JP2005223682A - Transmission/reception system, transmitter and transmitting method, receiver and receiving method, transmitter/receiver and transmitting/receiving method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To more easily perform more accurate communication. <P>SOLUTION: A transmitter 11 divides data for transmission to generate packet data, performs four arithmetic operations on a Galois field using the packet data, converts the packet data into conversion data to be actually transmitted, and then packetizes the converted data using a predetermined protocol such as UDP to transmit the data. A receiver 13 receives the packets supplied from the transmitter 11 and extracts the conversion data, and restores the original transmission data using the received converted data. In this case, the transmitter 11 transmits the conversion data whose number is equal to or larger than the number of data required for restoring the original data by the receiver 13 to the receiver 13, and the receiver 13 receives the conversion data whose number is at least the number required for restoring the original transmission data. This is applicable to a communication system, for example. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a transmission / reception system, a transmission apparatus and method, a reception apparatus and method, a transmission / reception apparatus and method, and a program, and in particular, a transmission / reception system capable of performing transmission / reception of data more accurately and easily, The present invention relates to a transmission device and method, a reception device and method, a transmission and reception device and method, and a program.

  Conventionally, in data communication, in order to transmit and receive data accurately, a transmission-side apparatus adds information for checking parity bits and the like to data, and a reception-side apparatus ensures that the received data is correct information. There is a method of performing error detection and correction processing.

  There are various methods of error detection and correction processing. For example, the syndrome is calculated by the syndrome registers S0, S1 to S (n-1), and after the calculation is completed, the syndrome register S0 has a single error. The values are loaded into the syndrome registers S1 to S (n-1) and the values of the syndrome registers S1 to S (n-1) are loaded into the data registers R1 to R (n-1), respectively, and the syndrome registers S1 to S (n -1) is used to calculate the power of α,..., Α (n-1), the values of the syndrome registers S1 to S (n-1) match the values of the data registers R1 to R (n-1) The count operation is performed in synchronization with the power operation, the count value at the time of coincidence detection is set as the data position containing the error, and the value of the syndrome register S0 is set as the magnitude of the error to correct the error. How to do it, In the data format, the identification data provided for each inner code sequence does not have 0, and when the decoded data is error-corrected by the outer code, 0 is continuously included in the data for a certain number or more. If it exists, it is determined whether it is the original data or an error state using the identification data, and if it is determined that the data having the value of 0 is in an error state, an inner code When an error flag is set in a sequence and error correction is performed using an outer code, if the number of data in the outer code sequence in which the error flag is not set is equal to or less than the normal error correction capability Q of the outer code, There is a method of forcibly converting data of Q + 1 or more into another value so that error correction of the data of the outer code sequence is not performed (see, for example, Patent Document 1 and Patent Document 2). .

  The above method is a method for correcting the error and restoring the correct data when the data received by the receiving device includes an error. For example, the receiving device cannot receive the data. (Lost) data cannot be recovered.

  In data communication, for some reason, a part (or all) of a packet group (data) transmitted by a transmission side device may not be received by the reception side device and may be lost.

  As a process for such a packet loss, for example, there is a method in which a receiving device that has lost a packet makes a retransmission request for the lost packet to a transmitting device. In other words, there is a method in which the receiving device has the lost packet transmitted again to the transmitting device and receives it again. Also, when the transmission side device transmits data using a communication medium that can only communicate in one direction, such as a satellite line, the retransmission request is different from the line used for transmission / reception of the first packet. There is also a method using a line.

  Further, for example, as shown in FIG. 1, when the transmission side apparatus repeatedly transmits the same data, and the reception side apparatus loses a packet, the data is transmitted from the next transmission (packet group). There is also a method using a carousel system that receives lost packets and restores data.

  FIG. 1 is a diagram illustrating an example of how a receiving device receives data. Since the transmission side device repeatedly transmits the same data 1, the reception side device repeatedly receives the same data, such as data 1A, data 1B, data 1C, and data 1D. Therefore, for example, even when the packet loss 2A occurs when the data 1A is received, the receiving side apparatus corresponds to the lost packet (packet loss 2A) of the data 1B to be received next. If the packet 2B is received, the data 1 can be restored using the packet 2B. Further, even if the packet 2B is lost when the data 1B is received, the receiving device can receive the packet 2C corresponding to the packet loss 2A of the data 1C to be received next. The data 1 can be restored using the packet 2C. Further, even when the packet 2C is lost, the receiving device only needs to receive the packet 2D. In this way, the receiving-side apparatus can receive each packet in at least one of the repeated transmissions, and if all packets can be received as a result, restores data 1. be able to.

Japanese Patent No. 3170920

Patent 3271208

  However, in the case of the method for making a retransmission request as described above, for example, in the case of communication for transmitting data to a plurality of devices such as multicast, each device on the receiving side includes each device on the receiving side. Since the retransmission requests from the receivers are concentrated, there is a problem that the processing load on the transmission side apparatus increases, and there is a possibility that the transmission processing cannot be performed normally.

  Also, in the case of the carousel communication as described above, as shown in FIG. 1, when a packet loss 2A occurs when receiving data 1A, the receiving-side apparatus transmits data 1B as the next transmission. It is necessary to wait until the packet 2B corresponding to the packet loss 2A is received. That is, in this case, the reception processing time in the receiving device becomes longer by the time required to receive the data 1, and the load of the receiving processing in the receiving device increases. there were. That is, as shown in FIG. 1, when a packet loss 2A occurs, the receiving device receives the packet 2B to be transmitted next (the time required for the receiving device to receive data 1). ) It is necessary to wait and reception processing time increases. Further, when the packet 2B is lost, the receiving device needs to further extend the standby time and wait until the next packet 2C is received.

  The present invention has been made in view of such a situation, and makes it possible to transmit and receive data accurately and more easily.

  The transmission / reception system of the present invention is a transmission / reception system including a transmission device that transmits transmission data and a reception device that receives transmission data transmitted by the transmission device, and the transmission device divides the transmission data. To generate a plurality of first data, and synthesize the plurality of generated first data by an operation on a predetermined Galois field to obtain a plurality of second data independent of each other. Each of the plurality of second data is packetized and transmitted to the receiving device, and the receiving device receives and receives the plurality of second data more than the number of the first data corresponding to the second data. Second data equal to or greater than the number of first data corresponding to the second data is retained, and the second data equal to or greater than the number of first data corresponding to the second data is retained. , Operations on Galois fields Performed, characterized in that to restore the first data corresponding to the second data.

  The transmission apparatus according to the present invention includes a data generation unit that generates a plurality of first data by dividing transmission data, and a plurality of first data generated by the data generation unit on a predetermined Galois field. It is data for restoring the first data by combining by calculation, and is obtained by converting the plurality of first data by the conversion means for converting into a plurality of second data independent from each other. Transmitting means for packetizing each of the plurality of pieces of second data and transmitting the packeted data to a receiving device is provided.

  The converting means includes a determinant generating means for generating a determinant for converting the first data into the second data using a predetermined coefficient matrix, and a determinant generated by the determinant generating means. Is calculated on the Galois field, and a calculation means for obtaining the second data can be provided.

  Each component of the coefficient matrix is a value obtained by applying an arithmetic operation in a power-of-base Galois field that is a common natural number in each row, and the exponent of the power to obtain each component arranged in the row direction is continuous. And the base value can be different for each row.

  A coefficient matrix supply unit that holds the coefficient matrix and supplies the coefficient matrix according to the request of the determinant generation unit is further provided. The determinant generation unit generates the determinant using the coefficient matrix supplied by the coefficient matrix supply unit. To be able to.

  The row number of the coefficient matrix corresponding to the second data, which is information used to restore the first data in the receiving device, is the second data obtained by converting the first data by the converting means. The information adding means for adding the information to be included is further provided, and the transmitting means can packet each of the plurality of second data to which the information is added by the information adding means and transmit it to the receiving apparatus.

  The converting means may convert a plurality of first data into second data larger than the number of first data.

  The transmission means further includes a transmission order control means for controlling the transmission order of the plurality of second data obtained by converting the plurality of first data by the conversion means, and the transmission means is arbitrarily controlled by the transmission order control means. A plurality of second data can be transmitted to the receiving device in the determined transmission order.

  The data generation unit divides the transmission data into blocks, and further generates a plurality of first data by dividing the block. The conversion unit generates a plurality of blocks generated by the data generation unit for each block. The first data can be converted into a plurality of second data.

  The transmission method of the present invention includes a data generation step for generating a plurality of first data by dividing transmission data, and a plurality of first data generated by the processing of the data generation step by a predetermined Galois field. It is data for restoring the first data by combining by the above calculation, and a conversion step for converting into a plurality of second data independent from each other, and a plurality of the first data by the processing of the conversion step A transmission control step of controlling the plurality of second data obtained by the conversion so as to be packetized and transmitted to the receiving device.

  The first program of the present invention includes a data generation step for generating a plurality of first data by dividing the transmission data, and a plurality of first data generated by the processing of the data generation step. This is data for restoring the first data by combining by calculation on the Galois field. The conversion step converts the first data into a plurality of second data independent from each other. The computer is caused to execute a transmission control step for controlling each of the plurality of second data obtained by converting the data to be packetized and transmitted to the receiving device.

  The receiving device of the present invention is data transmitted by a transmitting device, and a plurality of independent data converted by combining a plurality of first data obtained by dividing transmission data by a calculation on a predetermined Galois field. Receiving means for receiving second data equal to or more than the number of first data corresponding to the second data, and second data equal to or greater than the number of first data corresponding to the second data received by the receiving means. Using the second data that is equal to or greater than the number of the first data corresponding to the second data, the second data held by the holding means, And a restoring means for restoring the first data corresponding to the data.

  The restoring means includes a determinant generating means for generating a determinant for converting the second data into the first data using a predetermined coefficient matrix, and a determinant generated by the determinant generating means. Can be calculated on the Galois field and provided with calculation means for obtaining the first data.

  In each row of the coefficient matrix, each component is a power that has a common natural number as a base, and each component that is continuous in the row direction is configured so that a power exponent is continuous, and is a common power that is a base of the power The natural number values of can be different for each row.

  A coefficient matrix supply unit that holds the coefficient matrix and supplies the coefficient matrix according to the request of the determinant generation unit is further provided. The determinant generation unit generates the determinant using the coefficient matrix supplied by the coefficient matrix supply unit. To be able to.

  The determinant generating unit requests only the row component corresponding to the second data received by the receiving unit from the coefficient matrix held by the coefficient matrix supplying unit, and only the row component supplied based on the request. Can be used to generate the determinant.

  The determinant generating means adds a row component to the coefficient matrix supplying means based on the information added to the second data received by the receiving means and including the row number of the coefficient matrix corresponding to the second data. The determinant may be generated using only the row components requested and supplied based on the request.

  The plurality of first data and second data are data generated for each block of data for transmission, and the receiving means is equal to or greater than the number of first data corresponding to the second data for each block. The second data is received, the holding means holds the second data received by the receiving means for each block corresponding to the second data, and the restoring means has a plurality of second data corresponding to the same block. The first data can be restored using the second data.

  The reception method of the present invention is data transmitted by a transmission apparatus, and a plurality of independent data converted by combining a plurality of first data obtained by dividing transmission data by an operation on a predetermined Galois field. A reception control step for controlling the second data so as to receive more than the number of the first data corresponding to the second data, and a first data corresponding to the second data received by the processing of the reception control step. A second step of holding second data equal to or greater than the number of data, and second data equal to or greater than the number of first data corresponding to the second data and retained by the process of the retention step. And a restoration step of restoring the first data corresponding to the second data by performing a computation on the body.

  The second program of the present invention is data transmitted by the transmission device, and is converted from each other by combining a plurality of first data obtained by dividing the transmission data by calculation on a predetermined Galois field. The reception control step for controlling the plurality of second data so as to receive more than the number of the first data to which the second data corresponds corresponds to the second data received by the processing of the reception control step. A holding step for holding second data equal to or greater than the number of first data, and second data equal to or greater than the number of first data corresponding to the second data held by the process of the holding step. The computer performs an operation on the Galois field and causes the computer to execute a restoration step of restoring the first data corresponding to the second data.

