JP2017200134A - Communication device, communication system, communication method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce processing load of a communication device related to a process of transmitting a plurality of divided data received by the communication device from the other communication device.SOLUTION: A transmitting device 100 acquires content data, and divides the acquired content data into predetermined transmission units to generate a plurality of pieces of divided data. Here, the transmission device 100 generates the plurality of pieces of divided data to include an information addition area for a relay device 200 to add information including an identifier of a communication path 210 to the plurality of pieces of divided data and transmit the divided data. Then, the transmission device 100 transmits the generated plurality of pieces of divided data to the relay device 200.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a technique for transmitting divided data obtained by dividing content data into predetermined transmission units.

  Conventionally, there is a system that transmits content data such as an image captured by a camcorder by real-time streaming based on a protocol such as RTP (Real-time Transport Protocol). Also, content data can be transmitted with high communication efficiency by distributing a plurality of divided data (packets, etc.) obtained by dividing the content data through a plurality of communication paths such as 3G lines and LTE (Long Term Evolution) lines. There is a system to do. MPRTP (Multipath RTP) has been proposed in IETF (Internet Engineering Task Force) as a protocol for distributing and transmitting content data using a plurality of communication paths. MPRTP is a protocol obtained by extending the above RTP, and has a configuration in which information for identifying a communication path, a sequence number for each communication path, and the like are described in an extended header of the RTP packet. Japanese Patent Application Laid-Open No. 2004-228561 describes a technique for distributing a transmission packet to each interface in consideration of a load state of the network when data is transmitted through a plurality of network interfaces.

  When a transmission device (such as a camcorder) that acquires content data does not have a distributed transmission function, the transmission device transmits content data to a relay device that has a distributed transmission function. Can be considered to receive and distribute transmission.

Japanese Patent No. 5675757

  However, there may be a case where the processing load of the communication device is increased due to the processing in which the communication device transmits a plurality of pieces of divided data received from other communication devices. For example, when the transmission device transmits a plurality of packets to the relay device based on RTP, and the relay device adds information to the headers of the plurality of packets received from the transmission device and transmits the information using a plurality of communication paths based on MPRTP. think of. In this case, if an MPRTP packet having a header larger than the RTP packet received by the relay device is newly generated, there is a possibility that the processing load on the relay device may increase due to processing such as data copy.

  The present invention has been made in view of the above problems, and provides a technique for reducing the processing load of the communication device related to a process in which the communication device transmits a plurality of pieces of divided data received from another communication device. For the purpose.

  In order to solve the above problems, a communication apparatus according to the present invention has, for example, the following configuration. That is, an acquisition unit that acquires content data, and a generation unit that generates a plurality of divided data by dividing the content data acquired by the acquisition unit into a predetermined transmission unit, wherein another communication device is configured to generate the plurality of divisions. Generating means for generating the plurality of divided data such that an information addition area for adding information including an identifier of a communication path to data and transmitting the data is included in each of the plurality of divided data; and Transmitting means for transmitting the generated plurality of divided data to the other communication device.

  ADVANTAGE OF THE INVENTION According to this invention, the processing load of the said communication apparatus which concerns on the process which a communication apparatus transmits the some division | segmentation data received from the other apparatus can be reduced.

1 is a diagram illustrating a configuration of a communication system 10 according to an embodiment. It is a figure for demonstrating the function structure of the image transmission apparatus 100 and relay apparatus 200 which concern on embodiment. 2 is a block diagram illustrating a hardware configuration of an image transmission device 100. FIG. It is a figure for demonstrating the conversion process of the packet which concerns on embodiment. 4 is a flowchart for explaining the operation of the image transmission apparatus 100. 5 is a flowchart for explaining the operation of relay apparatus 200.

  Embodiments of the present invention will be described below with reference to the drawings. Note that the configurations described in the following embodiments are examples, and the present invention is not limited to the illustrated configurations.

[System configuration]
FIG. 1 shows an overall configuration of a communication system 10 according to the present embodiment. The communication system 10 includes three types of communication devices, and in the present embodiment, these communication devices are distinguished from the image transmission device 100 (hereinafter, the transmission device 100), the relay device 200, and the reception device 300. The transmission apparatus 100 is connected to the relay apparatus 200 via the communication path 110, and the relay apparatus 200 is further connected to the reception apparatus 300 via the communication path 210-1, the communication path 210-2, and the communication path 210-3. . In this embodiment, when there is no special designation, the communication path 210-1 to the communication path 210-3 are described as the communication path 210 without distinction. The relay apparatus 200 can transmit data in parallel using a plurality of communication paths 210. Note that the number of communication paths 210 is not limited to three, and may be any number.

