JP4658002B2 - Communication system, encoding device, and decoding device - Google Patents

Communication system, encoding device, and decoding device Download PDF

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JP4658002B2
JP4658002B2 JP2006227707A JP2006227707A JP4658002B2 JP 4658002 B2 JP4658002 B2 JP 4658002B2 JP 2006227707 A JP2006227707 A JP 2006227707A JP 2006227707 A JP2006227707 A JP 2006227707A JP 4658002 B2 JP4658002 B2 JP 4658002B2
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JP2008054014A (en
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力 佐々木
輝之 長谷川
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Kddi株式会社
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  The present invention relates to a plurality of communication apparatuses that transfer original data from a sender to a receiver, an encoding apparatus that encodes the original data with an error correction code and generates encoded data, and an encoding The present invention relates to a communication system including a decoding device that decodes data. The present invention also relates to an encoding device and a decoding device included in the communication system.

  In recent years, with the development of broadband, there is an increasing demand for distributing large-capacity video content over an IP (Internet Protocol) network. Some of such contents are highly broadcast and can be greatly reduced in network bandwidth by being distributed using multicast. However, IP multicast generally uses UDP (User Datagram Protocol) as a transport layer protocol and is very vulnerable to packet loss and the like.

Therefore, it is possible to make the distribution data redundant by a technique using error correction code (FEC: Forward Error Correction) and recover the packet loss to the extent of redundancy. In general, the sender performs redundancy (encoding), and the receiver performs recovery processing (decoding). However, the degree of redundancy should be determined in consideration of the quality of the network from the sender to each receiver. In one-to-many distribution such as multicast, the network quality of each distribution route is There are various cases, and setting the same value may be inefficient in design. For example, in a ubiquitous network in which wired and wireless are mixed, the wireless section is very low quality, whereas the wired section is high quality. Therefore, in such a case, it can be said that it is more efficient to make only a specific section highly reliable, and it can be realized by installing an FEC device (encoding device and decoding device) in a specific network (for example, non-conversion). Patent Document 1).
Toru Kondo and 4 others, "High-vision video wide-area transmission experiment using application gateway", Multimedia, Distributed, Cooperative and Mobile, (DICOMO) 2005 Symposium Proceedings, 2005, p. 521-524

  However, if an FEC device is installed directly on the communication path, not only high-reliability communication but also non-reliable communication will be interrupted when the FEC device is installed or when the FEC device fails. was there.

  The present invention has been made in view of the above-described problems, and is a communication system, an encoding device, and a communication device that can prevent a non-reliable communication from being interrupted at the time of installation or failure of the FEC device. An object of the present invention is to provide a decoding device.

The present invention has been made in order to solve the above-described problem, and a plurality of communication devices that transfer original data from a sender to a receiver, and encoding the original data with an error correction code. In a communication system including an encoding device that generates encoded data and a decoding device that decodes the encoded data, the encoding device is connected to a first communication device, and the decoding device includes: Connected to a second communication device, between the first communication device and the second communication device, from the sender to the receiver without passing through the encoding device or the decoding device. The original data transferred by the first communication device is transmitted by the encoding device in a second communication route that is at least partially different from the first communication route to which the original data can be transferred. The encoded data transmitted from the encoding device is received by the decoding device via the second communication device, and the data decoded by the decoding device is the second communication The original data is transmitted by multicast from the sender, and the encoding device generates and transmits a reception request for receiving the original data; and A first receiving means for receiving original data; an encoding means for encoding the received original data with an error correction code to generate encoded data; and a first receiving means for transmitting the encoded data. The decoding device recognizes to the second communication device that the communication path to the sender is in the direction of the decoding device. In order to prevent the participation request for receiving the multicast packet from the receiver from arriving at the first communication device via the first communication path, the path information regarding the path to the sender is Route information transmitting means for transmitting to the second communication device; second receiving means for receiving the encoded data; decoding means for decoding the received encoded data and generating the original data; And second data transmitting means for transmitting the original data as the original data transmitted from the sender by multicast .

