Frame format and frame assembling/disassembling method for the frame format

• US 6,931,009 B1
• Filed: 07/15/1998
• Issued: 08/16/2005
• Est. Priority Date: 07/15/1997
• Status: Expired due to Term

• Current Assignee: ViaSat Incorporated
• Original Assignee: ViaSat Incorporated
• Inventors: Agarwal, Anil K.
• Primary Examiner(s): PHAN, MAN U
• Application Number:
  US09/485,145
• Time in Patent Office: 2,589 Days
• Field of Search: 370/395, 370/474, 370/473, 370/471, 370/468, 370/252, 370/328, 370/338, 370/329, 370/330, 370/392, 370/401, 714/708, 714/774, 714/751, 714/755, 714/776, 714/781, 714/819
• US Class Current: 370/395.1
• CPC Class Codes: H04B 7/18582 Arrangements for data linking, i.e. for data framing, for error recovery, for multiple access
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/0075 Transmission of coding parameters to receiver H04L1/0023 takes precedence
• CPC Class Codes: H04L 1/0083 Formatting with frames or packets; Protocol or part of protocol for error control
• CPC Class Codes: H04L 1/0085 Formatting with cells
• CPC Class Codes: H04L 12/5601 Transfer mode dependent, e.g. ATM
• CPC Class Codes: H04L 2012/5607 Radio
• CPC Class Codes: H04L 2012/5608 Satellite
• CPC Class Codes: H04L 2012/5652 Cell construction, e.g. including header, packetisation, depacketisation, assembly, reassembly

Abstract

A method of assembling a plurality of frames including cell/packet-formatted data according to a predetermined frame format for transmission in a communication signal in a wireless or satellite environment. The method begins by assembling a data payload for each frame having a first variable size, including at least one of a partial data cell/packet and a complete data cell/packet. Then, for each frame a block code having a second variable size is generated for use in error correction. Each frame is provided with a frame header which defines aspects of said frame. Finally, the data payload, the block code and the format header are combined to form a frame corresponding to the plurality of frames, the format header defining a first portion of the frame, the data payload defining a second portion of the frame and the block code defining a third portion of the frame.

Claims

1. A method of assembling a plurality of frames including cell/packet-formatted data according to a predetermined frame format for transmission in a communication signal in a wireless or satellite system, said method comprising the steps of:

assembling a data payload for each frame having a first variable sizes including at least one of a partial data cell/packet and a complete data cell/packet;

generating for each frame a block code having a second variable size which is used for error correction;

providing for each frame a frame header which defines aspects of said frame; and

combining said data payload, said block code and said format header to form a corresponding frame of said plurality of frames, said format header defining a first portion of said frame, said data payload defining a second portion of said frame and said block code defining a third portion of said frame.

2. The method defined in claim 1, wherein said data payload comprises a partial ATM data cell.

3. The method defined in claim 1, wherein said data payload comprises a complete ATM data cell.

4. The method defined in claim 1, wherein said data payload further comprises at least one of a partial packet of compressed data and/or a complete packet of compressed data.

5. The method defined in claim 4, wherein said at least one of a partial packet of compressed data and/or a complete packet of compressed data includes at least one partial ATM data cell.

6. The method defined in claim 4, wherein said at least one of a partial packet of compressed data and/or a complete packet of compressed data includes at least one complete ATM data cell.

7. The method defined in claim 4, wherein said data payload comprises a complete ATM data cell a partial ATM data cell and a complete packet of compressed data.

8. The method defined in claim 1, wherein the step of providing a frame header comprises the steps of:

forming a first header field of said frame header which defines a number of data cell/packets in said data payload, said number of data cell/packets including only complete data cell/packets and any partial data cell/packet which follows said complete data cell/packets;

forming a second header field of said frame header which defines a size of a first partial data cell/packet that precedes any complete data cell/packets included in said data payload; and

forming a third header field of said frame header which defines a frame number of a corresponding one of said plurality of frames.

