Method and system for header compression

• US 7,430,617 B2
• Filed: 12/19/2003
• Issued: 09/30/2008
• Est. Priority Date: 12/19/2003
• Status: Active Grant

• Current Assignee: III Holdings 3, LLC
• Original Assignee: Nokia Corporation
• Inventors: Luoma, Juha-Pekka, Walsh, Rod, Saaranen, Anne
• Primary Examiner(s): Tran; Philip B
• Application Number:
  US10/739,066
• Publication Number:
  US 20050160184A1
• Time in Patent Office: 1,747 Days
• Field of Search: 709/247, 709/246, 709/238, 709/230, 370/392
• US Class Current: 709/247
• CPC Class Codes: H04L 12/1868 Measures taken after transmission, e.g. acknowledgments
• CPC Class Codes: H04L 12/1877 Measures taken prior to transmission
• CPC Class Codes: H04L 12/189 in combination with wireless systems selective distribution or broadcast in wireless communication networks H04W4/06
• CPC Class Codes: H04L 69/04 Protocols for data compression, e.g. ROHC
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers

Abstract

A compression context for a plurality of packets is established with a receiving device. Each of these packets is associated with one or more reliable multicast protocols, such as the Layered Coding Transform (LCT) protocol, the Asynchronous Layered Coding (ALC) protocol, the FLUTE protocol, the MUPPET protocol, and the NACK-Oriented Reliable Multicast (NORM) protocol. Upon establishment of the compression context, a compressed packet is generated for one of the plurality of packets and transmitted to the receiving device. The compressed packet has a reduced number of bits in its header. Upon receipt, the receiving device decompresses the compressed packet based on the compression context.

Claims

1. A packet transmission method, comprising:

(a) establishing with a receiving device a compression context for a plurality of packets, the plurality of packets associated with at least a reliable multicast protocol, wherein each of the plurality of packets includes a header having a plurality of header fields;

(b) generating a compressed packet for one of the plurality of packets, the compressed packet having a reduced number of bits in its header;

said compressed packet formed by compression in one of a plurality of states ranging from an initialization and refresh state for sending packets having substantially complete header information, to more compressed states for sending one or more packets with headers having progressively more compressed header information, said compression adaptively reverting from said more compressed states to said initialization and refresh state to accommodate unidirectional receivers of the multicast packets, wherein the reverting in compression states is triggered at an expiration of a timer or a sequence counter of the multicast packets; and

(c) transmitting the compressed packet to the receiving device.

2. The method of claim 1, wherein step (a) comprises transmitting one or more of the packets with uncompressed headers to the receiving device.

3. The method of claim 1, wherein step (a) further comprises storing a current value for one or more packet header fields.

4. The method of claim 1, wherein step (a) further comprises identifying one or more patterns of change in header fields.

5. The method of claim 1, wherein each of the plurality of packets are associated with the Layered Coding Transform (LCT) protocol.

6. The method of claim 5, wherein each of the plurality of packets are further associated with the Asynchronous Layered Coding (ALC) protocol.

7. The method of claim 6, wherein each of the plurality of packets are further associated with the FLUTE protocol.

8. The method of claim 6, wherein each of the plurality of packets are further associated with the MUPPET protocol.

9. The method of claim 5, wherein the plurality of packets each have the same Transport Object Identifier (TOI) flag.

10. The method of claim 5, wherein the plurality of packets each have the same Transport Session Identifier (TSI) flag.

11. The method of claim 1, wherein each of the plurality of packets are associated with the NACK-Oriented Reliable Multicast (NORM) protocol.

12. The method of claim 1, further comprising:

(d) identifying one or more header fields as compressible.

13. The method of claim 12, wherein step (d) comprises placing each of the header fields into one of a plurality of categories, the plurality of categories including:

a first category for header fields that do not change at all for the plurality of packets,

a second category for header fields that change only occasionally for the plurality of packets, and

a third category for header fields that changes for each of the plurality of packets.

14. The method of claim 13, wherein step (b) comprises:

eliminating any header fields corresponding to the first category; and

compressing any header fields corresponding to the second category.

15. The method of claim 1, wherein step (b) comprises replacing a field in the header of the one packet with a compressed header field having a reduced number of bits.

16. The method of claim 15, wherein the compressed field represents a change in value from a corresponding header field in a previous packet.

17. The method of claim 15, wherein step (b) further comprises performing variable length encoding on the compressed header field.

18. The method of claim 15, wherein step (b) further comprises performing Huffman encoding on the compressed header field.

19. The method of claim 1, wherein step (c) comprises encapsulating the compressed packet in a transmission frame of a layer two protocol.

20. A packet reception method, comprising:

(a) establishing with a transmitting device a compression context for a plurality of packets, the plurality of packets associated with at least a reliable multicast protocol, wherein each of the plurality of packets includes a header having a plurality of header fields;

(b) receiving a compressed packet from the transmitting device, the compressed packet having a reduced number of bits in its header;

said compressed packet formed by compression in one of a plurality of states ranging from an initialization and refresh state for sending packets having substantially complete header information, to more compressed states for sending one or more packets with headers having progressively more compressed header information, said compression adaptively reverting from said more compressed states to said initialization and refresh state to accommodate unidirectional receivers of the multicast packets, wherein the reverting in compression states is triggered at an expiration of a timer or a sequence counter of the multicast packets; and

(c) decompressing the compressed packet based on the compression context.

21. The method of claim 20, wherein step (a) comprises receiving one or more of the packets with uncompressed headers from the transmitting device.

22. The method of claim 20, wherein step (a) further comprises storing a current value for one or more packet header fields.

23. The method of claim 20, wherein step (a) further comprises identifying one or more patterns of change in header fields.