In the communication system of the present invention, wherein the second data transmission means decrypted device further packets to transferred the sender by the second communication device, to the encoding device by tunneling The first receiving means of the encoding device further receives a packet from the decoding device, and the first data transmitting means of the encoding device is further received by the first receiving means. The received packet from the decoding device is transmitted by returning the packet from the original transmission source to the sender.

The present invention also provides a reception request transmitting means for generating and transmitting a reception request for receiving original data transmitted from a sender to a receiver by multicast; a receiving means for receiving the original data; The original data is encoded with an error correction code, encoding means for generating encoded data, and data transmission means for transmitting the encoded data, and the receiving means further includes: A decoding device that decodes encoded data receives a packet to the sender transmitted by tunneling, and the data transmission unit further transmits the packet from the decoding device received by the receiving unit to the original The encoding apparatus is characterized by transmitting the packet back from the receiver.

Further, the present invention allows the communication device on the communication path from the sender to the receiver to recognize that the communication path to the sender is the direction of the decoding device, In order to prevent a join request for receiving a multicast packet from a receiver from arriving at the first communication device via the first communication route, route information regarding the route to the sender is transmitted to the communication device. The code transmitted by the encoding device that performs encoding by error correction code on the original data transmitted by multicast from the sender to the receiver, and generates encoded data Receiving means for receiving encoded data, decoding means for decoding the received encoded data and generating the original data, and the generated original data The data is decoding device characterized by comprising a data transmitting means for transmitting as the original data transmitted by multicast from said sender.

  Further, according to the present invention, the data transmission means further transmits a packet to the sender transferred by the communication device to the encoding device by tunneling. Device.

  According to the present invention, the encoding device is configured to transmit the encoded data from the encoding device to the decoding device on the second communication path that is at least partially different from the first communication path. Connected to the communication device, the decoding device is connected to the second communication device. As a result, data that is not subject to high reliability can be transferred via the first communication path, so that blocking of communication that is not subject to high reliability during installation or failure of the FEC device is prevented. The effect of being able to be obtained.

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

(First embodiment)
First, a first embodiment of the present invention will be described. FIG. 1 shows a configuration of a communication system according to the present embodiment. In order to perform multicast distribution, a sender apparatus 1 (sender) that transmits a multicast packet including data (original data) distributed from the sender to the receiver, and receiver apparatuses 2a and 2b that receive the multicast packet , 2c (recipient). Also, routers 3a, 3b, and 3c that transfer packets are provided between the sender device 1 and the receiver devices 2a, 2b, and 2c. In particular, the router 3a is an RP (Rendezvous Point) serving as the root of a multicast distribution tree.

  Encoders (encoding) for generating encoded data by encoding the original data with error correction codes at both ends of the section to be highly reliable (the section between the routers 3a and 3c in this embodiment) Device) and a decoder (decoding device) for decoding the encoded data. Conventionally, for example, an encoder is provided on the router 3a side on the communication path connecting the routers 3a and 3c, and a decoder is provided on the router 3c side. Therefore, when the encoder or the decoder fails, not only high-reliability multicast communication, There was a problem that communications that were not subject to reliability were interrupted.

  Therefore, in the present embodiment, an embodiment is realized in which the encoder and the decoder are not connected in series to the communication path through which the high reliability target packet passes but are connected as follows. As shown in FIG. 1, the encoder 4 has a communication path from the router 3a to the sender apparatus 1 so as not to include a highly reliable section on the communication path to the router 3a (first communication apparatus). It is connected to the router 3a. Similarly, the decoder 5 does not include a highly reliable section on the communication path to the router 3c (second communication apparatus) (not to include a communication path from the router 3c to each receiver apparatus). To the router 3c.

  Therefore, between the routers 3a and 3c, a first communication path including a communication path directly connecting the routers 3a and 3b, a communication path directly connecting the routers 3b and 3c, and the encoder 3 and the router 3d from the router 3a. Thus, there are at least two types of communication paths of the second communication path reaching the router 3c via the router 3b, the router 3c, and the decoder 5. This makes it possible to transfer packets between the routers 3a and 3c through the first communication path that does not pass through the encoder 4 and the decoder 5. On the other hand, the encoded packet from the encoder 4 can be transferred to the decoder 5 between the router 3a and the router 3c through a second communication path that is at least partially different from the first communication path.

