Data burst transmission methods in WLAN devices and systems

• US 20050068900A1
• Filed: 09/30/2003
• Published: 03/31/2005
• Est. Priority Date: 09/30/2003
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Stephens, Adrian P., Kitchin, Duncan
• Granted Patent: US 7,447,232 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04J 9/00 Multiplex systems in which each channel is represented by a different type of modulation of the carrier
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04L 9/40 Network security protocols
• 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 wireless local area network (WLAN) device transmits a header over an air interface, at a first modulation rate. The header may include an indication of a second modulation rate that will be used to transmit a consolidated payload. In one embodiment, the header includes information that enables a receiver to determine when an end of each of the multiple data units will occur. The device further transmits the consolidated payload at the second modulation rate. The consolidated payload includes multiple data units. In one embodiment, the consolidated payload includes information that enables the receiver to determine when an end of each of the multiple data units will occur.

Claims

1. A method comprising:

transmitting a header over an air interface, at a first modulation rate; and

transmitting the consolidated payload over the air interface, at a second modulation rate, wherein the consolidated payload includes multiple data units.

2. The method of claim 1, wherein the header includes an indication of the second modulation rate that will be used to transmit the consolidated payload, and wherein the header and the multiple data units form a portion of a single, self-describing, protocol data unit.

3. The method of claim 1, wherein the header includes information that enables a receiver to determine when an end of the consolidated payload will occur.

4. The method of claim 1, wherein the header includes information that enables a receiver to determine when an end of each of the multiple data units will occur.

5. The method of claim 1, wherein the consolidated payload further includes information that enables a receiver to determine when an end of each of the multiple data units will occur.

6. The method of claim 5, wherein the information includes multiple delimiters which include a delimiter for at least one of the multiple data units, wherein the delimiter for a data unit includes an indication of a length of the data unit, and wherein the delimiter is transmitted before the data unit at the second modulation rate.

7. The method of claim 6, wherein the delimiter further includes a validation field, which enables a receiver to determine whether the indication of the length is received correctly.

8. The method of claim 1, wherein transmitting the consolidated payload occurs within approximately one symbol width of an end of the header.

9. The method of claim 1, wherein the header is a physical device header, and wherein at least one of the multiple data units include a service data unit that is separately deliverable by a receiver.

10. The method of claim 1, wherein the first modulation rate is in a range of approximately 6 to 12 megabits per second.

11. The method of claim 1, wherein the second modulation rate is in a range of approximately 6 to 240 megabits per second.

12. A method comprising:

switching a transmitter to a first modulation rate;

transmitting a preamble over an air interface, at the first modulation rate, wherein the preamble enables a receiver to synchronize;

transmitting a header over the air interface, at the first modulation rate;

switching to a second modulation rate; and

transmitting a consolidated payload over the air interface, at the second modulation rate, wherein the consolidated payload includes multiple data units and information indicating the lengths of the multiple data units.

13. The method of claim 12, wherein the header includes an indication of the second modulation rate that will be used to transmit the consolidated payload.

14. The method of claim 12, wherein the information includes multiple delimiters which include a delimiter for at least one of the multiple data units, wherein the delimiter for a data unit includes an indication of a length of the data unit, and wherein the delimiter is transmitted before the data unit at the second modulation rate.

15. A method comprising:

switching a transmitter to a first modulation rate;

transmitting a preamble over an air interface, at the first modulation rate, wherein the preamble enables a receiver to synchronize;

transmitting a header over the air interface, at the first modulation rate, wherein the header includes information that enables the receiver to determine when an end will occur of each of multiple data units within a consolidated payload;

switching to a second modulation rate; and

transmitting the consolidated payload over the air interface, at the second modulation rate, wherein the consolidated payload includes the multiple data units.

16. The method of claim 15, wherein the header further includes an indication of the second modulation rate that will be used to transmit the consolidated payload, and wherein the header and the multiple data units form a portion of a single, self-describing, protocol data unit.