  The transmission / reception apparatus of the present invention includes a data generation unit that generates a plurality of first data by dividing transmission data, and a plurality of first data generated by the data generation unit on a predetermined Galois field. By combining by calculation, conversion means for converting into a plurality of second data independent from each other, and a plurality of second data obtained by converting the plurality of first data by the conversion means are respectively packetized. Transmitting means for transmitting to another transmitting / receiving apparatus; receiving means for receiving a plurality of second data transmitted by the other transmitting / receiving apparatus by a number equal to or more than the number of first data corresponding to the second data; Receiving means for holding second data that is equal to or more than the number of first data to which the second data corresponds, and the number of first data to which the second data corresponds, held by the holding means Less than Using the second data, performs an operation over a Galois field, characterized in that it comprises a restoring means for restoring the first data corresponding to the second data.

  According to the transmission / reception method of the present invention, a data generation step for generating a plurality of first data by dividing transmission data, and a plurality of first data generated by the processing of the data generation step, a predetermined Galois field By combining the above operations, a conversion step for converting into a plurality of second data independent of each other, and a plurality of second data obtained by converting the plurality of first data by the processing of the conversion step A transmission control step for controlling each packet to be transmitted to another transmission / reception device, and a plurality of second data transmitted by the other transmission / reception devices equal to or more than the number of first data corresponding to the second data A reception control step for controlling to receive, and a second number greater than the number of first data corresponding to the second data received by being controlled by the processing of the reception control step Using a holding control step for controlling to hold data, and second data that is controlled and held by the processing of the holding control step and is equal to or more than the number of first data corresponding to the second data, And a restoration step of restoring the first data corresponding to the second data by performing a computation on the body.

  A third program of the present invention includes a data generation step for generating a plurality of first data by dividing transmission data, and a plurality of first data generated by the processing of the data generation step, A synthesis step for converting into a plurality of second data independent from each other by synthesizing by computation on a Galois field, and a plurality of second data obtained by converting the plurality of first data by the processing of the conversion step A transmission control step for controlling each of the data to be packetized and transmitted to another transmission / reception device, and a plurality of second data transmitted by the other transmission / reception devices are converted into the first data corresponding to the second data. A reception control step for controlling to receive more than the number, and the number of the first data corresponding to the second data received by being controlled by the processing of the reception control step Using a holding control step for controlling to hold the second data, and second data that is controlled and held by the processing of the holding control step and is equal to or more than the number of first data corresponding to the second data Then, the computer performs a computation on the Galois field and performs a restoration step of restoring the first data corresponding to the second data.

  The transmission / reception system of the present invention includes a transmission device that transmits transmission data and a reception device that receives transmission data transmitted by the transmission device. In the transmission device, the transmission data is divided. A plurality of first data is generated, and the plurality of generated first data is converted into a plurality of second data independent from each other by being synthesized by an operation on a predetermined Galois field. The plurality of second data is packetized and transmitted to the receiving device. In the receiving device, the plurality of second data is received more than the number of the first data corresponding to the second data, Second data equal to or greater than the number of first data corresponding to the received second data is retained, and second data equal to or greater than the number of first data corresponding to the second data retained is retained. Use , Operation over a Galois field is performed, the first data corresponding to the second data is restored.

  In the transmission apparatus and method and the first program of the present invention, a plurality of first data is generated by dividing the transmission data, and the generated first data is stored on a predetermined Galois body. Is a data for restoring the first data by being synthesized by the above operation, converted into a plurality of second data independent of each other, and a plurality of the plurality of first data obtained by converting the plurality of first data The second data is packetized and transmitted to the receiving device.

  In the receiving apparatus and method and the second program of the present invention, a plurality of first data, which is data transmitted by the transmitting apparatus and is obtained by dividing the transmission data, is synthesized by calculation on a predetermined Galois field. The plurality of second data independent of each other converted by step (b) is received more than the number of first data corresponding to the second data, and the received second data is more than the number of first data corresponding to the second data. The second data is held, and the Galois field operation is performed using the second data that is equal to or more than the number of the first data corresponding to the held second data. Corresponding first data is restored.

  In the transmission / reception apparatus and method and the third program of the present invention, a plurality of first data is generated by dividing the transmission data, and the generated first data is stored on a predetermined Galois body. Are converted into a plurality of second data independent from each other, and a plurality of second data obtained by converting the plurality of first data are packetized to obtain other data. A plurality of second data transmitted to the transmission / reception device and transmitted by other transmission / reception devices are received and received by the second data corresponding to the second data, and the second data corresponding to the second data is received. Second data that is equal to or greater than the number of data of 1 is held, and computation on the Galois field is performed using the retained second data that is equal to or greater than the number of first data corresponding to the second data. Corresponding to the second data First data is restored.

  According to the present invention, data can be transmitted and received. In particular, data can be transmitted and received more accurately and easily.

  Embodiments of the present invention will be described below. Correspondences between constituent elements described in the claims and specific examples in the embodiments of the present invention are exemplified as follows. This description is to confirm that specific examples supporting the invention described in the claims are described in the embodiments of the invention. Therefore, even if there are specific examples that are described in the embodiment of the invention but are not described here as corresponding to the configuration requirements, the specific examples are not included in the configuration. It does not mean that it does not correspond to a requirement. On the contrary, even if a specific example is described here as corresponding to a configuration requirement, this means that the specific example does not correspond to a configuration requirement other than the configuration requirement. not.

  Further, this description does not mean that all the inventions corresponding to the specific examples described in the embodiments of the invention are described in the claims. In other words, this description is an invention corresponding to the specific example described in the embodiment of the invention, and the existence of an invention not described in the claims of this application, that is, in the future, a divisional application will be made. Nor does it deny the existence of an invention added by amendment.

  In the present invention, a transmission device (for example, the transmission device 11 in FIG. 2) that transmits data for transmission (for example, transmission data 41 in FIG. 4) and a reception device (for example, the transmission device 11 in FIG. 2) that receives transmission data transmitted by the transmission device. For example, a transmission / reception system (for example, the communication system 10 in FIG. 2) including the receiving device 13 in FIG. 2 is provided. The transmission device generates a plurality of first data (for example, the original data 43 in FIG. 4) by dividing the transmission data (for example, step S2 in FIG. 13), and the generated plurality of data The first data is synthesized by an operation on a predetermined Galois field to be converted into a plurality of second data (for example, converted data 44 in FIG. 4) independent from each other (for example, step S3 in FIG. 13). The obtained second data is packetized (for example, step S5 in FIG. 13) and transmitted to the receiving device (for example, step S7 in FIG. 13), and the receiving device receives the plurality of second data. Are received by the number of the first data corresponding to the second data (for example, step S61 in FIG. 16), and the second data equal to or more than the number of the first data corresponding to the received second data. (E.g. , Step S63 in FIG. 16), using the second data that is equal to or more than the number of the first data corresponding to the second data that is held, performs an operation on the Galois field, and corresponds to the second data The first data is restored (for example, step S65 in FIG. 16).

  In the present invention, a transmission device (for example, the transmission device 11 in FIG. 2) for transmitting transmission data (for example, the transmission data 41 in FIG. 4) to a reception device (for example, the reception device 13 in FIG. 2) is provided. . The transmission apparatus includes a data generation unit (for example, the block division unit 22 in FIG. 3) that generates a plurality of first data (for example, the original data 43 in FIG. 4) by dividing the transmission data, and data generation This is data for restoring the first data by combining the plurality of first data generated by the means by computation on a predetermined Galois field, and a plurality of second data independent of each other (for example, 4, conversion means (for example, conversion data generation unit 23 in FIG. 3) for converting into conversion data 44), and a plurality of second data obtained by converting a plurality of first data by the conversion means , Each of which is packetized (for example, step S5 in FIG. 13), and includes transmission means (for example, the UDP packetizing unit 25 to the Ethernet (R) processing unit 29 in FIG. 3) for transmitting to the receiving device.

  The conversion means uses a predetermined coefficient matrix (for example, a matrix in the first term on the right side of Expression (1)) to convert a first data into second data (for example, an expression). The determinant generating means (for example, the determinant generating unit 62 in FIG. 6) for generating (1)) and the determinant generated by the determinant generating means are calculated on the Galois field to obtain the second data. Calculation means (for example, the determinant calculation unit 64 and the Galois field calculation unit 66 in FIG. 6) can be provided.

  The apparatus further includes coefficient matrix supply means (for example, coefficient matrix supply unit 63 in FIG. 6) that holds the coefficient matrix and supplies the coefficient matrix according to the request of the determinant generation means. The determinant generation means is supplied by the coefficient matrix supply means. A determinant can be generated using the obtained coefficient matrix (for example, step S23 in FIG. 14).

  The row number of the coefficient matrix corresponding to the second data, which is information used to restore the first data in the receiving device, is the second data obtained by converting the first data by the converting means. The information adding means (for example, the header adding section 84 in FIG. 8) for adding information (for example, the line number 93 in FIG. 9) is further provided, and the transmitting means has a plurality of second information to which information is added by the information adding means. Can be packetized (for example, step S5 in FIG. 13) and transmitted to the receiving apparatus (for example, step S7 in FIG. 13).

  A transmission order control means (for example, the buffer 26 and the output control unit 27 in FIG. 3) for controlling the transmission order of the plurality of second data obtained by converting the plurality of first data by the conversion means; The transmission means may be configured to transmit the plurality of second data to the reception apparatus in the transmission order arbitrarily determined by the transmission order control means.

  The data generation means divides transmission data into blocks, and further generates a plurality of first data by dividing the blocks (for example, step S2 in FIG. 13). The plurality of first data generated by the data generation means can be converted into a plurality of second data (for example, step S3 in FIG. 13).

  In the present invention, there is a transmission method of a transmission apparatus (for example, the transmission apparatus 11 in FIG. 2) that transmits transmission data (for example, the transmission data 41 in FIG. 4) to a reception apparatus (for example, the reception apparatus 13 in FIG. 2). Provided. This transmission method divides the data for transmission (for example, step S1 in FIG. 13) to generate a plurality of first data (for example, original data 43 in FIG. 4) (for example, in FIG. 13). This is data for restoring the first data by synthesizing the plurality of first data generated by the processing of the step S2) and the data generation step by calculation on a predetermined Galois field, and is independent of each other. A conversion step (for example, step S3 in FIG. 13) for converting into a plurality of second data (for example, conversion data 44 in FIG. 4), and a plurality of first data obtained by the conversion step processing are obtained. Each of the plurality of second data is packetized (for example, step S5 in FIG. 13) and transmitted so as to be transmitted to the receiving device (for example, FIG. 3 in step S7) and a.

  In the present invention, transmission processing for transmitting transmission data (for example, transmission data 41 in FIG. 4) to a reception device (for example, reception device 13 in FIG. 2) is executed in a computer (for example, transmission device 11 in FIG. 2). A first program is provided. This first program divides the data for transmission (for example, step S1 in FIG. 13) and generates a plurality of first data (for example, original data 43 in FIG. 4) (for example, FIG. 4). 13 step S2) and data for restoring the first data by combining the plurality of first data generated by the processing of the data generation step by calculation on a predetermined Galois field, A conversion step (for example, step S3 in FIG. 13) for converting into a plurality of second data independent of each other (for example, conversion data 44 in FIG. 4), and a plurality of first data are converted by the processing of the conversion step. A transmission control step (for example, control is performed so that each of the obtained second data is packetized (for example, step S5 in FIG. 13) and transmitted to the receiving device. If, comprising the step S7) and FIG.

  In the present invention, a receiving device (for example, the receiving device 13 in FIG. 2) that receives data transmitted by a transmitting device (for example, the transmitting device 11 in FIG. 2) is provided. This receiving device is data transmitted by the transmitting device, and a plurality of first data (for example, original data 43 in FIG. 4) obtained by dividing transmission data (for example, transmitting data 41 in FIG. 4) is a predetermined Galois. A plurality of independent second data (for example, converted data 44 in FIG. 4) converted by being synthesized by computation on the body is received by the number of the first data corresponding to the second data. Receiving means (for example, the Ethernet (R) processing unit 101 to the application data extracting unit 103 in FIG. 10) and second data received by the receiving means that is equal to or more than the number of first data corresponding to the second data. Using the holding means (for example, the buffer unit 104 in FIG. 10) and the second data which is held by the holding means and is equal to or more than the number of the first data corresponding to the second data. Performs the operation of, and a first restoring means for restoring the data corresponding to the second data (e.g., packet data restoring unit 105 of FIG. 10).