  As described above, since packets that are not targeted for high reliability can be transferred via the first communication path, communication that is not targeted for high reliability is prevented when the FEC device is installed or when a failure occurs. be able to. In this embodiment, since the communication direction is basically determined, an encoder 4 is installed on the sender device 1 side, and a decoder 5 is installed on the receiver device side. In order to achieve high reliability for bidirectional communication, devices having both the encoder and decoder functions may be installed on the sender device 1 side and the receiver device side, respectively.

  Next, the configuration of the encoder 4 and the decoder 5 will be described. FIG. 2 shows the configuration of the encoder 4. The transmission / reception unit 41 has a function of receiving a packet of original data and the like and a function of transmitting a packet of encoded data and the like. The encoding unit 42 has a function of performing encoding (redundancy) using an error correction code on the original data received by the transmission / reception unit 41 to generate encoded data (redundant data). The storage unit 43 has a function of temporarily storing original data, encoded data, and the like. The control unit 44 performs information processing as necessary, and has a function of controlling the operation of each unit in the encoder 4.

  FIG. 3 shows the configuration of the decoder 5. The transmission / reception unit 51 has a function of receiving packets such as original data and encoded data, and a function of transmitting packets of original data obtained by decoding the encoded data. The decoding unit 52 has a function of decoding the encoded data received by the transmission / reception unit 51 and generating original data. The storage unit 53 has a function of temporarily storing original data, encoded data, and the like. The control unit 54 performs information processing as necessary and has a function of controlling the operation of each unit in the decoder 5.

  Next, the operation of the communication system at the time of multicast distribution will be described focusing on the operations of the encoder 4 and the decoder 5. When the receiver devices 2a, 2b, 2c, and 2d transmit a Join message for receiving the multicast packet of the original data to the upstream side, the multicast packets are transferred by the routers 3a, 3b, 3c, and 3d, and the receiver Delivered to the devices 2a, 2b, 2c, 2d. The encoder 4 participates in the multicast and encodes the original data included in the received multicast packet. More specifically, in the encoder 4, the control unit 44 generates a Join message (reception request) for receiving a multicast packet. The transmission / reception unit 41 transmits a Join message to the router 3a. The multicast packet is transferred to the encoder 4 by the router 3a that has received the Join message.

  The transmission / reception unit 41 receives this multicast packet. The encoding unit 42 encodes original data included in the received multicast packet to generate encoded data. The transmission / reception unit 41 transmits a packet including encoded data to the router 3d. The encoded data may be transmitted by multicast or unicast. The destination address of the packet including the encoded data is a destination address different from the multicast packet of the original data, and is set to the destination address of the multicast packet of the original data when the encoded data is transmitted by multicast. A multicast group address different from the multicast group address is set as the destination address of the multicast packet of the encoded data. When the encoded data is transmitted by unicast, the destination address of the encoded data packet is set to the address of the decoder.

  The decoder 5 receives the encoded data packet transmitted from the encoder 4 together with the multicast packet of the original data. More specifically, the control unit 54 of the decoder 5 generates a Join message for receiving a multicast packet of original data. The transmission / reception unit 51 transmits a Join message to the router 3c. The multicast packet is transferred to the decoder 5 by the router 3c that has received the Join message.

  When the encoded data is transmitted from the encoder 4 by multicast, the decoder 5 generates a Join message for receiving the multicast packet of the encoded data and transmits it to the router 3c. A multicast packet of encoded data is transferred to the decoder 5 by the router 3c that has received this Join message. When the encoded data is transmitted from the encoder 4 by unicast, the packet of the encoded data is transferred from the router 3c to the decoder 5 as it is.

  In the decoder 5, the transmission / reception unit 51 receives a multicast packet of original data and a packet of encoded data. The decoding unit 52 decodes the received encoded data and generates original data. Further, the control unit 54 determines whether or not the received original data has a loss, and when the loss is detected in the original data, notifies the decoding unit 52 of the loss. Based on the notification from the control unit 54, the decoding unit 52 outputs the data lost in the communication path among the generated original data to the transmission / reception unit 51 as recovery data. The transmission / reception unit 51 transmits the recovery data to the router 3c. The recovered data is a multicast packet having a source address that is the same as the source address of the multicast packet of the original data and a destination address that is the same as the destination address of the multicast packet of the original data (that is, from the sender device 1 by multicast). Sent as a multicast packet of the original data sent).