  The transmission device 100 divides image data acquired by imaging into packets, and transmits the packets to the relay device 200 via the communication path 110. In the present embodiment, the transmission device 100 transmits packetized image data by real-time streaming based on RTP (Real-time Transport Protocol). In the present embodiment, the image data transmitted by the transmission device 100 is a moving image, but the image data may be a still image. Further, the content data acquired and transmitted by the transmission device 100 is not limited to image data, and may be audio data, for example. Specific examples of the transmission device 100 include a digital camera, a video camera, a smartphone, a PC, a mobile phone, and the like. Specific examples of the communication path 110 include a wired LAN (Local Area Network) and a wireless LAN. Note that the communication path 110 is not limited to a LAN but may be a WAN (Wide Area Network) or a combination of a LAN and a WAN.

  The relay apparatus 200 receives a plurality of packets constituting the image data from the transmission apparatus 100, and transmits the received plurality of packets distributed over a plurality of communication paths 210. In the present embodiment, the relay device 200 transmits data based on MPRTP (Multipath RTP). MPRTP is a protocol that is an extension of RTP, and is a protocol for distributed transmission of content data using a plurality of communication paths 210. FIG. 4 shows an example of the RTP packet 400 and the MPRTP packet 410. The MPRTP packet 410 is a packet in which information related to the communication path 210 is added to the extension header of the RTP packet 400. Details of FIG. 4 will be described later.

  Each communication path 210 is a wireless communication line, a wired communication line, or a communication line that combines wireless and wired, and a device used for the path, a protocol used for communication, or both are different for each communication path 210. The communication path 210 includes, for example, a mobile communication network such as 3G, 4G, and LTE (Long Term Evolution), a wireless LAN such as WiFi (Wireless Fidelity), a wired LAN, and the Internet. For example, the relay apparatus 200 transmits a plurality of packets in parallel using a plurality of communication paths 210 that are mobile communication networks each having a different base station.

  When the relay apparatus 200 performs transmission in parallel through the plurality of communication paths 210, the communication band is widened and communication efficiency can be improved as compared with the case where transmission is performed through the single communication path 210. In addition, when a failure occurs in any of the plurality of communication paths 210 performing transmission in parallel, the relay apparatus 200 transmits another transmission of data transmitted through the communication path 210 in which the failure has occurred. Switch to the communication path 210. As a result, even if a failure occurs in any of the communication paths 210, communication can be continued, and communication delay and data loss can be reduced.

  Specific examples of the relay device 200 include a router, a server device, a smartphone, a PC, a mobile phone, and the like. The receiving device 300 receives the image data transmitted from the relay device 200 via the plurality of communication paths 210, and displays and stores the image data. Specific examples of the receiving device 300 include, but are not limited to, a PC, a smartphone, a television, and a mobile phone.

  It should be noted that a device that distributes and transmits packets constituting image data, such as the relay device 200, is preferably installed in an environment with good radio wave conditions such as outdoors, particularly when performing distributed transmission using a mobile communication network or the like. . On the other hand, devices such as camcorders that acquire image data may be used in environments with poor radio wave conditions, such as indoors. In such a case, in a conventional system, a device that performs distributed transmission using a mobile communication network is installed in an environment where the radio wave condition is good, and the device and the camcorder are connected by an SDI (Serial Digital Interface) cable. It was. A device that performs distributed transmission transmits an image received from a camcorder via an SDI cable using a mobile communication network.

  However, in communication using an SDI cable, the signal is greatly attenuated as the communication distance is longer, and the influence of the attenuation is greater as the amount of signal to be communicated is larger. Therefore, the higher the image data communicated via the SDI cable, the shorter the communication distance. Also, since the SDI cable is a coaxial cable and the coaxial cable with good communication quality tends to be thick, the handling of the cable is inconvenient when the camcorder connected with the SDI cable is moved.

  Therefore, the transmission apparatus 100 according to the present embodiment packetizes the image data and transmits the packetized data to the relay apparatus 200. As a result, the transmission device 100 and the relay device 200 are directly connected by an Ethernet (registered trademark) cable thinner than an SDI cable, connected via a wired LAN network already installed in a building, or connected by a wireless LAN. I can do it. As a result, the movement of the transmission apparatus 100 and the connection between the transmission apparatus 100 and the relay apparatus 200 are simplified. Further, when the transmission apparatus 100 packetizes image data and transmits it to the relay apparatus 200, the relay apparatus 200 performs packet conversion processing to perform distributed transmission. Therefore, the transmission apparatus 100 according to the present embodiment generates a packet that allows the relay apparatus 200 to simplify the conversion process.