9. The method defined in claim 8, wherein said step of providing said frame header further comprises the step of:

forming a fourth header field which defines a predetermined characteristic of said block code in accordance with said frame number of the s corresponding one of said plurality of frames.

10. The method defined in claim 9, wherein said predetermined characteristic corresponds to the second variable size of said block code.

11. The method defined in claim 9, wherein said predetermined characteristic corresponds to the second variable size of said block code of a current frame of said plurality of frames.

12. The method defined in claim 9, wherein said predetermined characteristic corresponds to the second variable size of said block code of a subsequent frame of said plurality of frames.

13. The method defined in claim 9, further comprising the step of selecting said second variable size of said block code in accordance with a bit error rate of said communication signal.

14. The method defined in claim 9, wherein said step of generating said block code comprises the step of generating said block code in accordance with Reed-Solomon Coding.

15. The method defined in claim 1, further comprising the step of selecting said second variable size of said block code in accordance with a bit error rate of said communication signal.

16. The method defined in claim 1, wherein said cell/packet is ATM-formatted.

17. The method defined in claim 1, wherein said cell/packet is one of frame relay-formatted, Internet-formatted or ISDN/SS#7-formatted.

18. The method defined in claim 1, wherein said step of assembling said data payload further comprises the step of including a pattern in said data payload for identifying the boundary of a corresponding frame in order to facilitate frame synchronization.

19. The method defined in claim 1, further comprising the step of interleaving a group of said plurality of frames.

20. The method defined by claim 19, wherein the step of interleaving further comprises the steps of:

segmenting the frames of said group into a plurality of segments; and

rearranging the order of said plurality of segments within said group.

21. The method defined by claim 20, wherein said step of interleaving is performed using a single buffer memory.

22. The method defined by claim 20, further comprising the step of transmitting said communication signal.

23. The method defined by claim 22, further comprising the step of transmitting said communication signal over a wireless network.

24. The method defined by claim 1, further comprising the step of transmitting said communication signal.

25. The method defined by claim 24, further comprising the step of transmitting said communication signal over a wireless network.

26. A method of disassembling a plurality of frames of a communication signal in a wireless or satellite system including cell/packet-formatted data, said frames each comprising, in accordance with a predetermined frame format, a frame header which defines aspects of a corresponding frame, a data payload having a first variable size, and a block code having a second variable size which is used for error correction, said data payload including at least one of a partial cell/packet, a complete cell/packet, a partial packet of compressed data and a complete packet of compressed data, said method comprising the steps of:

receiving a frame of said plurality of frames;

decoding said block code of said frame;

correcting errors of said frame created during a transmission thereof; and

extracting from said data payload the at least one of said partial cell/packets, said complete cell/packets, said partial packet of compressed data and said complete packet of compressed data in accordance with information included in said frame header.

27. The method defined in claim 26, wherein said second variable size depends on a bit error rate of said communication signal.

28. The method defined in claim 26, wherein said frame header comprises:

a first header field which defines a number of data cell/packets in said data payload, said number of data cell/packets including only complete data cell/packets and any partial data cell/packet which follows said complete data cell/packets;

a second header field which defines a size of a first partial data cell/packet that precedes any complete data cell/packets included in said data payload; and

a third header field which defines a frame number of a corresponding one of said plurality of frames.

29. The method defined in claim 28, wherein said frame header further comprises a fourth header field which defines a predetermined characteristic of said block code in accordance with said frame number of the corresponding one of said plurality of frames.

30. The method defined in claim 29, wherein said predetermined characteristic corresponds to the second variable size of said block code.

31. The method defined in claim 29, wherein said predetermined characteristic corresponds to the second variable size of said block code of a current frame of said plurality of frames.

32. The method defined in claim 29, wherein said predetermined characteristic corresponds to the second variable size of said block code of a subsequent frame of said plurality of frames.

33. The method defined in claim 29, wherein said second variable size of said block code depends on a bit error rate of said communication signal.

34. The method defined in claim 26, wherein said cells or packets are ATM formatted.

35. The method defined in claim 26, wherein said cells or packets are one of frame relay formatted, Internet-formatted and ISDN/SS#7 formatted.