17. The method of claim 15, wherein the header is a physical device header, and wherein at least one of the multiple data units include a service data unit that is separately deliverable by the receiver.

18. A method comprising:

receiving a header over an air interface, at a first modulation rate;

switching to a second modulation rate; and

receiving a consolidated payload, at the second modulation rate, wherein the consolidated payload includes multiple data units.

19. The method of claim 18, wherein the header includes an indication of the second modulation rate at which the consolidated payload is modulated, and wherein the header and the multiple data units form a portion of a single, self-describing, protocol data unit.

20. The method of claim 18, wherein the header further includes information indicating when an end of the consolidated payload will occur.

21. The method of claim 18, wherein the header further includes information indicating when an end of each of the multiple data units will occur.

22. The method of claim 18, wherein the consolidated payload further includes information indicating when an end of each of the multiple data units will occur.

23. The method of claim 22, wherein the information includes multiple delimiters which include a delimiter for at least one of the multiple data units, wherein the delimiter for a data unit includes an indication of a length of the data unit, and wherein the delimiter is received before the data unit at the second modulation rate.

24. The method of claim 23, wherein the delimiter further includes a validation field, the method further comprising:

determining whether the delimiter is valid using information in the validation field; and

if the delimiter is not valid, evaluating at least one delimiter-sized data segment received in the consolidated payload to attempt to find another possible delimiter.

25. The method of claim 18, further comprising determining whether an end of the consolidated payload has been reached based on a measurement of symbol energy.

26. The method of claim 18, further comprising determining that an end of the consolidated payload has been reached when the consolidated payload has at least reached a known length or duration.

27. The method of claim 18, wherein the header is a physical device header, and at least some of the multiple data units are service data units that are separately deliverable by a receiver.

28. The method of claim 18, wherein the first modulation rate is in a range of approximately 6 to 12 megabits per second.

29. The method of claim 18, wherein the second modulation rate is in a range of approximately 6 to 240 megabits per second.

30. An apparatus comprising:

a medium access control device, to provide multiple data units destined for a receiver to a physical device; and

the physical device, coupled to the medium access control device, which is operable to

transmit a header over an air interface, at a first modulation rate; and

transmit a consolidated payload over the air interface, at a second modulation rate, wherein the consolidated payload includes the multiple data units.

31. The apparatus of claim 30, wherein the header includes an indication of the second modulation rate that will be used to transmit the consolidated payload, and wherein the header and the multiple data units form a portion of a single, self-describing, protocol data unit.

32. The apparatus of claim 30, wherein the header includes information to enable a receiver to determine when an end of the consolidated payload will occur.

33. The apparatus of claim 30, wherein the header includes information to enable a receiver to determine when an end of each of the multiple data units will occur.

34. The apparatus of claim 30, wherein the consolidated payload further includes information that enables a receiver to determine when an end of each of the multiple data units will occur.

35. The apparatus of claim 34, wherein the information includes multiple delimiters which include a delimiter for each of the multiple data units, wherein the delimiter for a data unit includes an indication of a length of the data unit, and wherein the delimiter is to be transmitted before the data unit at the second modulation rate.

36. The apparatus of claim 30, wherein the header is a physical device header, and wherein at least some of the multiple data units are service data units that are separately deliverable by a receiver.

37. The apparatus of claim 30, further comprising one or more antennae, coupled to the physical device, which is operable to provide an interface between the air interface and the physical device.

38. The apparatus of claim 30, further comprising an optical transmission device, coupled to the physical device, which is operable to provide an interface between the air interface and the physical device.

39. An apparatus comprising:

a medium access control device, to receive multiple data units from a physical device; and

the physical device, coupled to the medium access control device, which is operable to

receive a header over an air interface, at a first modulation rate; and

switch to a second modulation rate and receive a consolidated payload, wherein the consolidated payload includes the multiple data units.

