Frame based MAC control in WLAN communication devices

• US 20050220108A1
• Filed: 09/13/2004
• Published: 10/06/2005
• Est. Priority Date: 03/31/2004
• Status: Abandoned Application

• Current Assignee: Advanced Micro Devices, Inc.
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Hensel, Ulrich, Baer, Matthias, Kern, William, Rosner, Stephan, Flemming, Ralf, Eckhardt, Uwe
• Application Number:
  US10/939,859
• Publication Number:
  US 20050220108A1
• Time in Patent Office: Days
• US Class Current: 370/392
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC
• CPC Class Codes: H04W 28/14 using intermediate storage
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 74/00 Wireless channel access
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A WLAN (Wireless Local Area Network) communication device and method are provided where a MAC (Medium Access Control) control unit controls access to a wireless medium. The MAC control unit is capable of selectively applying any one of at least two different control mechanisms to data to be transmitted. The data received from a target system comprises data frames, each having associated an individual control header comprising control information. The control information specifies at least one control mechanism to be applied to data of the associated data frame. The MAC control unit extracts control information from each control header associated to a data frame, and selects a control mechanism specified by the extracted control information.

Claims

1. A WLAN (Wireless Local Area Network) transmitter device comprising:

a transmission buffer for buffering data received from a target system, the buffered data comprising data to be transmitted over a wireless medium; and

a MAC (Medium Access Control) control unit for controlling access to said wireless medium,

wherein said MAC control unit is capable of selectively applying any one of at least two different control mechanisms to data to be transmitted,

wherein the data received from said target system comprises data frames each having associated an individual control header comprising control information, said control information specifying at least one control mechanism to be applied to data of the associated data frame, and

wherein said MAC control unit is arranged to extract control information from each control header associated to a data frame, and select a control mechanism specified by the extracted control information.

2. The WLAN transmitter device of claim 1, wherein said data frames are MSDU (MAC Service Data Unit) data frames.

3. The WLAN transmitter device of claim 2, further comprising a hardware queue for enqueuing requests comprising at least one MSDU data frame.

4. The WLAN transmitter device of claim 1, wherein said data frames are MMPDU (MAC Management Protocol Data Unit) data frames.

5. The WLAN transmitter device of claim 4, further comprising a hardware queue for enqueuing requests comprising at least one MMPDU data frame.

6. The WLAN transmitter device of claim 1, further comprising a hardware queue for enqueuing said data frames and associated control headers, wherein said control headers further comprise a pointer field for pointing to a respective next data frame enqueued in said transmission buffer.

7. The WLAN transmitter device of claim 6, wherein said control headers further comprise information indicating the length of the respective next data frame pointed to by said pointer field.

8. The WLAN transmitter device of claim 6, wherein said hardware queue is realized as on-chip memory.

9. The WLAN transmitter device of claim 1, further comprising a hardware queue for enqueuing said data frames and associated control headers, wherein said control headers further comprise a tag field indicating which one of the enqueued data frames is presently in service.

10. The WLAN transmitter device of claim 9, wherein said hardware queue is controlled by means of said tag field to operate as a wrap around counter.

11. The WLAN transmitter device of claim 1, wherein said MAC control unit is realized as microcomputerless, programmable hardware unit.

12. The WLAN transmitter device of claim 11, wherein said control information comprises MAC program information for programming said MAC control unit.

13. The WLAN transmitter device of claim 1, wherein said at least one control mechanism specified by said control information comprises a data security algorithm to be applied to data of the respective associated data frame.

14. The WLAN transmitter device of claim 1, wherein said at least one control mechanism specified by said control information comprises an RTS (Request To Send) frame control mechanism for transmitting an RTS frame prior to the respective associated data frame to be transmitted.

15. The WLAN transmitter device of claim 1, wherein said at least one control mechanism specified by said control information comprises an CTS (Clear To Send) frame control mechanism for transmitting an CTS frame prior to the respective associated data frame to be transmitted.

