Data communication system, data transmission apparatus, data reception apparatus, data communication method, and computer program

• US 20030120802A1
• Filed: 12/04/2002
• Published: 06/26/2003
• Est. Priority Date: 12/04/2001
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kohno, Michinari
• Granted Patent: US 7,315,898 B2
• Time in Patent Office: Days
• US Class Current: 709/237
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/65 Network streaming protocols, e.g. real-time transport protocol [RTP] or real-time control protocol [RTCP]
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04N 21/44209 Monitoring of downstream path of the transmission network originating from a server, e.g. bandwidth variations of a wireless network arrangements for maintenance or administration in data switching networks involving bandwidth and capacity management H04L41/0896
• CPC Class Codes: H04N 21/6375 for requesting retransmission , e.g. of data packets lost or corrupted during transmission from serverARQ protocols H04L1/18; implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP] H04L69/16

Abstract

In a data communication system, the function of automatic repeat request is provided for transmission of packets based on a data communication protocol such as the Real-Time Transport Protocol or the User Datagram Protocol. Lost packets are detected at various timings, for example, when the beginning packet of each frame is received, the final frame of each frame is received, at a time limit of processing, and at a regular interval, and retransmission requests are issued accordingly. A data reception terminal does not issue a retransmission request if associated retransmission data will not be in time for playing with consideration of processing time and roundtrip time, thereby avoiding the transmission of useless retransmission request packets and retransmission packets.

Claims

1. A data communication system for transferring streaming data, comprising:

a data transmission apparatus including a packet transmission processing unit for transmitting a plurality of data packets containing transmission data, and a retransmission control unit for extracting at least one data packet to be retransmitted according to a retransmission-request message packet received from said data reception apparatus; and

a data reception apparatus including a packet reception processing unit for receiving the plurality of data packets transmitted from said data transmission apparatus, and a retransmission-request processing control unit for determining whether to transmit a retransmission-request message packet that serves as a data-packet retransmission request to said data transmission apparatus, based on detection of at least one of a lost packet and an error in the plurality of data packets transmitted from said data transmission apparatus,

wherein said retransmission-request processing control unit determines whether one or more retransmission data packets associated with the retransmission request can be received in time for processing relating to playing of data contained in the one or more retransmission data packets, and determines whether to transmit the retransmission request on condition that the one or more retransmission data packets can be received in time.

2. A data communication system according to claim 1, wherein the data contained in the plurality of data packets is encoded data, and said retransmission-request processing control unit of said data reception apparatus determines whether the one or more retransmission data packets associated with the retransmission request can be received in time for processing, including decoding, relating to playing of the data contained in the one or more retransmission data packets.

3. A data communication system according to claim 1, wherein the retransmission request is a message packet including one or more sequence numbers that serve as identification data of one or more data packets to be retransmitted, and also including data of a designated count of duplicate retransmission of the one or more data packets associated with the one or more sequence numbers, and said data transmission apparatus executes duplicate retransmission of the one or more data packets associated with the one or more sequence numbers in accordance with the data of the designated count of duplicate retransmission designated in the retransmission-request message packet.

4. A data communication system according to claim 1, wherein the plurality of data packets transferred between said data transmission apparatus and said data reception apparatus includes motion picture data, and said retransmission-request processing control unit of said data reception apparatus, upon receiving a final data packet in a plurality of data packets containing data constituting a single picture frame of the motion picture data, detects at least one of a lost data packet and an error in the plurality of data packets containing the data constituting the picture frame to which the final data packet belongs.

5. A data communication system according to claim 1, wherein the plurality of data packets transferred between said data transmission apparatus and said data reception apparatus includes motion picture data, and said retransmission-request processing control unit of said data reception apparatus, upon receiving a beginning data packet in a plurality of data packets containing data constituting a single picture frame of the motion picture data, detects at least one of a lost data packet and an error in a plurality of data packets containing data constituting a picture frame previous to the picture frame to which the beginning data packet belongs.