40. The apparatus of claim 39, wherein the header includes an indication of the second modulation rate at which the consolidated payload is modulated, and wherein the header and the multiple data units form a portion of a single, self-describing, protocol data unit.

41. The apparatus of claim 39, wherein the header includes information indicating when an end of at least one of the multiple data units will occur.

42. The apparatus of claim 39, wherein the consolidated payload further includes information indicating when an end of at least one of the multiple data units will occur.

43. The apparatus of claim 42, wherein the information includes multiple delimiters which include a delimiter for at least one of the multiple data units, wherein the delimiter for a data unit includes an indication of a length of the data unit, and wherein the delimiter is to be received before the data unit at the second modulation rate.

44. The apparatus of claim 43, wherein the delimiter further includes a validation field, and wherein the physical device is further operable to:

determine whether the delimiter is valid using information in the validation field; and

if the delimiter is not valid, evaluate at least one delimiter-sized data segment received in the consolidated payload to attempt to find another possible delimiter.

45. The apparatus of claim 39, wherein the header is a physical device header, and at least some of the multiple data units are service data units that are separately deliverable by a receiver.

46. The apparatus of claim 39, further comprising one or more antennae, coupled to the physical device, which are operable to provide an interface between the air interface and the physical device.

47. The apparatus of claim 39, further comprising an optical transmission device, coupled to the physical device, which is operable to provide an interface between the air interface and the physical device.

48. A computer-readable medium having program instructions stored thereon to perform a method, which when executed within a wireless local area network device, result in:

transmitting a header over an air interface, at a first modulation rate; and

transmitting a consolidated payload over the air interface, at a second modulation rate, wherein the consolidated payload includes multiple data units.

49. The computer-readable medium of claim 48, wherein the header includes an indication of the second modulation rate that will be used to transmit the consolidated payload, and wherein the header and the multiple data units form a portion of a single, self-describing, protocol data unit.

50. The computer-readable medium of claim 48, wherein the header includes information that enables a receiver to determine when an end of at least one of the multiple data units will occur.

51. The computer-readable medium of claim 48, wherein the consolidated payload further includes information that enables a receiver to determine when an end of at least one of the multiple data units will occur.

52. The computer-readable medium of claim 51, wherein the information includes multiple delimiters which include a delimiter for at least one of the multiple data units, wherein the delimiter for a data unit includes an indication of a length of the data unit, and wherein the delimiter is transmitted before the data unit at the second modulation rate.

53. The computer-readable medium of claim 48, wherein the header is a physical device header, and wherein at least some of the multiple data units are service data units that are separately deliverable by a receiver.

54. A computer-readable medium having program instructions stored thereon to perform a method, which when executed within a wireless local area network device, result in:

receiving a header over an air interface, at a first modulation rate; and

switching to a second modulation rate and receiving a consolidated payload, wherein the consolidated payload includes multiple data units.

55. The computer-readable medium of claim 54, wherein the header includes an indication of the second modulation rate at which the consolidated payload is modulated, and wherein the header and the multiple data units form a portion of a single, self-describing, protocol data unit.

56. The computer-readable medium of claim 54, wherein the header includes information indicating when an end of at least one of the multiple data units will occur.

57. The computer-readable medium of claim 54, wherein the consolidated payload further includes information indicating when an end of at least one of the multiple data units will occur.

58. The computer-readable medium of claim 57, wherein the information includes multiple delimiters which include a delimiter for at least one of the multiple data units, wherein the delimiter for a data unit includes an indication of a length of the data unit, and wherein the delimiter is received before the data unit at the second modulation rate.

59. The computer-readable medium of claim 58, wherein the delimiter further includes a validation field, and executing the program instructions further results in:

determining whether the delimiter is valid using information in the validation field; and

if the delimiter is not valid, evaluating at least one delimiter-sized data segment received in the consolidated payload to attempt to find another possible delimiter.

60. The computer-readable medium of claim 54, wherein the header is a physical device header, and wherein at least some of the multiple data units are service data units that are separately deliverable by a receiver.