  However, since the router discards multicast packets received from different ports in the LAN (Local Area Network) segment, it is necessary to send recovery data multicast packets to the network that joins the same LAN as the original data multicast. There is. In a normal implementation, the router port that received the multicast packet of the original data is transmitted to the port belonging to the same LAN segment as the upstream. That is, in the router 3c, the segment of the port that receives the recovery data multicast packet is the same as the segment of the reception (upstream) port of the multicast packet of the original data. The recovery data multicast packet is handled as a multicast packet of the original data by the router 3c.

  In the present embodiment, since the original multicast packet itself is also transmitted downstream, the encoded data generated by the encoder 4 may be less than the original data. In addition, any FEC actually used may be used (in this example, packet loss is the target, so it is preferable to use an erasure code for packet loss). For example, every 5 packets, any number of them is used. Implementation can be considered in which one parity packet is generated by XORing these packets.

  Even if a packet loss occurs in the network, the lost packet is recovered as described above, so that the receiver devices 2a to 2c operate normally. Note that the recovery data multicast packet arrives at the receiver devices 2a to 2c with a delay of the original data multicast packet by the time required for communication between the router 3c and the decoder 5 and for decoding by the decoder 5, but the multicast itself Since there is no guarantee of the arrival order of the packets, the receiver apparatuses 2a to 2c usually have a function to withstand a slight inversion of the arrival order.

  As described above, according to the present embodiment, packets that are not targeted for high reliability can be transferred via a communication path different from that for multicast packets that are targeted for high reliability without going through the FEC device. Therefore, it is possible to prevent interruption of communication that is not subject to high reliability at the time of installation or failure of the FEC device. Also, since the multicast packet of the original data is transferred without going through the FEC device, it is possible to prevent the communication related to the multicast to be highly reliable from being interrupted.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. FIG. 4 shows the configuration of the communication system according to the present embodiment. In the present embodiment, a section sandwiched between the routers 3b and 3c is a section that is highly reliable. The encoder 4 is connected to the router 3b, and the decoder 5 is connected to the router 3c. Also in this embodiment, the encoder 4 generates a Join message and transmits it to the router 3b. Then, as in the first embodiment, the multicast packet of the original data is transferred to the encoder 4 by the router 3b that has received the Join message.

  In the encoder 4, the encoding unit 42 encodes original data included in the multicast packet received by the transmission / reception unit 41 to generate encoded data. The transmission / reception unit 41 transmits a packet including the encoded data to the router 3b. The transmission of this packet may be performed by multicast or unicast, as in the first embodiment. When the packet is transmitted by multicast, an address of a multicast group different from the address of the multicast group set as the destination address of the multicast packet of the original data is set as the destination address.

  In the decoder 5, the transmission / reception unit 51 receives a packet transmitted from the encoder 4. The decoding unit 52 decodes the received encoded data and generates original data. The transmission / reception unit 51 transmits the generated multicast packet of the original data to the router 3c. The source address of the multicast packet is the same as the source address of the multicast packet of the original data received by the encoder 4, and the destination address is also the same as the destination address of the multicast packet of the original data received by the encoder 4. Further, the port number of this multicast packet is also the same as the port number of the multicast packet of the original data received by the encoder 4, and the entire header of the multicast packet is the same as the header of the multicast packet of the original data received by the encoder 4. is there. Therefore, the multicast packet transmitted from the decoder 5 is transmitted as a multicast packet of original data transmitted from the sender device 1 by multicast.

  The router 3a recognizes that the multicast packet received from the decoder 5 is transmitted from the sender device 1, and transfers it to the receiver devices 2a to 2c. In this way, a series of multicast distribution is performed. In the first embodiment, since the multicast packet of the original original data is also transmitted downstream from the router 3a in FIG. 1, the amount of encoded data may be less than that of the original data. The original data multicast packet is not transmitted downstream from the router 3b in FIG. 2, and requires an amount of encoded data equal to or greater than the original data.