6. A data communication system according to claim 1, wherein said retransmission-request processing control unit of said data reception apparatus detects a lost data packet or an error in the received data packets on the basis of a time limit of a retransmission request for data contained in a data packet to be in time for processing relating to playing of the data.

7. A data communication system according to claim 1, wherein said retransmission-request processing control unit of said data reception apparatus detects at least one of a lost data packet and an error in the received data packets on the basis of a regular time interval.

8. A data communication system according to claim 1, wherein said retransmission-request processing control unit of said data reception apparatus controls transmission of an echo packet to said data transmission apparatus and reception of an echo-reply packet in response to the echo packet in order to measure a round-trip time between said data transmission apparatus and said data reception apparatus, and determines whether the one or more retransmission data packets associated with the retransmission request can be received in time for the processing relating to playing of the data contained in the one or more retransmission data packets, based on the roundtrip time calculated based on the echo packet and the echo-reply packet.

9. A data communication system according to claim 1, wherein the retransmission-request message packet created by said data reception apparatus includes at least one of sequence-number designation data designating one or more data packets and timestamp designation data designating a timestamp for one or more packets, and also includes an option value designating a range of the retransmission request, and said retransmission control unit of said data transmission apparatus extracts one or more packets to be retransmitted based on at least one of the sequence-number designation data and the timestamp designation data, and the option value, included in the retransmission-request message packet received from said data reception apparatus.

10. A data communication system according to claim 1, wherein each of the plurality of data packets has a format according to a Real-Time Transport Protocol, which serves as a data transfer protocol, and the retransmission request has a format according to a Real-Time Transport Control Protocol, which serves as a control protocol.

11. A data communication system according to claim 1, wherein said data reception apparatus transmits a retransmission request for a plurality of data packets using a single retransmission-request message packet to said data transmission apparatus.

12. A data communication system according to claim 1, wherein said data reception apparatus transmits an acknowledgement of reception of a plurality of data packets using a single reception-acknowledgement message packet to said data transmission apparatus.

13. A data transmission apparatus for transmitting streaming data, comprising:

a packet transmission processing unit for transmitting a plurality of data packets containing transmission data; and

a retransmission control unit for extracting at least one data packet to be retransmitted according to a retransmission request received from a data reception apparatus, wherein said data transmission apparatus executes duplicate retransmission of at least one designated data packet in accordance with data of a designated count of duplicate retransmission designated in a retransmission-request message packet received from said data reception apparatus.

14. A data transmission apparatus for transmitting streaming data, comprising:

a packet transmission processing unit for transmitting a plurality of data packets containing transmission data; and

a retransmission control unit for extracting at least one data packet to be retransmitted according to a retransmission request received from a data reception apparatus, wherein said retransmission control unit extracts at least one packet to be retransmitted based on at least one of sequence-number designation data designating at least one data packet and timestamp designation data for at least one packet, and an option value, included in a retransmission-request message packet received from said data reception apparatus.

15. A data reception apparatus for receiving streaming data, comprising:

a packet reception processing unit for receiving a plurality of data packets transmitted from a data transmission apparatus; and

a retransmission-request processing control unit for determining whether to transmit a retransmission-request message packet that serves as a data-packet retransmission request to said data transmission apparatus, based on detection of at least one of a lost packet and an error in the plurality of data packets transmitted from said data transmission apparatus, wherein said retransmission-request processing control unit determines whether one or more retransmission data packets associated with the retransmission request can be received in time for processing relating to playing of data contained in the one or more retransmission data packets, and determines to transmit the retransmission request on condition that the one or more retransmission data packets can be received in time.

16. A data reception apparatus according to claim 15, wherein the data contained in the plurality of data packets is encoded data, and said retransmission-request processing control unit determines whether the one or more retransmission data packets associated with the retransmission request can be received in time for processing, including decoding, relating to playing of the data contained in the one or more retransmission data packets.