  The restoration means uses a predetermined coefficient matrix (for example, the matrix of the first term on the right side of Expression (1)) to convert the second data into the first data (for example, Expression The determinant generating means (for example, the determinant creating unit 122 in FIG. 12) for generating (1)) and the determinant generated by the determinant generating means are calculated on the Galois field to obtain the first data. An arithmetic means (for example, a determinant arithmetic unit 124 and a Galois field arithmetic unit 125 in FIG. 12) can be provided.

  The apparatus further includes coefficient matrix supply means (for example, coefficient matrix supply unit 123 in FIG. 12) that holds the coefficient matrix and supplies the coefficient matrix according to the request of the determinant generation means. The determinant generation means is supplied by the coefficient matrix supply means. A determinant can be generated using the obtained coefficient matrix (for example, step S84 in FIG. 17).

  The determinant generating unit requests only the row component corresponding to the second data received by the receiving unit from the coefficient matrix held by the coefficient matrix supplying unit (for example, step S83 in FIG. 17). A determinant can be generated using only the row components supplied based on the row component.

  The determinant generating means is based on information (for example, line number 93 in FIG. 9) added to the second data received by the receiving means and including the row number of the coefficient matrix to which the second data corresponds. Thus, it is possible to request a row component from the coefficient matrix supply means and generate a determinant using only the row component supplied based on the request.

  The plurality of first data and second data are data generated for each block of transmission data (for example, the block 42 in FIG. 4), and the receiving means corresponds to the second data for each block. Second data that is equal to or greater than the number of first data to be received, the holding means holds the second data received by the receiving means for each block corresponding to the second data, and the restoring means includes: The first data can be restored using a plurality of second data corresponding to the same block.

  In the present invention, a receiving method of a receiving device (for example, the receiving device 13 in FIG. 2) that receives data transmitted by a transmitting device (for example, the transmitting device 11 in FIG. 2) is provided. This reception method is data transmitted by a transmission device, and a plurality of first data (for example, original data 43 in FIG. 4) obtained by dividing transmission data (for example, transmission data 41 in FIG. 4) is a predetermined Galois. A plurality of independent second data (for example, converted data 44 in FIG. 4) converted by being synthesized by computation on the body is received by the number of the first data corresponding to the second data. The reception control step (for example, step S61 in FIG. 16) to be controlled and the second data received by the processing of the reception control step hold second data that is equal to or more than the number of first data corresponding to the second data. Using the second data that is equal to or more than the number of the first data corresponding to the second data held by the holding step (for example, step S63 in FIG. 16) and the processing of the holding step, Performs the operation, including restoration step for restoring the first data corresponding to the second data (e.g., step S65 of FIG. 16) and.

  In the present invention, there is provided a second program for causing a computer (for example, the receiving device 13 in FIG. 2) to execute a receiving process for receiving data transmitted by a transmitting device (for example, the transmitting device 11 in FIG. 2). The second program is data transmitted by the transmission device, and a plurality of first data (for example, original data 43 in FIG. 4) obtained by dividing transmission data (for example, transmission data 41 in FIG. 4) is predetermined. The plurality of independent second data (for example, the converted data 44 in FIG. 4) converted by being synthesized by the arithmetic operation on the Galois field is equal to or more than the number of the first data corresponding to the second data. A reception control step (for example, step S61 in FIG. 16) for controlling reception, and second data that is received by the processing of the reception control step is equal to or more than the number of first data corresponding to the second data. Using the holding step (for example, step S63 in FIG. 16) to be held and the second data that is held by the processing of the holding step and that is equal to or more than the number of first data corresponding to the second data, Performs the operation on the A member, including restoration step for restoring the first data corresponding to the second data (e.g., step S65 of FIG. 16) and.

  In the present invention, a transmission / reception device (for example, the transmission / reception device 211 or the transmission / reception device 213 in FIG. 18) for transmitting / receiving transmission data (for example, transmission data 41 in FIG. 4) is provided. The transmission / reception apparatus includes a data generation unit (for example, the block division unit 22 in FIG. 3) that generates a plurality of first data (for example, the original data 43 in FIG. 4) by dividing the transmission data, and data generation Conversion means for converting a plurality of first data generated by the means into a plurality of second data independent of each other (for example, conversion data 44 in FIG. 4) by synthesizing by a calculation on a predetermined Galois field (For example, the converted data generating unit 23 in FIG. 3) and the plurality of second data obtained by converting the plurality of first data by the conversion unit are respectively packetized (for example, step S5 in FIG. 13). ) Transmitting means (for example, UDP packetizing unit 25 to Ethernet (R) processing unit 29 in FIG. 3) for transmitting to another transmitting / receiving device and a plurality of second data transmitted by the other transmitting / receiving device, Receiving means (for example, the Ethernet (R) processing unit 101 to application data extracting unit 103 in FIG. 10) that receives data equal to or more than the number of the first data corresponding to the data corresponds to the second data received by the receiving means. Holding means (for example, the buffer unit 104 in FIG. 10) that holds second data that is equal to or greater than the number of first data to be performed, and the number of first data that is held by the holding means and that corresponds to the second data A restoration unit (for example, the packet data restoration unit 105 in FIG. 10) is provided that performs an operation on a Galois field using the second data described above and restores the first data corresponding to the second data.

  In the present invention, a transmission / reception method of a transmission / reception apparatus (for example, transmission / reception apparatus 211 or transmission / reception apparatus 213 in FIG. 18) for transmitting / receiving transmission data (for example, transmission data 41 in FIG. 4) is provided. This transmission / reception method includes a data generation step (for example, step S2 in FIG. 13) for generating a plurality of first data (for example, original data 43 in FIG. 4) by dividing the transmission data, and a data generation step. A conversion step of converting a plurality of first data generated by the processing into a plurality of second data independent of each other (for example, conversion data 44 in FIG. 4) by combining them by a calculation on a predetermined Galois field. (For example, step S3 in FIG. 13) and a plurality of second data obtained by converting the plurality of first data by the process of the conversion step are respectively packetized (for example, step S5 in FIG. 13). A transmission control step (for example, the step of FIG. 13) that controls to transmit to another transmission / reception device (for example, the transmission / reception device 211 or 213 of FIG. 18). S7) and a reception control step (for example, FIG. 16) that controls a plurality of pieces of second data transmitted by other transmission / reception devices so as to receive more than the number of first data corresponding to the second data. Step S61) and a holding control step (for example, control is performed so as to hold the second data equal to or more than the number of the first data corresponding to the second data received by being controlled by the processing of the reception control step (for example, The calculation on the Galois field is performed using the second data which is controlled and held by the processing of the holding control step in step S63) of FIG. 16 and which is equal to or more than the number of the first data corresponding to the second data. Performing a restoration step (for example, step S65 in FIG. 16) for restoring the first data corresponding to the second data.

  In the present invention, a third program for causing a computer (for example, the transmission / reception apparatus 211 or 213 of FIG. 18) to execute transmission / reception processing for transmitting / receiving transmission data (for example, transmission data 41 of FIG. 4) is provided. . The third program includes a data generation step (for example, step S2 in FIG. 13) for generating a plurality of first data (for example, the original data 43 in FIG. 4) by dividing the transmission data, and data generation The plurality of first data generated by the processing of the step is synthesized by a calculation on a predetermined Galois field, thereby being converted into a plurality of second data independent of each other (for example, the conversion data 44 in FIG. 4). The conversion step (for example, step S3 in FIG. 13) and the plurality of second data obtained by converting the plurality of first data by the processing of the conversion step are each packetized (for example, the step in FIG. 13). S5) A transmission control step (for example, FIG. 1) for controlling transmission to another transmission / reception device (for example, the transmission / reception device 211 or 213 in FIG. 18). Step S7) and a reception control step (for example, FIG. 16) that controls a plurality of second data transmitted by other transmitting / receiving apparatuses so as to receive more than the number of first data corresponding to the second data. Step S61) and a holding control step (for example, control is performed so as to hold the second data equal to or more than the number of the first data corresponding to the second data received by being controlled by the processing of the reception control step (for example, The calculation on the Galois field is performed using the second data which is controlled and held by the processing of the holding control step in step S63) of FIG. 16 and which is equal to or more than the number of the first data corresponding to the second data. Performing a restoration step (for example, step S65 in FIG. 16) for restoring the first data corresponding to the second data.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 2 shows a configuration example of a communication system to which the present invention is applied.

  The communication system 10 in FIG. 2 is a network represented by a transmission device 11 that transmits data, a LAN (Local Area Network), the Internet, and the like. The communication system 10 is connected to the network 12 to which the transmission device 11 is connected, and the network 12. The reception device 13 receives data transmitted from the transmission device 11.

  When the transmission device 11 acquires content data for transmission (transmission data) such as download data supplied from the outside, the transmission device 11 divides the data for packet transmission (packet data) when the transmission data is divided and transmitted. Generate and use the packet data, perform four arithmetic operations on the Galois field to prevent overflow, convert it to conversion data to be actually transmitted, and then convert it to the specified data such as UDP (User Datagram Protocol) Packetize using protocol and send.

Note that a Galois field (a Galois extension field) is a finite number of elements, such as a set {0, 1, 2, 3, 4} of a remainder obtained by dividing an integer by a prime number (for example, 5 etc.), and four arithmetic operations Indicates a closed set, and a field having 2 ^w (2 to the power of w) element (element) (2 ^w Galois extension field) is represented as GF (2 ^w ). The transmission device 11 (reception device 13) can prevent occurrence of overflow of the calculation result by using the calculation on the Galois field.

  When receiving the packet (conversion data) supplied from the transmission device 11, the reception device 13 extracts the conversion data from the received packet, and restores the original transmission data using the received conversion data. At this time, the transmission apparatus 11 transmits more conversion data than the number necessary for the reception apparatus 13 to restore the original transmission data, and the reception apparatus 13 includes the converted data in the transmitted conversion data. To at least the number of pieces of converted data necessary to restore the original transmission data. A method for generating conversion data in the transmission device 11 and a method for restoring original transmission data in the reception device 13 will be described later.

  By doing so, the reception device 13 restores the transmission data transmitted by the transmission device 11 without making a retransmission request to the transmission device 11 even if the reception device 13 does not receive all the packets transmitted by the transmission device 11. be able to.

  FIG. 3 is a block diagram illustrating a detailed configuration example of the transmission device 11. A change in transmission data processed by the transmission apparatus 11 will be described with reference to FIG.

  In FIG. 3, the data division unit 21 of the transmission device 11 divides transmission data such as content data supplied from the outside of the transmission device 11 into blocks having a predetermined data size, and supplies the blocks to the block division unit 22. That is, the data dividing unit 21 accumulates the supplied transmission data in a buffer (not shown), and each time data of a predetermined data size is accumulated, it is used as a block in the block dividing unit 22. Supply.

  For example, in the case of FIG. 4, the transmission data 41 supplied to the transmission device 11 is divided into three blocks 42 indicated by numbers 1 to 3 by the data dividing unit 21.

  Returning to FIG. 3, similarly to the data dividing unit 21, the block dividing unit 22 further divides the transmission data in block units supplied from the data dividing unit 21 into a predetermined data size. That is, the block division unit 22 divides the transmission data in units of blocks into a data size (packet size) for packetization in the subsequent stage, and generates data for the packet (packet data). The block division unit 22 that has generated the packet data supplies it to the conversion data generation unit 23.

  For example, in the case of FIG. 4, each block 42 is divided by the block dividing unit 22 into original data 43 that is packet data having a data size when packetized. In the case of FIG. 4, each block is divided into three original data 43. For example, the block indicated by number 1 is divided into original data indicated by numbers 11 to 13, and the block indicated by number 2 is divided into original data indicated by numbers 21 to 23 and is indicated by number 3. Are divided into original data indicated by numbers 31 to 33.