  The Join message transmitted by the receiver apparatuses 2a to 2c to receive the multicast packet of the original data normally arrives at the router 3a via the routers 3c and 3b. Then, the router 3b then transmits to the sender apparatus. 1 starts to transfer the multicast packet from 1 to the router 3c. In this embodiment, since encoded data of an amount equal to or greater than that of the original data flows downstream, the router 3b does not need to transfer the multicast packet from the sender device 1 to the router 3c.

  Therefore, in this embodiment, in order to prevent an increase in the amount of communication due to the router 3b transferring the multicast packet from the sender device 1 to the router 3c, the Join message from the receiver devices 2a to 2c is decoded from the router 3c. 5 to be transferred. In order to do this, the router 3 c may recognize that the communication path to the sender device 1 is in the direction of the decoder 5. In the decoder 5 of the present embodiment, the control unit 54 generates routing information (route information) regarding the route to the sender device 1, and the transmission / reception unit 51 transmits the routing information to the router 3c. Based on this routing information, the router 3 c recognizes that the communication path to the sender device 1 is in the direction of the decoder 5. Thus, the multicast packet transmitted from the decoder 5 is transferred to the receiver devices 2a to 2c without being discarded by the router 3c.

  An example of the routing protocol handled here is OSPF (Open Shortest Path First). Normally, the routing information is defined by the destination address and the network address, so the decoder 5 needs to know the address or network address of the target multicast sender apparatus 1. As a device for notifying the router 3c of the routing information, a separate router may be installed between the decoder 5 and the router 3c.

  Regarding the notification of the routing information to the router 3 c by the decoder 5, there is a request that the communication path directed to the sender device 1 is not set in the direction of the decoder 5 as much as possible except for the router 3 c to which the decoder 5 is connected. Assuming that the packet is transferred to a communication path with a low cost, the cost of the decoder 5 to the sender device 1 is slightly smaller than the cost to the sender device 1 of another router connected to the router 3c. When the cost is transmitted to the other router through the decoder 5, if the cost becomes higher than the cost of the other router, rewriting of the transfer destination does not occur in the other router.

  For example, it is assumed that the cost related to one hop is cost 2, and a router other than the router 3c has the cost 30 as the cost to the sender device 1. The cost to the sender device 1 for other routers seen from the router 3c is 32. When the decoder 5 notifies the router 3c of the cost 29 as the cost to the sender device 1, the cost to the sender device 1 becomes the cost 31 in the router 3c, and the communication path to the sender device 1 is sent to the decoder 5. Turn to. On the other hand, in the other routers, the cost of the communication path to the sender device 1 via the decoder 5 is the cost 33, so that the routing table does not change.

  As described above, when the router 3c recognizes that the communication path to the sender device 1 is in the direction of the decoder 5, packets from the receiver devices 2a to 2c and the like to the sender device 1 (necessary for encryption communication). The key exchange packet or the like) also reaches the decoder 5. Therefore, the decoder 5 transmits the packets from the receiver apparatuses 2a to 2c to the encoder 4 as packets from the decoder 5 by tunneling. That is, the control unit 54 of the decoder 5 encapsulates the original packet by adding a new header to the packets from the receiver apparatuses 2a to 2c received by the transmission / reception unit 51, and the transmission / reception unit 51 The packet is transmitted to the encoder 4. As a result, the source of the new packet becomes the decoder 5.

  This packet is received by the encoder 4 via the routers 3c and 3b. The control unit 44 of the encoder 4 removes the header added by the decoder 5 from the packet from the decoder 5 received by the transmission / reception unit 41, and returns the packet to the original receiver device 2a to 2c. The transmission / reception unit 41 transmits the returned packet to the sender device 1.

  Also in the present embodiment, with respect to packets that are not targeted for high reliability (for example, packets from the receiver devices 2a to 2c to the transmitter device 1), the FEC device is connected via a communication path different from that of the multicast packet that is targeted for high reliability. Since it is possible to transfer without going through, it is possible to prevent interruption of communication that is not subject to high reliability when the FEC device is installed or at the time of failure.

