JP6587361B2 - System, apparatus, method and program for transmitting digital files - Google Patents

Description

  The present invention relates to a system, an apparatus, a method, and a program for transmitting a digital file.

  A television station relay vehicle transmits video captured by a camera to a remote location for editing and / or broadcasting. For example, the relay vehicle transmits video shot by a camera from the shooting location to the television station headquarters. At this time, the relay vehicle uses an FPU (Field Pickup Unit) device or the like to transmit video. Patent Document 1 discloses a technique for transmitting video to a remote place using an FPU device.

  In a conventional transmission system that transmits video from the transmission side to the reception side using an FPU device or the like, a reproduction transmission method is used. The reproduction transmission method is a method for transmitting video reproduced by a recording / reproducing device on the transmission side to the reception side. In the reproduction transmission method, the transmission side selects and reproduces a video to be transmitted from the captured video, and the reception side displays the received video on a monitor and records the video while confirming it. In the reproduction transmission method, video is shared in real time between the transmission side and the reception side.

  In the reproduction transmission method, video is transmitted through a one-way line. The one-way line is, for example, an ASI (Asynchronous Serial Interface) line. The official name of the ASI line is DVB (Digital Video Broadcasting) -ASI line. A unidirectional line can transmit a signal only in one direction, unlike a bidirectional line such as the Internet.

  In the field of broadcast video transmission, it is not assumed that such a one-way line transmits video other than the reproduction transmission method, and such a one-way line transmits video only by the reproduction transmission method. Has only been used.

JP 2003-51963 A

  As a result of intensive studies, the inventors of the present invention have found that a one-way line can be used in a method other than the reproduction transmission system. Specifically, the inventors of the present invention have found that a one-way line is practical for digital file transmission.

  An object of this invention is to provide the system, apparatus, method, and program which can transmit a digital file reliably via a one-way line | wire.

  A system for transmitting a digital file according to the present invention includes a transmission side device and at least one reception side device connected to the transmission side device via a one-way line, and the transmission side device includes a plurality of transmission side devices. The digital file divided into segments is configured to be transmitted to each of the at least one receiving device via the one-way line, and each of the at least one receiving device transmits the digital file to the at least one receiving device. The transmission side device is configured to receive from the transmission side device via a unidirectional line, and the transmission side device and each of the at least one reception side device are connected to each other via a bidirectional line, and the transmission side The apparatus transmits transmission-related information regarding the digital file transmitted from the transmission-side apparatus to the at least one reception-side apparatus via the bidirectional line. Each of the at least one receiving side device receives reception related information regarding the digital file received by the receiving side device to the transmitting side device via the bidirectional line. Configured to transmit.

  In an embodiment of the present invention, the at least one receiving device is one receiving device.

  In one embodiment of the present invention, the reception related information includes error segment identification information for identifying a segment in which an error has occurred among the plurality of segments of the digital file received by the one receiving device, When the transmission side apparatus receives the error segment identification information from the one reception side apparatus, based on the error segment identification information, the transmission side apparatus transmits the segment in which the error has occurred via the one-way line. It is configured to transmit again to the one receiving device.

  In an embodiment of the present invention, the division of the digital file into the plurality of segments is performed by the transmission side device.

  In one embodiment of the present invention, the number of divisions when the digital file is divided into the plurality of segments is variable.

  In one embodiment of the present invention, the reception related information includes information indicating a ratio of errors that occur when the transmission side device transmits the digital file to the one reception side device, and the transmission side device includes: The number of divisions of the digital file is increased as the error ratio is larger, and the number of divisions of the digital file is decreased as the error ratio is smaller.

  In one embodiment of the present invention, the bidirectional line includes a first bidirectional line and a second bidirectional line, and the transmission side device communicates with the management device via the first bidirectional line. And the transmission-related information is transmitted to the management device via the first bidirectional line, and the one receiving side device is configured to transmit the second bidirectional line via the second bidirectional line. Connected to the management device and configured to transmit the reception related information to the management device via the second bidirectional line, the management device receiving the transmission related information and the reception Based on the related information, the transmission status of the digital file is managed.

  In one embodiment of the present invention, the management device has a function of an electronic bulletin board, the transmission side device writes the transmission related information in a text format on the electronic bulletin board, and the one reception side device The reception related information is written in a text format on the electronic bulletin board, and the management device manages the transmission status of the digital file based on the transmission related information and the reception related information written on the electronic bulletin board.

  In one embodiment of the present invention, the one-way line is, for example, an ASI line.

  In an embodiment of the present invention, the at least one receiving device is a plurality of receiving devices.

  In one embodiment of the present invention, the reception related information transmitted from one receiving device of the plurality of receiving devices is information on the plurality of segments of the digital file received by the one receiving device. Error segment identification information for identifying a segment in which an error has occurred, and when the transmission side device receives the error segment identification information from the one reception side device, based on the error segment identification information, Of the segments, the segment in which the error has occurred is configured to be transmitted again to the one receiving apparatus via the one-way line.

  In an embodiment of the present invention, the division of the digital file into the plurality of segments is performed by the transmission side device.

  In one embodiment of the present invention, the number of divisions when the digital file is divided into the plurality of segments is variable and is determined for the plurality of receiving-side apparatuses as a whole.

  In one embodiment of the present invention, the number of divisions when the digital file is divided into the plurality of segments is variable and is determined for each of the plurality of receiving-side apparatuses.

  In one embodiment of the present invention, the reception-related information transmitted from the first receiving-side device among the plurality of receiving-side devices is transmitted from the transmitting-side device to the first receiving-side device. Including information indicating a rate of errors that have occurred during transmission, and the reception-related information transmitted from a second reception-side device among the plurality of reception-side devices is received by the transmission-side device from the second reception Including information indicating a ratio of errors generated when transmitting the digital file to the side apparatus, and the transmission side apparatus increases the first error side with respect to the first reception side apparatus. The number of divisions of the digital file transmitted to the receiving side device is increased, and the number of divisions of the digital file transmitted to the first receiving side device is decreased as the error rate decreases, and the second Receiving For the device, the greater the error rate, the greater the number of divisions of the digital file transmitted to the second receiving device, and the smaller the error rate, the second receiving device. The number of divisions of the digital file to be transmitted is reduced.

  In one embodiment of the present invention, the bidirectional line includes a first bidirectional line and a second bidirectional line, and the transmission side device communicates with the management device via the first bidirectional line. And the transmission-related information is transmitted to the management device via the first bidirectional line, and each of the plurality of reception side devices is configured to transmit the second bidirectional line. Is connected to the management device via the second bidirectional line, and is configured to transmit the reception related information to the management device via the second bidirectional line. Based on the reception related information, the transmission state of the digital file for each of the plurality of receiving side devices is managed.

  In one embodiment of the present invention, the management device has a function of an electronic bulletin board, the transmission side device writes the transmission related information in a text format on the electronic bulletin board, and each of the plurality of reception side devices The reception related information is written on the electronic bulletin board in a text format, and the management device is configured to respond to each of the plurality of receiving side devices based on the transmission related information and the reception related information written on the electronic bulletin board. The transmission status of the digital file is managed.

  In one embodiment of the present invention, the one-way line is, for example, a satellite line.

  The method for transmitting a digital file according to the present invention is executed in a system comprising a transmission side device and at least one reception side device connected to the transmission side device via a one-way line, and the transmission side device And each of the at least one receiving side device are connected to each other via a bidirectional line, and the method is such that the transmitting side device transmits a digital file divided into a plurality of segments via the one-way line. Transmitting to each of the at least one receiving device, each of the at least one receiving device receiving the digital file from the transmitting device via the one-way line, and the transmitting side A device transmits transmission related information regarding the digital file transmitted from the transmission side device via the bidirectional line to the at least one reception side. And each of the at least one receiving device transmits the reception related information regarding the digital file received by the receiving device to the transmitting device via the bidirectional line. Including.

  An apparatus for transmitting a digital file according to the present invention is connected to at least one receiving apparatus via a one-way line and a two-way line, and the apparatus receives the digital file divided into a plurality of segments. Transmitting to each of the at least one receiving device via a unidirectional line, and transmission related information about the digital file transmitted from the device to the at least one receiving device via the bidirectional line. And transmitting to each of the at least one receiving-side device and receiving reception-related information related to the digital file received by the receiving-side device via the bidirectional line. Has been.

  The method for transmitting a digital file of the present invention is executed in a device connected to at least one receiving device via a one-way line and a two-way line, and the method is a digital divided into a plurality of segments. Transmitting a file to each of the at least one receiving device via the one-way line, and transmitting at least one reception information related to the digital file transmitted from the device via the bidirectional line. Transmitting to each of the side devices, and receiving from each of the at least one receiving side devices information related to the digital file received by the receiving side device via the bidirectional line. .

  A program for transmitting a digital file of the present invention is executed in a device connected to at least one receiving device via a one-way line and a two-way line, and the device includes a processor unit, and the program is , When executed, transmitting a digital file divided into a plurality of segments to each of the at least one receiving device via the one-way line, and transmission related to the digital file transmitted from the device Transmitting information to each of the at least one receiving device via the bi-directional line, and receiving related information regarding the digital file received by the receiving device from each of the at least one receiving device. Is received by the processor unit through the bidirectional line.

  The apparatus for receiving a digital file of the present invention is connected to a transmission side apparatus via a one-way line and a two-way line, and the apparatus converts the digital file divided into a plurality of segments into the one-way line. Receiving from the transmission side apparatus via the transmission side apparatus, receiving transmission related information regarding the digital file transmitted from the transmission side apparatus from the transmission side apparatus via the bidirectional line, and receiving by the apparatus The reception-related information related to the digital file is transmitted to the transmission side device via the bidirectional line.

  The method for receiving a digital file according to the present invention is executed in a device connected to a transmission-side device via a one-way line and a two-way line, and the method includes a digital file divided into a plurality of segments. Receiving from the transmission side device via a unidirectional line; receiving transmission related information regarding the digital file transmitted from the transmission side device from the transmission side device via the bidirectional line; Transmitting reception-related information regarding the digital file received by a device to the transmission-side device via the bidirectional line.