  When the conversion data generation unit 23 acquires one block of packet data (original data) obtained by dividing the original transmission data, the conversion data generation unit 23 performs four arithmetic operations on the Galois field, converts the original data, and generates conversion data. Specifically, the conversion data generation unit 23 performs synthesis on the Galois field to synthesize the original data in one block by performing arithmetic operations on the Galois field to prevent overflow. A more specific generation method will be described later.

  This converted data is obtained by combining the original data in the block using four arithmetic operations on the Galois field. Further, as will be described later, a plurality of pieces of the converted data have the same data size as the original data, and a plurality of pieces of converted data are generated so that the converted data are independent from each other. Therefore, as will be described later, if the receiving device 13 can acquire a predetermined number (for example, the number of original data or more) of arbitrary conversion data, it can restore all the original data.

  For example, as shown in FIG. 4, the original data 43 is converted into converted data 44 in units of blocks. At that time, the conversion data generation unit 23 generates the conversion data 44 as many as the original data 43. In the case of FIG. 4, six converted data 44 are generated from three original data 43 in each block. For example, in the block 42 indicated by the number 1, the original data 43 indicated by the numbers 11 to 13 is converted into six converted data 44 indicated by the numbers 11 to 16, and in the block 42 indicated by the number 2, The original data 43 indicated by numbers 21 to 23 is converted into six converted data 44 indicated by numbers 21 to 26. In the block 42 indicated by number 3, the original data 43 indicated by numbers 31 to 33 is It is converted into six pieces of conversion data 44 indicated by numbers 31 to 36.

  The conversion data generation unit 23 supplies the conversion data obtained by converting the original data to the application data generation unit 24.

  The application data generation unit 24 adds a header to the conversion data supplied from the conversion data generation unit 23 to generate application data. The contents of the header will be described later. The application data generation unit 24 supplies the generated application data to the UDP packetization unit 25.

  The processes so far are the application layer, presentation layer, and session layer in the OSI layer model (Open Systems Interconnection layer model), which is a model of the seven-layer network protocol structure established by ISO (International Organization for Standardization). It is processing of.

  The UDP packetization unit 25 supplied with the application data packetizes the application data based on the UDP protocol, and supplies the generated UDP packet to the buffer 26.

  As shown in FIG. 5, the UDP packet 51 includes a 64-bit UDP header 52 and application data 53. The UDP header 52 includes information such as a transmission source port number, a transmission destination port number, a data length of the application data 53, and a checksum. The data size of the application data is a predetermined value that is arbitrarily determined, but is usually about 1 Kbyte.

  Returning to FIG. 3, the buffer 26 is configured by a semiconductor memory such as a RAM (Random Access Memory), accumulates the UDP packets supplied from the UDP packetizing unit 25, and based on the control of the output control unit 27, Output accumulated UDP packets.

  When the UDP packets are accumulated in the buffer 26, the output control unit 27 acquires the UDP packets in an arbitrary (random) order and supplies them to an IP (Internet Protocol) processing unit 28. That is, the buffer 26 and the output control unit 27 change (shuffle) the output order of the UDP packets generated in the UDP packetizing unit 25, and output the UDP packets including the converted data in an arbitrary order. At this time, the buffer 26 holds all the conversion data converted for each block, that is, all the conversion data corresponding to the transmission data, and the output control unit 27 stores all the conversion data (each conversion data). Shuffle output order).

  In general, when a packet is transmitted in a network or the like, a receiving side sometimes loses a plurality of consecutive packets in a burst manner (cannot be received). Therefore, when the transmission apparatus 11 outputs converted data in order, packet loss may be concentrated on one block due to such bursty packet loss. As will be described later, since it is necessary to receive a certain number of packets (conversion data) in order to restore the original data, if there is a bias in packet loss in this way, a specific block may not be restored. There is.

  Therefore, the buffer 26 and the output control unit 27 of the transmission device 11 shuffle the output order of the UDP packets as described above, and transmit the converted data of each block in the mixed order, thereby transmitting the packet. Even if a bursty packet loss occurs during transmission, it is possible to suppress the loss from being concentrated on a specific block, and it is possible to increase resistance to bursty packet loss. That is, the transmission device 11 can transmit data to the reception device 13 more accurately. Therefore, the communication system 10 can realize more accurate data transmission / reception.

  For example, as shown in FIG. 4, after the converted data 44 is converted into a UDP packet, the output order is shuffled and transmitted as a transmission packet 45 in an arbitrary order. In the case of FIG. 4, conversion data 44 indicated by numbers 11 to 16, conversion data 44 indicated by numbers 21 to 26, and numbers 31 to 36 corresponding to the three blocks 42 indicated by numbers 1 to 3, respectively. The conversion data 44 shown is shuffled and transmitted.

  The buffer 26 and the output control unit 27 may shuffle the transmission order of the conversion data corresponding to each block and transmit the conversion data in an arbitrary order. Therefore, the buffer 26 stores the conversion data. It goes without saying that the processing to be performed and the processing in which the output control unit 27 outputs the conversion data stored in the buffer 26 may be performed in parallel (in part or all of those processing).

  The processing by the UDP packetizing unit 25 to the output control unit 27 is processing of the transport layer in the OSI hierarchical model.

  The IP processing unit 28 performs processing of the network layer in the OSI hierarchical model, and converts each of the UDP packets supplied from the output control unit 27 into IP packets based on the IP protocol, and Ethernet (R) (Ethernet (R)) This is supplied to the processing unit 29. The Ethernet (R) processing unit 29 performs data link layer and physical layer processing based on the Ethernet (R) standard, further packetizes the IP packet supplied from the IP processing unit 28, and transmits the packet to the receiving device 13. As such, it is output to the network 12 via the cable 30.

  The packet output from the Ethernet (R) processing unit 29 is supplied to the receiving device 13 via the network 12.

  Thus, since the original data obtained by dividing the transmission data is not transmitted as it is, each is converted to conversion data including the contents of all the original data (all the original data in the block) and transmitted. The apparatus 11 can restore the original data (transmission data) if the receiving apparatus 13 acquires a predetermined number or more of the packets transmitted from the transmitting apparatus 11. . That is, the transmission device 11 can increase the tolerance of the reception device 13 against packet loss, and can transmit data so that data transmission / reception can be performed more accurately and easily.

  Note that the number of blocks 42, original data 43, converted data 44, and the like for one transmission data 41 shown in FIG. 4 is an example, and the number of pieces of data to be generated is other than the number shown in FIG. But of course. Further, the transmission order of the transmission packets 45 is also an example, and the transmission packets 45 may be transmitted in an order other than that shown in FIG.

Next, details of the conversion data generation unit 23 of FIG. 3 will be described. In the following, the transmission device 11 generates _N original data D (D _{1 to} D _N ) from one block of transmission data, converts the N original data D, and generates M pieces of original data D. A case where the conversion data S (S _{1 to} S _M ) is generated will be described. FIG. 6 is a block diagram illustrating a detailed configuration example of the conversion data generation unit 23.

  In FIG. 6, the original data supplied from the block dividing unit 22 in FIG. 3 is supplied to the original data holding unit 61 and held therein. When the original data holding unit 61 holds the original data for one block, the original data holding unit 61 supplies the original data to the determinant generation unit 62.

  When the original data for one block is acquired, the determinant generation unit 62 requests the coefficient matrix used for generation of the determinant for generating conversion data from the coefficient matrix supply unit 63. The coefficient matrix is a matrix of M rows and N columns prepared in advance and held in the coefficient matrix supply unit 63, and is a matrix for converting the original data to generate converted data. The value of each component of the coefficient matrix is determined so that the conversion data to be obtained are independent of each other. As will be described later, the total conversion data is obtained by integration of this coefficient matrix and a matrix having each original data as a component. Accordingly, each row of the coefficient matrix corresponds to different conversion data, and each component of each row is integrated with different original data.

  The coefficient matrix supply unit 63 that has requested such a coefficient matrix supplies the determinant generation unit 62 with a coefficient matrix that is held in advance in response to the request. When the determinant generation unit 62 acquires the coefficient matrix, the determinant generation unit 62 generates a determinant for generating conversion data corresponding to the block using the coefficient matrix and the original data for one block. Specifically, the matrix generation unit 62 generates a determinant as shown in the following expression (1).

In Expression (1), the first term on the right side is a coefficient matrix of M rows and N columns, which is a coefficient matrix supplied from the coefficient matrix supply unit 63. The determinant of this coefficient matrix is a van dermond determinant in which the coefficients in the row direction are not continuous, but the powers of the coefficients in the column direction are continuous (the exponent is a natural number with continuous exponents), and the Galois field The above calculation is also regular. That is, as shown in Equation (1), the component A _{ij in} the j-th row and i-th column of this coefficient matrix has a value “1” obtained by subtracting the value “1” from the column number i with the natural number r _j for each row as the base. This is a value r _j ⁽ⁱ⁻¹⁾ with “i−1” as a multiplier. Note that the value of the natural number r _j that is a common base in each row is an arbitrary natural number that is predetermined so as to be different from each other in each row. Therefore, in each row, the base value may be a continuous natural number, may not be continuous, or may not have regularity.

  Further, the multiplier value of each column has been described as “i−1” corresponding to the row number i. However, the present invention is not limited to this. For example, the first value such as “i” or “i + 1” is used. The multiplier in the column may be a value other than “0”. Further, the multiplier value of each column does not have to correspond to the row number i, and is continuous, for example, 3, 7, 9, 2,... Natural numbers may be arranged at random with respect to line numbers. However, the order is common in each row.

The second term on the right side is a matrix of the original data D (D _{1 to} D _N ), and the matrix on the left side is the converted data S (S _{1 to} S _M ) calculated by this determinant. In equation (1), multiplication is an operation on a Galois field (Gaaloa expansion field), and addition is performed by an EOR operation.

  Note that the relationship between the values of the variables M and N is M >> N. Since the generated conversion data S are independent of each other, the receiving device 13 can restore all the original data D if it receives the conversion data S more than the number of the original data D. However, since the receiving device 13 may not be able to receive some converted data S due to packet loss, the transmitting device 11 has more conversion data as much as possible, which is more than the number of original data and can realize transmission processing. S is generated. Therefore, here, the relationship between the value of the variable M indicating the number of the converted data S and the value of the variable N indicating the number of the original data D is set as described above, and the transmission device 11 has a sufficient number of conversions. Data shall be generated.

For example, if each part of the transmission device 11 performs an operation with 16 bits, the Galois field (Galois expansion field) in which the operation is performed is GF (2 ¹⁶ ), and the original is 65000 types. 65000 pieces of conversion data independent from each other can be generated. Therefore, for example, if the number of original data of each block is 2000, the transmission device 11 can transmit the conversion data packet of each block for a period of 30 times or more (65000/2000). In order to restore the original data, the receiving device 13 has only to receive any 2000 packets transmitted in this way, so that it is easy to restore the original data without requiring a retransmission request. It is. Of course, the value of the variable M may be any number as long as it is greater than or equal to the variable N, and the number of conversion data to be generated may be other than 65000.

  When such a determinant is generated, the determinant generator 62 supplies this determinant to the determinant calculator 64.

  The determinant is the same as a so-called simultaneous equation. The same applies to the following.

The determinant calculation unit 64 solves the determinant as shown in the equation (1), obtains conversion data S (S _{1 to} S _M ), and supplies the solution to the solution output unit 65. At this time, the determinant operation unit 64 causes the Galois field operation unit 66 to perform operations on the Galois field. That is, the determinant calculation unit 64 supplies the formula to the Galois field calculation unit 66 for the calculation on the Galois field. When the Galois field calculation unit 66 obtains the expression, it calculates the expression on a predetermined Galois field and supplies the calculation result to the determinant calculation unit 64.

