cell data is A counting unit (3) for counting the number of cells of the received cell data until the next boundary cell identification information indicates that the cell is the boundary cell (see FIG. 1);

When the number of count cells in the count section (3) matches the number of cells of the plurality of cell data constituting the one intermediate data unit on the transmission side (step 81 in FIG. 8). N = 8), in response to the error power not being detected by the error checking unit (5), the one intermediate data unit (CPCS-PDU) configured by the data configuration unit (2) is converted to the bucket by the bucket. The transfer packets (TS, 20) are transferred to the configuration unit (70), and the transfer buckets (TS, 20) are formed (see steps 91, 92, and 93 in FIG. 9).

When the number of count cells in the counting section (3) is smaller than the number of cells in the plurality of cell data composing the one intermediate data unit on the transmitting side (n <8 in step 81 in FIG. 8). Inspection results (see step 10 in FIG. 10) that the cell header of the received cell data has an error due to the error detection code data of the cell header of the received cell data having the small number of counted cells. In response to no error detection from the error checking unit (5), the one intermediate data unit (CPC) composed of the data configuration unit (2) S-PDU) is transferred to the above-mentioned bucket composing section (70) to constitute the above-mentioned plurality of transfer packets (TS, 20) (steps 103, 1 in FIG. 10). 04, 105, 106, 107, 108). According to the above-described basic embodiment of the present invention, it is possible to achieve the basic objective of reducing the assembly error of the intermediate data unit (CPCS-PDU) on the receiving side for the following reason.

First, when the number of counted cells in the counting section (3) matches the number of cells of a plurality of cell data constituting one intermediate data unit on the transmitting side, the data between one sub-block on the receiving side is set at an accurate cell number interval. Since the unit (CPCS-PDU) should be able to be configured, if no error is detected from the error check unit (5) for the error detection code data (CRC) added to this intermediate data unit (CPCS-PDU) One intermediate data unit (CPCS-PDU) configured by the data configuration unit (2) is transferred to the bucket configuration unit (70), and a plurality of transfer buckets (TS, 20) are configured. You.

On the other hand, even when the number of counted cells in the counting section (3) is a plurality of smaller that force than the number of cells of the cell ^data? Detection constituting the intermediate Detayuni' bets one sender, this number of counted cells is a small There is an error in the cell header of the received cell If power is detected, it can be considered that the reliability of both the boundary cell detection and the error detection of the cell header of the detected boundary cell is not sufficiently guaranteed. In such a case, the error detection unit (5) will make an error regarding the error detection code data (CRC) added to the intermediate data unit (CPC S-PDU) composed of the data configuration unit (2) on the receiving side. If no is detected, this intermediate data unit (CPCS-PDU) is considered to be accurate and true data. Therefore, also in this case, one intermediate data unit (CPCS-PDU) configured by the data configuration unit (2) is transferred to the packet configuration unit (70), and a plurality of transfer packets (TS, 20) are transmitted. , It is possible to achieve the above basic purpose.

Another basic embodiment of the invention is:

On the transmitting side, one intermediate data unit (CR) is added from a plurality of transfer packets (TS, 20) including a bucket header (201) and encoded data (203). CPC S-PDU), and by dividing the one intermediate data unit (CPC S-P DU), a plurality of cell data (3 01) and a data string (3 02) including a cell header (301) are divided. 30 and an ATM cell), and the cell header (30 1) of each of the plurality of cell data (30, ATM cells) has the corresponding cell data in the one intermediate data unit (CPC S— PDU) including boundary cell identification information indicating whether the cell is one of the first cell data in the evening and the last cell data.

A data receiving apparatus for receiving the plurality of cell data (30, ATM cells) transmitted above,

A data configuration unit (2) that forms one intermediate data unit (CPC S-PDU) in which error detection code data (CRC) is added from the plurality of cell data (30, ATM cells);

An error checker (5) for checking an error from the upper detection code data (CRC) added to the one intermediate data unit (CPCS-one PDU) composed of the data {f & i 2);

A plurality of transfer buckets (TS, 20) including a bucket header 01) and coded data (203) from the one intermediate data unit (CPCS-PDU) by t ^ ^: And a packet constituent part (70) that also forms

In response to the boundary cell identification information of the plurality of reception cell data (30, ATM cells), after the boundary cell identification information indicates that the reception cell data is an upper boundary cell, the subsequent reception cell data is A counting unit (3) for counting the number of cells of the received cell data until the next boundary cell identification information indicates that the cell is the boundary cell (see FIG. 1);

The number of count cells in the counting section (3) is the one intermediate data of the transmitting side. When the number of cells of the plurality of cell data constituting the unit matches the number of cells (see n = 8 in step 81 in FIG. 8), a response is made that no error is detected by the error checking unit (5). Then, the one intermediate data unit (CPCS-PDU) configured by the data configuration unit (2) is transferred to the bucket configuration unit (70), and the plurality of transfer buckets (TS, 20) are transferred to the bucket configuration unit (70). ) (See steps 91, 92, and 93 in Figure 9),

When the number of counted cells of the counting section (3) is larger than the number of cells of the plurality of cell data constituting the one intermediate data unit on the transmitting side (n> 8 in step 81 in FIG. 8). ), The cell count of the received cell data whose number of count cells of the above-mentioned control unit (3) matches the number of cells of the plurality of cell data constituting the above-mentioned one intermediate data unit on the transmitting side. Based on the error detection code data, it responds to the test result that the cell header of the received cell data has an error (see YES in step 131, FIG. 13). ), The one intermediate data unit (CPC S-PDU) configured by the data configuration unit (2) is transferred to the bucket configuration unit (70), and Specially, it consists of multiple transfer buckets (TS, 20). To (see steps 1 32, 1 33, 1 34, 1 3 5 in Figure 1 0).