16. The WLAN transmitter device of claim 1, wherein said at least one control mechanism specified by said control information comprises a preamble control mechanism for specifying whether a preamble is to be transmitted prior to the respective associated data frame to be transmitted.

17. The WLAN transmitter device of claim 1, wherein said at least one control mechanism specified by said control information comprises a preamble type control mechanism for selecting a preamble type to be transmitted prior to the respective associated data frame to be transmitted.

18. The WLAN transmitter device of claim 1, wherein said at least one control mechanism specified by said control information comprises a unicast control mechanism for specifying whether the respective associated data frame is to be transmitted as unicast data frame.

19. The WLAN transmitter device of claim 1, wherein said control headers further comprise transmitter statistics data.

20. The WLAN transmitter device of claim 19, wherein said transmitter statistics data hold status information indicating whether a service was cancelled, successfully finished, or is not yet finished.

21. The WLAN transmitter device of claim 19, wherein said transmitter statistics data hold transmission retry information.

22. The WLAN transmitter device of claim 19, wherein said transmitter statistics data hold time stamp information taken at the transmission end of the last transmission.

23. The WLAN transmitter device of claim 19, wherein said transmitter statistics data hold previously received RSSI (Received Signal Strength Indication) information.

24. The WLAN transmitter device of claim 19, wherein said transmitter statistics data hold signal quality information pertaining to a previously received acknowledgment frame.

25. The WLAN transmitter device of claim 19, wherein said transmitter statistics data hold antenna selection information pertaining to a previously received acknowledgment frame.

26. The WLAN transmitter device of claim 1, further comprising a physical layer interface unit connected to said transmission buffer for receiving from said transmission buffer data to be transmitted,

wherein said physical layer interface unit is a programmable unit further connected to said MAC control unit for receiving from said MAC control unit physical layer interface program information for programming said physical layer interface unit.

27. The WLAN transmitter device of claim 1, adapted to receive data from said target system via a PCI (Peripheral Component Interconnect), CF (Compact Flash), SD (Secure Digital) and/or SRAM (Static Random Access Memory) compliant data interface.

28. The WLAN transmitter device of claim 1, being IEEE 802.11 compliant.

29. An integrated circuit chip comprising:

a transmission buffer circuit for buffering data received from a target system, the buffered data comprising data to be transmitted over a wireless medium; and

a MAC (Medium Access Control) control circuit for controlling access to said wireless medium,

wherein said MAC control circuit is capable of selectively applying any one of at least two different control mechanisms to data to be transmitted,

wherein the data received from said target system comprises data frames each having associated an individual control header comprising control information, said control information specifying at least one control mechanism to be applied to data of the associated data frame, and

wherein said MAC control circuit is arranged to extract control information from each control header associated to a data frame, and select a control mechanism specified by the extracted control information.

30. A method of operating a WLAN (Wireless Local Area Network) transmitter device, comprising:

receiving data from a target system, the data comprising data to be transmitted over a wireless medium;

buffering the received data; and

controlling access to said wireless medium by selectively applying any one of at least two different control mechanisms to data to be transmitted,

wherein the data received from said target system comprises data frames each having associated an individual control header comprising control information, said control information specifying at least one control mechanism to be applied to data of the associated data frame, and

wherein controlling access to said wireless medium comprises;

extracting control information from each control header associated to a data frame; and

selecting a control mechanism specified by the extracted control information.

31. The method of claim 30, wherein said data frames are MSDU (MAC Service Data Unit) data frames.

32. The method of claim 31, further comprising:

enqueuing requests in a hardware queue, said requests comprising at least one MSDU data frame.

33. The method of claim 30, wherein said data frames are MMPDU (MAC Management Protocol Data Unit) data frames.

34. The method of claim 33, further comprising:

enqueuing requests in a hardware queue, said requests comprising at least one MMPDU data frame.