  Here, the calculation procedure in the integration of two matrices in the case of a normal decimal number will be described. First, each row of the first term matrix is integrated with each column of the second term matrix. Specifically, each row of the first term matrix and each column of the second term matrix are integrated for each corresponding component. For example, describing the first row of the first term, the component in the i-th column of that row is integrated with the component in the i-th row of each column in the second term. When integration is performed in this way, all integration results of each component are then added for each integration. For example, if the matrix of the first term is an N-column matrix and the matrix of the second term is an N-row matrix, in each multiplication of each row of the matrix of the first term and each column of the matrix of the second term Since the integration results of N components are respectively obtained, the N integration results are added, and the addition result is the integration result of the matrix row of the first term and the matrix column of the second term. It is said.

  In the determinant of Equation (1) described above, the calculation is basically performed by the same calculation procedure as that of the calculation procedure. However, since the original data D and the EOR conversion data S are binary bit strings, the bitwise EOR calculation is used instead of the addition processing of the integration results of the components in the calculation procedure in the case of the decimal number described above. It is done. Further, since the number of digits (number of bits) of each data is fixed, as described above, the integration is performed by a calculation on a predetermined Galois field to prevent overflow. That is, all four arithmetic operations in the equation (1) are performed by a calculation on a predetermined Galois field.

The calculation method will be specifically described in the order of the calculation procedure. The determinant calculation unit 64 converts each row of the coefficient matrix of the first term on the right side of the equation (3) to the second value on the right side as in the case of the decimal number described above. It integrates with a column of a matrix of terms (a matrix having the original data D _{1 to} D _N as components). Specifically, each column component of each row of the coefficient matrix of the first term on the right side is integrated with each component (original data D _{1 to} D _N ) of the matrix of the second term on the right side by calculation on a predetermined Galois field. To do.

  Next, the determinant operation unit 64 combines the integration results of these components by EOR operation for each bit corresponding to each other as described above. Specifically, the EOR operation will be described. The value of the EOR operation result of the value “0” and the value “0” is “0”, and the value of the EOR operation result of the value “0” and the value “1”. Is “1”, the value of the EOR operation result of the value “1” and the value “0” is “1”, and the value of the EOR operation result of the value “1” and the value “1” is “0”. It is. Therefore, for example, the EOR operation result of the bit string “11110000” and the bit string “10101010” is “01011010”. The determinant operation unit 64 repeats such EOR operation and synthesizes all the integration results of the components. The EOR calculation result is used as one conversion data S.

The above calculation is repeated for each row of the coefficient matrix of the first term on the right side of Equation (3), and converted data S _{1 to} S _M shown as the components of the matrix of the first term on all the left sides are obtained.

  As described above, in the conversion data generation unit 23, as shown in FIG. 7, the original data is converted to generate conversion data.

In FIG. 7, the original data 43 (original data D _{1 to} D _N ) of one block is packet size data like the packet data 71-1 to 71-N, and as described above, the converted data generation unit 23, the converted data 44 is converted. The conversion data 44 is composed of packet data 72-1 to 72-M. The packet data 72-1 to 72-M are data generated by using the original data D _{1 to} D _N (packet data 71-1 to 71-N) and the coefficient matrix described above, respectively, and the expression (1) Is the result of the operation. For example, the packet data 72-1 which is the first conversion data 44 includes the original data D _{1 to} D _N (packet data 71-1 to 71-N) and the calculation result of the first row of the coefficient matrix described above. Yes, packet data 72-2 which is the second conversion data 44 is the original data D _{1 to} D _N (packet data 71-1 to 71-N) and the calculation result of the second row of the coefficient matrix described above. The packet data 72-M, which is the M-th converted data 44, is the original data D _{1 to} D _N (packet data 71-1 to 71-N) and the calculation result of the M-th row of the coefficient matrix described above. is there. In FIG. 7, multiplication is an operation on a Galois field, and the maximum number of digits (number of bits) of the value does not change. Addition is performed by EOR operation for each bit.

  The solution output unit 65 supplies the solution calculated as described above to the application data generation unit 24 of FIG. 3 as conversion data S at a predetermined timing.

  Next, application data will be described.

  FIG. 8 is a block diagram illustrating a detailed configuration example of the application data generation unit 24 of FIG.

  First, before the packet data is supplied, the conversion data counter 82 and the block counter 83 are initialized.

  When the conversion data is supplied from the conversion data generation unit 23, the conversion data reception unit 81 counts up the conversion data counter 82 and the block counter 83 when the conversion data is the first packet data of the block. In addition, when the conversion data supplied from the conversion data generation unit 23 is not the first packet data of the block (the conversion data of the block has already been supplied), the conversion data reception unit 81 sets only the conversion data counter 82. Count up. The conversion data counter 82 and the block counter 83 supply the count value to the header adding unit 84 at a predetermined timing.

  Moreover, the conversion data reception part 81 initializes the count value of the conversion data counter 82, after processing the last conversion data of a block.

  Furthermore, the conversion data reception unit 81 supplies the conversion data to the header addition unit 84 when each counter is adjusted. The header adding unit 84 converts the count value supplied from the conversion data counter 82 and the block counter 83 to the conversion data supplied from the conversion data receiving unit 81 as conversion data as a header, as shown in FIG. Append and generate application data.

  In FIG. 9, application data 91 includes a block number 92 added as a header, a coefficient matrix row number 93 used when generating the conversion data, and conversion data 94. The block number 92 is a number for identifying each block, and a different value is assigned to each block. The value is a count value supplied from the block counter 83. Since the conversion data generation unit 23 converts the original data into conversion data in units of blocks and supplies the conversion data to the application data generation unit 24, the block counter 83 counts blocks corresponding to the supplied conversion data. By doing so, the block number 92 can be supplied.

The row number 93 is a row number of a coefficient matrix used for calculation when generating each conversion data corresponding to each conversion data. The value is a count value supplied from the conversion data counter 82. When the conversion data generation unit 23 converts the original data into conversion data, the conversion data generation unit 23 supplies the conversion data to the application data generation unit 24 in the converted order. That is, the conversion data generation unit 23 obtains each conversion data in order from the _first conversion data S ₁ to the M-th conversion data S _M in the above-described equation (1), and in the order obtained, the conversion data Data is supplied to the application data generation unit 24. Therefore, since the conversion data generation unit 23 supplies the conversion data to the application data generation unit 24 in the order of S ₁ , S ₂ , S ₃ ,..., S _M , the conversion data counter 82 supplies the conversion data to be supplied. By counting, the count value can be supplied as the row number of the coefficient matrix corresponding to each conversion data. This count value is reset for each block.

  Such a header is added to the conversion data 94 to generate application data 91. Information included in these headers is used when the original data is restored in the receiving device 13.

  Returning to FIG. 8, as described above, the header adding unit 84 that generated the application data supplies the generated application data to the UDP packetizing unit 25.

  In this way, the application data generation unit 24 adds the block number to the converted data, so that the receiving device 13 can identify the block corresponding to the received converted data, as will be described later. can do.

  Further, the application data generation unit 24 adds the row number to the converted data, so that the receiving device 13 can associate the received converted data with the coefficient matrix when restoring the original data, as will be described later. The determinant for restoring the original data can be generated easily and accurately.

  Next, the data receiving side will be described.

  FIG. 10 is a block diagram illustrating a detailed configuration example of the reception device 13 of FIG.

  A packet transmitted to the receiving device 13 via the network 12 is supplied to the Ethernet (R) processing unit 101 via the cable 100. The Ethernet (R) processing unit 101 performs data link layer and physical layer processing based on the Ethernet (R) standard, extracts IP packets from the supplied packets, and supplies them to the IP processing unit 102.

  The IP processing unit 102 performs network layer processing based on the IP protocol, extracts a UDP packet from the supplied IP packet, and supplies the UDP packet to the application data extraction unit 103. The application data extraction unit 103 performs transport layer processing based on the UDP protocol, extracts application data from the UDP packet, and supplies it to the buffer 104.

  The buffer 104 holds application data, manages the application data in units of blocks based on the block number added to the application data, for example, when acquiring the number of application data necessary to restore the original data, They are supplied to the packet data restoration unit 105 for each block.

  The packet data restoration unit 105 restores the original data in units of blocks based on the conversion data included in the supplied application data, and supplies it to the block data restoration unit 106. The block data restoration unit 106 restores block data using the original data (packet data) supplied from the packet data restoration unit 105, and supplies the block data to the reproduction output unit 107. The reproduction output unit 107 sequentially reproduces the block data at a predetermined timing and outputs the block data as one reception data (original transmission data) to the outside of the reception device 13.

  A packet transmitted from the transmission device 11 is transmitted toward the reception device 13, but may not be received by the reception device 13 due to various causes. For example, as illustrated in FIG. 11, when nine transmission packets 111 are transmitted from the transmission packet 111 transmitted by the transmission device 11, the reception device 13 restores the original data and restores one block data. Suppose that the receiving device 13 lost the packets of numbers 3, 7, and 8 of the transmission packet 111. That is, in the received packet 112, packets with packet numbers 3, 7, and 8 are lost. When three arbitrary packets are lost from the transmission packet 111 in this way, the receiving apparatus 13 uses three packets corresponding to the same block as the lost packet in addition to the packets with the packet numbers 1 to 9 described above (see FIG. 11, the original data can be restored if the packet numbers 10 to 12 are received. That is, if the receiving device 13 can receive a necessary number of packets from among the packets transmitted by the transmitting device 11, the receiving device 13 can be any packet as long as the packet corresponds to the same block. The data can be restored. Details of the restoration processing will be described later.

  Note that the processing executed by the modules after the buffer 104 described above is processing in the application layer, presentation layer, and session layer in the OSI hierarchical model.

  As described above, the receiving device 13 can restore the original data (data for transmission) by acquiring a predetermined number or more of arbitrary packets among the packets transmitted from the transmitting device 11. That is, the receiving device 13 can improve the resistance against packet loss by restoring the original data using the converted data transmitted by the transmitting device 11, more accurately transmitting and receiving data, and Data can be received to make it easier.

  Next, restoration of lost packets will be described.

  FIG. 12 is a block diagram illustrating a detailed configuration example of the packet data restoration unit 105.

  In FIG. 12, received packet data that is application data supplied from the buffer unit 104 in FIG. 10 is supplied to the received packet data holding unit 121. When the received packet data holding unit 121 acquires a sufficient number of application data for restoring the original data for one block, the determinant creating unit 122 stores the application data (transformed data) in the received packet data holding unit 121. Is requested and acquired, and the coefficient matrix is requested from the coefficient matrix supply unit 123 and acquired. At this time, the determinant creation unit 122 requests only the row corresponding to each conversion data of the coefficient matrix based on the row number 93 included in the header of the acquired application data. The coefficient matrix supply unit 123 holds in advance a coefficient matrix that is the same as the coefficient matrix used in the transmission apparatus 11 (shown in Expression (1)), and based on the request of the determinant creation unit 122, the coefficient matrix Only the requested row components of are supplied.

  When the determinant creating unit 253 acquires each piece of information as described above, the determinant creating unit 253 creates Formula (2) that is a determinant for restoring the original data.

In Expression (2), as in Expression (1), multiplication is an operation on a Galois field, and addition indicates an EOR operation. The matrix of the first term on the left side of Equation (2) is the coefficient matrix of M rows and N columns held in advance in the coefficient matrix supply unit 123, that is, the coefficient matrix shown in the first term on the right side of Equation (1) and each matrix It is a coefficient matrix cut out from a coefficient matrix having the same component value (the same coefficient matrix as the coefficient matrix used when the transmission apparatus 11 generates conversion data). Accordingly, the coefficient matrix of the first term on the left side of the equation (2) is the same as the coefficient matrix of the equation (1), and the component A _ij in the j-th row and the i-th column is based on the natural number r _j for each row. , A value r _j ⁽ⁱ⁻¹⁾ having a value “i−1” obtained by subtracting the value “1” from the column number i as a multiplier. However, the row component of the coefficient matrix shown in Expression (2) is configured only by the row component to which the packet received by the reception device 13 corresponds (that is, the row component specified in the row number 93 of the application data). Therefore, for example, when the receiving device 13 receives arbitrary N packets among the M packets transmitted by the transmitting device 11 and restores the original data from the N packets, this equation (2) The coefficient matrix is a matrix of N rows and N columns.