17. A data reception apparatus according to claim 15, wherein a message packet including one or more sequence numbers that serve as identification data of one or more data packets to be retransmitted, and also including data of a designated count of duplicate retransmission of the one or more data packets associated with the one or more sequence numbers is created and transmitted to said data transmission apparatus.

18. A data reception apparatus according to claim 15, wherein the plurality of data packets received by said data reception apparatus include motion picture data, and said retransmission-request processing control unit, upon receiving a final data packet in a plurality of data packets containing data constituting a single picture frame of the motion picture data, detects at least one of a lost data packet and an error in the plurality of data packets containing the data constituting the picture frame to which the final data packet belongs.

19. A data reception apparatus according to claim 15, wherein the plurality of data packets received by said data reception apparatus include motion picture data, and said retransmission-request processing control unit, upon receiving a beginning data packet in a plurality of data packets containing data constituting a single picture frame of the motion picture data, detects at least one of a lost data packet and an error in a plurality of data packets containing data constituting a picture frame previous to the picture frame to which the beginning data packet belongs.

20. A data reception apparatus according to claim 15, wherein said retransmission-request processing control unit detects at least one of a lost data packet and an error in the received data packets on the basis of a time limit of a retransmission request for data contained in a data packet to be in time for processing relating to playing of the data.

21. A data reception apparatus according to claim 15, wherein said retransmission-request processing control unit detects at least one of a lost data packet and an error in the received data packets on the basis of a regular time interval.

22. A data reception apparatus according to claim 15, wherein said retransmission-request processing control unit controls transmission of an echo packet to said data transmission apparatus and reception of an echo-reply packet in response to the echo packet in order to measure a round-trip time between said data transmission apparatus and said data reception apparatus, and determines whether the one or more retransmission data packets associated with the retransmission request can be received in time for the processing relating to playing of the data contained in the one or more retransmission data packets, based on the round-trip time calculated based on the echo packet and the echo-reply packet.

23. A data reception apparatus according to claim 15, wherein a retransmission-request message packet including at least one of sequence-number designation data designating one or more data packets and timestamp designation data designating a timestamp for one or more packets, and also including an option value designating a range of the retransmission request is created and transmitted to said data transmission apparatus.

24. A data reception apparatus according to claim 15, wherein each of the plurality of data packets has a format according to a Real-Time Transport Protocol, which serves as a data transfer protocol, and the retransmission request has a format according to a Real-Time Transport Control Protocol, which serves as a control protocol.

25. A data reception apparatus according to claim 15, wherein a retransmission request for a plurality of data packets is transmitted to said data transmission apparatus using a single retransmission-request message packet.

26. A data reception apparatus according to claim 15, wherein an acknowledgement of reception of a plurality of data packets is transmitted to said data transmission apparatus using a single reception-acknowledgement message packet.

27. A data communication method for transferring streaming data between a data transmission apparatus and a data reception apparatus, the method comprising the steps of:

a packet transmission processing step of transmitting a plurality of data packets containing transmission data;

a retransmission control step of extracting at least one data packet to be retransmitted according to a retransmission-request message packet received from said data reception apparatus;

a packet reception processing step of receiving the plurality of data packets transmitted from said data transmission apparatus; and

a retransmission-request processing control step of determining whether or not to transmit a retransmission-request message packet that serves as a data-packet retransmission request to said data transmission apparatus, based on detection of at least one of a lost packet and an error in the plurality of data packets transmitted from said data transmission apparatus, wherein it is determined in said retransmission-request processing control step whether one or more retransmission data packets associated with the retransmission request can be received in time for processing relating to playing of data contained in the one or more retransmission data packets, and it is determined that the retransmission request be transmitted on condition that the one or more retransmission data packets can be received in time.

28. A data communication method according to claim 27, wherein the data contained in the plurality of data packets is encoded data, and said retransmission-request processing control step executed at said data reception apparatus includes a step of determining whether the one or more retransmission data packets associated with the retransmission request can be received in time for processing, including decoding, relating to playing of the data contained in the one or more retransmission data packets.

