DYNAMIC STREAM INTERLEAVING AND SUB-STREAM BASED DELIVERY

• US 20080256418A1
• Filed: 04/15/2008
• Published: 10/16/2008
• Est. Priority Date: 06/09/2006
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Digital Fountain Incorporated (Qualcomm, Inc.)
• Inventors: Luby, Michael G., Watson, Mark, Vicisano, Lorenzo, Pakzad, Payam, Clish, Jourdan J.
• Granted Patent: US 9,178,535 B2
• Time in Patent Office: Days
• US Class Current: 714/762
• CPC Class Codes: H03M 13/1102 Codes on graphs and decoding on graphs, e.g. low-density parity check [LDPC] codes
• CPC Class Codes: H03M 13/15 Cyclic codes, i.e. cyclic shifts of codewords produce other codewords, e.g. codes defined by a generator polynomial, Bose-Chaudhuri-Hocquenghem [BCH] codes H03M13/17 takes precedence
• CPC Class Codes: H03M 13/1515 Reed-Solomon codes
• CPC Class Codes: H03M 13/27 using interleaving techniques
• CPC Class Codes: H03M 13/2789 Interleaver providing variable interleaving, e.g. variable block sizes
• CPC Class Codes: H03M 13/353 Adaptation to the channel
• CPC Class Codes: H03M 13/373 with erasure correction and erasure determination, e.g. for packet loss recovery or setting of erasures for the decoding of Reed-Solomon codes
• CPC Class Codes: H03M 13/3761 using code combining, i.e. using combining of codeword portions which may have been transmitted separately, e.g. Digital Fountain codes, Raptor codes or Luby Transform [LT] codes
• CPC Class Codes: H03M 13/6508 Flexibility, adaptability, parametrability and configurability of the implementation
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27

Abstract

A communications system can provide methods of dynamically interleaving streams, including methods for dynamically introducing greater amounts of interleaving as a stream is transmitted independently of any source block structure to spread out losses or errors in the channel over a much larger period of time within the original stream than if interleaving were not introduced, provide superior protection against packet loss or packet corruption when used with FEC coding, provide superior protection against network jitter, and allow content zapping time and the content transition time to be reduced to a minimum and minimal content transition times. Streams may be partitioned into sub-streams, delivering the sub-streams to receivers along different paths through a network and receiving concurrently different sub-streams at a receiver sent from potentially different servers. When used in conjunction with FEC encoding, the methods include delivering portions of an encoding of each source block from potentially different servers.

Claims

1. In a communication system including at least one sender and at least one receiver, a method of transmitting a content stream comprising:

forming a connection between a receiver and a first sender;

receiving at the receiver a first content stream transmitted from the first sender, wherein the first content stream contains an initial amount of interleaving; and

adjusting the amount of interleaving contained in the first content stream during the transmission of the first content stream independently of the source block structure of the first content stream.

2. The method of claim 1 wherein the initial amount of interleaving in the first content stream is configured so that there is no initial interleaving in the first content stream.

3. The method of claim 1 wherein the amount of interleaving in the first content stream is adjusted from the initial amount to a steady state amount.

4. The method of claim 3 wherein the interleaving in the first content stream linearly transitions between the initial amount and the steady state amount.

5. The method of claim 1 wherein the amount of interleaving contained in the first content stream is adjusted as a function of time.

6. The method of claim 1 wherein the amount of interleaving contained in the first content stream is adjusted as a function of the difference between the playback rate of the first content stream and the transmission rate of the first content stream.

7. The method of claim 1 wherein the amount of interleaving contained in the first content stream is adjusted as a function of the amount of data loss experienced at the receiver.

8. The method of claim 1 wherein the source block structure of the first content stream does not change during the transmission of the first content stream.

9. The method of claim 1 further comprising:

building a reserve buffer of content from the first content stream.

10. The method of claim 9 wherein the reserve buffer is built concurrently with any adjustments made to the amount of interleaving in the first content stream.

11. The method of claim 1 further comprising:

forming a second connection between the receiver and a second sender;

receiving at the receiver a second content stream transmitted from the second sender connected to the receiver, wherein the second content stream contains an initial amount of interleaving;

adjusting the amount of interleaving contained in the second content stream delivered to the receiver during the transmission of the second content stream independently of the source block structure of the second content stream; and

transitioning between the first content stream and the second content stream in a manner that keeps the aggregate transmission rate of the content streams approximately level.

12. The method of claim 11 wherein the transition between the first content stream and the second content stream is carried out over time as a function of the amount of interleaving contained in the two streams.

13. In a sender that transmits data over a channel, a method of transmitting a content stream comprising:

forming a connection between a sender and a receiver;

sending to the receiver a content stream, wherein the content stream contains an initial amount of interleaving; and

adjusting the amount of interleaving contained in the content stream during the transmission of the content stream independently of the source block structure of the content stream.

14. In a receiver that receives data over a channel, a method of receiving a content stream comprising:

forming a connection between a receiver and a first sender;

receiving a first content stream transmitted from the first sender, wherein the first content stream contains an initial amount of interleaving that can be adjusted during the transmission of the content stream independently of the source block structure of the content stream.

15. In a communication system including at least one sender and at least one receiver, a method of transmitting a content stream comprising:

forming a connection between a receiver and a plurality of senders;

receiving at the receiver a content stream transmitted from the plurality of senders, wherein each sender transmits a different sub-stream of the content stream to the receiver and each sub-stream contains an initial amount of interleaving; and

adjusting the amount of interleaving contained in each content sub-streams during the transmission of the content sub-streams independently of the source block structure of the content sub-streams.

16. The method of claim 15 wherein the source block structure of the content sub-streams does not change during the transmission of the content sub-streams.

17. The method of claim 15 wherein the amount of interleaving contained in each content sub-stream is independent of the amount of interleaving contained in the other content sub-streams.