Header compression enhancement for broadcast/multicast services

• US 20050090273A1
• Filed: 04/27/2004
• Published: 04/28/2005
• Est. Priority Date: 08/08/2003
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Wang, Jun, Jin, Haipeng, Hsu, Raymond Tah-Sheng, Veerepalli, Sivaramakrishna
• Granted Patent: US 7,822,067 B2
• Time in Patent Office: Days
• US Class Current: 455/502
• 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: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 72/30 Resource management for broadcast services

Abstract

Methods and apparatus for compression of headers in broadcasting BCMCS services in a wireless communication system are described. Techniques used in BCMCS systems without feedback include sending static context information during BCMCS service initialization for use in a decompressor in a mobile station. Techniques used in BCMCS systems with feedback include receiving feedback from distributed mobile station decompressors and adjusting the broadcasting compressor in response to the feedback. Techniques that reduce the number of operating states in both the compressor and the decompressor are described. Techniques to classify flows so that a reduced number of contexts are used to compress/decompress session packet headers in a push-to-talk service are described.

Claims

1. A method of broadcasting over a communication channel in a wireless communication system, the method comprising:

providing a decompressor with context initialization information that permits correct decompression of data packets; and

operating a compressor in a First Order State and sending data packets that include dynamic and static parameters of the compressor context;

operating the compressor in a Second Order State and sending data packets that include dynamic parameters of the compressor context; and

changing operation of the compressor between the First Order State and the Second Order State.

2. A method as defined in claim 1, wherein changing operation of the compressor occurs at periodic intervals.

3. A method as defined in claim 1, wherein changing operation of the compressor is in response to feedback from the decompressor.

4. A method as defined in claim 3, wherein the feedback includes a request from the decompressor.

5. A method as defined in claim 1, further comprising providing context initialization information for use in the decompressor.

6. A method as defined in claim 5, wherein the context includes the static parameters.

7. A method as defined in claim 5, wherein the context initialization information is provided during service discovery.

8. A method as defined in claim 5, wherein the context initialization information is provided in response to a decompressor request.

9. A method as defined in claim 1, wherein changing operation of the compressor occurs following a predetermined number of broadcast data transmissions.

10. A method of broadcasting over a communication channel in a wireless communication system, the method comprising:

providing a decompressor with context initialization information and static parameters that permits correct decompression of data packets; and

operating the compressor thereafter in one of a plurality of states and sending data packets that include update parameters of the compressor context until termination of the broadcast operation.

11. A method as defined in claim 10, wherein the update parameters are static parameters.

12. A method as defined in claim 10, wherein the update parameters are dynamic parameters.

13. A compressor for communications over a wireless communication channel, the compressor comprising a processor that performs a broadcast operation by establishing an initialization context for a broadcast session that includes dynamic and static parameters for use in a decompressor, and thereafter operating in a broadcast session in which the processor updates the dynamic and static parameters of the decompressor until termination of the broadcast session.

14. A compressor as defined in claim 13, wherein the compressor updates the parameters in response to feedback received from at least one decompressor.

15. A decompressor for communications over a wireless communication channel, the decompressor comprising a processor that enters a broadcast session by receiving an initialization state that establishes an initialization context that that includes dynamic and static parameters, and thereafter operating in a broadcast session in which the processor receives updates to the dynamic and static parameters of the decompressor until termination of the broadcast operation.

16. A decompressor as defined in claim 15, wherein the decompressor generates feedback requesting desired update parameters from the compressor.

17. A compressor comprising a processor that starts a broadcast session by generating an initialization state that establishes an initialization context that includes dynamic and static parameters for use in a decompressor and then operates in one of two conditions, the conditions comprising:

a First Order State that compresses data to be decompressed using the dynamic and static parameters; and

a Second Order State that reestablishes the dynamic parameters for use in the decompressor;

wherein the compressor is in the initialization state once at a beginning of the broadcast session, and then is in either the First Order State or Second Order State.

18. A compressor as defined in claim 17, wherein the compressor alternates operation between the First Order and Second Order States.

19. A compressor as defined in claim 18, wherein the compressor alternates operation at periodic intervals.

20. A compressor as defined in claim 18, wherein the compressor alternates operation between the First Order and Second Order States following a predetermined number of data transmissions.

21. A compressor as defined in claim 18, wherein the compressor alternates operation between the First Order State and Second Order State in response to feedback.

22. A compressor as defined in claim 21, wherein the feedback includes a request to change States.

23. A compressor as defined in claim 17, further comprising re-initializing the context for use in a decompressor.

24. A compressor as defined in claim 23, wherein re-initializing the context is in response to a request.

25. A decompressor comprising:

a processor that starts a broadcast session by receiving data for an initialization state that creates an initial context using dynamic and static parameters established by a compressor and then operates during the broadcast session in one of the two conditions, the conditions comprising;

a Static Context State that decompresses data using the dynamic and static parameters; and

a Full Context State that re-establishes the dynamic parameters for use in decompression.