[Function configuration]
Next, functional configurations of the transmission device 100 and the relay device 200 according to the present embodiment will be described with reference to FIG. The transmission apparatus 100 includes an image data acquisition unit 101 (hereinafter, acquisition unit 101), an encoding unit 102, a packet generation unit 103, and a data transmission unit 104. On the other hand, the relay device 200 includes a data reception unit 201, a data holding unit 202, a header conversion unit 203, a transmission control unit 204, a communication I / F (interface) 205-1, a communication I / F 205-2, and a communication I / F 205-. 3. In this embodiment, when there is no special designation | designated, communication I / F205-1 thru | or communication I / F205-3 are described as communication I / F205 without distinguishing. The relay device 200 has the same number of communication I / Fs 205 corresponding to each of the plurality of communication paths 210.

  The acquisition unit 101 performs imaging by controlling a lens and an imaging sensor (not shown) included in the transmission device 100, and acquires image data before encoding. The encoding unit 102 converts the image data acquired by the acquisition unit 101 into, for example, H.264. The encoding is performed by an encoding method such as H.264 or HEVC. The packet generation unit 103 divides the encoded image data encoded by the encoding unit 102 into a format corresponding to a protocol (for example, RTP) used for data transmission by the data transmission unit 104 to generate a packet. Here, the packet generation unit 103 generates a packet so that the relay apparatus 200 can easily perform a process of distributed transmission of a plurality of packets received from the transmission apparatus 100. Details of packet generation will be described later. The data transmission unit 104 transmits the packet generated by the packet generation unit 103 to the relay device 200 via the communication path 110.

  The data reception unit 201 receives a packet transmitted from the transmission device 100 via the communication path 110. The data holding unit 202 holds the packet received by the data receiving unit 201. The header conversion unit 203 acquires information about the communication path 210 used by the relay apparatus 200 for data transmission from the transmission control unit 204, and converts the header of the packet held by the data holding unit 202 based on the information. I do. The transmission control unit 204 distributes and transmits the plurality of packets whose headers have been converted by the header conversion unit 203 to the receiving apparatus 300 through the plurality of communication paths 210 via the plurality of communication I / Fs 205.

[Hardware configuration]
FIG. 3 is a block diagram illustrating a hardware configuration of the transmission device 100. The transmission device 100 includes a CPU 121, a ROM 122, a RAM 123, an auxiliary storage device 124, a display unit 125, an operation unit 126, a communication unit 127, an imaging unit 128, and a bus 129. Note that the relay apparatus 200 does not include the imaging unit 128, but the other configuration of the relay apparatus 200 is the same as that of the transmission apparatus 100.

  The CPU 121 controls the entire transmission apparatus 100 using computer programs and data stored in the ROM 122 and RAM 123. That is, the CPU 121 controls each component shown in FIG. 3 to realize each functional unit of the transmission device 100 shown in FIG. The ROM 122 stores programs and parameters that do not need to be changed. The RAM 123 temporarily stores programs and data supplied from the auxiliary storage device 124 and data supplied from the outside via the communication unit 127. The auxiliary storage device 124 is composed of, for example, a hard disk drive device and stores content data such as still images and moving images.

  The display unit 125 includes a liquid crystal display, for example, and displays a GUI (Graphical User Interface) for the user to operate the transmission device 100. The operation unit 126 includes button switches and dials, and inputs various instructions to the CPU 121 in response to user operations. The communication unit 127 communicates with an external device such as the relay device 200. For example, when the transmission device 100 is connected to an external device by wire, a LAN cable or the like is connected to the communication unit 127. Note that when the transmission device 100 has a function of performing wireless communication with an external device, the communication unit 127 includes an antenna. The imaging unit 128 includes a lens, an imaging sensor, and the like, and performs imaging to acquire image data. Image data acquired by the imaging unit 128 is stored in the RAM 123 or the auxiliary storage device 124. The bus 129 connects the units of the transmission device 100 and transmits information.

  In this embodiment, the CPU 121 executes a program to control communication between the transmission device 100 and an external device via the communication unit 127. However, at least a part of communication between the transmission device 100 and the external device is controlled. The communication unit 127 may be controlled by hardware processing. In the present embodiment, the display unit 125 and the operation unit 126 exist inside the transmission device 100, but at least one of the display unit 125 and the operation unit 126 exists as another device outside the transmission device 100. Good. In this case, the CPU 121 operates as a display control unit that controls the display unit 125 and an operation control unit that controls the operation unit 126. Furthermore, the imaging unit 128 may exist outside the transmission device 100 as an imaging device. In this case, the communication unit 127 receives and acquires the image data generated by the imaging device imaging.

