Data transmission method and data transmission apparatus

• US 8,516,326 B2
• Filed: 06/29/2012
• Issued: 08/20/2013
• Est. Priority Date: 11/30/1998
• Status: Expired due to Fees

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Fukushima, Hideaki, Horii, Seiji, Ohnishi, Tatsuya, Hagai, Makoto, Matsui, Yoshinori, Miyazaki, Akihiro
• Primary Examiner(s): BRITT, CYNTHIA H
• Application Number:
  US13/537,860
• Publication Number:
  US 20120269054A1
• Time in Patent Office: 417 Days
• Field of Search: 714748-750
• US Class Current: 714/748
• CPC Class Codes: H04L 1/008 where the control data relates to payload of a different packet
• CPC Class Codes: H04L 1/1642 Formats specially adapted for sequence numbers
• CPC Class Codes: H04L 1/1809 Selective-repeat protocols
• CPC Class Codes: H04L 1/1838 for semi-reliable protocols, e.g. for less sensitive applications such as streaming video buffer level management for video bitstream receiver H04N21/44004
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 1/1877 for semi-reliable protocols, e.g. for less sensitive applications like streaming video buffer level management for video bitstream control arrangements H04N21/44004
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements

Abstract

A data transmission apparatus including a receiving unit for receiving transmitted packets; a priority decision unit; a retransmission packet storage unit; a retransmission instruction receiving unit for receiving a retransmission request from a terminal at the receiving end; a retransmission decision unit; a transmission queue management unit; and a transmission unit.

Claims

1. A data transmission method for transmitting data in units of packets, each of the packets have a sequence number and timestamp, said method comprising:

a receiving step of receiving a retransmission request for a retransmission packet instead of a lost original packet; and

a retransmitting step of performing retransmission of the retransmission packet having an original sequence number for the original packet and a sequence number for the retransmission packet.

2. The data transmission method of claim 1, wherein the original sequence number is same value as a value stored in the original packet for the received retransmission request.

3. The data transmission method of claim 2, wherein the sequence number for the retransmission packet is incremented by one every time a retransmission packet is transmitted, and can be used to judge a lost packet in the transmitted retransmission packet.

4. The data transmission method of claim 2, wherein the sequence number for the retransmission packet is included in an RTP header, which can be used to judge a lost packet in the transmitted packet.

5. The data transmission method of claim 2, wherein the retransmission packet is a high priority packet.

6. The data transmission method of claim 2, wherein the retransmitting step is performed when the retransmission packet is a high priority packet, and the retransmitting step is not performed when the retransmission packet is not a high priority packet.

7. The data transmission method of claim 2, wherein the retransmitting step is performed in a case where a time at which a data receiving apparatus receives the retransmission packet is within an arrival time limit of the retransmission packet.

8. A data transmission method for receiving data in units of packets, each of the packets have a sequence number and timestamp, said method comprising:

a detecting step of detecting a lost packet;

a transmitting step of transmitting a retransmission request for a retransmission packet instead of an original packet that is the lost packet detected by the detecting step; and

a receiving step of performing reception of the retransmission packet which is retransmitted based on the retransmission request, the retransmission packet having an original sequence number for the original packet and a sequence number for the retransmission packet.

9. The data transmission method of claim 8, wherein the original sequence number is same value as a value stored in the original packet for the received retransmission request.

10. The data transmission method of claim 9, wherein the sequence number for the retransmission packet is incremented by one every time a retransmission packet is transmitted, and can be used to judge a lost packet in the transmitted retransmission packet.

11. The data transmission method of claim 9, wherein the sequence number for the retransmission packet is included in an RTP header, which can be used to judge a lost packet in the transmitted packet.

12. The data transmission method of claim 9, wherein the retransmission packet is a high priority packet.

13. The data transmission method of claim 9, wherein the receiving step is performed when the retransmission packet is a high priority packet, and the receiving step is not performed when the retransmission packet is not a high priority packet.

14. The data transmission method of claim 9, wherein the transmitting step is performed in a case where a time at which a data receiving apparatus receives the retransmission packet is within an arrival time limit of the retransmission packet.

15. A data transmission apparatus for transmitting data in units of packets, each of the packets have a sequence number and timestamp, said apparatus comprising:

a receiving unit for receiving a retransmission request for a retransmission packet instead of a lost original packet; and

a transmitting unit for performing retransmission of the retransmission packet having an original sequence number for the original packet and a sequence number for the retransmission packet.

16. The data transmission apparatus of claim 15, wherein the original sequence number is same value as a value stored in the original packet for the received retransmission request.

17. The data transmission apparatus of claim 16, wherein the sequence number for the retransmission packet is incremented by one every time a retransmission packet is transmitted, and can be used to judge a lost packet in the transmitted retransmission packet.

18. The data transmission apparatus of claim 16, wherein the sequence number for the retransmission packet is included in an RTP header, which can be used to judge a lost packet in the transmitted packet.

19. The data transmission apparatus of claim 16, wherein the retransmission packet is a high priority packet.

20. The data transmission apparatus of claim 16, wherein the transmitting unit performs retransmission of the retransmission packet when the retransmission packet is a high priority packet, and the retransmitting step is not performed when the retransmission packet is not a high priority packet.

21. The data transmission apparatus of claim 16, wherein the transmitting unit performs retransmission of the retransmission packet in a case where a time at which a data receiving apparatus receives the retransmission packet is within an arrival time limit of the retransmission packet.

22. A data transmission apparatus for receiving data in units of packets, each of the packets have a sequence number and timestamp, said apparatus comprising:

a detection unit for detecting a lost packet;

a transmitting unit for transmitting a retransmission request for a retransmission packet instead of an original packet that is the lost packet detected by the detecting step; and

a receiving unit for performing reception of the retransmission packet which is retransmitted based on the retransmission request, the retransmission packet having an original sequence number for the original packet and a sequence number for the retransmission packet.

23. The data transmission apparatus of claim 22, wherein the original sequence number is same value as a value stored in the original packet for the received retransmission request.

24. The data transmission apparatus of claim 23, wherein the sequence number for the retransmission packet is incremented by one every time a retransmission packet is transmitted, and can be used to judge a lost packet in the transmitted retransmission packet.

25. The data transmission apparatus of claim 23, wherein the sequence number for the retransmission packet is included in an RTP header, which can be used to judge a lost packet in the transmitted packet.

26. The data transmission apparatus of claim 23, wherein the retransmission packet is a high priority packet.

27. The data transmission apparatus of claim 23, wherein the receiving unit performs reception of the retransmission packet when the retransmission packet is a high priority packet, and the receiving step is not performed when the retransmission packet is not a high priority packet.

28. The data transmission apparatus of claim 23, wherein the transmitting unit performs retransmission of the retransmission packet in a case where a time at which a data receiving apparatus receives the retransmission packet is within an arrival time limit of the retransmission packet.