Communication apparatus, communication method and computer readable medium

• US 9,191,158 B2
• Filed: 10/30/2007
• Issued: 11/17/2015
• Est. Priority Date: 11/17/2006
• Status: Active Grant

• Current Assignee: Hisense Visual Technology Co., Ltd. (Qingdao Huatong State-Owned Capital Operation (Group) Co., Ltd.)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Gondo, Shunichi, Ajitomi, Daisuke, Irie, Yuji, Matsuzawa, Shigeo, Ise, Kotaro
• Primary Examiner(s): Torres, Joseph D
• Application Number:
  US11/928,653
• Publication Number:
  US 20080222494A1
• Time in Patent Office: 2,940 Days
• Field of Search: 714/776, 714/766
• US Class Current: 1/1
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/1819 with retransmission of additional or different redundancy
• CPC Class Codes: H04L 1/1835 Buffer management
• CPC Class Codes: H04L 1/1845 Combining techniques, e.g. code combining

Abstract

There is provided with a communication method including: attempting to receive a media packet from a network; storing a received media packet in a first buffering unit; receiving an FEC packet including redundant data to recover a lost media packet and information which specifies a plurality of media packets associated with the redundant data; storing a received FEC packet in a second buffering unit; selecting the FEC packet from the second buffering unit; dividing FEC operation processing to be carried out using the redundant data included in selected FEC packet and the media packets related to the redundant data into a plurality of processes and sequentially carrying out each process so that one process is carried out every time the receiving of a media packet is attempted; and inserting a media packet recovered through the FEC operation processing in the first buffering unit.

Claims

1. A communication apparatus including a computer, the computer comprising:

a reception attempting unit implemented by processing circuitry and configured to attempt to receive a media packet from a network;

a first buffering unit implemented by the processing circuitry and configured to perform buffering of media packets received by the reception attempting unit;

a FEC packet receiver configured to receive an FEC (Forward Error Correction) packet including both redundant data and information which specifies a plurality of media packets associated with the redundant data;

a second buffering unit implemented by the processing circuitry and configured to perform buffering of FEC packets received by the FEC packet receiver;

a selection unit implemented by the processing circuitry and configured to select one of the FEC packets from the second buffering unit;

an FEC operation processing unit implemented by the processing circuitry and configured to perform FEC operation processing using the redundant data, which is included in the selected one of the FEC packets, and using the media packets related to the redundant data which are present in the first buffering unit to thereby recover a lost media packet in a case that one of the plurality of media packets, related to the redundant data included in the selected FEC packet, is lost,

wherein the FEC operation processing unit specifies at least one packet, which has not yet been specified, among the selected FEC packet and the media packets related to the redundant data and carries out a next operation based on the specified packet(s) and a result of a latest operation being the operation which has been most recently carried out before the next operation is carried out, each time the reception attempting unit attempts to receive any media packet from the network,

a media packet insertion unit implemented by the processing circuitry and configured to insert a media packet recovered through the FEC operation processing in the first buffering unit; and

a media packet delivery unit implemented by the processing circuitry and configured to sequentially deliver the media packets in the first buffering unit to a pre-specified application.

2. The apparatus according to claim 1, wherein the media packet and the FEC packet are compliant with an RTP (Real-time Transport Protocol) protocol.

3. The apparatus according to claim 1, wherein the FEC operation processing unit erases, when the media packets associated with the redundant data is delivered to the application, the FEC packet including the redundant data from the second buffering unit.

4. The apparatus according to claim 1, wherein the operation is an exclusive OR (XOR) operation among the specified packet(s) and the latest operation.

5. The apparatus according to claim 1, wherein when a predetermined time elapses after the first buffering unit obtains the media packet from the reception attempting unit, the media packet delivery unit delivers the media packet to the application.

6. The apparatus according to claim 5, wherein the media packet delivery unit calculates a difference between a reception time of a packet received first out of the FEC packet and the media packets associated with the FEC packet and a reception time of the packet received last, as a delay time,

calculates an FEC operation time required for the FEC operation processing by multiplying a media packet reception interval given beforehand by a number of times the FEC operation processing unit specifies said at least different one packet, and

sums up the delay time and the FEC operation time to thereby obtain the predetermined time.

7. The apparatus according to claim 6, further comprising a reception interval measurement unit configured to measure reception intervals of the media packets,

wherein the media packet delivery unit uses an average of the reception intervals of the media packets measured by the reception interval measurement unit as the media packet reception interval.

8. A communication method for a communication apparatus comprising:

attempting to receive a media packet from a network;

storing a received media packet in a first buffering unit performing buffering of media packets;

receiving an FEC (Forward Error Correction) packet including both redundant data and information which specifies a plurality of media packets associated with the redundant data;

storing a received FEC packet in a second buffering unit performing buffering of FEC packets;

selecting one of the FEC packets from the second buffering unit;

performing FEC operation processing using the redundant data, which is included in the selected one of the FEC packets, and using the media packets related to the redundant data which are present in the first buffering unit to thereby recover a lost media packet in a case that one of the plurality of media packets related to the redundant data included in the selected FEC packet is lost,

wherein the FEC operation processing includes specifying at least one different packet, which has not yet been specified, among the selected FEC packet and the media packets related to the redundant data and carrying out a next operation based on the specified packet(s) and a result of a latest operation being the operation which has been most recently carried out before a next operation is carried out, each time a step of the attempting attempts to receive any media packet from the network;

inserting a media packet recovered through the FEC operation processing in the first buffering unit; and

sequentially delivering the media packets in the first buffering unit to a pre-specified application.

9. A non-transitory computer readable medium storing a computer program for causing a computer to execute instructions to perform the steps of:

attempting to receive a media packet from a network;

storing a received media packet in a first buffering unit performing buffering of media packets;

receiving an FEC (Forward Error Correction) packet including both redundant data and information which specifies a plurality of media packets associated with the redundant data;

storing a received FEC packet in a second buffering unit performing buffering of FEC packets;

selecting one of the FEC packets from the second buffering unit;

performing FEC operation processing using the redundant data, which is included in the selected one of the FEC packets, and using the media packets related to the redundant data which are present in the first buffering unit to thereby recover a lost media packet in a case that one of the plurality of media packets, related to the redundant data included in the selected FEC packet, is lost,

wherein the FEC operation processing includes specifying at least one different packet, which has not yet been specified, among the selected FEC packet and the media packets related to the redundant data and carrying out a next operation based on the specified packet(s) and a result of a latest operation being the operation which has been most recently carried out before the next operation is carried out, each time a step of the attempting attempts to receive any media packet from the network;

inserting a media packet recovered through the FEC operation processing in the first buffering unit; and

sequentially delivering the media packets in the first buffering unit to a pre-specified application.