[Operation flow]
Next, the operation flow of the transmission apparatus 100 will be described with reference to FIG. The process illustrated in FIG. 5 is started at a timing when the user performs an operation for causing the transmission apparatus 100 to start transmission of a captured image. However, the start timing of the process shown in FIG. 5 is not limited to the above timing. The processing shown in FIG. 5 is realized by the CPU 121 of the transmission apparatus 100 developing and executing a program stored in the ROM 122 on the RAM 123.

  In step S501, the acquisition unit 101 captures an image and acquires image data. In step S <b> 502, the encoding unit 102 acquires encoded image data by encoding the image data acquired by the acquisition unit 101. Note that the content data acquired by the transmission device 100 is not limited to image data. For example, the acquisition unit 101 may collect sound to acquire audio data, and the encoding unit 102 may acquire encoded audio data. In step S503, the packet generation unit 103 divides the encoded image data acquired by the encoding unit 102 into predetermined transmission units, and generates a plurality of pieces of divided data. In the present embodiment, the divided data generated by the packet generation unit 103 is the RTP packet 400. However, the present invention is not limited to this, and the divided data may be an arbitrary PDU (Protocol Data Unit). In S504, the data transmission unit 104 transmits the plurality of divided data generated by the packet generation unit 103 to the relay device 200. The transmission of the divided data is performed based on RTP, for example.

  Note that the relay device 200 that has received a plurality of pieces of divided data transmitted from the transmission device 100 adds information including the identifier of the communication path 210 to each piece of divided data in order to transmit the divided data through a plurality of communication paths. To do. Specifically, the relay apparatus 200 converts the RTP packet 400 received from the transmission apparatus 100 into an MPRTP packet 410 by adding an MPRTP header including an identifier of the communication path 210, and the converted packet is based on MPRTP. And distributed transmission. Therefore, in order to simplify the packet conversion processing by the relay apparatus 200, the packet generation unit 103 of the transmission apparatus 100 has an information addition area for adding information including the identifier of the communication path 210 to each of the plurality of divided data. Division data is generated so as to be included.

  Here, the packet conversion processing according to the present embodiment will be described with reference to FIG. In FIG. 4, an RTP packet 400 is a packet generated by the packet generation unit 103, and an extension header includes a dummy header 401 that is an information addition area. On the other hand, the MPRTP packet 410 is a packet obtained by converting the RTP packet 400 by the relay device 200, and includes an MPRTP header 411 for distributed transmission to the plurality of communication paths 210 in the extension header. That is, the header conversion unit 203 of the relay apparatus 200 generates the MPRTP packet 410 by overwriting the MPRTP header 411 on the dummy header 401 portion of the RTP packet 400.

  In the example of FIG. 4, the extension header of the RTP packet 400 includes only the dummy header 401, but information other than the dummy header 401 such as information related to FEC (Forward Error Correction) may be included as the extension header. Further, the packet generated as the divided data by the packet generation unit 103 may be a packet having a format different from that of the RTP packet 400 in which the information addition area is included in the header. In this case, the data transmission unit 104 transmits data based on a protocol different from RTP.

  Since both the RTP packet 400 and the MPRTP packet 410 have an extension header, 1 is set to the value of the identifier “x” indicating the presence or absence of the extension header. An extension header identifier 402 in the dummy header 401 is set with an identifier indicating that the RTP packet 400 has the dummy header 401 as an information addition region, and length 403 includes information indicating the length of the dummy region 404. Is set. Since the dummy header 401 is an information addition area to which the MPRTP header 411 is added, it is desirable that the dummy header 401 has the same length as the MPRTP header 411 to be added. The length 403 indicates the length of the dummy area 404 in units of 32 bits. In the example of FIG. 4, 2 indicating the length of two blocks is set as the length 403 value.

  Note that the packet generation unit 103 may include supplementary information for the relay apparatus 200 to determine the communication path 210 for transmitting the MPRTP packet 410 in the dummy area 404 in the RTP packet 400. The supplemental information is information based on the content of the payload of the RTP packet 400, for example, information according to the type of the RTP packet 400. Specifically, when the RTP packet 400 having supplementary information is a packet constituting a frame of image data encoded based on inter-frame prediction, the information indicates the frame type of the frame. The frame type in the present embodiment is any one of an I frame (Intra-coded Frame), a P frame (Predicted Frame), and a B frame (Bi-directional Predicted Frame). By including such supplementary information in the RTP packet 400, the relay apparatus 200 can perform control to transmit a highly important packet such as a packet corresponding to the I frame through the highly reliable communication path 210. Further, for example, the supplemental information may be information corresponding to the relationship between the RTP packet 400 having the supplemental information and other packets included in the plurality of RTP packets 400 transmitted by the transmission device 100. By including such supplementary information in the dummy area 404, the transmission apparatus 100 can inform the relay apparatus 200 which RTP packet 400 should be transmitted through the same communication path 210 as any other RTP packet 400. The contents of supplementary information are not limited to these examples.