The matrix of the second term on the left side of Equation (2) is a matrix having the original data D _{1 to} D _N to be restored as components, and the matrix on the right side is one of the received converted data S (S _{1 to} S _M ) As a component. That is, Equation (2) is a system of equations to the original data D ₁ to D _N variables, packet data restoring unit 105, by solving the simultaneous equations, to restore the original data D ₁ to D _N.

  The determinant creation unit 122 arranges the received conversion data S based on the row number 93 included in the header of the application data, and extracts and obtains the row component of the row number 93 of the coefficient matrix from the coefficient matrix supply unit 123. By doing so, Formula (2) is created.

When the determinant creating unit 122 creates the determinant as described above, the determinant creating unit 122 supplies it to the determinant calculating unit 124. Determinant calculation unit 124 calculates the determinant on the Galois field (Galois field), for example, using the Gaussian elimination, solving of the original data D ₁ to D _N. Any method may be used as long as it can calculate the lost original data.

When the solutions of the original data D _{1 to} D _N are obtained, the determinant operation unit 124 supplies the solutions to the solution output unit 126. The solution output unit 126 supplies the solution as original data to the block data restoration unit 106 in FIG.

  As described above, when the packet data restoration unit 105 performs the restoration process, the reception device 13 can easily restore the original data without making a retransmission request to the transmission device 11. In addition, as described with reference to FIG. 11, the reception device 13 can restore the original data by acquiring a predetermined number of arbitrary conversion data among the conversion data transmitted by the transmission device 11. Therefore, for example, even if packets are lost, it is only necessary to arbitrarily receive the same number of lost packets as compared with the case where packets are transmitted by the carousel method. The reception process can be executed at a higher speed.

  Next, the process flow of each unit described above in the transmission apparatus 11 will be described.

  When the supply of transmission data from the outside is started, the transmission device 11 starts data transmission processing. A data transmission process by the transmission device 11 of FIG. 3 will be described with reference to a flowchart of FIG.

  First, when transmission data is supplied from the outside, the data division unit 21 of the transmission device 11 divides the transmission data into blocks and supplies the divided block data to the block division unit 22 in step S1. In step S2, the block dividing unit 22 further divides the supplied block data into packet data, and supplies the packet data to the converted data generating unit 23 as original data. The following processing is performed in units of blocks.

  In step S3, the conversion data generation unit 23 supplied with the packet data executes conversion data generation processing, performs four arithmetic operations on the Galois field, converts the original data to generate conversion data, The data is supplied to the data generation unit 24. Details of the conversion data generation processing will be described with reference to the flowchart of FIG.

  The application data generation unit 24 supplied with the conversion data executes application data generation processing in step S4, generates application data, and supplies the generated application data to the UDP packetization unit 25. Details of the application data generation process will be described later with reference to the flowchart of FIG.

  The UDP packetization unit 25 supplied with the application data converts the application data into a UDP packet and supplies it to the buffer 26 in step S5. The buffer 26 temporarily holds the supplied UDP packet, and in step S6, the output control unit 27 takes out the UDP packet held in the buffer 26 in an arbitrary order, thereby changing the transmission order of the UDP packet. . The output control unit 27 supplies the extracted UDP packet to the IP processing unit 28. In step S7, the IP processing unit 28 converts the supplied UDP packet into an IP packet and supplies the packet to the Ethernet (R) processing unit 29. The Ethernet (R) processing unit 29 further packetizes the supplied IP packet. Thus, the packets (each including a UDP packet) are transmitted to the network 12 (receiving device 13) via the cable 30 in the order changed by the output control unit 27.

  Then, in step S8, the block division unit 22 determines whether or not processing has been completed for all blocks constituting transmission data supplied from the outside to the transmission device 11, and determines that the processing has not been completed. Returns the process to step S2, and repeats the subsequent processes. If it is determined that the transmission process has been completed for all blocks, the block dividing unit 22 proceeds to step S9, performs the termination process, and then terminates the data transmission process.

  The data transmission process is executed as described above. As a result, the transmission device 11 converts the original data into converted data using the four arithmetic operations on the Galois field and then transmits the converted data to the reception device 13. Therefore, the reception device 13 sends an arbitrary packet (converted data) to a predetermined value. If more than a few are received, the data can be transmitted easily and accurately so that the original data can be restored. In addition, since the transmission device 11 shuffles the transmission order of packet data and transmits the packet data in an order independent of the packet number, it is possible to increase the resistance of the reception device 13 to bursty packet loss. That is, the communication system 10 in FIG. 2 can perform more accurate communication more easily.

  Next, the conversion data generation process executed in step S3 of FIG. 13 will be described with reference to the flowchart of FIG.

  The original data holding unit 61 of the conversion data generating unit 23 supplied with the original data from the block dividing unit 22 temporarily holds the supplied original data and holds one block in step S21.

  When the original data holding unit 61 holds the original data for one block, the determinant generating unit 62 requests the coefficient matrix from the coefficient matrix supplying unit 73 in step S22. Based on the request, the coefficient matrix supply unit 63 supplies a previously prepared coefficient matrix (the matrix of the first term on the right side of the equation (1)) to the determinant generation unit 62.

  In step S23, the determinant generation unit 62 that has acquired the coefficient matrix acquires the original data for one block held in the original data holding unit 61, and generates conversion data like Expression (1). Generate a determinant for The determinant generating unit 62 that has generated the determinant supplies it to the determinant calculating unit 64.

  In step S24, the determinant operation unit 64 supplied with the determinant performs four arithmetic operations (including EOR operation) on the Galois field, calculates the determinant, and outputs the solution (transformed data S) as a solution. Supply to unit 65.

  In step S25, the solution output unit 65 outputs the supplied solution as transmission conversion data to the application data generation unit 24, returns the processing to step S4 in FIG. 13, and executes the subsequent processing.

  As described above, the conversion data generation unit 23 performs four arithmetic operations (including EOR calculation) on the Galois field using original data and a coefficient matrix prepared in advance, and generates conversion data. As a result, the transmission apparatus 11 can restore the original data (transmission data) if the reception apparatus 13 acquires a predetermined number or more of the packets transmitted from the transmission apparatus 11. be able to. That is, the transmission device 11 can increase the tolerance of the reception device 13 against packet loss, and can transmit data so that data transmission / reception can be performed more accurately and easily. Moreover, since the transmission apparatus 11 transmits after shuffling the transmission order of the packets of the conversion data, it is possible to increase the resistance of the reception apparatus 13 against bursty packet loss.

  Next, details of the application data generation processing executed in step S4 of FIG. 13 will be described with reference to the flowchart of FIG.

  For example, before the packet data is supplied, such as when the power is turned on, in step S41, the conversion data reception unit 81 of the application data generation unit 24 initializes the count values of the conversion data counter 82 and the block counter 83, respectively. Set the value to “0”.

  In step S42, the conversion data reception unit 81 determines whether conversion data has been received. If it is determined that conversion data has been received, the conversion data reception unit 81 proceeds to step S43, and the received conversion data is the first packet data in the block. It is determined whether or not. If it is determined that the packet data is the first packet data in the block, the conversion data receiving unit 81 proceeds to step S44, increments the block counter 83 to increase the count value by “1”, and proceeds to step S45. Proceed. If it is determined in step S43 that the conversion data of the block has already been received and the received conversion data is not the first packet data in the block, the conversion data reception unit 81 omits the process of step S44. Then, the process proceeds to step S45.

  In step S <b> 45, the conversion data receiving unit 81 increments the conversion data counter 82 to increase the count value by “1” and supplies the received conversion data to the header adding unit 84. In step S46, the header adding unit 84 to which the conversion data is supplied acquires count values from the conversion data counter 82 and the block counter 83, and the conversion data counter 82 uses the count value of the block counter 83 as the block number as the conversion data. Are added as row numbers (coefficient matrix row numbers corresponding to the conversion data), and the converted data to which the count values are added is supplied to the UDP packetizing unit 25 as application data in step S47.

  After completing the process in step S47, the header adding unit 84 advances the process to step S48. If it is determined in step S42 that conversion data has not been received, the conversion data reception unit 81 omits steps S43 to S47 and proceeds to step S48.

  In step S48, the header adding unit 84 determines whether or not all the conversion data of the block has been processed. If it is determined that there is still unprocessed packet data, the process returns to step S42, and the subsequent processing is performed. repeat. If it is determined in step S48 that all packet data has been processed, the header adding unit 84 ends the application data generation process and returns the process to step S5 in FIG.

  As described above, the header adding unit 84 of the application data generating unit 24 adds the block number to the converted data, so that the receiving device 13 can identify the block of the received data as described later. Can be processed in units. Further, the header adding unit 84 adds the row number to the converted data, so that the receiving device 13 restores the original data by associating the received converted data with the coefficient matrix based on the row number, as will be described later. A determinant can be generated.

  Next, the flow of processing executed by the receiving device 13 will be described.

  First, data reception processing by the receiving device 13 of FIG. 10 will be described with reference to the flowchart of FIG.

  When a packet is transmitted from the transmission device 11 to the reception device 13, and the packet is supplied to the Ethernet (R) processing unit 101 via the cable 100, the Ethernet (R) processing unit 101, in step S61, Receive the packet. The Ethernet processing unit 101 that has received the packet extracts an IP packet from the packet and supplies it to the IP processing unit 102. The IP processing unit 102 extracts a UDP packet from the IP packet and supplies it to the application data extraction unit 103.

  The application data extraction unit 103 supplied with the UDP packet extracts application data from the UDP packet and supplies it to the buffer unit 104 in step S62. In step S63, the buffer unit 104 classifies and holds the supplied application data for each block. In step S64, the buffer unit 104 determines whether or not the application data is held by the number of original data for one block. . That is, the buffer unit 104 accumulates the application data of each block for a predetermined time, and holds the application data of a predetermined number or more, the packet data restoration unit stores the application data of the target block accumulated so far in step S64. It supplies to 105.

  If it is determined in step S64 that the application data for one block has not been held yet, the buffer unit 104 returns the process to step S61 and repeats the subsequent processes. That is, the reception device 13 waits until a predetermined time elapses in the buffer unit 104 while repeating the processing of steps S61 to S64.

  In step S65, the packet data restoration unit 105 executes the original data restoration process using the supplied application data, and restores the original data from the converted data. The details of the original data restoration process will be described later with reference to the flowchart of FIG. The packet data restoring unit 105 that restored the original data supplies the restored original data to the block data restoring unit 106.

  In step S <b> 66, the block data restoration unit 106 restores block data by combining the supplied original data, and supplies the restored block data to the reproduction output unit 107. The reproduction output unit 107 temporarily holds the supplied block data, and reproduces and outputs the block data at a predetermined timing so that the block data sequentially supplied from the block data restoration unit 106 is continuously output. Thus, the block data is concatenated and output to the outside of the receiving apparatus 13 as reception data equivalent to the transmission data before transmission.

  In step S67, the reproduction output unit 107 determines whether or not to end the data reception process, and determines that all block data as one reception data has not been processed and the data reception process is not ended. The processing is returned to step S61, and the subsequent processing is repeated in each section.

  If it is determined in step S67 that the data reception process is to be terminated, the reproduction output unit 107 causes each unit to execute a termination process in step S68, and the data reception process is terminated.

  By executing the data reception process as described above, the reception device 13 can realize a high-speed restoration process with a high restoration performance without increasing the manufacturing cost. Data can be received accurately.

  Next, details of the original data restoration process executed in step S65 of FIG. 16 will be described with reference to the flowchart of FIG.

  In the receiving device 13, when the received packet data (application data) is supplied to the received packet data holding unit 121 of the packet data restoring unit 105, the received packet data holding unit 121 uses the information as a determinant creating unit 122. To supply.

  The determinant creation unit 253 starts the original data restoration process based on the information, acquires application data (conversion data) from the received packet data holding unit 121 in step S81, and acquires the application data acquired in step S82. The received conversion data is aligned with reference to the line number of the.

  In step S83, the determinant creation unit 122 obtains a necessary part (row component) from the coefficient matrix (M rows and N columns) held in the coefficient matrix supply unit 123 based on the row number of the application data. To do.