24. The method of claim 20, wherein each of the plurality of packets are associated with the Layered Coding Transform (LCT) protocol.

25. The method of claim 24, wherein each of the plurality of packets are further associated with the Asynchronous Layered Coding (ALC) protocol.

26. The method of claim 25, wherein each of the plurality of packets are further associated with the FLUTE protocol.

27. The method of claim 25, wherein each of the plurality of packets are further associated with the MUPPET protocol.

28. The method of claim 24, wherein the plurality of packets each have the same Transport Object Identifier (TOI) flag.

29. The method of claim 24, wherein the plurality of packets each have the same Transport Session Identifier (TSI) flag.

30. The method of claim 20, wherein each of the plurality of packets are associated with the NACK-Oriented Reliable Multicast (NORM) protocol.

31. The method of claim 20, wherein step (c) comprises performing variable length decoding on the compressed packet.

32. The method of claim 20, wherein step (c) comprises performing Huffman decoding on the compressed packet.

33. A system, comprising:

a context database for storing a compression context for a plurality of packets, the plurality of packets associated with at least a reliable multicast protocol, wherein each of the plurality of packets includes a header having a plurality of header fields;

a compressor for generating a compressed packet for one of the plurality of packets, the compressed packet having a reduced number of bits in its header;

said compressed packet formed by compression in one of a plurality of states ranging from an initialization and refresh state for sending packets having substantially complete header information, to more compressed states for sending one or more packets with headers having progressively more compressed header information, said compression adaptively reverting from said more compressed states to said initialization and refresh state to accommodate unidirectional receivers of the multicast packets, wherein the reverting in compression states is triggered at an expiration of a timer or a sequence counter of the multicast packets; and

a sender for transmitting the compressed packet to a receiving device.

34. The system of claim 33, wherein each of the plurality of packets are associated with the Layered Coding Transform (LCT) protocol.

35. The system of claim 34, wherein each of the plurality of packets are further associated with the Asynchronous Layered Coding (ALC) protocol.

36. The system of claim 35, wherein each of the plurality of packets are further associated with the FLUTE protocol.

37. The system of claim 35, wherein each of the plurality of packets are further associated with the MUPPET protocol.

38. The system of claim 33, wherein each of the plurality of packets are associated with the NACK-Oriented Reliable Multicast (NORM) protocol.

39. A system, comprising:

a context database for storing a compression context for a plurality of packets, the plurality of packets associated with at least a reliable multicast protocol, wherein each of the plurality of packets includes a header having a plurality of header fields;

a receiver for receiving a compressed packet from a transmitting device, the compressed packet corresponding to one of the plurality of packets and having a reduced number of bits in its header;

said compressed packet formed by compression in one of a plurality of states ranging from an initialization and refresh state for sending packets having substantially complete header information, to more compressed states for sending one or more packets with headers having progressively more compressed header information, said compression adaptively reverting from said more compressed states to said initialization and refresh state to accommodate unidirectional receivers of the multicast packets, wherein the reverting in compression states is triggered at an expiration of a timer or a sequence counter of the multicast packets; and

a decompressor for generating an uncompressed packet from the compressed packet based on the compression context.

40. The system of claim 39, wherein each of the plurality of packets are associated with the Layered Coding Transform (LCT) protocol.

41. The system of claim 40, wherein each of the plurality of packets are further associated with the Asynchronous Layered Coding (ALC) protocol.

42. The system of claim 41, wherein each of the plurality of packets are further associated with the FLUTE protocol.

43. The system of claim 41, wherein each of the plurality of packets are further associated with the MUPPET protocol.

44. The system of claim 39, wherein each of the plurality of packets are associated with the NACK-Oriented Reliable Multicast (NORM) protocol.

45. A computer program product comprising a computer useable storage medium having computer program logic recorded thereon for enabling a processor in a computer system of a device to transmit packets, the computer program logic comprising:

program code for enabling the processor to establish with a receiving device a compression context for a plurality of packets, the plurality of packets associated with at least a reliable multicast protocol, wherein each of the plurality of packets includes a header having a plurality of header fields;

program code for enabling the processor to generate a compressed packet for one of the plurality of packets, the compressed packet having a reduced number of bits in its header;

said compressed packet formed by compression in one of a plurality of states ranging from an initialization and refresh state for sending packets having substantially complete header information, to more compressed states for sending one or more packets with headers having progressively more compressed header information, said compression adaptively reverting from said more compressed states to said initialization and refresh state to accommodate unidirectional receivers of the multicast packets, wherein the reverting in compression states is triggered at an expiration of a timer or a sequence counter of the multicast packets; and

program code for enabling the processor to transmit the compressed packet to the receiving device.

46. A computer program product comprising a computer useable storage medium having computer program logic recorded thereon for enabling a processor in a computer system of a device to receive packets, the computer program logic comprising:

program code for enabling the processor to establish with a transmitting device a compression context for a plurality of packets, the plurality of packets associated with at least a reliable multicast protocol, wherein each of the plurality of packets includes a header having a plurality of header fields;

program code for enabling the processor to receive a compressed packet from the transmitting device, the compressed packet having a reduced number of bits in its header;

said compressed packet formed by compression in one of a plurality of states ranging from an initialization and refresh state for sending packets having substantially complete header information, to more compressed states for sending one or more packets with headers having progressively more compressed header information, said compression adaptively reverting from said more compressed states to said initialization and refresh state to accommodate unidirectional receivers of the multicast packets, wherein the reverting in compression states is triggered at an expiration of a timer or a sequence counter of the multicast packets; and

program code for enabling the processor to decompress the compressed packet based on the compression context.