According to the other basic embodiment of the present invention described above, it is possible to achieve the basic purpose of reducing the error of assembling the intermediate data unit (CPCS-PDU) on the receiving side for the following reasons. It becomes possible.

First, when the number of count cells in the count unit (3) matches the number of cells of a plurality of cell data constituting one intermediate data unit on the transmitting side, one intermediate data unit on the receiving side is set at an accurate interval of the number of cells. If the error check unit (5) does not detect the error detection code data (CRC) added to this intermediate data unit (CP CS-PDU) Then, one intermediate data unit (CPC S-PDU) configured by the data configuration unit (2) is transferred to the bucket configuration unit (70), and a plurality of transfer buckets (TS, 20) are configured.

On the other hand, the number of count cells in the count unit (3) must be larger than the number of cells of a plurality of cell data constituting one intermediate data unit on the transmission side; Similarly, if the cell header of the received cell data whose cell count matches the number of cells of a plurality of cell data that constitute one intermediate data unit on the transmitting side contains an error, the same applies. It can be considered that the reliability of both the boundary cell detection and the error detection of the cell header of the detected boundary cell is not sufficiently guaranteed. Even in such a case, the error check unit (5) issues an error regarding the error detection code data (CRC) added to the intermediate data unit (CPCS-PDU) composed of the data configuration unit (2) on the receiving side. If no is detected, this intermediate data unit (CPCS-1 PDU) is considered to be accurate and true data. Therefore, also in this case, the data structure One intermediate data unit (CPC S-PDU) composed of the part (2) is transferred to the bucket constituent part (70) to form a plurality of transfer buckets (TS, 20). Objective can be achieved.

A data receiving device according to a more preferred embodiment of the present invention,

The packet header (201) of the transfer bucket (TS, 20) composed of the one intermediate data unit (CPCS-PDU) according to the reception / configuration in the bucket configuration unit (70). ) Is further provided with a transfer packet synchronization pattern checker (6) (see FIG. 1) for checking whether or not the pattern matches a predetermined pattern (see FIG. 1). When the number of cells is smaller than the number of cells of the plurality of cell data constituting the one intermediate data unit on the transmitting side (see n <8 in step 81 of FIG. 8), the number of count cells The error detection code data of the cell header of the small received cell data indicates that there is no error in the cell header of the received cell data (see N0 in step 101 of FIG. 10). Responds, and the number of count cells of Responds to the fact that the number of cells of the plurality of cell data constituting the one intermediate data unit is equal to or greater than half the number of cells (see n> 3 in step 11 of FIG. 11), and further transfers the data. In response to the inspection output of the packet synchronization pattern inspection unit (6), the predetermined number of the plurality of transfer buckets (TS, 20) composed of the one intermediate data unit (CPCS-PDU) are used. The partial data of the one intermediate data unit (CPCS-PDU) corresponding to the transfer bucket (TS, 20) including the synchronization pattern that matches the pattern of (1) is transferred to the bucket configuration unit (70). Characterized in that the transfer bucket (TS, 20) including the synchronization pattern that matches the predetermined pattern is configured (steps 112, 113, 114, 1 in FIG. 11). 15 and 1 16).

According to a more preferred embodiment of the present invention, the data of the TS packet which is the correct transfer packet included in one intermediate data unit CP SC-PDU is taken out for the following reason, and the amount of data discard is determined. It is possible to achieve the secondary object of the present invention, that is, to reduce the amount of light.

First, the number of counted cells in the counting section (3) is smaller than the number of cells in a plurality of cells constituting one intermediate data unit on the transmitting side (n <8), and the number of counted cells is small. There is no error in the cell header of the received cell data due to the error detection code data of the cell header of the cell data, and the number of count cells in the count section (3) constitutes one intermediate data unit on the transmission side. If more than half the number of cells of the cell data of the transmitter (see n> 3), some of the cell data that constitutes one intermediate data unit on the transmitting side will be lost during transmission and reception. Very likely. In such a case, a predetermined pattern among a plurality of transfer packets (TS, 20) composed of one intermediate data unit (CPC S-P DU) The partial data of one intermediate data unit (CPCS-PDU) corresponding to the transfer packet (TS, 20) including the synchronization pattern that matches the packet is transferred to the bucket forming unit (70) and Since the transfer bucket (TS, 2 ()) including the synchronization pattern matching the above pattern is configured, the above-described secondary object of the present invention can be achieved. A data receiving device according to a specific embodiment of the present invention includes:

A data decoding unit (92, see FIG. 5) for decoding the plurality of transfer buckets (TS, 20) configured by the bucket configuration unit (70) into desired program data;

The packet header (201) of the transfer bucket (TS, 20) composed of the one intermediate data unit (CPCS-PDU) according to the reception configuration in the bucket configuration unit (70) When it is checked by the transfer packet synchronization pattern checker (6) that the synchronization pattern matches the predetermined pattern, the packet of the packet header (201) of the transfer packet (TS, 20) is checked. An identification field for comparing the packet identification field data (PID) with the packet identification field data (PID) of a plurality of transfer buckets (TS, 20) storing the program data of the selected program. And a plurality of transfer buckets (TSs) composed of the one intermediate data unit (CPCS-PDU). , 20) matches the above predetermined pattern The partial data of the one intermediate data unit (CPCS-PDU) corresponding to the transfer packet (TS, 20) including the synchronization pattern to be transferred is transferred to the bucket forming unit (70), and the predetermined pattern is transmitted. When the above-mentioned transfer packet (TS, 20) including the above-mentioned synchronization pattern is constructed (see steps 112, 113, 114, 115, 116 of FIG. 11), Of the intermediate data unit (CPCS-PDU) other than the above-mentioned partial data is not effectively used and discarded due to the configuration of the transfer bucket (TS, 20) Things,

When effectively discarding the data other than the partial data, when the identification field comparing unit (11, 12) detects a match between the two bucket identification field data with respect to the effective discarded data, The detection result of the effective discard match is transmitted to the data decoding unit (92, see FIG. 5).