  On the other hand, the MPRTP header 411 includes a Subflow ID 412 that is an identifier for identifying the communication path 210 used for transmission of the packet among the plurality of communication paths 210. Also included is a Subflow-specific Seq Number 413 that is an independent sequence number for each communication path 210. The receiving apparatus 300 confirms the Subflow IDs 412 of the plurality of MPRTP packets 410 received from the relay apparatus 200, thereby determining whether these packets have been transmitted through different communication paths 210 or the same communication path 210. Can be identified. In addition, the receiving apparatus 300 confirms the Subflow-specific Seq Number 413 and the Subflow ID 412 of the plurality of MPRTP packets 410 received continuously. If there is a packet loss, a loss occurs in the Subflow-specific Seq Number 413 corresponding to the Subflow ID 412 of the communication path 210 that should have received the packet. Thereby, the receiving apparatus 300 can identify the communication path 210 corresponding to the lost packet.

  Next, the operation flow of the relay apparatus 200 will be described with reference to FIG. The process illustrated in FIG. 6 is started at the timing when the transmission apparatus 100 and the relay apparatus 200 perform the process for starting communication. However, the start timing of the process shown in FIG. 6 is not limited to the above timing. The processing shown in FIG. 6 is realized by the CPU 121 of the relay apparatus 200 developing the program stored in the ROM 122 on the RAM 123 and executing it.

  In step S <b> 601, the data receiving unit 201 acquires the received divided data (RTP packet 400) obtained by dividing the content data into predetermined transmission units, and causes the data holding unit 202 to hold the acquired divided data. In step S <b> 602, the header conversion unit 203 analyzes the RTP packet 400 held by the data holding unit 202. Based on the analysis result, in step S <b> 603, the transmission control unit 204 determines the communication path 210 to be used for transmitting the MPRTP packet 410. As a method for determining the communication path 210, for example, H.264. For example, there is a method of determining the communication path 210 in accordance with the frame type of image data encoded according to an encoding method based on inter-frame prediction such as H.264 or HEVC. In addition, the relay apparatus 200 may determine the communication path 210 for each packet based on the communication quality of each communication path 210, for example, the error rate or the delay time.

  Note that when the transmitting apparatus 100 includes supplementary information such as information based on the contents of the payload in the dummy area 404 of the RTP packet 400, the header conversion unit 203 may analyze only the header of the RTP packet 400 in S602. Then, the transmission control unit 204 may determine a communication path for transmitting the MPRTP packet 410 based on the content of the supplementary information included in the dummy header 401 of the RTP packet 400. By doing so, the processing load of the relay apparatus 200 related to the packet analysis is reduced.

  In S <b> 604, based on the analysis result in S <b> 602, the header conversion unit 203 determines whether or not the information addition area (dummy header 401) is included in the extension header of the RTP packet 400 acquired by the data reception unit 201. In this embodiment, the header conversion unit 203 determines whether or not the dummy header 401 is included by checking the extension header identifier 402 of the RTP packet 400. However, the present invention is not limited to this. For example, the transmission device 100 may separately transmit a message for notifying transmission of a packet including the dummy header 401 to the relay device 200. If the header conversion unit 203 determines that the dummy header 401 is included, the header conversion unit 203 rewrites the extension header of the RTP packet 400 for MPRTP in S605. Specifically, as described with reference to FIG. 4, the added divided data in which the information (MPRTP header 411) including the identifier of the communication path 210 is added to the information addition area (dummy header 401) of the divided data (RTP packet 400). (MPRTP packet 410) is generated. The contents of the added MPRTP header 411 are determined according to the communication path 210 determined in S603.

  On the other hand, the relay apparatus 200 may receive an RTP packet 400 that does not include the dummy header 401 from an external apparatus. In this case, the relay apparatus 200 cannot directly overwrite the MPRTP header 411 in the RTP packet 400 as in the process in S605. Therefore, if it is determined in S604 that the dummy header 401 is not included, the process proceeds to S607.