35. The method of claim 30, further comprising:

enqueuing said data frames and associated control headers in a hardware queue, wherein said control headers further comprise a pointer field for pointing to a respective next data frame enqueued.

36. The method of claim 35, wherein said control headers further comprise information indicating the length of the respective next data frame pointed to by said pointer field.

37. The method of claim 35, wherein said hardware queue is realized as on-chip memory.

38. The method of claim 30, further comprising:

enqueuing said data frames and associated control headers in a hardware queue, wherein said control headers further comprise a tag field indicating which one of the enqueued data frames is presently in service.

39. The method of claim 38, further comprising:

controlling said hardware queue by means of said tag field to operate as a wrap around counter.

40. The method of claim 30, wherein controlling access to said wireless medium comprises operating microcomputerless, programmable hardware.

41. The method of claim 40, wherein said control information comprises MAC (Medium Access Control) program information for programming a MAC control unit.

42. The method of claim 30, wherein said at least one control mechanism specified by said control information comprises a data security algorithm to be applied to data of the respective associated data frame.

43. The method of claim 30, wherein said at least one control mechanism specified by said control information comprises an RTS (Request To Send) frame control mechanism for transmitting an RTS frame prior to the respective associated data frame to be transmitted.

44. The method of claim 30, wherein said at least one control mechanism specified by said control information comprises an CTS (Clear To Send) frame control mechanism for transmitting an CTS frame prior to the respective associated data frame to be transmitted.

45. The method of claim 30, wherein said at least one control mechanism specified by said control information comprises a preamble control mechanism for specifying whether a preamble is to be transmitted prior to the respective associated data frame to be transmitted.

46. The method of claim 30, wherein said at least one control mechanism specified by said control information comprises a preamble type control mechanism for selecting a preamble type to be transmitted prior to the respective associated data frame to be transmitted.

47. The method of claim 30, wherein said at least one control mechanism specified by said control information comprises a unicast control mechanism for specifying whether the respective associated data frame is to be transmitted as unicast data frame.

48. The method of claim 30, wherein said control headers further comprise transmitter statistics data.

49. The method of claim 48, wherein said transmitter statistics data hold status information indicating whether a service was cancelled, successfully finished, or is not yet finished.

50. The method of claim 48, wherein said transmitter statistics data hold transmission retry information.

51. The method of claim 48, wherein said transmitter statistics data hold time stamp information taken at the transmission end of the last transmission.

52. The method of claim 48, wherein said transmitter statistics data hold previously received RSSI (Received Signal Strength Indication) information.

53. The method of claim 48, wherein said transmitter statistics data hold signal quality information pertaining to a previously received acknowledgment frame.

54. The method of claim 48, wherein said transmitter statistics data hold antenna selection information pertaining to a previously received acknowledgment frame.

55. The method of claim 30, further comprising:

extracting physical layer interface program information from control headers for programming a physical layer interface unit.

56. The method of claim 30, wherein the data is received from said target system via a PCI (Peripheral Component Interconnect), CF (Compact Flash), SD (Secure Digital) and/or SRAM (Static Random Access Memory) compliant data interface.

57. The method of claim 30, for operating an IEEE 802.11 compliant WLAN transmitter device.

58. A computer readable storage medium storing instructions that, when executed on a processor, cause the processor to associate individual control headers to individual data frames to be sent to a WLAN (Wireless Local Area Network) communication device, said individual control headers containing control information specifying at least one of at least two different control mechanisms to be applied to data of the associated data frame by a MAC (Medium Access Control) control unit of said WLAN communication device.

59. A method of controlling operation of a WLAN (Wireless Local Area Network) communication device, comprising:

associating individual control headers to individual data frames to be sent to said WLAN communication device, said individual control headers containing control information specifying at least one of at least two different control mechanisms to be applied to data of the associated data frame by a MAC (Medium Access Control) control unit of said WLAN communication device; and

sending the data frames and associated control headers to said WLAN communication device.