According to a specific embodiment of the present invention, it is another object of the present invention to minimize the deterioration of program data such as video and audio due to data discard for the following reasons. Becomes possible.

That is, when the above-mentioned data is effectively discarded, the match detection result of the identification field comparison unit (11, 12) indicating that there is data to be discarded from an early point is transmitted to the data decoding unit (92). Therefore, the data decoding unit (92) can perform a corresponding process in response to this, so that it is possible to achieve another subsidiary object of the present invention described in the above description. Other objects and features of the present invention will become apparent from the following examples. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a diagram showing a data receiving apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a TS bucket.

FIG. 3 is a diagram showing an ATM cell.

Fig. 4 is a diagram showing the relationship between the TS bucket and ATM cells.

FIG. 5 is a diagram showing a data receiving apparatus studied before the filing.

FIG. 6 is a diagram showing an ATM-TS converter of the data receiving device of FIG.

FIG. 7 is a diagram showing a TS decoding unit of the data receiving device of FIG.

FIG. 8 is a flowchart showing the processing contents of the data receiving device of FIG.

FIG. 9 is a flowchart showing the processing contents of the processing A in FIG.

FIG. 10 is a flowchart showing the processing contents of the processing B in FIG.

FIG. 11 is a flowchart showing the processing contents of the processing D in FIG.

FIG. 12 is a flowchart showing the processing contents of the processing E in FIG.

FIG. 13 is a flowchart showing the processing contents of the processing C in FIG.

FIG. 14 is a diagram showing a data receiving device according to the second embodiment of the present invention.

FIG. 15 is a diagram showing a data receiving device according to the third embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. FIG. 1 shows a configuration of an ATM-TS conversion section of a data receiving apparatus according to a first embodiment of the present invention.

The difference between the configuration of the ATM-TS converter in FIG. 1 and that of the ATM-TS converter in FIG. 6 will be described below.

First, in Fig. 1, instead of the cell synchronization unit 911 of the ATM-TS conversion unit in Fig. 6, a function to detect ATM cell headers to detect cell synchronization and to detect ATM cell delimiters is provided. A cell synchronization unit 1 is provided which has a function of outputting error information indicating the presence or absence of an error in a cell header.

Further, in FIG. 1, a cell number counting unit 3, a TS packet synchronization byte inspection unit 6, and a TS packet filter control unit 80 are newly provided. Hereinafter, these are a cell synchronization unit 1, a CPSC-PDU assembly unit 2, a cell number counting unit 3, an inter-user display inspection unit 4, a CRC inspection unit 5, a TS packet synchronization byte inspection unit 6, and a TS bucket filter unit. 70, the function of the ATM-TS converter comprising the TS bucket filter controller 80 will be described.

Cell synchronizer 1 receiving ATM cells as received data Information and the cell header error presence / absence information are supplied to the cell number counting section 3, while the boundary of eight ATM cells constituting one intermediate data unit, CP SC—PDU, is the ATM cell identification information (for example, the last ATM cell). The identification information and the display between the ATM layer and the user are supplied to the inter-user display inspection unit 4. Further, the synchronization pattern (specific pattern) of the packet header of the TS packet is supplied from the cell synchronization unit 1 to the TS bucket synchronization byte inspection unit 6.

The CRC checker 5 performs a CRC check on the CP SC-PDU, which is one intermediate data unit assembled by the CP SC-PDU assembler 2. Similar to the above, the CRC check for the CPSC-PDU is performed using the 384 bytes of the CPSC-PDU as the dividend and a certain generator polynomial as the divisor. As a result of this division, when the remainder is 0, it is determined that there is no error in CPSC-PDU, and when it is not 0, it is determined that there is an error in CPSC-PDU.

Therefore, the cell count unit 3 receives the ATM cell delimitation detection information and cell header error presence / absence information from the cell synchronization unit 1, the boundary ATM cell identification information from the inter-user display inspection unit 4, and the Intermediate data unit CP SC—Based on the CRC check result of the PDU, the first ATM cell of the intermediate data unit CP SC—PDU is set to 1 and then to the ATM cell whose border ATM cell identification information (display between users) becomes 1. While counting the number of ATM cells, the CPSC—PDU delimiter is notified to the CPSC—PDU assembly unit 2, CRC check unit 5, and TS bucket synchronization byte check unit 6. The details of the procedure for obtaining the CP SC-PDU delimiter will be described later.

On the other hand, the TS packet synchronization byte inspection unit 6 determines that the synchronization byte of the TS bucket composed of the intermediate data unit CPSC-PDU is stored in the ATM cell, and the value of the synchronization byte is the byte. Checks whether it matches 0 X 47 (specific pattern, synchronization pattern). Further, the TS packet filter control unit 80 refers to the inspection result of the CRC inspection unit 5 and the inspection result of the TS bucket synchronization byte inspection unit 6 and extracts the TS bucket from the CPSC-PDU.

The CPSC—PDU assembly unit 2 removes the header from the ATM cell, assembles a CPSC-PDU, and sends it to the Ts packet filter unit 70. In addition, the CRC check unit 5 performs a CRC check on the assembled CP SC-PDU to detect the presence or absence of an error in the CP SC-PDU.