  In this process, the coefficient matrix supply unit 123 may extract a portion (row component) requested by the determinant creation unit 122 from the coefficient matrix and supply it to the determinant creation unit 122. Then, the determinant creation unit 122 may cut out a necessary portion (row component) from the coefficient matrix of M rows and N columns supplied from the coefficient matrix supply unit 123.

  That is, the determinant creation unit 122 extracts row components corresponding to the conversion data of the coefficient matrix, and acquires a new coefficient matrix having these as components.

  In step S84, the determinant creating unit 122 creates a determinant (for example, the formula (2)) for restoring the original data using the obtained coefficient matrix and the converted data, and the created determinant is This is supplied to the determinant calculation unit 124.

  In step S85, the determinant computing unit 124 computes the supplied determinant on the Galois field using the Galois field computing unit 125, and obtains a solution by a computing method such as Gaussian elimination. The solution is supplied to the solution output unit 126. In step S86, the solution output unit 125 supplies the supplied solution as original data to the block data restoration unit 106, ends the original data restoration processing, and returns the processing to step S66 in FIG.

  By performing the restoration process as described above, the packet data restoration unit 105 can realize a restoration process with high restoration performance. That is, the receiving device 13 can receive data more easily and accurately.

  As described above, in the communication system 10 shown in FIG. 2, the transmission device 11 blocks a plurality of original data generated by dividing the transmission data using the calculation on the Galois field (Gaaloa expansion field). Each of the blocks is combined and converted to generate a plurality of converted data (more than the number of original data) for each block, and transmit them to the receiving device 13. The receiving device 13 receives at least the number of original data for each block of the plurality of converted data transmitted as described above, and restores the original data using the converted data equal to or more than the number of received original data. . By doing in this way, the transmitter 11 and the receiver 13 can transmit and receive data more easily and more accurately.

  Note that such converted data is made redundant data of the original data (since each converted data includes the contents of the original data), the transmitting device 11 transmits it together with the redundant data original data, and the receiving device 13 receives them. Only when the original data is lost, the lost original data may be restored using the received redundant data. In the case of this method, it is only necessary that the original data lost by the receiving device 13 can be restored. Therefore, the transmitting device 11 can reduce the number of redundant data (converted data) to be transmitted, and the receiving device 13 If the original data is not lost, the restoration process of the original data can be omitted.

  However, it is rare that packet loss (original data loss) does not occur in actual communication. Further, in the case of this method, for example, the transmission device 11 can mutually communicate in the case of original data and the case of redundant data. A header including different contents must be added to generate and transmit two types of application data, and the receiving device 13 determines whether the received packet is a packet of original data or a packet of redundant data. And processing each as separate data, determining whether or not the original data is lost, or restoring the lost original data using the received redundant data only when the original data is lost For example, it is necessary to create a determinant for the calculation and perform an operation to restore the original data. 13 manufacturing cost of some concern that increased.

  In the case of the communication method in the communication system 10 shown in FIG. 2 described above, it is possible to easily transmit and receive data without requiring such complicated processing, and the original data as described above. Can be restored from any conversion data, so that data can be transmitted and received more accurately.

  Furthermore, in the case of the communication method in the communication system 10 shown in FIG. 2, the receiving device 13 can restore the original data from arbitrary converted data, so that, for example, the transmitting device 11 transmits a packet group including the converted data. Even if packet reception is started in the middle of the transmission, the original data can be restored if more converted data than the number of original data can be received for all blocks. This is more effective in one-to-many communication such as multicast or broadcast.

  In the above description, the communication system 10 has been described as configured by the transmission device 11 that transmits data and the reception device 13 that receives data. However, the configuration of the communication system is not limited to this, and the communication system is, for example, As shown in FIG. 18, the transmission device 11 and the reception device 13 of FIG. 1 are each configured as a module, which is a transmission unit and a reception unit, and is configured by two transmission / reception devices including both of them. Good.

  18, the communication system 201 includes a transmission / reception device 211 and a transmission / reception device 213 connected to the network 212, similar to the network 12 of FIG. 2. The transmission / reception device 211 includes a transmission unit 221 and a reception unit 222, and the transmission / reception device 213 includes a transmission unit 231 and a reception unit 232. The transmission unit 221 and the transmission unit 231 have basically the same configuration as the transmission device 11 in FIG. 2 and operate in the same manner, and thus detailed description thereof is omitted.

  In FIG. 18, the receiving unit 222 and the receiving unit 232 have basically the same configuration as the receiving device 13 in FIG. 2 and operate in the same manner, and thus detailed description thereof is omitted.

  That is, the communication system 201 in FIG. 18 includes a transmission / reception device 211 and a transmission / reception device 213 each having a built-in transmission unit and reception unit, and the conversion data obtained by converting the original data using the operations described above. By using this, communication processing is performed without retransmission control.

  In this way, even in bidirectional communication, the receiving unit can realize a restoration process that is high speed and has high restoration performance without increasing the manufacturing cost. Therefore, the transmission / reception device 211 and the transmission / reception device 213 can transmit and receive data more easily and accurately.

  In FIG. 2, the communication system 10 has been described as being configured by one transmission device 11 and one reception device 13, but not limited thereto, a plurality of transmission devices or a plurality of reception devices. An apparatus may be included.

  FIG. 19 is a diagram showing a configuration example of a content distribution system to which the present invention is applied. The server 311 of the content distribution system 301 is connected to a network 312 that is equivalent to the network of FIG. 2, and includes a plurality of terminal devices 313 and 314 that are also connected to the network 312.

  In FIG. 19, the server 311 has the same function as the transmission device 11, and transmits content data such as image data and audio data to each of the terminal device 313 and the terminal device 314 via the network 312. The data is divided, the above-described calculation is performed on the original data, and the converted data obtained by converting the original data is packetized and transmitted to the multicast.

  Each of the terminal device 313 and the terminal device 314 has the same function as that of the receiving device 13, receives each packet supplied from the server 311, restores the original data as described above, etc. Restore and play the data.

  Note that the server 311 may download and distribute the content data, or may perform streaming distribution.

  As described above, when the server 311 distributes a packet to a plurality of terminal devices 313 and 314, when the terminal device 313 and the terminal device 314 lose a packet, the retransmission request for the packet is set to the server 311. As a result, reproduction requests are concentrated on the server 311, and the load on the server 311 increases and there is a possibility that the server 311 will be down. Therefore, as described above, the server 311 generates the conversion data and distributes it, so that even if the terminal device 313 and the terminal device 314 lose the packet, the content data is not requested even if the packet is lost. Can be restored. Therefore, an increase in load on the server 311 can be suppressed, and a stable content data distribution service can be provided.

  In the above description, the data sizes (block sizes) of the blocks obtained by dividing the transmission data have been described as being common to each other. However, the present invention is not limited to this, and the blocks may of course have different block sizes. . In this case, for example, the transmission device 11 adds the block size information of the block together with the block number to the header of the application data, and the reception device 13 receives the block based on the block size information. The number of packets may be determined.

  In the above description, the transmission data, which is content data, has been described as being cut out in order from the beginning to the end of the data. However, any block cutting method may be used. However, the block generation method is determined in advance in each device of the communication system 10 or the transmission device 11 supplies the reception device 13 with information on the method, so that the transmission device 11 and the reception device 13 can generate the block. It is necessary to share. Based on the information, the reception device 13 restores the transmission data from the block by a method corresponding to the block generation method by the transmission device 11.

  Since a block is a unit of processing, it is actually preferable that the transmission apparatus 11 divides content data according to the processing flow to generate a block. Therefore, the transmission device 11 may be extracted in a discrete manner from the content data according to a certain rule according to the order of processing, for example, to form one block.

  Of course, the above-described method of transmitting converted data and the method of using a retransmission request may be used in combination. In that case, if a packet loss occurs, the receiving device first tries to restore the original data using the received converted data, and if it cannot restore, it sends a retransmission request for the lost packet to the transmission source. To do. In this way, since the number of retransmission requests can be reduced, it is possible to reduce the processing load due to the retransmission request in both the transmission side and reception side devices. That is, the load on the entire system can be reduced.

  In the above description, it has been described that the transmission device 11 performs the conversion data generation processing and the data transmission processing at the same time. However, the present invention is not limited to this. For example, the transmission device 11 acquires the transmission data in advance and uses it as described above. Of course, the converted data may be converted and stored, and the stored converted data may be supplied based on the request of the receiving device 13.

  In the equations (1) and (2), as a coefficient matrix, it is of course possible to use a matrix in which the respective components are exchanged between the above-described coefficient matrix rows and columns. However, in this case, the rows are not necessarily independent from each other, and the receiving device 13 does not necessarily obtain all the solutions (N original data can be restored from N converted data). It is necessary to receive many (as margin) packets. Then, the receiving device 13 restores N original data by building N simultaneous equations independent of each other from the received N + α packets and solving them. For example, the reception device 13 creates a determinant as described above using the received N + α conversion data, and solves it while performing pivot selection.

  In the communication system 10 of FIG. 2, the network 12 to which the transmission device 11 and the reception device 13 are connected may be partly or wholly configured by wire or may be configured by radio. Good. The network 12 may be configured by a plurality of networks. That is, the transmission device 11 and the reception device 13 may be connected via a plurality of routers or the like.

  Furthermore, the transmission device 11 and the reception device 13 may include configurations other than those described above. For example, a display unit such as a monitor may be provided, or an input unit such as a keyboard and buttons may be provided.

  The series of processes described above can be executed by hardware or can be executed by software. In this case, for example, the transmission device 11 and the reception device 13 in FIG. 2 include a personal computer as shown in FIG.

  In FIG. 20, the CPU 411 of the personal computer 401 executes various processes in accordance with a program stored in a ROM (Read Only Memory) 412 or a program loaded from the storage unit 423 to the RAM 413. The RAM 413 also appropriately stores data necessary for the CPU 411 to execute various processes.

  The CPU 411, the ROM 412, and the RAM 413 are connected to each other via the bus 414. An input / output interface 420 is also connected to the bus 414.

  The input / output interface 420 includes an input unit 421 including a keyboard and a mouse, a display including a CRT and an LCD, an output unit 422 including a speaker, a storage unit 423 including a hard disk, a modem, and the like. A communication unit 424 is connected. The communication unit 424 performs communication processing via the network 12 including the Internet.

  A drive 425 is connected to the input / output interface 420 as necessary, and a removable medium 426 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory is appropriately mounted, and a computer program read from them is Installed in the storage unit 423 as necessary.

  When the above-described series of processing is executed by software, a program constituting the software is installed from a network or a recording medium.

  For example, as shown in FIG. 20, the recording medium is distributed to distribute the program to the user separately from the apparatus main body, and includes a magnetic disk (including a flexible disk) on which the program is recorded, an optical disk ( Removable media 426 composed of CD-ROM (compact disk-read only memory), DVD (digital versatile disk), magneto-optical disk (including MD (mini-disk) (registered trademark)), or semiconductor memory In addition to being configured, it is configured by a ROM 412 in which a program is recorded and a hard disk included in the storage unit 423, which is distributed to the user in a state of being incorporated in the apparatus main body in advance.

  In the present specification, the step of describing the program recorded on the recording medium is not limited to the processing performed in chronological order according to the described order, but is not necessarily performed in chronological order. It also includes processes that are executed individually.

  Further, in this specification, the system represents the entire apparatus constituted by a plurality of apparatuses.

