Data transmission in non-reliable networks

• US 7,051,358 B2
• Filed: 03/02/2001
• Issued: 05/23/2006
• Est. Priority Date: 03/02/2000
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Hakenberg, Rolf, Burmeister, Carsten, Wiebke, Thomas
• Primary Examiner(s): Srivastava, Vivek
• Assistant Examiner(s): Ustaris, Joseph G.
• Application Number:
  US09/796,756
• Publication Number:
  US 20010025239A1
• Time in Patent Office: 1,908 Days
• Field of Search: 725/114, 725/131, 725/144, 725/151, 725/116, 725/146, 375/240.12, 375/240.13, 375/240.14, 375/240.15, 375/240.27, 375/240.26
• US Class Current: 725/114
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/2416 Real-time traffic
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames
• CPC Class Codes: H04L 47/34 ensuring sequence integrity, e.g. using sequence numbers
• CPC Class Codes: H04L 47/38 by adapting coding or compression rate
• CPC Class Codes: H04N 19/107 between spatial and temporal predictive coding, e.g. picture refresh
• CPC Class Codes: H04N 19/166 concerning the amount of transmission errors, e.g. bit error rate [BER]
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/89 involving methods or arrangements for detection of transmission errors at the decoder
• CPC Class Codes: H04N 21/6377 directed to server one-way streaming services wherein the source is controlled by the destination H04L65/613
• CPC Class Codes: H04N 21/658 Transmission by the client directed to the server
• CPC Class Codes: H04W 28/10 Flow control between communication endpoints
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]

Abstract

The present invention relates to a method and apparatus for transmitting video and/or audio data in a non-reliable and bandlimited network from a server to a client. The network may for instance be a wireless network. The data stream includes P-frames and I-frames. If during transmission a frame gets lost, the client notifies the server of the data loss when the next packet is received at the client correctly. The server then skips all the P-frames of the current P-frame sequence and continues the transmission with the next I-frame. Preferably, each packet has assigned a sequence number and the message from the client includes the sequence number of the currently received packet. The server may ignore a message from the client if the client'"'"'s request for skipping the P-frames has already been executed. It is preferred to make use of the present invention for streaming MPEG data.

Claims

1. A method for transmitting a data stream including video and/or audio data in a non-reliable network from a server to a client, the data stream comprising data frames including P-frames and I-frames, the method comprising:

transmitting the data stream from the server;

receiving a non-acknowledgment message indicating that at least one P-frame of the data stream has not been received, the non-acknowledgment message being received by the server from the client through the non-reliable network; and

in response to receiving the non-acknowledgment message, skipping transmission of the P-frames, including the at least one P-frame, up to a next I frame which follows the at least one P-frame in the data stream, and continuing transmitting of the data stream beginning with the next I-frame.

2. The method according to claim 1, further comprising:

ignoring a subsequent non-acknowledgment message from the client indicating that said at least one P-frame has not been received if the non-acknowledgment message has already been received from the client.

3. The method according to claim 1, wherein the non-acknowledgment message includes a sequence number of a received P-frame that follows the at least one P-frame in the data stream, said method further comprising:

evaluating the sequence number to determine if said skipping has already been executed, and if said skipping has already been executed, ignoring the non-acknowledgment message.

4. A server for transmitting a data stream including video and/or audio data in a non-reliable network from said server to a client, the data stream comprising data frames including P-frames and I-frames, said server comprising:

a transmitter operable to transmit the data stream from said server;

a receiver operable to receive a non-acknowledgment message indicating that at least one P-frame of the data stream has not been received, the non-acknowledgment message being received by said receiver from the client through the non-reliable network; and

a controller operable, in response to the non-acknowledgment message being received, to skip transmission of the P-frames, including the at least one P-frame, up to a next I frame which follows the at least one P-frame in the data stream, and to continue transmission of the data stream beginning with the next I-frame.

5. The server according to claim 4, wherein said controller is operable to ignore a subsequent non-acknowledgment message from the client indicating that said at least one P-frame has not been received if said server has already received the non-acknowledgment message from the client.

6. The server according to claim 4, wherein:

the non-acknowledgment message includes a sequence number of a received P-frame that follows the at least one P-frame in the data stream; and

said controller is operable to evaluate the sequence number to determine if the skipping of the P-frames including the at least one P-frame has already been executed, and to ignore the non-acknowledgment message if the skipping has already been executed.