Next, the processing flow of the entire ATM-TS conversion unit of the present embodiment in FIG. 1 will be described in detail. First, the cell synchronization unit 1 detects a break of the received ATM cell. Next, the inter-user display inspection unit 4 checks the inter-user display in the cell header. Since the CP SC—PDU consists of eight ATM cells, ATM cells with a user-to-user indication of one usually appear at intervals of eight cells. Here, for the sake of explanation, the ATM cell next to the ATM cell for which the user inquiry indication was 1 last time is called a reference cell. FIG. 8 shows the top-level flowchart of the processing of the CPSC-PDU assembling unit 2 of the ATM-TS conversion unit after cell synchronization. In the ATM-TS conversion section of this embodiment, when the count result of the cell number counting section 3 in step 81 is n, (l) n = 8 by the cell count result n, (2) n When <8, (3) n> 8, the following three cases are performed, and for these three cases, processing A, processing B, and processing C are performed in steps 82, 83, and 84, respectively. . Hereinafter, these processes A, B, and C will be described.

Fig. 9 shows the flowchart of process A. Process A is a process when the display interval between users is correct. In this case, the CPSC-PDU assembling unit 2 assembles the CPSC-PDU from eight cells from the reference cell to the ATM cell where the user-to-user indication is 1, and performs a CRC check on the CPSC-PDU in steps 91 and 92. This is performed by the CRC checker 5. The result of this CRC check, if undetected error power, data force of TS bucket bets CPSC- PDU by TS bucket preparative filter unit 70 in step ^93? Is Ri issued preparative is output as TS. Conversely, if an error is detected, step 94 discards the CP SC-PDU data.

FIG. 10 shows a flowchart of the process B. Process B is a process in the case where a cell whose display between users is 1 appears at the nth cell (where n <8) from the reference cell.

The CP SC—PDU assembling unit 2 first checks in step 101 whether there is a cell header error in the n-th cell where the indication between users is 1 by referring to the error information of the cell synchronizing unit 1. . If there is no error, there is a possibility that an ATM cell has been lost, so the processing D described later is performed in step 102. On the other hand, if there is an error in the cell header, in step 103, reference is made to the display between users in the 8-cell S from the reference cell. If the display between reference users in step 103 is 1, or even if the display between reference users in step 103 is 0, the cell header in the eighth cell is incorrect and the display between reference users may be incorrect. If it is confirmed in step 104 that there is a possibility, the CRC checker 5 makes 8 cells from the reference cell as a temporary CPSC-PDU in step 105, and Perform C RC inspection. Step: If no error is detected as a result of the CRC check in step 07, it is determined that the tentative CPSC-PDU is a true CPSC-PDU, and in step 108, a TS bucket filter unit is generated from this CPSC-PDU. Extract TS packets through 70. On the other hand, force Step 1 03 displayed for 8 cells th reference user from the reference cell is ^0? Confirmed, if it is confirmed further erroneous Riganai that force header to the cell in step 1 04, or step, If the error power ^{s is} detected as a result of the CRC check for the temporary CPSC PDU in 106 and 107, the process E described later is performed in step 109.

Next, the processing D will be described. FIG. 11 shows a flowchart of the processing D. processing D is the process when the display between users is 1 in the nth cell (n x 8) from the reference cell, and there is no cell header error in the nth cell. In this case, it is possible that (8-n) of the eight ATM cells that make up the CP SC-PDU of one intermediate data unit have lost power. In process D, the TS bucket synchronization byte determines whether the value of the synchronization byte of the TS bucket composed of the intermediate data unit CP SC—PDU matches 0x47 (specific pattern, synchronization pattern). Inspection unit 6: Determines which of the two TS buckets caused the cell loss by examining, and extracts the TS bucket in the CPCS that has been correctly received.

In this process D, first, in step 1 1 1, it is checked whether or not the number n of cells from the reference cell to the cell whose display between users is 1 is greater than 3. Here, n cells from the reference cell to the cell having a user-to-user indication of 1 are assumed to be temporary CPSC-PDUs. When n is 3 or less, the data amount of the temporary CPSC—PDU is 144 bytes 1 cell 48 bytes X 3 cells) or less, and the packet length of the TS packet is less than 188 bytes. In this case, since there is no valid TS bucket in the temporary CPSC-PDU, the data of the temporary CPSC-PDU is discarded.

If it is confirmed in Step 1 1 1 that the number of cells of the temporary CPSC—PDU is greater than 3, the TS packet synchronization byte checker 6 proceeds to Step 1 12 with the temporary CPSC—PDU in the temporary PDU. Examine the synchronization byte in the TS bucket. The long-term byte of the TS bucket is the first byte of the TS bucket and is 0x47. Since two TS buckets are continuous in a normal CPS C—PDU, the first byte of the CPS C—PDU and the 189th byte counted from the first are the TS synchronization bytes. CP SC—Based on the last byte of the PDU, the 196th (= 188 + 8) and 376th bytes from the back are the TS synchronization bytes (see Figure 4) . Therefore, according to steps 113 and 114, if the first byte of the temporary CPSC-PDU and the 1189th byte from the head are 0X47, the temporary CPSC-PDU It is determined that the first TS bucket from the front of the two TS buckets stored therein is included, and the first TS bucket is extracted in step 1 15. On the other hand, according to step 115, if the last 196 bytes of the temporary CP SC—PDU are TS synchronization bytes, it is determined that the second TS bucket of the CP SC—PDU is included. Then, in step 1 16, the second TS packet is extracted. In this way, in process D, when it is determined that the TS packet is included in the temporary CPSC-PDU, the TS packet is extracted and the other data in the temporary CPSC-PDU is extracted. Discard.