  A program for receiving a digital file according to the present invention is executed in a device connected to a transmission side device via a one-way line and a two-way line, and the device includes a processor unit, and the program is executed. Then, receiving the digital file divided into a plurality of segments from the transmission side device via the one-way line, and transmitting transmission related information regarding the digital file transmitted from the transmission side device to the bidirectional line Receiving from the transmission side device via the transmission, and transmitting reception related information regarding the digital file received by the device to the transmission side device via the bidirectional line. To do.

  According to the present invention, it is possible to provide a system, apparatus, method, and program capable of reliably transmitting a digital file via a one-way line.

1 is a diagram schematically illustrating that a system 1000 for transmitting a digital file according to the present invention transmits an image to a remote place using a one-way line. FIG. It is a block diagram which shows an example of a structure of the system 1000 for transmitting the digital file of this invention. It is a figure which shows an example of the flow of a signal in the process for transmitting the digital file in the system 1000 for transmitting the digital file of this invention. 10 is a flowchart illustrating an example of a process 400 performed by the transmission-side apparatus 210 for dividing the digital file into a plurality of segments. It is a block diagram which shows an example of a structure of the system 2000 which is an alternative structure of the system 1000 for transmitting the digital file of this invention. It is a figure which shows an example of the flow of the signal in the process for transmitting the digital file in the system 2000 for transmitting the digital file of this invention. It is a block diagram which shows an example of a structure of the system 3000 which is an alternative structure of the system 1000 for transmitting the digital file of this invention. FIG. 11 is a block diagram illustrating an example of a configuration of a system 4000 that is an alternative configuration of the system 3000 for transmitting a digital file according to the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1. System for transmitting digital files

  FIG. 1 schematically illustrates that a system 1000 for transmitting a digital file according to the present invention transmits video to a remote location using a one-way line.

  The system 1000 of the present invention transmits a digital video file from the transmission side 200 to the reception side 300. By playing back the digital video file on the receiving side 300, the receiving side 300 can view and edit the video. For example, the transmission side 200 is a relay vehicle, and the reception side 300 is a television station head office. For example, the transmission side 200 is a television station headquarters, and the reception side 300 is an affiliated television station. For example, the transmission side 200 is a destination base station (for example, a base station of a baseball field), and the reception side 300 is a television station head office.

  The transmission side 200 and the reception side 300 are connected to each other by a one-way line 400. The one-way line 400 is an arbitrary line capable of one-way communication. The one-way line 400 may be a wireless line or a wired line. The one-way line 400 may be, for example, a terrestrial microwave line using terrestrial microwaves depending on the transmission path, and may be, for example, a satellite line using satellites as described later.

  The one-way line 400 is, for example, an ASI line according to the signal format to be transmitted. The ASI line is a dedicated line assigned to each television station, in contrast to a public line such as the Internet. This dedicated line is also referred to as a private line because it is used jointly by private stations. Even when the infrastructure is down at the time of a disaster or when the Internet cannot be used in a remote place, video can be transmitted over a commercial line. The ASI line is, for example, a commercial line that can transmit signals at a maximum of 270 Mbps, a line that uses terrestrial microwaves that can transmit signals at about 30 to 50 Mbps, or a satellite line that uses satellites, as will be described later. It can be. The one-way line 400 is, for example, an SDI (Serial Digital Interface) line according to the signal format to be transmitted. The SDI line can be, for example, a commercial line capable of transmitting a signal at a maximum of 1.5 Gbps.

  The one-way line 400 includes not only a line in which only one-way communication is physically possible but also a line in which a one-way line is functionally possible. For example, a satellite line capable of bidirectional communication can be used as the one-way line 400. For example, an IP line capable of bidirectional communication (for example, a private LAN line, the Internet, etc.) can be used as a one-way line. This can be accomplished, for example, by using a protocol for utilizing the line as a one-way line.

  The transmission side 200 and the reception side 300 are connected to each other by a bidirectional line 500. The bidirectional line 500 is an arbitrary network capable of bidirectional communication. The bidirectional line 500 may be a wireless line or a wired line. The bidirectional line can be, for example, the Internet or a satellite line.

  The transmission side 200 is provided with a transmission side device 210, and the reception side 300 is provided with a reception side device 310. The transmission side device 210 includes a computer device 220 and a transmitter 230. The receiving side device 310 includes a computer device 320 and a receiver 330.

  On the transmission side 200, the video digital file is input to the computer device 220 of the transmission side device 210. For example, a digital file input to the computer apparatus 220 is stored in an arbitrary storage medium and input to the computer apparatus 220 via the storage medium. The storage medium is, for example, an optical disk, a memory card, a USB, or the like. The storage medium may be, for example, a built-in memory of a portable information terminal such as a smartphone. The digital file may be, for example, a file that records video shot by a camera installed in a relay car, or a file that records video shot by a general viewer with the camera of their mobile information terminal. May be.

  On the transmission side 200, the computer device 220 divides the input digital file into a plurality of segments. In this example, the computer device 220 divides the digital file into five segments. The number by which the computer device 220 divides the digital file is not limited to 5, and the number by which the computer device 220 divides the digital file may be any number greater than or equal to 2. Further, the number by which the computer device 220 divides the digital file may be variable or fixed.

  On the transmission side 200, the computing device 220 provides multiple segments of the digital file to the transmitter 230. At this time, the data format of the plurality of segments of the digital file provided by the computer device 220 to the transmitter 230 may be any data format. For example, computing device 220 may provide multiple segments to transmitter 230 in the form of IP packets. If the data format of the plurality of segments of the digital file is not a data format that can be transmitted by the transmitter 230, the converter built in the transmitter 230 or an external converter of the transmitter 230 transmits the data format by the transmitter 230. It may be converted into a possible data format.

  On the transmission side 200, the transmitter 230 transmits a plurality of segments of the digital file via the one-way line 400.

  On the reception side 300, the receiver 330 receives a plurality of segments transmitted from the transmission side 200 via the one-way line 400. After receiving the plurality of segments, the receiver 330 provides the plurality of segments to the computer device 320. At this time, the data format of the plurality of segments provided to the computer device 320 by the receiver 330 may be any data format. For example, receiver 330 may provide multiple segments to computer device 320 in the form of IP packets. If the data format of the plurality of segments is not a data format that can be processed by the computer device 320, the converter built in the receiver 330 or an external converter of the receiver 330 can handle the data format that can be processed by the computer device 320. You may convert it to a format.

  On the receiving side 300, the computer device 320 receives a plurality of segments and generates a digital video file by integrating the received plurality of segments.

  In this way, a digital video file can be transmitted via the one-way line 400. Since the video digital file does not need to be reproduced for transmission, the digital file can be transmitted in a shorter transmission time than the reproduction transmission method. Further, since it is not necessary to record while reproducing the video on the receiving side 300 and no user operation is required on the receiving side 300, it is possible to reduce the labor cost related to video transmission. This leads to work style reform.

  In order to realize transmission of a plurality of segments of a digital file via such a one-way line 400, it is important to manage the transmission status of the digital file. In the system 1000 of the present invention, a bidirectional line 500 is used to manage the transmission status of digital files.

  For example, the computer apparatus 220 on the transmission side 200 manages transmission related information regarding the digital file transmitted from the transmission side 200 via the bidirectional line 500 in order to manage the transmission status of the digital file. Transmit to. Transmission-related information includes, for example, information indicating the start of transmission of a digital file, information indicating the number of segments of the transmitted digital file, information indicating the size of the transmitted digital file, and extension of the transmitted digital file It includes information indicating a child, information indicating that transmission of the digital file is to be ended, and the like.

  For example, the computer apparatus 320 on the receiving side 300 manages the reception-related information related to the digital file received by the receiving side 300 via the bidirectional line 500 in order to manage the transmission status of the digital file. Transmit to. The reception related information includes, for example, information requesting retransmission of the digital file, information indicating the number of segments of the received digital file, information identifying the segment in which the error has occurred, and information on an error that has occurred when transmitting the digital file. It includes information indicating the ratio, information indicating the size of the received digital file, MD5 hash value generated from the received digital file, information indicating that reception of the digital file has ended, and the like.

  In the transmission of a plurality of segments of a digital file via the one-way line 400, an error may occur in some of the transmitted segments. In the system 1000 of the present invention, the computer device 320 on the receiving side 300 can request retransmission by transmitting reception-related information even when an error occurs.

  At this time, if the entire digital file in which an error has occurred is retransmitted, the transmission time for the entire digital file is again taken. Further, when the amount of transmitted signals is large, the frequency of occurrence of errors increases. There is a good chance that the error will not be resolved even if the entire digital file is retransmitted, and the entire digital file must be retransmitted until the error is resolved.

  In the system 1000 of the present invention, it is possible to solve the problem when an error occurs by retransmitting only the segment in which the error has occurred based on the reception related information. For example, if an error occurs in the second segment and the fifth segment among five transmitted segments, instead of resending the entire digital file in which the error occurred, only the second segment and the fifth segment are transferred. It can be resent. Thereby, the transmission time can be shortened. Moreover, the frequency with which errors occur can be reduced by reducing the amount of transmitted signal. Even when an error occurs in retransmission, only the segment in which an error has occurred among the retransmitted segments needs to be retransmitted, so that the amount of transmitted signals can be gradually reduced. Thereby, the transmission time can be further shortened.

  In the system 1000 of the present invention, it is possible to grasp the transmission status based on the transmission related information and the reception related information, and it is possible to retransmit even when an error occurs as described above. Thereby, the digital file to be transmitted can be reliably transmitted to the receiving side 300.

  The system 1000 of the present invention can use a dedicated line such as an ASI line as the one-way line 400. For this reason, even when the infrastructure is down at the time of a disaster or when the Internet cannot be used in a remote place, a digital file can be reliably transmitted.

  In the system 1000 of the present invention, in the configuration using the satellite line as the bidirectional line 500, the satellite as the bidirectional line 500 can be used even when the infrastructure is down at the time of a disaster or when the Internet cannot be used in a remote place. Transmission related information and reception related information can be transmitted and received via a line. As a result, the transmission status of the digital file can be managed, and the digital file can be transmitted efficiently and reliably. Further, in the configuration using the Internet as the bidirectional line 500, when the infrastructure is down at the time of disaster or when the Internet cannot be used in a remote place, transmission related information and reception related information are transmitted via the bidirectional line 500. Although transmission and reception cannot be performed, in this case, by continuously transmitting a plurality of segments of the digital file from the transmission side 200, the digital file can be reliably transmitted without managing the transmission status. .