29. A data communication method according to claim 27, wherein the retransmission request is a message packet including one or more sequence numbers that serve as identification data of one or more data packets to be retransmitted, and also including data of a designated count of duplicate retransmission of the one or more data packets associated with the one or more sequence numbers, and said data transmission apparatus executes duplicate retransmission of the one or more data packets associated with the one or more sequence numbers in accordance with the data of the designated count of duplicate retransmission designated in the retransmission-request message packet.

30. A data communication method according to claim 27, wherein the plurality of data packets transferred between said data transmission apparatus and said data reception apparatus includes motion picture data, and said retransmission-request processing control step executed at said data reception apparatus includes a step of detecting, upon receiving a final data packet in a plurality of data packets containing data constituting a single picture frame of the motion picture data, a lost data packet or an error in the plurality of data packets containing the data constituting the picture frame to which the final data packet belongs.

31. A data communication method according to claim 27, wherein the plurality of data packets transferred between said data transmission apparatus and said data reception apparatus includes motion picture data, and said retransmission-request processing control step executed at said data reception apparatus includes a step of detecting, upon receiving a beginning data packet in a plurality of data packets containing data constituting a single picture frame of the motion picture data, a lost data packet or an error in a plurality of data packets containing data constituting a picture frame previous to the picture frame to which the beginning data packet belongs.

32. A data communication method according to claim 27, wherein said retransmission-request processing control step executed at said data reception apparatus includes a step of detecting at least one of a lost data packet and an error in the received data packets on the basis of a time limit of a retransmission request for data contained in a data packet to be in time for processing relating to playing of the data.

33. A data communication method according to claim 27, wherein said retransmission-request processing control step executed at said data reception apparatus includes a step of detecting at least one of a lost data packet and an error in the received data packets on the basis of a regular time interval.

34. A data communication method according to claim 27, further comprising the step of controlling transmission of an echo packet to said data transmission apparatus and reception of an echo-reply packet in response to the echo packet in order to measure a round-trip time between said data transmission apparatus and said data reception apparatus, and said retransmission-request processing control step includes a step of determining whether the one or more retransmission data packets associated with the retransmission request can be received in time for the processing relating to playing of the data contained in the one or more retransmission data packets, based on the round-trip time calculated based on the echo packet and the echo-reply packet.

35. A data communication method according to claim 27, wherein the retransmission-request message packet created by said data reception apparatus includes at least one of sequence-number designation data designating one or more data packets and timestamp designation data designating a timestamp for one or more packets, and also includes an option value designating a range of the retransmission request, and in said retransmission control step executed at said data transmission apparatus, one or more packets to be retransmitted are extracted based on at least one of the sequence-number designation data and the timestamp designation data, and the option value, included in the retransmission-request message packet received from said data reception apparatus.

36. A data communication method according to claim 27, wherein each of the plurality of data packets has a format according to a Real-Time Transport Protocol, which serves as a data transfer protocol, and the retransmission request has a format according to a Real-Time Transport Control Protocol, which serves as a control protocol.

37. A data communication method according to claim 27, further comprising the step of transmitting a retransmission request for a plurality of data packets to said data transmission apparatus using a single retransmission-request message packet.

38. A data communication method according to claim 27, further comprising the step of transmitting an acknowledgement of reception of a plurality of data packets to said data transmission apparatus using a single reception-acknowledgement message packet.

39. A computer readable medium storing a computer readable program for receiving streaming data, said computer readable program comprising the steps of:

a packet reception processing step of receiving a plurality of data packets transmitted from a data transmission apparatus; and

a retransmission-request processing control step of determining whether to transmit a retransmission-request message packet that serves as a data-packet retransmission request to said data transmission apparatus, based on detection of at least one of a lost packet and an error in the plurality of data packets transmitted from said data transmission apparatus, wherein said retransmission-request processing control step includes a step of determining whether one or more retransmission data packets associated with the retransmission request can be received in time for processing relating to playing of data contained in the one or more retransmission data packets, and determining that the retransmission request be transmitted on condition that the one or more retransmission data packets can be received in time.