Next, the processing E will be described. Fig. 12 shows the flowchart of process E. In process E, next, the cell in which the display between users is 1 is waited in step 122, and the cell in which the display between users is 1 and the immediately preceding cell in step 122 are totaled 8 cells in total. CP As SC—PDU, the CRC is checked in step 123. As a result of the CRC inspection, if it is determined in step 124 that there is no error, the temporary CPSC-PDU is determined to be a true CPSC-PDU, and in step 125, a TS bucket is extracted. Conversely, if an error is detected in the CRC check in step 124, the processing returns to the beginning of processing E again through the data discarding in step 126 and the one-cell advance processing in step 127, and the error-free true CP SC — Repeat until a PDU is found. Next, the process C will be described. Process C is a process when the number of cells from the reference cell to the next cell where the display between users becomes 1 exceeds eight. FIG. 13 shows a flowchart of the process C. In process C, first, if it is confirmed in step 13 1 that there is an error in the cell header of cell 8 H from the reference cell and there is a possibility that the display between the reference users is wrong, From Steps 8 and 9 as the temporary CP SC-P DU, in steps 133 and 134, the CRC inspection unit 5 performs a CRC inspection on the temporary CP SC-P DU. If there is no error as a result of the CRC check in step 134, the tentative CPSC-PDU is regarded as a true CPSC-PDU. To extract two TS buckets. The process is performed again with the next cell of the taken out CP SC-PDU as the reference cell (see FIG. 8). If it is confirmed in step 13 that there is no error in the header of the eighth cell from the reference cell, or if an error is detected as a result of the CRC check in step 134, Then, set n = 4, and try to extract the previous packet part by processing D (see Fig. 11), and then search for the next true CPSC-PDU by processing E (see Fig. 12).

As described above, the ATM-TS converter of the data receiving apparatus of the present embodiment shown in FIG. 1 performs the above-described processing in accordance with the number of cells from the reference cell to the cell where the next display between users becomes one. A, Process B and Process C are performed, and when the process for the CPSC-PDU is completed, the same process is repeated with the cell immediately after the completed CPSC-P DU as the next reference cell ( (See Figure 8).

As described above, in the present embodiment, the intermediate data unit CPSC-PDU can be correctly assembled even when the display between users is incorrect due to an error in the cell header. Also, when cells constituting the CPSC-PDU are missing, the data of the TS bucket to be discarded can be minimized.

Further, the present invention is not limited to the above-described specific embodiments, and various modifications can be made within the scope of the basic technical idea.

In the above embodiment, one intermediate data unit CPSC—PDU is divided into eight ATM cells, and the boundary ATM cell identification information between ATM layers is displayed by the last ATM cell among the eight ATM cells. What was the last ATM cell identification information that distinguished whether or not it is ^? Conversely, whether it was the first ATM cell among the eight ATM cells The head ATM cell identification information to be distinguished may be used. In this case, the cell synchronization unit 1 may receive the ATM cell as the received data and supply this head ATM cell identification information to the inter-user display inspection unit 4. Not to mention that.

In the above-described process D, a process for improving the reliability of the TS bucket extracted from the temporary CPSC-PDU may be added. For example, it is conceivable to extract TS packets only if there are no cell header errors for all eight ATM cells that make up the temporary CPSC-PDU. This ensures that the possibility of bit errors in the CPSC-PDU is low, and improves the reliability of the extracted TS bucket.

Also, in process E described above, the cell header of the cell with the user indication of 1 and the 7 cells immediately before it are treated as the temporary CPSC-PDU, even if the indication between the users is 0, there is an error in the cell header of that cell. If this is confirmed in another step between step 121 and step 122, the cell and the seven cells immediately before it are used as a temporary C PSC-PDU, and the CRC An inspection may be performed. This makes it possible to correctly assemble the CPSC-PDU even if the display between users is incorrect.

Next, a second embodiment of the present invention will be described. FIG. 14 shows the ATM-TS converter of the data receiving device of the present embodiment.

In the present embodiment shown in FIG. 14, a TS bucket PID acquisition unit 11 and a PID comparison unit 12 are added to the ATM-TS conversion unit of FIG. 1, and the data discard information is transmitted to the TS bucket filter control unit 80 of FIG. This is configured by using a TS bucket filter control unit 81 to which a function of outputting a is added. Hereinafter, the TS bucket PID acquisition unit 11, the PID comparison unit 12, and the TS bucket filter control unit 81 will be described.

If the TS bucket synchronization byte inspection unit 6 detects that the synchronization byte (synchronization pattern) of the specific pattern of the TS bucket header to be discarded is correct, the TS bucket PID acquisition unit 11 Get the PID (bucket identification field data) in the TS bucket header.

In the PID comparison unit 12, the PID acquired by the TS packet PID acquisition unit 11 and the PID of the TS bucket storing the video data of the program selected by the data receiving device at that time (hereinafter referred to as video PID) ) As well as the PID of the TS bucket in which audio data is stored (hereinafter referred to as audio PID). As a result of these comparisons, if the PID acquired by the TS bucket PID acquisition unit 11 is equal to the video PID or the audio PID, the PID comparison unit 12 outputs the video data discard information and the audio data discard information, respectively. I do. The video data discard information and the audio data discard information are respectively supplied to the video decoder 922 and the audio decoder 923 of the TS decoder 92. (See Figure 7). The video PID and the audio PID are provided from the TS decoding unit 92 (see FIGS. 5 and 7), similarly to the program time information PCR_PID described later.