  In step S607, the header conversion unit 203 newly secures a storage area for packet generation. In step S <b> 608, the header conversion unit 203 copies only the header portion of the RTP packet 400 held by the data holding unit 202 to the secured storage area. Here, if the value of the identifier indicating the presence or absence of the extension header is 0 (header extension is invalid) in the copied header, the header conversion unit 203 rewrites the value to 1 (header extension is valid). In step S <b> 609, the header conversion unit 203 writes the MPRTP header 411 in the reserved storage area as the extension header of the header portion of the copied RTP packet 400. In S610, the header conversion unit 203 copies the payload data of the RTP packet 400 held by the data holding unit 202 to the reserved storage area as payload data following the MPRTP header 411. As a result, the MPRTP packet 410 including the MPRTP header 411 is generated in the reserved storage area.

  The MPRTP packet 410 generated by the processing of S605 and the MPRTP packet 410 generated by the processing of S607 to S610 have the same contents, but the processing load of the relay apparatus 200 related to the generation is different. Since the process of S605 only overwrites the MPRTP header 411 in the dummy header 401 portion of the RTP packet 400, the process is simple and the load on the relay apparatus 200 is small. On the other hand, since the processes from S607 to S610 include a process of copying the RTP packet 400, the load applied to the relay apparatus 200 by the process is larger than the process of S605. Further, when the processing from S607 to S610 is performed, the relay device 200 secures a storage area for the packet copy destination, so that the memory resource consumption of the relay device 200 is larger than that in the case where the processing of S605 is performed.

  In S <b> 606, the transmission control unit 204 transmits the MPRTP packet 410 generated in S <b> 605 or S <b> 610 to the receiving apparatus 300 through the communication path 210 according to the content of the MPRTP header 411. That is, the transmission control unit 204 distributes and transmits a plurality of MPRTP packets 410 having different Subflow IDs 502 through different communication I / Fs 205.

  In the above description, the case where the relay apparatus 200 receives the RTP packet 400 as the divided data and the MPRTP packet 410 is distributedly transmitted has been described. However, the packet received by the relay apparatus 200 is a packet having a different format from the RTP packet 400. May be. That is, when the relay apparatus 200 determines that the information addition area is included in the header of the received packet, the relay apparatus 200 may generate and transmit the added packet to which the information including the identifier of the communication path 210 is added. . Further, the packet transmitted by the relay apparatus 200 is not limited to the MPRTP packet 410, and the relay apparatus 200 may perform transmission through the communication path 210 corresponding to the identifier added to the packet. Further, the divided data is not limited to a packet and may be an arbitrary PDU.

  As described above, the transmission device 100 according to the present embodiment acquires content data and divides the acquired content data into predetermined transmission units to generate a plurality of divided data. Here, the transmission apparatus 100 generates the plurality of pieces of divided data so that the relay apparatus 200 includes an information addition region for adding information including the identifier of the communication path 210 to the pieces of divided data and transmitting the information. . Then, the transmission device 100 transmits the generated plurality of divided data to the relay device 200. Thereby, when the relay apparatus 200 transmits a plurality of pieces of divided data received from the transmission apparatus 100, the process of converting the divided data received by the relay apparatus 200 for distributed transmission is simplified, and the processing load of the relay apparatus 200 is reduced. Can be reduced. Further, since the conversion process is simplified, the consumption of memory resources of the relay device 200 is reduced, and the delay from when the relay device 200 receives data until it is distributedly transmitted is also reduced.

  Also, the relay device 200 according to the present embodiment acquires the divided data obtained by dividing the content data into predetermined transmission units, and the divided data acquired by the information addition area for adding information including the identifier of the communication path 210. Is included. When the relay device 200 determines that the information addition area is included in the acquired divided data, the added divided data in which information including the identifier of the communication path 210 is added to the information addition area of the divided data. Is generated. Furthermore, the relay device 200 transmits the generated added divided data through the communication path 210 according to the information including the identifier of the communication path 210 added to the added divided data. Thereby, the relay device 200 transmits a plurality of pieces of divided data through the plurality of communication paths 210 by converting the divided data by a simple process when the acquired divided data includes an information addition region. Can do. As a result, the processing load on the relay device 200 can be reduced.

  In the present embodiment, the case has been described in which the entire MPRTP header 411 is added as information including the identifier of the communication path 210 to the RTP packet 400 received by the relay apparatus 200 from the transmission apparatus 100. However, the present invention is not limited to this, and the information including the identifier of the communication path 210 added by the relay apparatus 200 may be a part of the MPRTP header 411. For example, the transmission device 100 generates an RTP packet 400 in which a part of the MPRTP header 411 is written in the dummy header 401 and transmits the RTP packet 400 to the relay device 200. Then, the relay device 200 may add a portion of the MPRTP header 411 that has not yet been written in the dummy header 401 of the RTP packet 400 received from the transmission device 100. As a result, the processing load related to the packet conversion processing of the relay device 200 can be greatly reduced.