  In the example described above, transmission of a digital video file has been described. However, the digital file transmitted by the system of the present invention is not limited to a digital file in which video is recorded. It can be a digital file in which arbitrary data is recorded. For example, it may be a digital file in which audio is recorded.

2. Configuration of System for Transmitting Digital File FIG. 2 shows an example of the configuration of a system 1000 for transmitting a digital file of the present invention.

  The system 1000 of the present invention includes a transmission side device 210 and a reception side device 310. The transmission side device 210 includes a computer device 220 and a transmitter 230 connected to the computer device 220. The receiving side device 310 includes a computer device 320 and a receiver 330 connected to the computer device 320. The computer device 220 of the transmission side device 210 and the computer device 320 of the reception side device 310 are connected to each other via a bidirectional line 500. The transmitter 230 of the transmission side device 210 and the receiver 330 of the reception side device 310 are connected to each other via a one-way line 400. A mode in which the computer device 220 and the transmitter 230 are connected is not limited. The computer device 220 and the transmitter 230 may be connected wirelessly or may be connected by wire. A mode in which the computer device 320 and the receiver 330 are connected is not limited. The computer device 320 and the receiver 330 may be connected wirelessly or may be connected by wire.

  The computer device 220 of the transmission side device 210 includes an interface unit 221, a receiving unit 222, a processor unit 223, and a memory unit 224.

  The interface unit 221 is configured to control communication with the outside of the computer device 220. The interface unit 221 can transmit a signal to the outside of the computer device 220 and receive a signal from the outside of the computer device 220. For example, the interface unit 221 transmits transmission-related information to the computer device 320 of the reception-side device 310 via the bidirectional line 500. For example, the interface unit 221 receives reception-related information from the computer device 320 of the reception-side device 310 via the bidirectional line 500. For example, the interface unit 221 transmits a control signal to the transmitter 230. The interface unit 221 can transmit and receive signals of any format.

  The receiving unit 222 is configured to receive a digital file from the outside of the computer device 220. The receiving unit 222 can receive a digital file in an arbitrary format. It does not matter how the receiving unit 222 receives the digital file. For example, a digital file may be directly received from a camera that has shot a video, or a digital file read from a storage medium storing the digital file may be received.

  The processor unit 223 controls the overall operation of the computer device 220. The processor unit 223 reads a program stored in the memory unit 224 and executes the program. Thereby, it is possible to make the computer apparatus 220 function as an apparatus that executes a desired step. For example, the processor unit 223 can perform processing for transmitting a digital file. For example, the processor unit 223 can perform a process of dividing the received digital file into a plurality of segments. The processor unit 223 may be implemented by a single processor or a plurality of processors.

  The memory unit 224 stores a program for executing processing in the computer device 220, data necessary for executing the program, and the like. The memory unit 224 stores, for example, a program for transmitting a digital file (for example, a program that realizes processing shown in FIGS. 3, 4, and 6 described later). The memory unit 224 may store an application that implements an arbitrary function such as a function of dividing a digital file into a plurality of segments. The memory unit 224 may store transmission-related information used in the previous digital file transmission process. The memory unit 224 may store reception-related information received from the computer device 320 of the reception-side device 310 in the previous digital file transmission process. Here, it does not matter how the program is stored in the memory unit 224. For example, the program may be preinstalled in the memory unit 224. Alternatively, the program may be installed in the memory unit 224 by being downloaded via the bidirectional line 500. The memory unit 224 can be implemented by any storage means.

  The transmitter 230 of the transmission side device 210 includes an interface unit 231, a processor unit 232, and a memory unit 233.

  The interface unit 231 is configured to control communication with the outside of the transmitter 230. The interface unit 231 can transmit a signal to the outside of the transmitter 230 and receive a signal from the outside of the transmitter 230. For example, the interface unit 231 transmits a plurality of segments of a digital file to the receiver 330 via the one-way line 400. For example, the interface unit 231 receives a control signal from the computer device 220. The interface unit 231 can transmit and receive signals of any format.

  The processor unit 232 controls the overall operation of the transmitter 230. The processor unit 232 reads a program stored in the memory unit 233 and executes the program. Thereby, it is possible to make the transmitter 230 function as an apparatus that executes a desired step. For example, the processor unit 232 can perform processing for transmitting a digital file. The processor unit 232 may be implemented by a single processor or may be implemented by a plurality of processors.

  The memory unit 233 stores a program for executing processing in the transmitter 230, data necessary for executing the program, and the like. The memory unit 233 stores, for example, a program for transmitting a digital file (for example, a program for realizing processing shown in FIGS. 3 and 6 described later).

  The computer device 320 of the receiving side device 310 includes an interface unit 321, an output unit 322, a processor unit 323, and a memory unit 324.

  The interface unit 321 is configured to control communication with the outside of the computer device 320. The interface unit 321 can transmit a signal to the outside of the computer device 320 and receive a signal from the outside of the computer device 320. For example, the interface unit 321 receives transmission-related information from the computer device 220 of the transmission-side device 210 via the bidirectional line 500. For example, the interface unit 321 transmits the reception related information to the computer device 220 of the transmission side device 210 via the bidirectional line 500. For example, the interface unit 321 transmits a control signal to the receiver 330. The interface unit 321 can transmit and receive signals of any format.

  The output unit 322 is configured to output the received digital file to the outside of the computer device 320. The output unit 322 can output a digital file in an arbitrary format. It does not matter how the output unit 322 outputs the digital file. For example, when the output unit 322 includes a display screen and a playback device, a video played back from a digital file may be displayed on the display screen. For example, when the output unit 322 includes a storage unit, the digital file is stored in the storage unit, and an external device outside the computer device 320 accesses the storage unit so that the external device acquires the digital file. May be. For example, the output unit 322 may transmit a digital file to the outside of the computer device 320 via the bidirectional line 500.

  The processor unit 323 controls the overall operation of the computer device 320. The processor unit 323 reads a program stored in the memory unit 324 and executes the program. As a result, the computer device 320 can function as a device that executes a desired step. For example, the processor unit 323 can perform a process of receiving a digital file. For example, the processor unit 323 can perform a process of generating a digital file by integrating a plurality of received segments. The processor unit 323 may be implemented by a single processor or a plurality of processors.

  The memory unit 324 stores a program for executing processing in the computer device 320, data necessary for executing the program, and the like. The memory unit 324 stores, for example, a program for receiving a digital file (for example, a program for realizing processing shown in FIGS. 3 and 6 described later). The memory unit 324 may store, for example, an application that implements an arbitrary function such as a function of generating a received digital file by integrating a plurality of received segments. Here, it does not matter how the program is stored in the memory unit 324. For example, the program may be preinstalled in the memory unit 324. Alternatively, the program may be installed in the memory unit 324 by being downloaded via the bidirectional line 500. The memory unit 324 can be implemented by any storage means.

  The receiver 330 of the receiving side device 310 includes an interface unit 331, a processor unit 332, and a memory unit 333.

  The interface unit 331 is configured to control communication with the outside of the receiver 330. The interface unit 331 can transmit a signal to the outside of the receiver 330 and receive a signal from the outside of the receiver 330. For example, the interface unit 331 receives a plurality of segments of a digital file from the transmitter 230 of the transmission side device 210 via the one-way line 400. For example, the interface unit 331 receives a control signal from the computer device 320. The interface unit 331 can transmit and receive signals of any format.

  The processor unit 332 controls the operation of the entire receiver 330. The processor unit 332 reads a program stored in the memory unit 333 and executes the program. As a result, the receiver 330 can be made to function as a device that executes a desired step. For example, the processor unit 332 can perform processing for receiving a digital file. The processor unit 332 may be implemented by a single processor or may be implemented by a plurality of processors.

  The memory unit 333 stores a program for executing processing in the receiver 330, data necessary for executing the program, and the like. The memory unit 333 stores, for example, a program for receiving a digital file (for example, a program for realizing processing shown in FIGS. 3 and 6 described later).

  In the example described above, the computer apparatus 220 and the transmitter 230 of the transmission-side apparatus 210 have been described as separate hardware, but the present invention is not limited to this. Each component of the computer device 220 and the transmitter 230 of the transmission-side device 210 may be located in a single piece of hardware, or may exist in a plurality of pieces of hardware. When each component is located in a single hardware, the interface unit 221 and the interface unit 231, the processor unit 223 and the processor unit 232, and the memory unit 224 and the memory unit 233 are the same component, respectively. There may be another component. When each component exists in a plurality of hardware, the aspect in which each hardware is connected does not matter. Each hardware may be connected wirelessly or may be connected by wire.

  In the above-described example, the computer device 320 and the receiver 330 of the reception-side device 310 have been described as separate hardware, but the present invention is not limited to this. Each component of the computer device 320 and the receiver 330 of the receiving device 310 may be located in a single piece of hardware, or may be in a plurality of pieces of hardware. When each component is located in a single hardware, the interface unit 321 and the interface unit 331, the processor unit 323 and the processor unit 332, and the memory unit 324 and the memory unit 333 are respectively the same component. There may be another component. When each component exists in a plurality of hardware, the aspect in which each hardware is connected does not matter. Each hardware may be connected wirelessly or may be connected by wire.

  In the following, each component of the computer device 220 and the transmitter 230 of the transmission side device 210 is located in a single hardware, and each component of the computer device 320 and the receiver 330 of the reception side device 310 is a single component. An example of the processing of the system 1000 of the present invention when located in hardware will be described.

3. Processing in System for Transmitting Digital File FIG. 3 shows an example of signal flow in processing for transmitting a digital file in the system 1000 for transmitting a digital file of the present invention. In FIG. 3, the signal flow through the one-way line 400 is represented by a solid line, and the signal flow through the bidirectional line 500 is represented by a broken line.

  Before the process for transmitting the digital file is started, the digital file is input to the transmission side device 210, and the transmission side device 210 divides the input digital file into a plurality of segments. A segment number is assigned to each of the plurality of segments.

  In step S <b> 301, the transmission-side apparatus 210 transmits transmission-related information to the reception-side apparatus 310 via the bidirectional line 500. The transmission-related information includes at least information indicating that transmission of the digital file is started. For example, information indicating the number of segments of the transmitted digital file, information indicating the size of the transmitted digital file, and transmitted digital Information indicating an extension of the file may be further included. The reception side device 310 receives transmission related information from the transmission side device 210 via the bidirectional line 500.