36. The method defined in claim 26, wherein a group of said plurality of frames is interleaved, and wherein prior to the step of extracting said group of said plurality of frames is de-interleaved.

37. The method defined in claim 36, wherein the group of said plurality of frames comprises a plurality of segments, and

wherein the step of de-interleaving further comprises the steps of:

rearranging the order of said plurality of segments within said group; and

recreating each of the frames of said group in an original form.

38. The method defined by claim 37, wherein said step of interleaving is performed using a single buffer memory.

39. An apparatus for assembling a plurality of frames including cell- or packet-formatted data according to a predetermined frame format for transmission in a communication signal in a wireless or satellite system, said apparatus comprising:

an assembling circuit for assembling a data payload for each frame having a first variable size, said data payload including at least one of a partial data cell/packet and a complete data cell/packet;

a generating circuit for generating a block code having a second variable size for each frame, said block code being generated for error correction;

a header generating circuit for generating a flame header for each frame which defines aspects of said frame; and

a frame integrating circuit for combining said data payload, said block code and said format header to form a corresponding frame of said plurality of frames;

wherein said format header defines a first portion of said frame, said data payload defines a second portion of said frame and said block code defines a third portion of said frame.

40. The apparatus defined by claim 39, further comprising:

an interleaving circuit for interleaving a group of said plurality of frames.

41. The apparatus defined by claim 40, wherein said interleaving circuit further comprises:

a frame segmenting circuit for segmenting the frames of said group into a plurality of segments; and

a segment rearranging circuit for rearranging the order of said plurality of segments within said group.

42. The apparatus defined by claims 39, wherein said cell/packet format comprises one of an ATM, Internet, ISDN/SS#7 or frame relay-format.

43. The apparatus defined in claim 41, wherein said second variable size of said block code depends on a bit error rate of said communication signal.

45. The apparatus defined by claim 43, wherein said group of said plurality of frames is interleaved, and wherein said apparatus further comprises a de-interleaving circuit for de-interleaving said group of said plurality of frames.

47. The apparatus defined in claim 41, wherein said second variable size of said block code depends on a bit error rate of said communication signal.

44. An apparatus for disassembling a plurality of frames of a communication signal in a wireless or satellite system comprising cell- or packet-formatted data, said frames each comprising, in accordance with a predetermined frame format, a frame header which defines aspects of a corresponding frame, a data payload having a first variable size, and a block code having a second variable size which is used for error correction, said data payload including at least one of a partial cell or packet, a complete cell or packet, a partial packet of compressed data and/or a complete packet of compressed data, said apparatus comprising:

a frame receiving circuit for receiving a frame of said plurality of frames;

a decoding circuit for decoding said block code of said frame, said decoder correcting errors of said frame created during a transmission thereof; and

a data extracting circuit for extracting from said data payload the at least one of said partial cell or packet, said complete cell or packet, said partial packet of compressed data and said complete packet of compressed data in accordance with information included in said frame header.

46. The apparatus defined by claim 44, wherein said cell or packet have one of an ATM format, Internet format, ISDN/SS#7 format or frame relay format.

48. A method of disassembling a plurality of frames of a communication signal in a wireless or satellite system including asynchronous transfer mode (ATM) formatted data, said flames each comprising, in accordance with a predetermined frame format, a frame header which defines aspects of a corresponding frame, a data payload having a first variable size, and a block code having a second variable size which is used for error correction, said data payload including at least one of a partial ATM cell, a complete ATM cell, a partial packet of compressed data and a complete packet of compressed data, said method comprising the steps of:

receiving a frame of said plurality of frames;

decoding said block code of said frame;

correcting errors of said frame created during a transmission thereof if a number of said error is less than a predetermined amount;

discarding said frame if the number of said errors is equal to or greater than a predetermined amount; and

extracting from said data payload the at least one of said partial ATM cell, said complete ATM cell, said partial packet of compressed data and said complete packet of compressed data in accordance with information included in said frame header, if the number of said errors is less than said predetermined amount.