26. A decompressor as defined in claim 25, further comprising re-initializing the initial context.

27. A decompressor as defined in claim 25, wherein the decompressor stores static parameters for use during the entire broadcast session.

28. A decompressor as defined in claim 25, wherein the decompressor alternates operation between the Static Context and Full Context States based on errors during decompression.

29. A decompressor as defined in claim 25, wherein the decompressor alternates operation between the Static Context and Full Context States based on a CRC error rate.

30. A decompressor as defined in claim 25, wherein the decompressor generates feedback.

31. A decompressor as defined in claim 30, wherein the feedback is a request to a compressor to change states.

32. A decompressor as defined in claim 31, wherein the request is generated based on errors during decompression.

33. A decompressor as defined in claim 31, wherein the request is generated based on a CRC error rate.

34. A wireless communication system comprising:

a compressor configured to initialize a context for use in a decompressor, and then to alternate operation between a First Order State where the compressor sends data packets that include dynamic and static parameters of the context and a Second Order State where the compressor sends data packets that include dynamic parameters of the context; and

a decompressor configured to receive and use the initialization context and then to alternate operation between a Static Context State where received data packets include dynamic and static parameters of the context and a Full Context State where received data packets include dynamic parameters of the context, whereby the compressor and decompressor alternate operation between states in a predetermined manner.

35. A wireless communication device comprising a decompressor configured to receive and use initialization context data and then to alternate operation between a Static Context State where received data packets include dynamic and static context parameters and a Full Context State where received data packets include dynamic context parameters, whereby the decompressor alternates between the Static Context and Full Context States in a predetermined manner.

36. A wireless communication device as defined in claim 35, wherein the decompressor alternates operation between the Full Context and Static Context States based on errors during decompression.

37. A wireless communication device as defined in claim 35, further comprising re-initializing the context.

38. A wireless communication infrastructure comprising a compressor configured to establish an initialization context state that includes dynamic and static context parameters for use in a decompressor and then to alternate operation between a First Order State that compresses data to be decompressed using the dynamic and static parameters and a Second Order State that reestablishes the dynamic parameters for use in the decompressor;

wherein the compressor is in the initialization context state once at a beginning of a broadcast session, and then the compressor is in either the First Order or Second Order States.

39. A wireless communication infrastructure as defined in claim 38, wherein the compressor alternates operation between the First Order and Second Order States.

40. A wireless communication infrastructure as defined in claim 39, wherein the compressor alternates between the First Order and Second Order States in a predetermined manner.

41. A wireless communication infrastructure as defined in claim 39, wherein the compressor alternates between the First Order and Second Order States at periodic intervals.

42. A wireless communication infrastructure as defined in claim 39, wherein the compressor alternates operation between the First and Second States following a predetermined number of data transmissions.

43. A wireless communication infrastructure as defined in claim 39, wherein the compressor alternates between the First Order and Second Order States in response to feedback.

44. A wireless communication infrastructure as defined in claim 43, wherein the feedback includes a request to change States.

45. A wireless communication infrastructure as defined in claim 38, further comprising re-initializing the context for use in a decompressor.

46. A wireless communication infrastructure as defined in claim 45, wherein re-initializing the context is in response to a request.

47. A method of multicast wireless communications between a group of users, the method comprising:

determining that a destination address in a data stream is a multicast address;

classifying the data stream based on parameters within the data stream; and

establishing a single context for the multicast session.

48. A method as defined in claim 47, wherein classification of the data stream is based on a destination address.

49. A method as defined in claim 47, wherein the classification of the data stream is based on a destination port.

50. A method as defined in claim 47, wherein the classification of the data stream is based on an IP version.

51. A method as defined in claim 47, wherein the classification of the data stream is based on an EP protocol field.

52. A method as defined in claim 47, wherein the multicast session is a Push-To-Talk session.

53. A method as defined in claim 47, wherein a compressor uses the single context to compress data packets send to multiple users.

54. A method as defined in claim 47, wherein a decompressor uses the single context to decompress data packets received from multiple users.

55. A computer readable media embodying a method of header compressing, the method comprising:

establishing an initialization context that includes dynamic and static parameters for use in a decompressor;

entering a First Order State that reestablishes dynamic and static parameters in a decompressor; and

entering a Second Order State that reestablishes dynamic parameters in the decompressor, wherein the compressor is in the initialization state once at a beginning of a session, and then the compressor alternates operation between the first and second states in a predetermined manner.

56. A computer readable media embodying a method of header decompression, the method comprising:

receiving an initialization context with dynamic and static parameters established by a compressor;

entering a Static Context State that receives and re-establishes the dynamic and static parameters in the decompressor context; and

entering a Full Context State that receives and re-establishes the dynamic parameters for use in decompression, wherein the decompressor is then in either the Static Context or Full Context State.