In particular, when performing data discarding, the TS packet filter control unit 81 transmits the presence / absence of data discarding to the subsequent TS decoding unit 92 (see FIGS. 5 and 7) as data discarding information. The TS decoding section 92 receives the data discard information and performs a data discard handling process in response to the data discard information.

As described above, in this embodiment, the TS decoding unit 92 (see FIGS. 5 and 7) at the subsequent stage can be notified in advance that the time axis of the TS will be discontinuous due to data discarding. It is possible to minimize the adverse effect on video and audio decoding due to discontinuity. Also, by transmitting video data discard information and audio data discard information to the video decoder and audio decoder, respectively, it is possible to take countermeasures against data discard in advance, and to minimize the impact of data discard. It becomes possible. As a result, it is possible to reduce the adverse effect on the TS caused by the loss or error of the ATM cell.

In this embodiment, in the PID comparison unit 12, the force ^s shown when the PID to be compared with the PID of the TS packet to be discarded is a video PID and an audio PID, and the PID to be compared is limited to these two. It is not something to be done. For example, if one program of TS consists of video, audio, and other elements, it is possible that the PID of the TS bucket in which that element is stored can also be compared. Needless to say.

Next, a third embodiment of the present invention will be described. FIG. 15 shows the ATM-TS conversion unit of the data receiving device of the present embodiment. In this embodiment, a dummy packet indicating the discontinuity of the time axis of the TS is inserted into the TS instead of the data discard information by adding the dummy-bucket generation unit 10 to the ATM-TS conversion unit of FIG. is there.

In the dummy bucket generation unit 10, when discarding TS bucket data in the ATM-TS conversion unit, the PID of the TS packet storing the currently selected program time information PCR (Program Clock Reference) is stored. (Hereinafter referred to as PCR-PID) as a dummy TS bucket having a PID. Also, this dummy bucket is no. After the first 4 bytes of the TS bucket header, there is an adaptation-field ¾r, and the discontinuity of the adaptation-field W is one indicator (Koren fec table /: 1. The PCR-PID is TS This is provided from the decoding unit 92 (see FIGS. 5 and 7) In the TS bucket filter unit 71, the TS bucket extracted from the CPSC-PDU and the dummy bucket generated by the dummy bucket generation unit 10 The switching timing is controlled by the TS bucket filter control unit 81. In this embodiment, the information indicating the discontinuity of the time axis is embedded in the TS using the dummy bucket, thereby transmitting the data discard to the TS decoding unit without changing the processing of the Ts decoding unit. It becomes possible.

As described above, the components constituting the ATM-TS converter described in detail for the various embodiments of the present invention do not necessarily need to be dedicated hardware. For example, using hardware such as a CPU (Central Processing Unit) and a memory (Memory Unit), the functions of each component are realized by software such as a subroutine program of an application program stored in the memory. Is also possible.

According to the embodiment of the present invention, it is possible to configure a correct CPSC-PDU even when the display between users is incorrect. Also, by examining the synchronization byte of the TS bucket in the CP SC-PDU, it becomes possible to extract the TS packet from the CP SC-PDU with cell loss. Therefore, the amount of data discard can be minimized.

Furthermore, when discarding data, it is possible to minimize the adverse effects of data discarding by notifying the video decoder and audio decoder in the TS decoder after the ATM-TS converter of the data discard. Becomes

Therefore, according to the embodiment of the present invention, the quality of video and audio output in TS can be improved.

According to the present invention, it is possible to provide a data receiving apparatus capable of reducing an error in assembling one intermediate data unit CP SC-PDU due to an error in a cell header of an ATM cell as received data. . Industrial applicability

INDUSTRIAL APPLICABILITY The present invention can be used for a data receiving device of a data transmitting / receiving system that transmits / receives a stream obtained by multiplexing data such as video and audio in the ATM cell system. In particular, a data receiving device that receives video and audio data multiplexed by TS (Transport Stream) defined by the MPEG2 (Moving Picture Experts Group 2) system standard, and then divides the data into ATM cells and receives the transmitted data Applicable to

Claims

The scope of the claims

. In the transmission side, constitute an error detection code ^Detaka? Appended one intermediate Detayuni' bets from a plurality of transfer packets including a header and encoded data to the packet, by resolution of the intermediate Detayuni' bets該Hi convex A plurality of cell data including a cell header and a sequence of data are configured and transmitted, and each of the cell headers of the plurality of cell data has corresponding cell data transmitted from the one intermediate data unit. Boundary cell identification information indicating whether the cell data is one of the first cell data and the last cell data of the plurality of cell data, and

A data receiving device for receiving the transmitted plurality of cell data, wherein the data forming unit comprises one interrogation data unit to which error detection code data is added from the plurality of received cell data. When,

An error checking unit for checking an error from the error detection code data added to the one intermediate data unit configured by the data configuration unit;

A bucket forming unit forming a plurality of transfer buckets including the header and the coded data from the one intermediate data unit by the above-mentioned receiving structure, and the boundary cell identification of the plurality of received cell data; In response to the information, the boundary cell identification information indicates that the reception cell data is the boundary cell, and then the next boundary cell identification information indicates that the subsequent reception cell data is the boundary cell. A counting unit for counting the number of cells of the received cell data,

When the number of count cells in the Ji recording component matches the number of cells of the plurality of cell data constituting the one intermediate data unit on the transmitting side, it is determined that no error is detected from the error detection unit. In response, the above-mentioned interrogative data unit composed of the data constituent unit is transferred to the bucket constituent unit, and the plurality of transfer packets are formed.