(Third embodiment)
Next, a third embodiment of the present invention will be described. FIG. 5 shows the configuration of the communication system according to the present embodiment. In the present embodiment, it is assumed that a packet of original data is transmitted from the sender device 1 to the receiver device 2a by unicast. Similar to the first and second embodiments, the encoder 4 needs to receive a target packet. For example, it can be implemented by the following two methods. The first method is a method of receiving a duplicate packet generated by router mirroring. The second method is a method in which the encoder 4 notifies the router 3b of the routing information and directs the router 3b to transfer the target packet to the encoder 4.

  FIG. 5A shows a packet flow realized by the first method. The router 3b transmits the unicast packet copied by mirroring to the encoder 4. The encoder 4 transmits a packet including encoded data obtained by encoding original data included in the received unicast packet toward the router 3b. With regard to the transmission of this packet, the address of the decoder 5 may be used as the destination, and it may be transmitted by tunneling or unicast, or may be transmitted by multicast. In the case of multicast, in order to receive a multicast packet, the decoder 5 generates and transmits a Join message.

  The decoder 5 receives the packet from the encoder 4. Further, the router 3 c duplicates the unicast packet from the sender device 1 by mirroring and transmits it to the decoder 5. The decoder 5 also receives this unicast packet. The decoder 5 decodes the received encoded data, and recovers data lost on the communication path as recovery data. The decoder 5 transmits a packet including the recovery data to the router 3c as a unicast packet from the sender device 1. The unicast packet transmitted from the decoder 5 is transferred to the receiver apparatus 2a by the router 3c. If there is no packet loss, all unicast packets are transferred from the router 3c to the receiver device 2a. Therefore, it is sufficient for the decoder 5 to recover and transmit data by the amount of packet loss.

  On the other hand, FIG. 5B shows a packet flow realized by the second method. Based on the routing information notified from the encoder 4, the router 3 b recognizes that the communication path to the receiver device 2 a is the direction of the encoder 4, and transfers the unicast packet from the transmitter device 1 to the encoder 4. The encoder 4 transmits a packet including encoded data obtained by encoding original data included in the received unicast packet toward the router 3b. With regard to the transmission of this packet, the address of the decoder 5 may be used as the destination, and it may be transmitted by tunneling or unicast, or may be transmitted by multicast. In the case of multicast, in order to receive a multicast packet, the decoder 5 generates and transmits a Join message.

  The decoder 5 receives the packet from the encoder 4. The decoder 5 decodes the received encoded data and generates original data. The decoder 5 transmits a packet including the original data to the router 3c as a unicast packet from the sender device 1. The unicast packet transmitted from the decoder 5 is transferred to the receiver apparatus 2a by the router 3c.

  In the above, packets that can be made highly reliable by mirroring can be set by mirroring, and can usually be specified for each destination, transmission source, port number, and the like. On the other hand, when the encoder 4 notifies the router 3b of the routing information, since it notifies for each destination network address or host address, it cannot be narrowed down to the port number or the like.

  Also in this embodiment, packets that are not targeted for high reliability can be transferred without going through the FEC device via a different communication path from the multicast packets that are targeted for high reliability. It is possible to prevent interruption of communication that is not subject to high reliability in the event of a failure or failure. In the first method shown in FIG. 5A, since the original unicast packet is also transferred without going through the FEC device, it is possible to prevent the communication related to the unicast to be highly reliable from being interrupted. be able to.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and includes design changes and the like without departing from the gist of the present invention. .

It is a block diagram which shows the structure of the communication system by the 1st Embodiment of this invention. It is a block diagram which shows the structure of the encoder with which the communication system by the 1st Embodiment of this invention is provided. It is a block diagram which shows the structure of the decoder with which the communication system by the 1st Embodiment of this invention is provided. It is a block diagram which shows the structure of the communication system by the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the communication system by the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Sender apparatus, 2a, 2b, 2c, 2d ... Receiver apparatus, 3a, 3b, 3c, 3d ... Router, 4 ... Encoder, 5 ... Decoder, 41, 51 ..Transmission / reception unit, 42 ... Encoding unit, 43,53 ... Storage unit, 44,54 ... Control unit, 52 ... Decoding unit

