Forward error correction and interleaving of network frames

• US 7,774,489 B2
• Filed: 04/06/2009
• Issued: 08/10/2010
• Est. Priority Date: 01/04/2002
• Status: Active Grant

• Current Assignee: Scientific-Atlanta LLC (Cisco Systems, Inc.)
• Original Assignee: Scientific-Atlanta LLC (Cisco Systems, Inc.)
• Inventors: Schoenblum, Joel W.
• Primary Examiner(s): Eng; David Y
• Application Number:
  US12/419,120
• Publication Number:
  US 20090193318A1
• Time in Patent Office: 491 Days
• Field of Search: 709/231, 709/236, 709/246, 709/247
• US Class Current: 709/231
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 12/56 Packet switching systems
• CPC Class Codes: H04L 2012/6483 Video, e.g. MPEG
• CPC Class Codes: H04L 65/1026 at the edge
• CPC Class Codes: H04L 65/1036 at the edge
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/70 Media network packetisation
• CPC Class Codes: H04L 65/762 at the source reformatting of additional data in video distribution servers H04N21/2355

Abstract

A network stream transmitter receives a transport stream having content packets and packets to be filtered out and is adapted to selectively encapsulate content packets into network frames.

Claims

1. A method, comprising:

receiving a variable number of content packets in plural network frames, at least a portion of the plural network frames of varying size;

determining which of the plural network frames is largest in size;

padding one or more of the plural network frames that are smaller than the largest size to generate equi-sized network frames among all of the plural network frames;

generating a defined quantity of repair network frames of the same size as the equi-sized network frames;

removing the padding from the one or more plural network frames; and

providing the plural network frames and the repair frames.

2. The method of claim 1, further comprising processing the equi-sized network frames, wherein processing comprises providing a forward error correction (FEC) header in the respective equi-sized network frames.

3. The method of claim 2, wherein the FEC header comprises an index number that denotes frame positions among the repair frames and the equi-sized frames.

4. The method of claim 1, wherein providing comprises passing the plural network frames and the repair frames to an interleaver module, the interleaver module configured to interleave the plural network frames and the repair frames with other encoded blocks.

5. A system, comprising:

a forward error correction (FEC) module, the FEC module configured to;

receive a variable number of content packets in plural network frames, at least a portion of the plural network frames of varying size;

determine which of the plural network frames is largest in size;

pad one or more of the plural network frames that are smaller than the largest size to generate equi-sized network frames among all of the plural network frames;

generate a defined quantity of repair network frames of the same size as the equi-sized network frames;

remove the padding from the one or more plural network frames; and

provide the plural network frames and the repair frames to an interleaver module.

6. The system of claim 5, wherein the FEC module is further configured to process the equi-sized network frames, wherein processing comprises providing a forward error correction (FEC) header in respective equi-sized network frames.

7. The system of claim 6, wherein the FEC header comprises an index number that denotes frame positions among the repair frames and the equi-sized frames.

8. The system of claim 5, further comprising the interleaver module and an interleaver buffer, the interleaver module configured to buffer the plural network frames and the repair frames in the interleaver buffer.

9. The system of claim 5, wherein the interleaver module is further configured to receive a configuration message, the configuration message providing an indication of an epoch value, e.

10. The system of claim 9, wherein the epoch value is an operator adjustable parameter.

11. The system of claim 9, wherein the interleaver module is further configured to buffer the plural network frames and the repair frames in the interleaver buffer according to a first orientation and extract the same according to a second orientation, the buffering up to the epoch value.

12. The system of claim 11, wherein the first orientation comprises columns and the second orientation comprises rows.

13. The system of claim 12, wherein the interleaver module is further configured to buffer successive blocks of the plural network frames and the repair frames in successive columns in the interleaver buffer until an eth block of the plural is buffered in the eth column.

14. The system of claim 13, wherein within each of the successive columns, the interleaver module is further configured to arrange the plural network frames and the repair frames sequentially from 1−

N_B+R, where N_B corresponds to the network frames and R corresponds to the repair frames.

15. The system of claim 13, further comprising an output buffer, wherein the interleaver module is further configured to extract and provide to the output buffer a first network frame of each of the blocks before a second network frame of a first block is extracted.

16. A system, comprising:

an interleaver buffer; and

an interleaver module configured to;

receive a configuration message, the configuration message providing an indication of an epoch value, e;

buffer plural network frames and the repair frames in the interleaver buffer according to a first orientation up to the epoch value;

extract the buffered frames according to a second orientation; and

provide the extracted frames to an output buffer.

17. The system of claim 16, wherein the epoch value is an operator adjustable parameter.

18. The system of claim 16, wherein the first orientation comprises columns and the second orientation comprises rows.

19. The system of claim 18, wherein the interleaver module is further configured to buffer successive blocks of the plural network frames and the repair frames in successive columns in the interleaver buffer until an eth block of the plural is buffered in the eth column.

20. The system of claim 19, wherein within each of the successive columns, the interleaver module is further configured to arrange the plural network frames and the repair frames sequentially from 1−

N_B+R, where N_B corresponds to the network frames and R corresponds to the repair frames, wherein the interleaver module is further configured to extract and provide to the output buffer a first network frame of each of the blocks before a second network frame of a first block is extracted.