  In step S302, the receiving side device 310 prepares for reception of the digital file in response to the transmission related information including information indicating that transmission of the digital file is started. For example, the reception-side device 310 activates the interface unit 331 of the receiver 330 and prepares for reception of the digital file. For example, the receiving-side apparatus 310 checks information indicating the extension of the transmitted digital file that can be included in the transmission-related information, and determines whether the extension of the transmitted digital file is a receivable extension. It is also possible. If the extension is not receivable, in step S303, a notification indicating that reception is not possible may be transmitted to the transmission-side apparatus 210 via the bidirectional line 500 instead of the reception preparation completion information, and the process may be terminated.

  When the reception side device 310 is ready to receive the digital file, in step S303, the reception side device 310 transmits reception preparation completion information indicating that the digital file reception preparation is completed via the bidirectional line 500. To the side device 210. The transmission side device 210 receives the reception preparation completion information from the reception side device 310 via the bidirectional line 500.

  In step S304, the transmission side device 210 starts transmission of the digital file divided into a plurality of segments in response to the reception preparation completion information. The transmission side device 210 transmits the first segment of the digital file divided into n segments to the reception side device 310 via the one-way line 400, and the digital file divided into n segments is transmitted. The second segment is transmitted to the receiving apparatus 310 via the unidirectional line 400, and the third segment of the digital file divided into n segments is transmitted to the receiving apparatus via the unidirectional line 400. 310,... And the nth segment of the digital file divided into n segments is transmitted to the receiving side device 310 via the one-way line 400. The receiving side device 310 receives n segments of the digital file from the transmitting side device 210 via the one-way line 400.

  When the transmission of all the segments of the digital file is completed, in step S305, the transmission-side apparatus 210 transmits the transmission-related information to the reception-side apparatus 310 via the bidirectional line 500. The transmission-related information includes at least information indicating that transmission of the digital file is to be terminated. For example, information indicating the number of segments of the transmitted digital file, information indicating the size of the transmitted digital file, and transmitted digital Information indicating an extension of the file may be further included. The reception side device 310 receives transmission related information from the transmission side device 210 via the bidirectional line 500.

  In step S306, the receiving side device 310 compares the received digital file segment with the received transmission-related information to determine whether there is a shortage of the digital file segment to be transmitted. For example, the receiving side device 310 compares the information indicating the number of segments of the digital file to be transmitted included in the received transmission related information with the number of segments of the digital file actually received, thereby transmitting the file. Determine if there are not enough segments of the digital file to be played. For example, the receiving side device 310 is transmitted by comparing the information indicating the size of the transmitted digital file included in the received transmission related information with the total size of the segments of the actually received digital file. Determine if there are not enough digital file segments.

  For example, when it is determined that there are not enough segments of the digital file to be transmitted, it is determined which segment is missing by referring to the segment number assigned to each of the plurality of segments. Can do. Thereby, error segment identification information for identifying a segment in which an error has occurred is generated.

  For example, if it is determined that there are not enough segments of the digital file to be transmitted, the ratio of the number of segments of the digital file actually received to the number of segments of the transmitted digital file or transmitted By calculating the ratio of the total size of the actually received digital file segment to the size of the digital file, it is possible to determine the percentage of errors that occurred when transmitting the digital file. As a result, information indicating the ratio of errors that occur when transmitting the digital file is generated.

  For example, if it is determined that there are not insufficient segments of the digital file to be transmitted, the receiving side device 310 integrates the plurality of received segments to generate a received digital file. At this time, the receiving side device 310 can generate, for example, an MD5 hash value from the generated received digital file in order to confirm the matching of the subsequent digital file. Alternatively, the receiving side device 310 can read the size of the generated received digital file for later confirmation of the digital file match.

  In step S <b> 307, the reception side device 310 transmits the reception related information to the transmission side device 210 via the bidirectional line 500. The reception related information includes, for example, information indicating the number of segments of the received digital file, information requesting retransmission of the digital file, error segment identification information, information indicating a rate of errors that occurred when transmitting the digital file, It includes information indicating the size of the received digital file, an MD5 hash value generated from the received digital file, and information indicating that reception of the digital file has ended. If it is determined in step S306 that there are not enough segments of the digital file to be transmitted, the reception related information includes at least information requesting retransmission of the digital file, and preferably the received digital file It further includes information indicating the number of segments, error segment identification information, or information indicating the rate of errors that occurred when transmitting the digital file. If it is determined in step S306 that the segment of the digital file to be transmitted is not insufficient, the reception related information includes at least information indicating that reception of the digital file has ended, and preferably the received digital file Or an MD5 hash value generated from the received digital file.

  After step S307, the transmission side apparatus 210 performs a process in response to the reception related information received from the reception side apparatus 310.

  For example, when the reception-related information received from the reception-side device 310 includes information indicating that reception of the digital file has been completed, the transmission-side device 210 transmits the digital file transmitted to the reception-side device 310 and the reception-side device. Check if the digital file received by 310 matches. For example, the transmission-side apparatus 210 compares the MD5 hash value generated from the transmitted digital file with the MD5 hash value generated from the reception digital file that can be included in the reception-related information. It is confirmed whether the digital file transmitted to 310 matches the digital file received by the receiving side device 310. If the MD5 hash values match, the transmission of the digital file is successful and the process ends. If the MD5 hash values do not match, the transmission of the digital file has failed, and the user of the transmission-side apparatus 210 may be notified to that effect. For example, the transmitting device 210 is transmitted to the receiving device 310 by comparing the size read from the transmitted digital file with the size read from the received digital file that may be included in the reception related information. Whether the received digital file and the digital file received by the receiving-side device 310 match. If the file sizes match, the digital file transmission is successful and the process ends. If the file sizes do not match, the transmission of the digital file has failed, and the user of the transmission-side apparatus 210 may be notified accordingly.

  For example, when the reception-related information received from the reception-side device 310 includes information requesting retransmission of a digital file, the transmission-side device 210 performs digital file retransmission processing. In the digital file retransmission process, the transmission side device 210 transmits the digital file to be retransmitted divided into a plurality of segments to the reception side device 310 via the one-way line 400. The subsequent processing is the same as the processing in steps S305 to S307. The digital file retransmission process is repeated until, for example, the transmission-side apparatus 210 receives reception-related information including information indicating that the reception of the digital file has ended. As a result, the digital file to be transmitted can be reliably transmitted to the receiving-side apparatus 310.

  In the digital file retransmission process, the transmission-side apparatus 210 may retransmit all segments of the digital file to be transmitted, but preferably retransmits only the segment in which an error has occurred. This is achieved by referring to error segment identification information that can be included in the reception related information and identifying a segment in which an error has occurred based on the error segment identification information. It is possible to shorten the transmission time by retransmitting only the segment in which the error has occurred instead of retransmitting all the segments of the digital file in which the error has occurred.

  For example, when the reception-related information received from the reception-side device 310 includes information requesting retransmission of the digital file and information indicating the ratio of errors that occurred when transmitting the digital file, the transmission-side device 210 The digital file is retransmitted by changing the number of divisions of the digital file into a plurality of segments. For example, the number of divisions may be increased as the error ratio increases, and the number of divisions may be decreased as the error ratio decreases.

  In the system 1000 of the present invention, when the transmission side apparatus 210 divides the digital file into a plurality of segments before the process for transmitting the digital file shown in FIG. 3 is started, the process shown in FIG. You may divide into segments.

  FIG. 4 shows an example of a process 400 performed in the transmission-side apparatus 210 for dividing a digital file into a plurality of segments.

  Before the process 400, the memory unit 224 of the transmission side apparatus 210 stores the transmission related information used in the previous digital file transmission process and the reception related information received in the previous digital file transmission process. It shall be. The stored transmission related information includes at least information indicating the number of segments of the digital file to be transmitted. The stored reception-related information includes at least information indicating a rate of errors that have occurred when transmitting the digital file.

  In step S401, the transmission-side apparatus 210 refers to the transmission-related information and the reception-related information stored in the memory unit 224, and occurred when transmitting the division number in the previous transmission process and the digital file in the previous transmission process. Acquires information indicating the error rate.

  In step S402, the transmission-side apparatus 210 determines whether or not the ratio of errors that occurred when transmitting a digital file in the previous transmission process is greater than a predetermined value. The predetermined value may be an arbitrary value. For example, the predetermined value may be a specific threshold (for example, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, etc.) or in the previous transmission It may be the error rate. If the error rate is greater than the predetermined value, the process proceeds to step S403. If the error rate is equal to or less than the predetermined value, the process proceeds to step S404.

  In step S403, the transmission-side apparatus 210 increases the number of divisions when dividing the digital file into a plurality of segments, compared to the number of divisions in the previous transmission process. The degree to which the number of divisions is increased does not matter. For example, the transmission-side apparatus 210 may increase the number of divisions by 1, or may increase the number of divisions by 10.

  In step S404, the transmission-side apparatus 210 determines whether the ratio of errors that occurred when transmitting the digital file is smaller than a predetermined value. The predetermined value is the same value as that in step S402. If the error rate is smaller than the predetermined value, the process proceeds to step S405. If the error rate is equal to the predetermined value, the process proceeds to step S406.

  In step S405, the transmission-side apparatus 210 reduces the number of divisions when dividing the digital file into a plurality of segments, compared to the number of divisions in the previous transmission process. The degree to which the number of divisions is reduced does not matter. For example, the transmission-side apparatus 210 may decrease the number of divisions by 1, or may decrease the number of divisions by 10.

  In step S406, the transmission side apparatus 210 maintains the division number when dividing the digital file into a plurality of segments at the division number in the previous transmission process.

  In step S407, the transmission-side apparatus 210 divides the digital file into a plurality of segments with the number of divisions increased in step S403, the number of divisions decreased in step S405, or the number of divisions maintained in step S406.

  By referring to the information in the previous digital file transmission process, the number of divisions increases as the error rate increases, and the number of divisions decreases as the error rate decreases, so the appropriate number of divisions according to the error rate Can divide and transmit a digital file, and efficient file transmission is possible.

  In the example described above, the transmission side apparatus 210 has been described as dividing the input digital file into a plurality of segments, but the present invention is not limited to this. Instead of the transmission side device 210 dividing the digital file into a plurality of segments, a device different from the transmission side device 210 may divide the digital file into a plurality of segments. At this time, the transmission side device 210 receives a digital file divided into a plurality of segments.