The number of count cells of the above-mentioned force count forms the above-mentioned one intermediate data unit on the transmitting side. 1. When the number of cells of the plurality of cell data is smaller than the number of cells of the plurality of cell data, the number of the count cells is small. Responds to the test result that the header of the received cell data has an error by the error detection code data of the cell header of the cell data, and no error is detected from the error detection unit. In response to this, the one [Pi] data unit composed of the data configuration unit is transferred to the bucket configuration unit, and the plurality of transfer packets are configured. Data receiver.

A transfer for checking whether or not the synchronous pattern strength ^{f of the} bucket header of the transfer bucket composed of the one intermediate data unit according to the reception configuration in the bucket forming unit ^f matches a predetermined pattern. It further comprises a packet synchronization pattern inspection unit,

The number of force cells in the power point unit is equal to the one intermediate delay on the transmitting side. When the number of cells of the plurality of cell data constituting the nit is smaller than the number of cells of the plurality of cell data, it is required that the cell header of the received cell data has no error by the error detection code data of the cell header of the received cell data having the small number of counted cells. In response to the inspection result, the number of cells in the counting unit is more than half the number of cells of the plurality of cell data constituting the one intermediate data unit on the transmitting side. In response to the inspection output of the transfer packet synchronization pattern inspection unit, a transfer including a synchronization pattern that matches the predetermined pattern among the plurality of transfer buckets composed of the one intermediate data unit. The partial data of the above-mentioned one intermediate data unit corresponding to the packet is transferred to the above-mentioned bucket constituting section, and the above-mentioned predetermined pattern and Match the data receiving apparatus according to claim 1, characterized in that it is made arsenide Symbol transfers packets Toga構 containing the synchronization pattern.

A data decoding unit that decodes the plurality of transfer buckets configured by the bucket configuration unit into desired program data;

In the above-mentioned packet forming unit, the above-mentioned transfer is performed when the synchronization pattern of the packet header of the above-mentioned packet header of the above-mentioned transfer packet composed of the above-mentioned one intermediate data unit by the above-mentioned reception and structure matches the above-mentioned predetermined pattern. When inspected by the packet synchronization pattern inspection unit, the packet data of the plurality of transfer packets stored with the field data for bucket identification of the bucket header of the transfer packet and the program data of the selected program ^f. An identification field comparison unit that compares the data with the field data for identification.

Among the plurality of transfer buckets composed of the one intermediate data unit, the partial data of the one intermediate data unit corresponding to the transfer packet including the synchronization pattern that matches the predetermined pattern is the bucket. is transferred to the component, when it is the transfer bucket ^crossing? configuration including the synchronization pattern consistent with the predetermined pattern, data other than the one intermediate Detayuni' DOO data sac Chi the partial data transfer packets Are not effectively used due to the composition of the

When the data other than the partial data is effectively discarded, the identification field comparing unit detects a match between the two packet identification field data with respect to the effective discard data. 3. The data receiving apparatus according to claim 2, wherein, in this case, the detection result of the effective discard match is transmitted to the data decoding unit.

On the transmitting side, one intermediate data unit to which error detection code data is added is composed of a plurality of transfer packets including a packet header and encoded data, and the cell header and the data are divided by dividing the one intermediate data unit. A plurality of cell data including a column and the like are configured and transmitted, and each cell data of the above plurality of cell data is read. Indicates whether the corresponding cell data is a boundary cell of one of the first cell data and the last cell data of the above plurality of cell data composed of the one intermediate data unit. Including boundary cell identification information;

A data receiving device for receiving the transmitted plurality of cell data, comprising: a data constituent unit forming one intermediate data unit to which an error detection code data is added from the plurality of received cell data;

An error checking unit for checking an error from the detection code data added to the one intermediate data unit configured by the data configuration unit;

A packet configuring unit configured to form a plurality of transfer buckets including a bucket header and encoded data from the one intermediate data unit according to the reception configuration, and responding to the boundary cell identification information of the plurality of received cell data; After the boundary cell identification information indicates that the reception cell data is the boundary cell, the reception cell data until the next boundary cell identification information indicates that the subsequent reception cell data is the boundary cell. And a counting unit for counting the number of cells of

When the number of count cells in the counting unit matches the number of cells of the plurality of cell data constituting the one intermediate data unit on the transmitting side, a response is returned to the error detecting unit that no error is detected. intermediate Detayuni' DOO above SL one constituted by the de one data structure portion is transferred to the bucket preparative component is composed of the plurality of transfer buckets crossing ^s and,

When the number of count cells in the counting unit is larger than the number of cells of the plurality of cell data constituting the one intermediate data unit on the transmitting side, the number of counting cells in the counting unit is one in the transmitting side. Inspection result that the cell header of the received cell data has an error due to the detection code data of the cell header of the received cell data that matches the number of cells of the plurality of cell data constituting the intermediate data unit of the above in response to further error power from the error check ^unit? intermediate Detayuni' preparative defined above which is constituted by the data structure portion in response one can not be detected is transferred to the path Kek preparative component, said plurality of transfer A data receiving device comprising a bucket.

A transfer packet for checking whether or not a synchronization pattern of the bucket header of the transfer bucket composed of the one intermediate data unit according to the reception configuration in the bucket configuration unit matches a predetermined pattern. Further comprising a synchronous pattern inspection unit,

When the number of count cells in the counting section is smaller than the number of cells of the plurality of cell data constituting the one intermediate data unit on the transmitting side, the cell header of the received cell data having the smaller number of counted cells is used. Responds to the test result that the cell header of the received cell data has no error with the error detection code data of Responds that the number of counted cells in the counting section is equal to or greater than half the number of cells of the plurality of cell data constituting the one intermediate data unit on the transmitting side, and further includes the transfer packet synchronization pattern. In response to the inspection output of the inspection unit, one of the plurality of transfer buckets composed of the one intermediate data unit corresponding to the transfer packet including the synchronization pattern that matches the predetermined pattern. 5. The transfer packet according to claim 4, wherein partial data of an intermediate data unit is transferred to the bucket configuring unit, and the transfer packet including the synchronization pattern matching the predetermined pattern is configured. Data receiving device.