  In the present embodiment, the case where the transmission apparatus 100 transmits data to one relay apparatus 200 has been described. However, the present invention is not limited to this, and the transmission device 100 may transmit the acquired content data to the plurality of relay devices 200. Also, the relay apparatus 200 that performs distributed transmission (transmit based on MPRTP) is transmitted to a plurality of relay apparatuses 200 that are transmission destinations, and data is transmitted via a single communication path 210 without performing distributed transmission (to RTP). Relay device 200 (which performs transmission based on the network) may be included. In such a case, the transmission apparatus 100 acquires information indicating whether each relay apparatus 200 performs distributed transmission using the plurality of communication paths 210. The transmission device 100 may acquire this information from each relay device 200 or may be acquired from other external devices. Further, the user may directly input this information by operating the transmission device 100.

  The transmitting apparatus 100 that has acquired information indicating whether to perform distributed transmission generates a plurality of RTP packets 400 including the dummy header 401 and a plurality of RTP packets 400 not including the dummy header 401 from the same content data. The transmitting apparatus 100 transmits a plurality of RTP packets 400 including the dummy header 401 to the relay apparatus 200 that transmits data through the plurality of communication paths 210. The transmission apparatus 100 transmits the RTP packet 400 that does not include the dummy header 401 to the relay apparatus 200 that transmits data through the single communication path 210. Thereby, the data amount of packets received by the relay device 200 that transmits data through the single communication path 210 is reduced while reducing the load related to the packet conversion processing of the relay device 200 that transmits data through the plurality of communication paths 210. It can be prevented from becoming unnecessarily large.

  In the present embodiment, the case where the relay apparatus 200 transmits data in parallel through the plurality of communication paths 210 has been mainly described, but the present invention is not limited to this. For example, the relay apparatus 200 may select one of a plurality of communication paths 210 such as a wired LAN and a wireless LAN and use it for data transmission. Also in this case, when transmitting the divided data received from the transmission apparatus 100, the relay apparatus 200 adds information for identifying the communication path 210 used for transmission to the information addition area of the divided data. As a result, the receiving device 300 that has received data from the relay device 200 can determine what communication path 210 the data is transmitted through.

  The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions. Further, the program may be provided by being recorded on a computer-readable recording medium.

100 Transmitting device 200 Relay device 210 Communication path

Claims (20)