4). Alternative Configuration of System for Transmitting Digital File FIG. 5 shows an example of the configuration of a system 2000 that is an alternative configuration of the system 1000 for transmitting the digital file of the present invention. In FIG. 5, the same reference numerals are given to the same elements as those shown in FIG. 2, and description thereof is omitted here.

  The system 2000 of the present invention includes a transmission side device 210 and a reception side device 310. The transmission side device 210 includes a computer device 220 and a transmitter 230 connected to the computer device 220. The receiving side device 310 includes a computer device 320 and a receiver 330 connected to the computer device 320. The computer device 220 of the transmission side device 210 and the computer device 320 of the reception side device 310 are connected to each other via a bidirectional line 500. The transmitter 230 of the transmission side device 210 and the receiver 330 of the reception side device 310 are connected to each other via a one-way line 400. A mode in which the computer device 220 and the transmitter 230 are connected is not limited. The computer device 220 and the transmitter 230 may be connected wirelessly or may be connected by wire. A mode in which the computer device 320 and the receiver 330 are connected is not limited. The computer device 320 and the receiver 330 may be connected wirelessly or may be connected by wire.

  The bidirectional line 500 includes a first bidirectional line 501 and a second bidirectional line 502. The first bidirectional line 501 connects the computer device 220 of the transmission side device 210 and the management device 600 to each other. The second bidirectional line 502 connects the computer device 320 of the receiving side device 310 and the management device 600 to each other.

  The management device 600 is configured to manage the transmission status of digital files. For example, the management apparatus 600 has a function of an electronic bulletin board, and manages the transmission status of digital files based on information written on the electronic bulletin board. The management device 600 is an FTP server, for example. The management apparatus 600 includes an interface unit 601, a processor unit 602, and a memory unit 603.

  The interface unit 601 is configured to control communication with the outside of the management apparatus 600. The interface unit 601 can transmit a signal to the outside of the management apparatus 600 and receive a signal from the outside of the management apparatus 600. For example, the interface unit 601 receives transmission-related information from the computer device 220 of the transmission-side device 210 via the first bidirectional line 501. For example, the interface unit 601 receives reception-related information from the computer device 320 of the reception-side device 310 via the second bidirectional line 502. The interface unit 601 can transmit and receive signals of any format.

  The processor unit 602 controls the overall operation of the management apparatus 600. The processor unit 602 reads a program stored in the memory unit 603 and executes the program. As a result, the management apparatus 600 can function as an apparatus that executes a desired step. For example, the processor unit 602 can perform processing for an electronic bulletin board function. The processor unit 602 may be implemented by a single processor or may be implemented by a plurality of processors.

  The memory unit 603 stores a program for executing processing in the management apparatus 600, data necessary for executing the program, and the like. The memory unit 603 may store an application that implements an arbitrary function such as a function of an electronic bulletin board. The memory unit 603 can be implemented by any storage unit.

  Each component of the management apparatus 600 may be located in a single hardware, or may exist in a plurality of hardware. When it exists in several hardware, the aspect to which each hardware is connected is not ask | required. Each hardware may be connected wirelessly or may be connected by wire.

  In the following, each component of the computer device 220 and the transmitter 230 of the transmission side device 210 is located in a single hardware, and each component of the computer device 320 and the receiver 330 of the reception side device 310 is a single component. An example of the processing of the system 2000 of the present invention when located in hardware will be described.

  FIG. 6 shows an example of a signal flow in a process for transmitting a digital file in the system 2000 for transmitting a digital file of the present invention. In FIG. 6, a signal flow through the one-way line 400 is represented by a solid line, and a signal flow through the first bidirectional line 501 and the second bidirectional line 502 is represented by a broken line.

  In the example shown in FIG. 6, the management apparatus 600 has a function of an electronic bulletin board.

  Before the process for transmitting the digital file is started, the digital file divided into a plurality of segments is input to the transmission-side apparatus 210. Here, the transmission-side apparatus 210 may divide the input digital file into a plurality of segments, or the transmission-side apparatus 210 may receive a digital file that has been divided into a plurality of segments in advance. A segment number is assigned to each of the plurality of segments.

  In step S601, the transmission-side apparatus 210 writes the transmission-related information on the electronic bulletin board of the management apparatus 600 by transmitting the transmission-related information to the management apparatus 600 via the first bidirectional line 501. The transmission related information may be in text format. The transmission-related information includes at least information indicating that transmission of the digital file is started. For example, information indicating the number of segments of the transmitted digital file, information indicating the size of the transmitted digital file, and transmitted digital Information indicating an extension of the file may be further included.

  In step S602, the receiving-side apparatus 310 monitors the electronic bulletin board of the management apparatus 600 via the second bidirectional line 502, and when transmission-related information is written on the electronic bulletin board of the management apparatus 600, the transmission-related apparatus 310 Information is acquired from the electronic bulletin board of the management apparatus 600 via the second bidirectional line 502.

  In step S <b> 603, the reception-side apparatus 310 prepares for reception of the digital file in response to the transmission related information acquired from the electronic bulletin board of the management apparatus 600. For example, the reception-side device 310 activates the interface unit 331 of the receiver 330 and prepares for reception of the digital file. For example, the receiving-side apparatus 310 checks information indicating the extension of the transmitted digital file that can be included in the transmission-related information, and determines whether the extension of the transmitted digital file is a receivable extension. It is also possible. If the extension is not receivable, in step S604, a notification that reception is not possible is transmitted to the management apparatus 600 via the second bidirectional line 502 instead of the reception preparation completion information. You may write on an electronic bulletin board.

  When the reception side device 310 is ready to receive a digital file, in step S604, the reception side device 310 transmits reception preparation completion information indicating that the digital file reception preparation is completed to the second bidirectional line 502. To the management apparatus 600, and writes it on the electronic bulletin board of the management apparatus 600. The reception preparation completion information may be in a text format.

  In step S605, the transmission-side apparatus 210 monitors the electronic bulletin board of the management apparatus 600 via the first bidirectional line 501, and when the reception preparation completion information is written on the electronic bulletin board of the management apparatus 600, the reception apparatus 210 Preparation completion information is acquired from the electronic bulletin board of the management apparatus 600 via the first bidirectional line 501.

  In step S606, the transmission side apparatus 210 starts transmission of the digital file divided into a plurality of segments. The transmission side device 210 transmits the first segment of the digital file divided into n segments to the reception side device 310 via the one-way line 400, and the digital file divided into n segments is transmitted. The second segment is transmitted to the receiving apparatus 310 via the unidirectional line 400, and the third segment of the digital file divided into n segments is transmitted to the receiving apparatus via the unidirectional line 400. 310,... And the nth segment of the digital file divided into n segments is transmitted to the receiving side device 310 via the one-way line 400. The receiving side device 310 receives n segments of the digital file from the transmitting side device 210 via the one-way line 400.

  When the transmission of all the segments of the digital file is completed, in step S607, the transmission-side apparatus 210 transmits the transmission-related information to the management apparatus 600 via the first bidirectional line 501, so that the electronic device of the management apparatus 600 is transmitted. Write on the bulletin board. The transmission-related information includes at least information indicating that transmission of the digital file is to be terminated. For example, information indicating the number of segments of the transmitted digital file, information indicating the size of the transmitted digital file, and transmitted digital Information indicating an extension of the file may be further included.

  In step S608, the receiving-side apparatus 310 monitors the electronic bulletin board of the management apparatus 600 via the second bidirectional line 502, and when transmission-related information is written on the electronic bulletin board of the management apparatus 600, the transmission-related apparatus Information is acquired from the electronic bulletin board of the management apparatus 600 via the second bidirectional line 502.

  In step S609, the receiving-side apparatus 310 compares the received digital file segment with the transmission-related information acquired from the electronic bulletin board to determine whether the digital file segment to be transmitted is insufficient. For example, the receiving-side device 310 compares the information indicating the number of segments of the digital file to be transmitted that can be included in the acquired transmission-related information with the number of segments of the actually received digital file, Determine if there are not enough segments in the digital file to be transmitted. For example, the receiving side device 310 is transmitted by comparing information indicating the size of the digital file to be transmitted that can be included in the acquired transmission-related information with the total size of the segments of the actually received digital file. Determine if there are not enough segments in the digital file to be processed.

  For example, when it is determined that there are not enough segments of the digital file to be transmitted, it is determined which segment is missing by referring to the segment number assigned to each of the plurality of segments. Can do. Thereby, error segment identification information for identifying a segment in which an error has occurred is generated.

  For example, if it is determined that there are not enough segments of the digital file to be transmitted, the ratio of the number of segments of the digital file actually received to the number of segments of the transmitted digital file or transmitted By calculating the ratio of the total size of the actually received digital file segment to the size of the digital file, it is possible to determine the percentage of errors that occurred when transmitting the digital file. As a result, information indicating the ratio of errors that occur when transmitting the digital file is generated.

  For example, if it is determined that there are not insufficient segments of the digital file to be transmitted, the receiving side device 310 integrates the plurality of received segments to generate a received digital file. At this time, the receiving side device 310 can generate, for example, an MD5 hash value from the generated received digital file in order to confirm the matching of the subsequent digital file. Alternatively, the receiving side device 310 can read the size of the generated received digital file for later confirmation of the digital file match.

  In step S <b> 610, the reception-side apparatus 310 writes the reception related information on the electronic bulletin board of the management apparatus 600 by transmitting it to the management apparatus 600 via the second bidirectional line 502. The reception related information includes, for example, information indicating the number of segments of the received digital file, information requesting retransmission of the digital file, error segment identification information, information indicating a rate of errors that occurred when transmitting the digital file, It includes information indicating the size of the received digital file, an MD5 hash value generated from the received digital file, and information indicating that reception of the digital file has ended. If it is determined in step S609 that there are insufficient segments of the digital file to be transmitted, the reception related information includes at least information requesting retransmission of the digital file, and preferably the received digital file It further includes information indicating the number of segments, error segment identification information, or information indicating the rate of errors that occurred when transmitting the digital file. If it is determined in step S609 that there are no shortage segments of the digital file to be transmitted, the reception related information includes at least information indicating that reception of the digital file has ended, and preferably the received digital file Or an MD5 hash value generated from the received digital file.

