Data transmission method and data transmission apparatus

• US 20080209300A1
• Filed: 02/25/2008
• Published: 08/28/2008
• Est. Priority Date: 11/30/1998
• Status: Active Grant

• Current Assignee: Akihiro Miyazaki, Hideaki Fukushima, Makoto Hagai, Seiji Horii, Tatsuya Ohnishi, Yoshinori Matsui
• Original Assignee: Akihiro Miyazaki, Hideaki Fukushima, Makoto Hagai, Seiji Horii, Tatsuya Ohnishi, Yoshinori Matsui
• Inventors: Miyazaki, Akihiro, Matsui, Yoshinori, Hagai, Makoto, Horii, Seiji, Ohnishi, Tatsuya, Fukushima, Hideaki
• Granted Patent: US 8,261,147 B2
• Time in Patent Office: Days
• 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. (canceled)

2. A data transmission method for transmitting data in units of packets, said method comprising:

a first step of performing transmission of the packets, each of the packets having a first sequence number indicating a reproduction order of the packet;

a second step of receiving a retransmission request for a retransmission packet;

a third step of judging whether retransmission of the packet, which packet is indicated by the received retransmission request, should be performed or not; and

a fourth step of performing, on a basis of the judgment result, transmission of the retransmission packet having a first sequence number indicating a reproduction order of the packet, and a second sequence number indicating a transmission order, which can be used to judge a transmission error in the transmitted retransmission packet.

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

4. The data transmission method of claim 2, wherein the second sequence number assigned to the retransmission packet is included in an RTP header.

5. The data transmission method of claim 2, wherein the third step is performed only when the retransmission packet is a high priority packet.

6. The data transmission method of claim 2, wherein the second 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.

7. A data transmission method for receiving data in units of packets, said method comprising:

a first step of detecting an occurrence of a transmission error in any of the packets, each of the packets having a first sequence number indicating a reproduction order of the packet;

a second step of transmitting a retransmission request for a retransmission packet corresponding to one of the packets in which a transmission error has occurred; and

a third step of performing reception of the retransmission packet which is transmitted on a basis of the retransmission request, the retransmission packet having a first sequence number indicating a reproduction order of the packet, and a second sequence number indicating a transmission order, which can be used to judge a transmission error in the transmitted retransmission packet.

8. The data transmission method of claim 7, wherein the retransmission packet is a high priority packet.

9. The data transmission method of claim 7, wherein the second sequence number assigned to the retransmission packet is included in an RTP header.

10. The data transmission method of claim 7, wherein the second step is performed only when the retransmission packet is a high priority packet.

11. The data transmission method of claim 7, wherein the first 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.

12. A data transmission apparatus for transmitting data in units of packets, said apparatus comprising;

a transmission unit for performing transmission of the packets, each of the packets having a first sequence number indicating a reproduction order of the packet;

a retransmission instruction receiving unit for receiving a retransmission request for a retransmission packet; and

a judgment unit for judging whether retransmission of the packet, which packet is indicated by the received retransmission request, should be performed or not;

wherein said transmission unit performs transmission of the retransmission packet on a basis of the judgment result of the judgment unit, and

wherein the retransmission packet has a first sequence number indicating a reproduction order of the packet, and a second sequence number indicating a transmission order, which can be used to judge a transmission error in the transmitted retransmission packet.

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

14. The data transmission apparatus of claim 12, wherein the second sequence number assigned to the retransmission packet is included in an RTP header.

15. The data transmission apparatus of claim 12, wherein the transmission unit transmits the retransmission packet only when the retransmission packet is a high priority packet.

16. The data transmission apparatus of claim 12, wherein the retransmission instruction receiving unit receives the retransmission request 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.

17. A data reception apparatus for receiving data in units of packets, said apparatus comprising:

a detection unit for detecting an occurrence of a transmission error in any of the packets, each of the packets having a first sequence number indicating a reproduction order of the packet;

a retransmission instruction output unit for transmitting a retransmission request for a retransmission packet; and

a receiving unit for performing reception of the retransmission packet which is transmitted on a basis of the retransmission request;

wherein the retransmission packet has a first sequence number indicating a reproduction order of the packet, and a second sequence number indicating a transmission order, which can be used to judge a transmission error in the transmitted retransmission packet.

18. The data reception apparatus of claim 17, wherein the retransmission packet is a high priority packet.

19. The data reception apparatus of claim 17, wherein the second sequence number assigned to the retransmission packet is included in an RTP header.

20. The data reception apparatus of claim 17, wherein the reception unit receives the retransmission packet only when the retransmission packet is a high priority packet.

21. The data reception apparatus of claim 17, wherein the retransmission instruction output unit transmits the retransmission request in a case where a time at which the data reception apparatus receives the retransmission packet is within an arrival time limit of the retransmission packet.