Claims (5)

  1. A plurality of communication devices that transfer original data from a sender to a receiver, an encoding device that encodes the original data with an error correction code and generates encoded data, and the encoded data In a communication system including a decoding device for decoding,
    The encoding device is connected to a first communication device, the decoding device is connected to a second communication device, and the encoding is performed between the first communication device and the second communication device. In the second communication path that is at least partially different from the first communication path that can transfer the original data from the sender to the receiver without passing through a device or the decoding device, the first communication path The original data transferred by the communication device is received by the encoding device, the encoded data transmitted from the encoding device is received by the decoding device via the second communication device, Data decrypted by the decryption device is transmitted to the second communication device,
    The original data is transmitted by multicast from the sender,
    The encoding apparatus includes: a first reception request transmission unit that generates and transmits a reception request for receiving the original data; a first reception unit that receives the original data; and the received original data On the other hand, an encoding unit that performs encoding using an error correction code and generates encoded data, and a first data transmission unit that transmits the encoded data,
    The decoding device causes the second communication device to recognize that the communication path to the sender is in the direction of the decoding device, and issues a participation request for receiving a multicast packet from the receiver. In order not to arrive at the first communication device via one communication route, route information transmission means for transmitting route information related to the route to the sender to the second communication device, and the encoded data Second receiving means for receiving, decoding means for decoding the received encoded data and generating the original data, and the original data generated by multicast transmission from the sender And a second data transmitting means for transmitting as data.
  2. The decrypted second data transmission means of the device further, the packet to the sender, which is transferred by the second communication device, transmits to the encoding device by tunneling,
    The first receiving unit of the encoding device further receives a packet from the decoding device, and the first data transmitting unit of the encoding device is further received by the first receiving unit. The communication system according to claim 1, wherein the packet from the decoding device is sent back to the packet from the original transmission source to the sender.
  3. A reception request transmitting means for generating and transmitting a reception request for receiving original data transmitted by multicast from the sender to the receiver;
    Receiving means for receiving the original data;
    Encoding means for encoding the received original data with an error correction code to generate encoded data;
    Data transmission means for transmitting the encoded data;
    With
    The receiving means further receives a packet to the sender transmitted by tunneling from a decoding device that decodes the encoded data, and the data transmitting means further receives the decoding received by the receiving means. An encoding apparatus, wherein a packet from the apparatus is transmitted back to the original packet from the recipient.
  4. A multicast packet from the receiver by causing the communication device on the communication path from the sender to the receiver to recognize that the communication path to the sender is the direction of the decoding device. Route information transmitting means for transmitting route information about the route to the sender to the communication device so as not to arrive at the first communication device via the first communication route. ,
    Receiving means for receiving the encoded data transmitted by the encoding device that encodes the original data transmitted by multicast from the sender to the receiver using an error correction code and generates encoded data When,
    Decoding means for decoding the received encoded data and generating the original data;
    Data transmitting means for transmitting the generated original data as the original data transmitted by multicast from the sender;
    A decoding apparatus comprising:
  5.   5. The decoding apparatus according to claim 4, wherein the data transmission means further transmits a packet to the sender transferred by the communication apparatus to the encoding apparatus by tunneling.
JP2006227707A 2006-08-24 2006-08-24 Communication system, encoding device, and decoding device Expired - Fee Related JP4658002B2 (en)

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US8958460B2 (en) 2008-03-18 2015-02-17 On-Ramp Wireless, Inc. Forward error correction media access control system
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JPH05284146A (en) * 1992-03-30 1993-10-29 Nippon Telegr & Teleph Corp <Ntt> Parallel information block transmitting system
JP2006165643A (en) * 2004-12-02 2006-06-22 Kddi Corp Communication system, delay insertion server, backup server, and communication control apparatus

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JPH05284146A (en) * 1992-03-30 1993-10-29 Nippon Telegr & Teleph Corp <Ntt> Parallel information block transmitting system
JP2006165643A (en) * 2004-12-02 2006-06-22 Kddi Corp Communication system, delay insertion server, backup server, and communication control apparatus

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