  In step S611, the transmission-side apparatus 210 monitors the electronic bulletin board of the management apparatus 600 via the first bidirectional line 501, and when reception-related information is written on the electronic bulletin board of the management apparatus 600, the transmission-related apparatus 210 Information is acquired from the electronic bulletin board of the management apparatus 600 via the first bidirectional line 501.

  After step S611, the transmission-side apparatus 210 performs a process in response to the reception related information acquired from the electronic bulletin board of the management apparatus 600. Since this process is the same as the process performed after step S307 by the system 1000 of the present invention, a description thereof is omitted here.

  By managing the transmission status of the digital file via the electronic bulletin board of the management apparatus 600 as in the process shown in FIG. 6, the necessity of synchronizing the transmission side apparatus 210 and the reception side apparatus 310 can be eliminated. it can. Thereby, complicated synchronization processing can be avoided, and the configurations and settings of the devices of the transmission side device 210 and the reception side device 310 can be simplified.

  In the above-described example, the management apparatus 600 has an electronic bulletin board function. However, the present invention is not limited to this. The management device 600 can include any means that enables the transmission status of the digital file to be managed through the transmission side device 210 and the reception side device 310. For example, a configuration in which the management apparatus 600 actively transmits transmission-related information or reception-related information to the reception-side apparatus 310 or the transmission-side apparatus 210 is also within the scope of the present invention.

  In the example described above, “one-to-one” communication between one transmission-side device 210 and one reception-side device 310 has been described as an example, but the present invention is not limited to this. The present invention is also applicable to “one-to-many” communication between one transmission-side device 210 and a plurality of reception-side devices. For example, it is a case where a digital video file is simultaneously transmitted from one base station to a plurality of base stations. “One-to-many” communication may be performed, for example, by using a satellite line as a one-way line.

  FIG. 7 shows an example of the configuration of a system 3000 that is an alternative configuration of the system 1000 for transmitting a digital file of the present invention. In FIG. 7, the same elements as those shown in FIG. 2 are denoted by the same reference numerals, and the description thereof is omitted here. A system 3000 of the present invention shown in FIG. 7 is a system that performs “one-to-many” communication.

The system 3000 according to the present invention includes a transmission side device 210 ′ and a plurality of reception side devices 310 _{1 to} 310 _m . The transmission-side device 210 ′ includes a computer device 220 ′ and a transmitter 230 ′ connected to the computer device 220 ′. The first receiving device 310 ₁ includes a computer device 320 ₁ and a receiver 330 ₁ connected to the computer device 320 ₁ , and the second receiving device 310 ₂ includes a computer device 320 ₂ and a computer device. 320 and a connected receiver 330 _{2 2,} ... receiving device 310 _m of the m includes a computer device 320 _m, and a receiver 330 _m the connected to the computer apparatus 320 _m. 'Computer device 220' transmission-side apparatus 210, via a bidirectional line 500 ₁ is connected to the first reception-side apparatus 310 ₁ of computer system 320 _1, via a bidirectional line 500 _2, the second It is connected to the computer device 320 ₂ on the reception side apparatus 310 _2, through the ... bidirectional line 500 _m, and is connected to the computer apparatus 320 _m of the receiving apparatus 310 _m of the m. 'Transmitter 230' transmission-side apparatus 210 via a one-way line 400, a first receiver 330 ₁ of the receiving side apparatus 310 _1, the second receiving-side apparatus 310 _second receiver ₃₃₀ 2, ... It is connected to the receiver 330 _m of the m-th receiving side device 310 _m . A mode in which the computer device 220 ′ and the transmitter 230 ′ are connected is not limited. The computer device 220 ′ and the transmitter 230 ′ may be connected wirelessly or may be connected by wire. Computer apparatus 320 ₁ and the receiver 330 _1, the computer apparatus 320 ₂ and the receiver ₃₃₀ 2, aspects ... computer apparatus 320 _m and the receiver 330 _m is connected is not limited. The computer device 320 ₁ and the receiver 330 ₁ , the computer device 320 ₂ and the receiver 330 ₂ ,..., The computer device 320 _m and the receiver 330 _m may be connected wirelessly or may be connected by wire. .

The one-way line 400 may be an ASI line or an SDI line, for example. The one-way line 400 may preferably be a satellite line used in “one-to-many” communication. The bidirectional lines 500 _{1 to} 500 _m can be, for example, the Internet.

Although not shown, the computer device 220 ′ of the transmission-side device 210 ′ includes an interface unit, a reception unit, a processor unit, and a memory unit, like the computer device 220 of the transmission-side device 210 described above. The interface unit, the reception unit, the processor unit, and the memory unit of the computer device 220 of the transmission side device 210 ′ are the interface unit 221, reception unit 222, processor unit 223, and memory unit 224 of the computer device 220 of the transmission side device 210 described above. The interface unit of the computer device 220 of the transmission side device 210 ′ may be similar, but is adapted for “one-to-many” communication via the bidirectional lines 500 _{2 to} 500 _m .

  Although not shown, the transmitter 230 ′ of the transmission-side device 210 ′ includes an interface unit, a processor unit, and a memory unit, similarly to the transmitter 230 of the transmission-side device 210 described above. The interface unit, the processor unit, and the memory unit of the transmitter 230 ′ of the transmission side device 210 ′ may be the same as the interface unit 231, the processor unit 232, and the memory unit 233 of the transmitter 230 of the transmission side device 210 described above. However, the interface unit of the transmitter 230 ′ of the transmission side device 210 ′ is adapted for “one-to-many” communication via the one-way line 400.

Although not shown, each of the computer devices 320 _{1 to} 320 _m of the plurality of receiving side devices 310 _{1 to} 310 _m includes an interface unit similar to the above-described interface unit 321, output unit 322, processor unit 323, and memory unit 324, output unit, the processor unit includes a memory unit, the receiver ₃₃₀ 1 to 330 _m of the plurality of receiving devices ₃₁₀ 1 to 310 _m, the interface unit 331 described above, the processor unit 332, similar to the interface unit and the memory unit 333 A processor unit and a memory unit.

  Note that each component of the computer device 220 ′ and the transmitter 230 ′ of the transmission-side device 210 ′ may be located in a single hardware or may exist in a plurality of hardware. When each component is located in a single piece of hardware, the interface portion of computer device 220 ′ and the interface portion of transmitter 230 ′, the processor portion of computer device 220 ′ and the processor portion of transmitter 230 ′, and The memory unit of the computer apparatus 220 ′ and the memory unit of the transmitter 230 ′ may be the same component or different components. When each component exists in a plurality of hardware, the aspect in which each hardware is connected does not matter. Each hardware may be connected wirelessly or may be connected by wire.

In addition, each component of the computer device and the receiver of each of the plurality of receiving side devices 310 _{1 to} 310 _m may be located in a single hardware, or may be present in a plurality of hardware. Good. When each component is located in a single piece of hardware, the interface unit of the computer device and the interface unit of the receiver, the processor unit of the computer device and the processor unit of the receiver, and the memory unit and receiver of the computer device The memory units may be the same component or different components. When each component exists in a plurality of hardware, the aspect in which each hardware is connected does not matter. Each hardware may be connected wirelessly or may be connected by wire.

In the processing for transmitting the digital file in the system 3000 of the present invention, between the transmission-side apparatus 210 'and the signal flow between the receiving device 310 _1, the transmission-side apparatus 210' and the receiving-side apparatus 310 ₂ The signal flow between the transmission side device 210 ′ and the reception side device 310 _m is the signal flow between the transmission side device 210 and the reception side device 310 shown in FIG. Since it is the same, description is abbreviate | omitted here.

After step S307 shown in FIG. 3, the transmission side device 210 ′ performs a process in response to the reception related information received from each of the plurality of reception side devices 310 _{1 to} 310 _m .

For example, when the reception related information received from any of the plurality of reception side devices 310 _{1 to} 310 _m includes information indicating that the reception of the digital file has been completed, the transmission side device 210 ′ It is confirmed whether the digital file transmitted to the device matches the digital file received by the receiving device. Here, it is assumed that reception-related information received from the first receiving-side apparatus 310 ₁ includes information indicating the end of reception of the digital file as an example. For example, the transmission-side apparatus 210 ', and MD5 hash value generated from the first digital file transmitted to the receiving device 310 ₁ may be included in the first reception-related information from the receiving apparatus 310 _1, by comparing the MD5 hash value generated from the received digital file, the digital file and matches received by the digital file and a first receiving device 310 ₁ is transmitted first to the receiving apparatus 310 ₁ Make sure that If the MD5 hash values match, the transmission of the digital file to the _first receiving device 310 ₁ is successful, and the processing for the first receiving device 310 ₁ ends. If the MD5 hash values do not match, the transmission of the digital file to the _first receiving device 3101 has failed, and the user of the transmitting device 210 may be notified of this failure. For example, the transmission-side apparatus 210 'includes a size read from the transmitted digital file first to the receiving apparatus 310 _1, may be included in the first reception-related information from the receiving device 310 _1, the received digital by comparing the size read from the file, check the digital file received by the digital file and the first receiving-side apparatus 310 ₁ is transmitted first to the receiving apparatus 310 ₁ is coincident To do. If the size of the file matches, the transmission of the first digital file to the receiving apparatus 310 ₁ is successful, the process for the first receiving-side apparatus 310 ₁ ends. If the file sizes do not match, the transmission of the digital file to the _first receiving side device 3101 has failed, and the user of the transmitting side device 210 may be notified accordingly.

For example, when the reception related information received from any of the plurality of reception side devices 310 _{1 to} 310 _m includes information requesting retransmission of the digital file, the transmission side device 210 ′ Resend the digital file. For example, if it contains information reception-related information received from the second receiving-side apparatus 310 ₂ and the fourth receiving apparatus 310 4 _(not shown) requests a retransmission of the digital file, the transmission-side apparatus 210 ' performs retransmission processing of the digital file to at least a second receiver-side apparatus 310 ₂ and the fourth receiving device 310 _4. In this case, retransmission processing may be performed on all of the plurality of receiving devices ₃₁₀ 1 to 310 _m, conducted only for the second receiving-side apparatus 310 ₂ and the fourth receiving apparatus 310 ₄ May be. When performing retransmission processing only to a specific receiving device, for example, transmission related information is transmitted only to a specific receiving device that performs retransmission processing, and only a specific receiving device receives a digital file. Also good. In the digital file retransmission process, the transmission side apparatus 210 ′ transmits the digital file to be retransmitted divided into a plurality of segments to the reception side apparatus via the one-way line 400. The subsequent processing is the same as the processing in steps S305 to S307. The digital file retransmission process is repeated until, for example, the transmission-side apparatus 210 ′ receives reception-related information including information indicating that reception of the digital file has ended from the target reception-side apparatus. Accordingly, the digital file to be transmitted can be reliably transmitted to each of the plurality of receiving side devices 310 _{1 to} 310 _m .