A communication device,
Acquisition means for acquiring content data;
A generation means for generating a plurality of divided data by dividing the content data acquired by the acquisition means into a predetermined transmission unit, and another communication device adds information including a communication path identifier to the plurality of divided data Generating means for generating the plurality of divided data such that an information addition area for transmission is included in each of the plurality of divided data;
A communication device comprising: a transmission unit configured to transmit the plurality of pieces of divided data generated by the generation unit to the other communication device.   The other communication device determines a communication path for transmission of the divided data to which the information including the identifier of the communication path is added in the information addition area of the divided data generated by the generation unit. The communication apparatus according to claim 1, further comprising supplementary information.   The communication apparatus according to claim 2, wherein the supplementary information corresponding to a type of the divided data is included in the information addition area of the divided data generated by the generation unit.   The generation unit generates the plurality of divided data so that each of the plurality of divided data includes information indicating that the divided data includes the information addition area. 4. The communication device according to any one of 3. A second generation unit configured to divide the content data acquired by the acquisition unit into a predetermined transmission unit and generate a plurality of divided data not including the information addition region;
The transmission means transmits the plurality of divided data generated by the generation means to another communication apparatus that transmits data through a plurality of communication paths, and transmits the data through a single communication path. The communication apparatus according to claim 1, wherein a plurality of pieces of divided data generated by the second generation unit are transmitted.   The communication apparatus according to claim 1, wherein the generation unit generates a packet including the information addition area in a header as the divided data. The generation unit generates an RTP (Real-time Transport Protocol) packet in which the information addition area is included in an extension header as the divided data,
The transmission means transmits the plurality of divided data generated by the generation means to the other communication device based on RTP,
The communication apparatus according to claim 1, wherein the information including the identifier of the communication path is the whole or a part of an MPRTP (Multipath RTP) header. Obtaining means for obtaining divided data obtained by dividing content data into predetermined transmission units;
A discriminating unit for discriminating that an information addition area for adding information including an identifier of a communication path is included in the divided data acquired by the acquiring unit;
When the determination unit determines that the information addition area is included in the divided data acquired by the acquisition unit, information including an identifier of the communication path is added to the information addition area of the division data. Generating means for generating added divided data;
A communication apparatus comprising: a transmission unit configured to transmit the added divided data generated by the generation unit through a communication path according to information including an identifier of the communication path added to the added divided data. Based on the supplementary information included in the information addition area of the divided data acquired by the acquisition means, the added divided data in which information including the identifier of the communication path is added to the information addition area of the divided data is transmitted. Determining means for determining a communication path;
The added divided data generated by the generating unit includes the added divided data in which information including the identifier of the communication path according to the determination by the determining unit is added to the information addition region of the divided data acquired by the acquiring unit. The communication apparatus according to claim 8, wherein the communication apparatus is data.   The determination unit includes an identifier of the communication path in the information addition region of the divided data based on the type of the divided data indicated by the supplementary information included in the information addition region of the divided data acquired by the acquisition unit. The communication apparatus according to claim 9, wherein a communication path for transmitting the added divided data to which information is added is determined.   The identifier of the communication path is information for identifying a plurality of communication paths with different devices and / or protocols used for communication on the communication path. The communication apparatus as described in. The acquisition means acquires a packet in which content data is divided into the predetermined transmission units,
The determination means determines that the information addition area is included in the header of the packet acquired by the acquisition means,
The generation unit includes the identifier of the communication path in the information addition region of the packet when the determination unit determines that the information addition region is included in the header of the packet acquired by the acquisition unit. The communication apparatus according to claim 8, wherein an added packet to which information is added is generated. The acquisition unit acquires an RTP (Real-time Transport Protocol) packet in which content data is divided into the predetermined transmission units,
The determination means determines that the information addition area is included in an extension header of the RTP packet acquired by the acquisition means,
When the determination unit determines that the information addition region is included in the extension header of the RTP packet acquired by the acquisition unit, the generation unit adds the communication path to the information addition region of the RTP packet. 13. The MPRTP packet to which an entire or part of an MPRTP (Multipath RTP) header is added as information including an identifier is generated as the added divided data. 13. Communication device. A communication system having a first communication device and a second communication device,
The first communication device is
Acquisition means for acquiring content data;
Generating means for dividing the content data obtained by the obtaining means into predetermined transmission units and generating divided data including an information addition area for adding information;
Transmission means for transmitting the divided data generated by the generation means to the second communication device,
The second communication device is
Second acquisition means for acquiring the divided data transmitted by the transmission means;
Second generation means for generating added divided data in which information including a communication path identifier is added to the information addition area of the divided data acquired by the second acquisition means;
And second transmission means for transmitting the added divided data generated by the second generation means through a communication path according to information including the identifier of the communication path added to the added divided data. Communication system. The second communication device adds information including a communication path identifier to the information addition area of the divided data based on supplementary information included in the information addition area of the divided data acquired by the second acquisition unit. Determining means for determining a communication path for transmitting the added divided data;
In the added divided data generated by the second generation unit, information including the identifier of the communication path according to the determination by the determination unit is added to the information addition region of the divided data acquired by the second acquisition unit. The communication system according to claim 14, wherein the communication data is added divided data. An acquisition process for acquiring content data;
A generation step of dividing the content data acquired in the acquisition step into predetermined transmission units to generate a plurality of divided data, wherein the communication device adds information including a communication path identifier to the plurality of divided data. Generating a plurality of pieces of divided data such that an information addition region for transmission is included in each of the plurality of pieces of divided data;
And a transmission step of transmitting the plurality of divided data generated in the generation step to the communication device.   The other communication device determines a communication path for transmitting the divided data to which the information including the identifier of the communication path is added in the information addition area of the divided data generated in the generation step. The communication method according to claim 16, further comprising supplementary information. An acquisition step of acquiring divided data obtained by dividing content data into predetermined transmission units;
A determination step of determining that an information addition region for adding information including an identifier of a communication path is included in the divided data acquired in the acquisition step;
When it is determined in the determination step that the information addition area is included in the divided data acquired in the acquisition step, information including the identifier of the communication path is added to the information addition area of the division data. Generating the generated added divided data; and
A transmission step of transmitting the added divided data generated in the generation step through a communication path according to information including the identifier of the communication path added to the added divided data. . Based on the supplementary information included in the information addition area of the divided data acquired in the acquisition step, the added divided data in which information including the identifier of the communication path is added to the information addition area of the divided data is transmitted. A determination step for determining a communication path to be performed;
The added divided data generated in the generation step is added with information including an identifier of the communication path according to the determination in the determination step added to the information addition region of the divided data acquired in the acquisition step. The communication method according to claim 18, wherein the communication method is divided data.   A program for causing a computer to operate as the communication device according to any one of claims 1 to 13.

Images