According to the reception / configuration in the packet configuration section, the synchronization pattern of the bucket header of the transfer bucket composed of one intermediate data unit matches the predetermined pattern. ⁵ 'The transfer packet When the packet is inspected by the synchronization pattern inspection unit, the packet identification field data of the bucket header of the transfer packet and the packet identification field data of a plurality of transmission packets storing the program data of the selected program are stored. And an identification field comparing unit for comparing

The partial data of the one intermediate data unit corresponding to the transfer packet including a synchronization pattern that matches the predetermined pattern among the plurality of transfer buckets composed of the one intermediate data unit. Is transferred to the above-mentioned bucket constituting unit, and when the above-mentioned transfer bucket including the above-mentioned synchronization pattern matching the predetermined pattern is formed, the above-mentioned portion of the data of the one intermediate data unit is generated. Data other than data is not effectively used due to the configuration of the transfer packet, but is effectively destroyed.

When the above data other than the above partial data is effectively discarded, the discrimination field ratio of 1¾ is higher, and the values of the above two packet discrimination field data are obtained for child discard data. 6. The data receiving device 1a according to claim 5, wherein in the case, the detection result of the effective discard-match is sent to the data recovery device SΓ, ΐ.

On the transmitting side, one intermediate data unit to which error detection code data is added is composed of a plurality of transfer packets including a packet header and encoded data, and the cell header and data are divided by dividing the one intermediate data unit. A plurality of cell data including a column is composed and transmitted, and each cell header of the plurality of cell data has a corresponding cell data composed of the one intermediate data unit. Boundary cell identification information indicating whether the boundary cell is one of the first cell data and the last cell data, A data receiving device for receiving the transmitted plurality of cell data, comprising: a data constituent unit forming one intermediate data unit added with error detection code data from the plurality of received cell data;

When the number of count cells of the counting unit matches the number of cells of the plurality of cell data constituting the one intermediate data unit on the transmission side, it is determined that no error is detected from the error detection unit. In response, the one intermediate data unit configured by the data configuration unit is transferred to the bucket configuration unit, and the plurality of transfer buckets are configured.

When the number of count cells of the counting section is smaller than the number of cells of the plurality of cell data constituting the one intermediate data unit on the transmitting side, the number of count cells is smaller than the number of cell headers of received cell data. The error detection code data responds to the check result indicating that there is an error in the cell header of the received cell data, and further comprises the data configuration unit in response to no error being detected from the error check unit. The one intermediate data unit that has been transferred is transferred to the bucket forming unit, where the plurality of transfer buckets ^s ′ are formed, and

When the number of count cells in the counting unit is larger than the number of cells of the plurality of cell data constituting the one intermediate data unit on the transmitting side, the number of counting cells in the counting unit is one in the transmitting side. Inspection that there is an error in the cell header of the received cell data according to the error detection code data of the cell header of the received cell data that matches the number of cells of the plurality of cell data constituting the intermediate data unit of the above. In response to the result, and further, in response to the error power s not being detected by the error checking unit, the one intermediate data unit formed by the data forming unit is transferred to the packet forming unit, and the plurality of intermediate data units are transferred to the packet forming unit. A data receiving device comprising a transfer bucket.

Transfer packet synchronization for checking whether or not the above-mentioned bucket header synchronization pattern of the above-mentioned bucket header of the above-mentioned bucket composed of the above-mentioned one intermediate data unit by the above-mentioned reception unit matches with the predetermined pattern. It further comprises a butterfly inspection section, When the number of count cells in the counting section is smaller than the number of cells of the plurality of cell data constituting the one intermediate packet on the transmitting side, the number of count cells is small. In response to the test result indicating that there is no error in the cell header of the received cell data by the error detection code data of one of the cell headers, In response to the fact that the number of cells of the plurality of cell data constituting the one intermediate data unit is equal to or more than half the number of cells, and in response to the inspection output of the transfer packet synchronization pattern inspection unit, The one intermediate data unit corresponding to a transfer packet including a synchronous pattern matching the predetermined pattern among the plurality of transfer packets composed of the one intermediate data unit. 8. The transfer packet according to claim 7, wherein the partial data of the packet is transferred to the packet forming unit, and the transfer packet including the synchronization pattern matching the predetermined pattern is formed. Data receiving device.

The transfer packet synchronization pattern checking unit that the bucket synchronization pattern of the bucket header of the transfer bucket composed of the one intermediate data unit by the reception and configuration in the bucket configuration unit matches the predetermined pattern. When the packet is inspected in the above step, the packet identification field data of the bucket header of the transmission bucket is compared with the packet identification field data of a plurality of transmission packets storing the program data of the selected program. An identification field comparing unit,

Among the plurality of transfer buckets composed of the one intermediate data unit, the partial data of the one intermediate data unit corresponding to the transfer packet including the synchronization pattern that matches the predetermined pattern is the bucket. When the transfer bucket force ⁵ ′ is transferred to the packet configuration unit and includes the synchronous pattern matching the predetermined pattern, the portion of the data of the one intermediate data unit is formed. Data other than data is not effectively used due to the configuration of the transfer packet, but is effectively discarded.

When effectively discarding the data other than the partial data, if the identification field comparing unit detects a match between the two packet identification field data with respect to the effective discarded data, the effective discarding is performed. 9. The data receiving apparatus according to claim 8, wherein a detection result of the coincidence is transmitted to the data decoding unit.