In the digital file retransmission process, the transmission-side apparatus 210 ′ may retransmit all segments of the digital file to be transmitted, but preferably retransmits only the segment in which an error has occurred. This is achieved by referring to error segment identification information that can be included in the reception related information and identifying a segment in which an error has occurred based on the error segment identification information. It is possible to shorten the transmission time by retransmitting only the segment in which the error has occurred instead of retransmitting all the segments of the digital file in which the error has occurred. For example, when a digital file retransmission process is performed on the second receiving side device 310 ₂ and the fourth receiving side device 310 ₄ (not shown), the segment in which an error has occurred in the _second receiving side device 310 ₂ And the segment in which the error occurred in the _fourth receiving apparatus 3104 may be different. At this time, the second receiving-side apparatus 310 in the ₂ and segment error occurs in the fourth receiving device 310 ₄ both the segment error occurs the second receiving apparatus 310 ₂ and the fourth receiving side may be retransmitted with respect to both the device 310 _4, the segment error occurs in the second receiving-side apparatus 310 ₂ retransmits only to ₂ second receiving device 310, a fourth recipient a segment error occurs in the apparatus 310 ₄ may be retransmitted only for the fourth receiving device 310 _4.

For example, the reception related information received from any _one of the plurality of receiving side devices 310 _{1 to} 310 _m includes information requesting retransmission of the digital file, information indicating the rate of errors that occurred when transmitting the digital file, and The transmission side apparatus 210 ′ changes the number of divisions of the digital file into a plurality of segments, and performs retransmission processing of the digital file on the reception side apparatus. For example, the number of divisions may be increased as the error ratio increases, and the number of divisions may be decreased as the error ratio decreases. The number of divisions of a digital file into a plurality of segments may be determined for a plurality of receiving apparatuses as a whole, or may be determined for each of a plurality of receiving apparatuses to which a digital file is retransmitted. For example, the ratio of errors included in reception-related information received from a plurality of receiving side devices 310 _{1 to} 310 _m is averaged, and the larger the average error ratio, the more the number of divisions, and the smaller the average error ratio. You may make it reduce a division | segmentation number so that. For example, it indicates that the second reception-related information received from the receiving device 310 _two of the plurality of receiving devices ₃₁₀ 1 to 310 _m is large proportion of errors, a plurality of receiving devices ₃₁₀ 1 to 310 _m If a fourth reception-related information received from the receiving apparatus 310 ₄ of the proportion of error is small among increases the number of divisions of the digital file to be retransmitted to the second receiving device 310 _2, it may be to reduce the number of divisions of the digital file to be retransmitted to the fourth receiving device 310 _4. For example, when the transmission side device 210 ′ divides the digital file into a plurality of segments, the transmission side device 210 ′ may divide the digital file into a plurality of segments by the process shown in FIG.

When video is transmitted to multiple receivers using a satellite link as a unidirectional link in the conventional playback transmission system, video is recorded simultaneously at the same time on multiple receivers, so the recording work is performed at the same time. It was necessary for all the receivers to perform all at once. If the recording start operation was missed, it was necessary to resend only for the receiving side, and the recording required manpower. In the system 3000 of the present invention, a digital video file needs to be reproduced for transmission even in “one-to-many” communication between one transmission-side device 210 ′ and a plurality of reception-side devices 310 _{1 to} 310 _m. Therefore, it is possible to transmit a digital file in a shorter transmission time than the reproduction transmission method. Further, there is no need to record while playing video in a plurality of receiving devices ₃₁₀ 1 to 310 _m, for operation by the user in a plurality of receiving devices ₃₁₀ 1 to 310 _m is not necessary, labor costs related to video transmission It is also possible to reduce. This leads to work style reform.

  FIG. 8 shows an example of the configuration of a system 4000 that is an alternative configuration of the system 3000 for transmitting the digital file of the present invention. In FIG. 8, the same elements as those shown in FIG. 7 are denoted by the same reference numerals, and description thereof is omitted here. A system 4000 of the present invention shown in FIG. 8 is a system that performs “one-to-many” communication, and includes a management device 600 ′ that manages the transmission status of digital files.

The system 4000 of the present invention includes a transmission side device 210 ′ and a plurality of reception side devices 310 _{1 to} 310 _m . 'Computer device 220' transmission-side apparatus 210, via a bidirectional line 500, a first receiving-side apparatus 310 ₁ of the computer device 320 _1, the second receiving-side apparatus 310 ₂ of the computer device ₃₂₀ 2, ... It is connected to the computer device 320 _m of the m-th receiving side device 310 _m . 'Transmitter 230' transmission-side apparatus 210 via a one-way line 400, a first receiver 330 ₁ of the receiving side apparatus 310 _1, the second receiving-side apparatus 310 _second receiver ₃₃₀ 2, ... It is connected to the receiver 330 _m of the m-th receiving side device 310 _m .

The bidirectional line 500 includes a first bidirectional line 501 and a plurality of second bidirectional lines 502 _{1 to} 502 _m . The first bidirectional line 501 connects the computer apparatus 220 ′ of the transmission side apparatus 210 ′ and the management apparatus 600 ′ to each other. Each of the plurality of the second bidirectional line ₅₀₂ 1 to 502 _m, a first receiving-side apparatus 310 ₁ of the computer device 320 _1, the second receiving-side apparatus 310 ₂ of the computer device ₃₂₀ 2, ... in the m connecting the computer apparatus 320 _m of the receiving apparatus 310 _m management device 600 'and each other. The first bidirectional line 501 and the plurality of bidirectional lines 502 _{1 to} 502 _m can be, for example, the Internet.

The management device 600 ′ is configured to manage the transmission status of the digital file for each of the plurality of reception side devices 310 _{1 to} 310 _m . For example, the management device 600 ′ has a function of an electronic bulletin board, and manages the transmission status of digital files based on information written on the electronic bulletin board. The management device 600 ′ is, for example, an FTP server. Although not shown, the management device 600 ′ includes an interface unit, a processor unit, and a memory unit, similarly to the management device 600 described above. The interface unit, the processor unit, and the memory unit of the management device 600 ′ may be the same as the interface unit 601, the processor unit 602, and the memory unit 603 of the management device 600 described above. It is adapted for “one-to-many” communication via the second bidirectional lines 502 _{1 to} 502 _m .

In the processing for transmitting the digital file in the system 4000 of the present invention, the signal flow between 'the management device 600' transmission-side apparatus 210 and the receiving-side apparatus 310 _1, the transmission-side apparatus 210 'and the management device 600' a signal flow between the receiving apparatus 310 _2, each of the signal flow between 'the management device 600' ... transmission side apparatus 210 and the receiving-side apparatus 310 _m, the transmission side shown in FIG. 6 Since the flow of signals among the apparatus 210, the management apparatus 600, and the receiving apparatus 310 is the same, the description thereof is omitted here. After step S611 shown in FIG. 6, the transmission side device 210 ′ performs a process in response to the reception related information acquired from the electronic bulletin board of the management device 600 ′. Since this process is the same as the process performed after step S307 by the system 3000 of the present invention, a description thereof is omitted here.

By managing the transmission state of the digital file via the electronic bulletin board of the management apparatus 600 ′, it is possible to eliminate the necessity of synchronizing the transmission side apparatus 210 ′ and the plurality of reception side apparatuses 310 _{1 to} 310 _m . Accordingly, complicated synchronization processing can be avoided, and the configuration and setting of the devices of the transmission side device 210 ′ and the plurality of reception side devices 310 _{1 to} 310 _m can be simplified. This effect is significant in “one-to-many” communication involving a plurality of devices for video transmission.

In the example described above, the management apparatus 600 ′ has been described as having an electronic bulletin board function, but the present invention is not limited to this. The management device 600 ′ may include any means that enables the transmission status of the digital file to be managed through the transmission side device 210 ′ and the plurality of reception side devices 310 _{1 to} 310 _m . For example, a configuration in which the management device 600 ′ actively transmits transmission-related information or reception-related information to the plurality of reception side devices 310 _{1 to} 310 _m or the transmission side device 210 ′ is also within the scope of the present invention.

  The present invention is not limited to the embodiment described above. It is understood that the scope of the present invention should be construed only by the claims. It is understood that those skilled in the art can implement an equivalent range based on the description of the present invention and the common general technical knowledge from the description of specific preferred embodiments of the present invention.

  The present invention is useful for providing a system, apparatus, method, and program capable of reliably transmitting a digital file via a one-way line.