It is a figure explaining the data transmission method by the conventional carousel system. It is a figure which shows the structural example of the communication system to which this invention is applied. It is a block diagram which shows the structural example of the transmitter of FIG. It is a figure which shows the flow of a process of the data in the transmitter of FIG. It is a schematic diagram which shows the structural example of a UDP packet. It is a block diagram which shows the detailed structural example of the conversion data generation part of FIG. It is a schematic diagram explaining the mode of the production | generation of conversion data. It is a block diagram which shows the detailed structural example of the application data generation part of FIG. It is a schematic diagram which shows the structural example of application data. FIG. 3 is a block diagram illustrating a configuration example of a receiving device in FIG. 2. It is a figure which shows the example of a mode that a packet is lost. It is a block diagram which shows the detailed structural example of the packet data decompression | restoration part of FIG. It is a flowchart explaining the example of a data transmission process. It is a flowchart explaining the example of a conversion data production | generation process. It is a flowchart explaining the example of an application data generation process. It is a flowchart explaining the example of a data reception process. It is a flowchart explaining the example of an original data restoration process. It is a figure which shows the other structural example of the communication system to which this invention is applied. It is a figure which shows the structural example of the content delivery system to which this invention is applied. And FIG. 16 is a block diagram illustrating a configuration example of a personal computer.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Communication system 11 Transmission apparatus 12 Network 13 Reception apparatus 21 Data division part 22 Block division part 23 Conversion data generation part 24 Application data generation part 25 UDP packetization part 26 Buffer 27 Output control part 28 IP processing unit, 29 Ethernet (R) processing unit, 30 cable, 41 transmission data, 42 blocks, 43 original data, 44 conversion data, 45 transmission packet, 61 original data holding unit, 62 determinant generation unit, 63 coefficient matrix Supply unit, 64 determinant operation unit, 65 solution output unit, 66 Galois field operation unit, 81 conversion data reception unit, 82 conversion data counter, 83 block counter, 84 header addition unit, 91 application data, 92 block number, 93 Line number, 94 conversion data, 100 cable, 101 Ethernet (R) processing unit, 102 IP processing unit, 103 application data extraction unit, 104 buffer unit, 105 packet data restoration unit, 106 block data restoration unit, 107 reproduction output unit, 121 reception packet data holding unit, 122 determinant creation unit, 123 coefficient matrix supply unit, 124 determinant calculation unit, 125 Galois field calculation unit, 126 solution output unit, 201 communication system, 211 transmission / reception device, 212 network, 213 transmission / reception device , 221 transmitting unit, 222 receiving unit, 231 transmitting unit, 232 receiving unit, 301 content distribution system, 311 server, 312 network, 313 terminal device, 314 terminal device, 401 personal Computer, 411 CPU, 412 ROM, 413 RAM, 414 bus, 420 input-output interface, 421 input unit, 422 output unit, 423 storage unit, 424 communication unit, 425 drive, 426 a removable media

Claims (23)

A transmission / reception system comprising: a transmission device that transmits data for transmission; and a reception device that receives the transmission data transmitted by the transmission device,
The transmission device generates a plurality of first data by dividing the transmission data, and combines the plurality of generated first data by an operation on a predetermined Galois field, thereby Converting into a plurality of independent second data, the plurality of obtained second data, respectively packetized and transmitted to the receiving device,
The receiving device receives a plurality of the second data more than the number of the first data corresponding to the second data, and the received second data corresponds to the first data. The second data that is greater than or equal to the number of the second data is retained, and the second data that is greater than or equal to the number of the first data corresponding to the retained second data is used to perform an operation on the Galois field. The transmission / reception system characterized by restoring the first data corresponding to the second data. A transmission device that transmits data for transmission to a reception device,
Data generating means for generating a plurality of first data by dividing the transmission data;
A plurality of the first data generated by the data generating means is data for restoring the first data by combining the first data by an operation on a predetermined Galois field. A conversion means for converting the data into two data;
A transmission device comprising: a transmission unit configured to packetize and transmit a plurality of the second data obtained by converting the plurality of first data by the conversion unit to the reception device. The converting means includes
Determinant generating means for generating a determinant for converting the first data into the second data using a predetermined coefficient matrix;
The transmission apparatus according to claim 2, further comprising: a calculation unit that calculates the determinant generated by the determinant generation unit on the Galois field and obtains the second data. Each component of the coefficient matrix is a value obtained by applying an arithmetic operation to a base that is a common natural number in each row, and the exponent of the power to obtain each component arranged in the row direction is The transmitting apparatus according to claim 3, wherein the transmitting apparatus is a continuous integer and the base values are different from each other for each row. A coefficient matrix supply unit that holds the coefficient matrix and supplies the coefficient matrix according to a request of the determinant generation unit;
The transmission apparatus according to claim 3, wherein the determinant generation unit generates the determinant using the coefficient matrix supplied from the coefficient matrix supply unit. The second data corresponding to the second data obtained by converting the first data by the conversion means corresponds to the second data, which is information used to restore the first data in the receiving device. Further comprising information adding means for adding information including the row number of the coefficient matrix;
The transmission apparatus according to claim 3, wherein the transmission means packetizes each of the plurality of second data to which the information is added by the information addition means, and transmits the packetized data to the reception apparatus. The transmission device according to claim 2, wherein the conversion unit converts a plurality of the first data into the second data larger than the number of the first data. A transmission order control means for controlling the transmission order of the plurality of second data obtained by converting the plurality of first data by the conversion means;
The transmission apparatus according to claim 2, wherein the transmission means transmits a plurality of the second data to the reception apparatus in the transmission order arbitrarily determined by the transmission order control means. The data generation means divides the transmission data into blocks, and further generates a plurality of the first data by dividing the block.
The transmission device according to claim 2, wherein the conversion unit converts the plurality of first data generated by the data generation unit into a plurality of the second data for each block. A transmission method of a transmission device for transmitting data for transmission to a reception device,
A data generation step of generating a plurality of first data by dividing the transmission data;
Data for restoring the first data by combining a plurality of the first data generated by the processing of the data generation step by an operation on a predetermined Galois field, and a plurality of independent data A conversion step for converting to the second data of
A transmission control step of controlling the plurality of second data obtained by converting a plurality of the first data by the processing of the conversion step so as to be packetized and transmitted to the receiving device, respectively. A transmission method characterized by the above. In a program for causing a computer to perform transmission processing for transmitting data for transmission to a receiving device,
A data generation step of generating a plurality of first data by dividing the transmission data;
Data for restoring the first data by combining a plurality of the first data generated by the processing of the data generation step by an operation on a predetermined Galois field, and a plurality of independent data A conversion step for converting to the second data of
A transmission control step of controlling the plurality of second data obtained by converting a plurality of the first data by the processing of the conversion step so as to be packetized and transmitted to the receiving device, respectively. A program characterized by A receiving device for receiving data transmitted by a transmitting device,
A plurality of independent second data converted by combining a plurality of first data obtained by dividing the transmission data by calculation on a predetermined Galois field, which is data transmitted by the transmission device, Receiving means for receiving more than the number of the first data corresponding to the second data;
Holding means for holding the second data equal to or more than the number of the first data corresponding to the second data received by the receiving means;
Using the second data that is greater than or equal to the number of the first data corresponding to the second data, which is held by the holding means, performs an operation on the Galois field and corresponds to the second data And a restoring means for restoring the first data. The restoration means includes
Determinant generating means for generating a determinant for converting the second data into the first data using a predetermined coefficient matrix;
The receiving apparatus according to claim 12, further comprising: an arithmetic unit that calculates the determinant generated by the determinant generating unit on the Galois field to obtain the first data. In each row of the coefficient matrix, each component is a power based on a common natural number, each component that is continuous in the row direction is configured such that an exponent of the power is continuous, and at the base of the power The receiving apparatus according to claim 13, wherein the common natural number value is different for each row. A coefficient matrix supply unit that holds the coefficient matrix and supplies the coefficient matrix according to a request of the determinant generation unit;
The receiving apparatus according to claim 13, wherein the determinant generating unit generates the determinant using the coefficient matrix supplied from the coefficient matrix supplying unit. The determinant generating unit requests only a row component corresponding to the second data received by the receiving unit from the coefficient matrix held by the coefficient matrix supplying unit, and is supplied based on the request. The receiving apparatus according to claim 15, wherein the determinant is generated using only the row component. The determinant generating unit is configured to supply the coefficient matrix based on information including a row number of the coefficient matrix corresponding to the second data, which is added to the second data received by the receiving unit. The receiving apparatus according to claim 16, wherein the row component is requested from a means, and the determinant is generated using only the row component supplied based on the request. The plurality of the first data and the second data are data generated for each block of the transmission data,
The receiving means receives, for each block, the second data that is equal to or more than the number of the first data to which the second data corresponds,
The holding means holds the second data received by the receiving means for each block corresponding to the second data,
The receiving device according to claim 12, wherein the restoration unit restores the first data by using a plurality of the second data corresponding to the same block. A receiving method of a receiving device for receiving data transmitted by a transmitting device,
A plurality of independent second data converted by combining a plurality of first data obtained by dividing the transmission data by calculation on a predetermined Galois field, which is data transmitted by the transmission device, A reception control step of controlling the second data to receive more than the number of the first data corresponding to the second data;
A holding step for holding the second data equal to or more than the number of the first data corresponding to the second data, which is received by the processing of the reception control step;
Using the second data that is equal to or more than the number of the first data corresponding to the second data, which is held by the processing in the holding step, performs an operation on the Galois field, and the second data And a restoration step of restoring the first data corresponding to the receiving method. In a program for causing a computer to perform reception processing for receiving data transmitted by a transmission device,
A plurality of independent second data converted by combining a plurality of first data obtained by dividing the transmission data by calculation on a predetermined Galois field, which is data transmitted by the transmission device, A reception control step of controlling the second data to receive more than the number of the first data corresponding to the second data;
A holding step for holding the second data equal to or more than the number of the first data corresponding to the second data, which is received by the processing of the reception control step;
Using the second data that is equal to or more than the number of the first data corresponding to the second data, which is held by the processing in the holding step, performs an operation on the Galois field, and the second data A restoration step of restoring the first data corresponding to the program. A transmission / reception device for transmitting / receiving data for transmission,
Data generating means for generating a plurality of first data by dividing the transmission data;
Conversion means for converting the plurality of first data generated by the data generation means into a plurality of second data independent from each other by synthesizing by a calculation on a predetermined Galois field;
A plurality of the second data obtained by converting a plurality of the first data by the conversion means, respectively, and transmitting the packetized data to other transmission / reception devices;
Receiving means for receiving a plurality of the second data transmitted by the other transmission / reception device by the number of the first data corresponding to the second data;
Holding means for holding the second data equal to or more than the number of the first data corresponding to the second data received by the receiving means;
Using the second data that is greater than or equal to the number of the first data corresponding to the second data, which is held by the holding means, performs an operation on the Galois field and corresponds to the second data And a restoring means for restoring the first data to be transmitted and received. A transmission / reception method of a transmission / reception apparatus for transmitting / receiving data for transmission,
A data generation step of generating a plurality of first data by dividing the transmission data;
A conversion step of converting the plurality of first data generated by the processing of the data generation step into a plurality of second data independent from each other by synthesizing by a calculation on a predetermined Galois field;
A transmission control step for controlling the plurality of second data obtained by converting a plurality of the first data by the processing of the conversion step to be packetized and transmitted to the other transmission / reception devices;
A reception control step of controlling a plurality of the second data transmitted by the other transmission / reception apparatus so as to receive more than the number of the first data corresponding to the second data;
A holding control step for controlling the second data to be held in excess of the number of the first data corresponding to the second data, which is controlled and received by the processing of the receiving control step;
Performing computation on the Galois field using the second data which is controlled and held by the process of the holding control step and is equal to or more than the number of the first data corresponding to the second data, And a restoration step of restoring the first data corresponding to the second data. In a program for causing a computer to perform transmission / reception processing for transmitting / receiving data for transmission,
A data generation step of generating a plurality of first data by dividing the transmission data;
A conversion step of converting the plurality of first data generated by the processing of the data generation step into a plurality of second data independent from each other by synthesizing by a calculation on a predetermined Galois field;
A transmission control step of controlling the plurality of second data obtained by converting a plurality of the first data by the processing of the conversion step to be packetized and transmitted to the other transmission / reception devices;
A reception control step of controlling a plurality of the second data transmitted by the other transmission / reception apparatus so as to receive more than the number of the first data corresponding to the second data;
A holding control step for controlling the second data to be held in excess of the number of the first data corresponding to the second data, which is controlled and received by the processing of the receiving control step;
Performing computation on the Galois field using the second data equal to or more than the number of the first data corresponding to the second data, controlled and held by the processing of the holding control step, And a restoration step of restoring the first data corresponding to the second data.

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