200 Transmission side 210, 210 ′ Transmission side device 220, 220 ′ Computer device 230, 230 ′ Transmitter 300 Reception side 310 Reception side device 320 Computer device 330 Receiver 400 Unidirectional line 500 Bidirectional line 600, 600 ′ Management apparatus 1000 2000, 3000, 4000 system

Claims (21)

A system for transmitting a digital file, the system comprising:
A transmission side device;
And at least one receiving side device connected to the transmitting side device via a one-way line,
The transmission side device is configured to transmit a digital file divided into a plurality of segments to each of the at least one reception side device via the one-way line,
Each of the at least one receiving device is configured to receive the digital file from the transmitting device via the one-way line;
The transmission side device and each of the at least one reception side device are connected to each other via a bidirectional line,
The bidirectional line includes a first bidirectional line and a second bidirectional line;
The transmission side device is connected to a management device via the first bidirectional line,
The transmission side device is configured to transmit transmission related information regarding the digital file transmitted from the transmission side device to the management device via the first bidirectional line,
Each of the at least one receiving device is connected to the management device via the second bidirectional line;
Each of the at least one receiving side device is configured to transmit reception related information regarding the digital file received by the receiving side device to the management device via the second bidirectional line ,
The management device has a function of an electronic bulletin board,
The transmission side device writes the transmission related information on the electronic bulletin board in a text format,
Each of the at least one receiving side device writes the reception related information on the electronic bulletin board in a text format,
The management device is configured to manage the transmission status of the digital file to each of the at least one receiving device based on the transmission related information and the reception related information written on the electronic bulletin board. The system.   The system of claim 1, wherein the at least one receiving device is a receiving device. The reception related information includes error segment identification information for identifying a segment in which an error has occurred among the plurality of segments of the digital file received by the one receiving-side device,
When the transmission side apparatus receives the error segment identification information from the one reception side apparatus, based on the error segment identification information, the transmission side apparatus transmits the segment in which the error has occurred via the one-way line. The system according to claim 2, wherein the system is configured to transmit again to the one receiving device.   The system according to claim 2 or 3, wherein the division of the digital file into the plurality of segments is performed by the transmission-side apparatus.   The system according to claim 4, wherein the number of divisions when dividing the digital file into the plurality of segments is variable. The reception related information includes information indicating a rate of errors that occur when the transmission side device transmits the digital file to the one reception side device,
The transmission side device
The greater the error rate, the greater the number of divisions of the digital file,
The system according to claim 5, wherein the system is configured to decrease the number of divisions of the digital file as the error rate decreases. The one-way line is ASI line system according to any one of claims 2-6.   The system of claim 1, wherein the at least one receiving device is a plurality of receiving devices. Reception-related information transmitted from one of the plurality of receiving devices identifies a segment in which an error has occurred among the plurality of segments of the digital file received by the one receiving device. Error segment identification information
When the transmission side apparatus receives the error segment identification information from the one reception side apparatus, based on the error segment identification information, the transmission side apparatus transmits the segment in which the error has occurred via the one-way line. 9. The system of claim 8 , wherein the system is configured to transmit again to the one receiving device. The system according to claim 8 or 9 , wherein the division of the digital file into the plurality of segments is performed by the transmission side device. The system according to claim 10 , wherein the number of divisions when dividing the digital file into the plurality of segments is variable and determined for the plurality of receiving-side apparatuses as a whole. The system according to claim 10 , wherein the number of divisions when dividing the digital file into the plurality of segments is variable and is determined for each of the plurality of receiving-side apparatuses. The reception-related information transmitted from the first receiving device among the plurality of receiving devices is an error generated when the transmitting device transmits the digital file to the first receiving device. The reception related information transmitted from the second receiving side device among the plurality of receiving side devices includes information indicating the ratio, and the transmitting side device transmits the digital file to the second receiving side device. Including information indicating the percentage of errors that occurred during
The transmission side device
For the first receiving device:
The greater the error rate, the greater the number of divisions of the digital file transmitted to the first receiving device,
The smaller the error rate, the smaller the number of divisions of the digital file transmitted to the first receiving device,
For the second receiving device,
The greater the error rate, the greater the number of divisions of the digital file transmitted to the second receiving device,
13. The system according to claim 12 , wherein the system is configured to reduce the number of divisions of the digital file transmitted to the second receiving device as the error rate decreases. The system according to any one of claims 8 to 13 , wherein the one-way line is a satellite line. A method for transmitting a digital file, wherein the method is performed in a system comprising a transmission side device and at least one reception side device connected to the transmission side device via a one-way line, The transmission side device and each of the at least one receiving side device are connected to each other via a bidirectional line, and the bidirectional line includes a first bidirectional line and a second bidirectional line, The transmission side device is connected to the management device via the first bidirectional line, and each of the at least one reception side device is connected to the management device via the second bidirectional line. The management device has a function of an electronic bulletin board, and the method includes:
The transmission side device transmits a digital file divided into a plurality of segments to each of the at least one reception side device via the one-way line;
Each of the at least one receiving device receives the digital file from the transmitting device via the one-way line;
The transmission side device transmits transmission related information regarding the digital file transmitted from the transmission side device to the management device via the first bidirectional line, and the transmission side device Writing transmission-related information in text format on the electronic bulletin board ;
Each of the at least one receiving side device transmits reception related information regarding the digital file received by the receiving side device to the management device via the second bidirectional line, the at least one receiving side device comprising: each of the one receiving apparatus writes a text format the received related information in the electronic bulletin board, and that seen including,
The management device is configured to manage the transmission status of the digital file to each of the at least one receiving device based on the transmission related information and the reception related information written on the electronic bulletin board. Is that way. An apparatus for transmitting a digital file, wherein the apparatus is connected to each of at least one receiving-side apparatus via a one-way line and a bidirectional line, and the bidirectional line is a first both And a second bidirectional line, wherein the device is connected to a management device via the first bidirectional line, and the management device is connected via the second bidirectional line. Connected to each of the at least one receiving device, the management device has a function of an electronic bulletin board ,
Transmitting a digital file divided into a plurality of segments to each of the at least one receiving device via the one-way line;
Transmitting transmission-related information regarding the digital file transmitted from the device to the management device via the first bidirectional line, the device transmitting the transmission-related information to the electronic bulletin board in a text format. Write in, and
The method comprising: obtaining a reception-related information for the at least one each of thus received the digital file of the receiving apparatus from the management device via the first bidirectional line, the received related information, wherein Each of the at least one receiving side device is written in text format on the electronic bulletin board, and the management device is based on the transmission related information and the reception related information written on the electronic bulletin board. A device configured to manage the transmission status of the digital file for each of the two receiving devices. A method for transmitting a digital file, wherein the method is performed in a device connected to each of at least one receiving device via a unidirectional line and a bidirectional line , the bidirectional line comprising: One bidirectional line and a second bidirectional line, wherein the device is connected to the management device via the first bidirectional line, and the management device is connected to the second bidirectional line. Connected to each of the at least one receiving-side device, the management device has a function of an electronic bulletin board, and the method includes:
Transmitting a digital file divided into a plurality of segments to each of the at least one receiving device via the one-way line;
Transmitting transmission-related information regarding the digital file transmitted from the device to the management device via the first bidirectional line, the device transmitting the transmission-related information to the electronic bulletin board in a text format. Write in, and
The method comprising: obtaining a reception-related information for the at least one each of thus received the digital file of the receiving apparatus from the management device via the first bidirectional line, the received related information, wherein Each of the at least one receiving side device is written in text format on the electronic bulletin board, and the management device is based on the transmission related information and the reception related information written on the electronic bulletin board. Configured to manage the transmission status of the digital file for each of two receiving devices . A program for transmitting a digital file, wherein the program is executed in a device connected to each of at least one receiving side device via a one-way line and a two-way line, and the device includes a processor unit. The bidirectional line includes a first bidirectional line and a second bidirectional line, and the device is connected to a management device via the first bidirectional line, and the management device Is connected to each of the at least one receiving side device via the second bidirectional line, the management device has a function of an electronic bulletin board, and the program is executed,
Transmitting a digital file divided into a plurality of segments to each of the at least one receiving device via the one-way line;
Transmitting transmission-related information regarding the digital file transmitted from the device to the management device via the first bidirectional line, the device transmitting the transmission-related information to the electronic bulletin board in a text format. Write in, and
The method comprising: obtaining a reception-related information for the at least one each of thus received the digital file of the receiving apparatus from the management device via the first bidirectional line, the received related information, wherein Each of the at least one receiving side device is written in text format on the electronic bulletin board, and the management device is based on the transmission related information and the reception related information written on the electronic bulletin board. A program for causing the processor unit to perform a process including: managing the transmission status of the digital file for each of the two receiving-side devices . An apparatus for receiving a digital file, wherein the apparatus is connected to a transmission-side apparatus via a one-way line and a bidirectional line, and the bidirectional line includes a first bidirectional line and a second line. The device is connected to a management device via the second bidirectional line, and the management device is connected to the transmission side device via the first bidirectional line. Connected, the management device has a function of an electronic bulletin board ,
Receiving a digital file divided into a plurality of segments from the transmission side device via the one-way line;
Obtaining transmission-related information related to the digital file transmitted from the transmission-side device from the management device via the second bidirectional line , wherein the transmission-related information is acquired by the transmission-side device by the electronic device. Written in text form on the bulletin board ,
Transmitting reception-related information about the digital file received by the device to the management device via the second bidirectional line, the device sending the reception-related information to the electronic bulletin board in a text format And the management device is configured to manage the transmission status of the digital file to the device based on the transmission related information and the reception related information written on the electronic bulletin board. Configured to do the device. A method for receiving a digital file, wherein the method is performed in a device connected to a transmission side device via a one-way line and a bidirectional line, the bidirectional line being a first bidirectional line. And the second bidirectional line, wherein the device is connected to the management device via the second bidirectional line, and the management device transmits the transmission via the first bidirectional line. The management device has the function of an electronic bulletin board, and the method includes:
Receiving a digital file divided into a plurality of segments from the transmission side device via the one-way line;
Obtaining transmission-related information related to the digital file transmitted from the transmission-side device from the management device via the second bidirectional line , wherein the transmission-related information is acquired by the transmission-side device by the electronic device. Written in text form on the bulletin board ,
Transmitting reception-related information about the digital file received by the device to the management device via the second bidirectional line, the device sending the reception-related information to the electronic bulletin board in a text format And the management device is configured to manage the transmission status of the digital file to the device based on the transmission related information and the reception related information written on the electronic bulletin board. Including a method. A program for receiving a digital file, wherein the program is executed in a device connected to a transmission side device via a one-way line and a two-way line, and the device includes a processor unit, and the two-way The line includes a first bidirectional line and a second bidirectional line, the device is connected to a management device via the second bidirectional line, and the management device is Are connected to the transmission side device via the bidirectional line, the management device has a function of an electronic bulletin board, and the program is executed,
Receiving a digital file divided into a plurality of segments from the transmission side device via the one-way line;
Obtaining transmission-related information related to the digital file transmitted from the transmission-side device from the management device via the second bidirectional line , wherein the transmission-related information is acquired by the transmission-side device by the electronic device. Written in text form on the bulletin board ,
Transmitting reception-related information about the digital file received by the device to the management device via the second bidirectional line, the device sending the reception-related information to the electronic bulletin board in a text format And the management device is configured to manage the transmission status of the digital file to the device based on the transmission related information and the reception related information written on the electronic bulletin board. The program which makes the said processor part perform the process containing.