Apparatus and method capable of providing quality of service channel access in a wireless network

• US 20050243788A1
• Filed: 04/28/2004
• Published: 11/03/2005
• Est. Priority Date: 04/28/2004
• Status: Active Grant

• Current Assignee: Tahoe Research Limited (f/k/a Learndale Limited) (Vector Capital Corporation)
• Original Assignee: Intel Corporation
• Inventors: Janczak, Tomasz K.
• Granted Patent: US 7,366,153 B2
• Time in Patent Office: Days
• US Class Current: 370/341
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling
• CPC Class Codes: H04W 74/085 collision avoidance
• CPC Class Codes: H04W 74/0866 using a dedicated channel for access

Abstract

Briefly, in accordance with one embodiment of the invention, an apparatus with capabilities to communicate in a wireless network, comprising a channel access scheme providing access to the wireless network, the access scheme using a modulo N backoff scheme providing a modulo N backoff; and the channel access scheme further providing traffic prioritization

Claims

1. An apparatus, comprising:

a channel access scheme providing access to a wireless network, said access scheme using a modulo N backoff scheme providing a modulo N backoff; and

said channel access scheme further providing traffic prioritization.

2. The apparatus of claim 1, wherein said traffic prioritization is accomplished by using an AIFS interval defined on a per-class basis.

3. The apparatus of claim 2, wherein one slot difference in AIFS intervals correspond to N-value difference in backoff counters in said modulo N backoff scheme.

4. The apparatus of claim 1, wherein said modulo N backoff is aligned with an EDCF algorithm.

5. The apparatus of claim 1, wherein said AIFS interval replaced a DFIS interval.

6. The apparatus of claim 2, wherein decrementing a backoff counter takes place at the beginning or end of a foreign transmission period.

7. The apparatus of claim 2, wherein a contention window associated with said channel access scheme has a window range of <

0,3>

and said modulo N is modulo 4 improving the probability of strict-priority precedence of real-time traffic over non-real time packets.

8. The apparatus of claim 2, wherein said access scheme using a modulo N backoff scheme providing a modulo N backoff with prioritization comprises:

(a) setting b=random(0, CW);

(b) waiting AIFS after medium busy;

(c) transmitting one slot burst if b≦

N, and if b=0 transmitting a packet;

if b≠

0, wait one slot, set b=b −

1 and, if slot is idle, repeat until b=0;

if slot is not idle, return to step (b); and

(d) waiting one slot if b≧

N, and, if slot is idle, setting b=b−

N and repeating until b<

N;

if slot is not idle, determine if b=0 and if so, transmit packet;

if b≠

0, wait one slot, set b=b−

1 and, if slot idle, repeat until b=0;

if slot is not idle return to step (b).

9. The apparatus of claim 2, wherein the number of backoff slots in said access scheme using a modulo N backoff scheme is expressed as:

MBL_k,N =[k/N]+1 +(k mod N)

where,

k=a drawn random backoff counter,

N=modulo number.

10. The apparatus of claim 2, wherein said modulo N backoff scheme is a modulo 4 scheme and wherein said CW is quadrupled after each collision to a maximum of 4 CW increases.

42. The apparatus of claim 1, wherein said wireless network is a wireless local area network (WLAN).

47. The apparatus of claim 1, wherein said modulo N backoff scheme is augmented with a modified CW increase scheme, modulo N/CWinc₋

factor/CWinc₋

limit.

11. A method, comprising:

providing a channel access scheme to a wireless network, said access scheme using a modulo N backoff scheme providing a modulo N backoff; and

prioritizing traffic seeking access to said wireless network.

12. The method of claim 11, wherein said traffic prioritization is accomplished by using an AIFS interval defined on a per-class basis.

13. The method of claim 12, wherein one slot difference in said AIFS intervals correspond to N-value difference in backoff counters in said modulo N backoff scheme.

14. The method of claim 11, wherein said modulo N backoff is aligned with an EDCF algorithm.

15. The method of claim 11, wherein said AIFS interval replaced a DFIS interval.

16. The method of claim 12, wherein decrementing a backoff counter takes place at the beginning of a foreign transmission period.

17. The method of claim 12, wherein a contention window associated with said channel access scheme has a window range of <

0,3>

and said modulo N is modulo 4 ensuring strict-priority precedence of real-time traffic over non-real time packets.

18. The method of claim 12, wherein said access scheme using a modulo N backoff scheme providing a modulo N backoff with prioritization comprises:

(a) setting b=random(0, CW);

(b) waiting AIFS after medium busy;

(c) transmitting one slot burst if b<

N, and if b=0 transmitting a packet;

if b≠

0, wait one slot, set b=b−

1 and, if slot is idle, repeat until b=0;

if slot is not idle, return to step (b); and

(d) waiting one slot if b≧

N, and, if slot is idle, setting b=b−

N and repeating until b<

N;

if slot is not idle, determine if b=0 and if so, transmit packet;

if b≠

0, wait one slot, set b=b-1 and, if slot idle, repeat until b=0;

if slot is not idle return to step (b).

19. The method of claim 12, wherein the number of backoff slots in said access scheme using a modulo N backoff scheme is expressed as:

MBL_k,N=[k/N]+1+(k mod N)

where,

k=a drawn random backoff counter,

N=modulo number.

20. The method of claim 12, wherein said modulo N backoff scheme is a modulo 4/4/4.

43. The method of claim 11, wherein said wireless network is a wireless local area network (WLAN).

21. An article comprising a storage medium having stored thereon instructions, that, when executed by a computing platform, establishes a channel access scheme providing access to a wireless network, said access scheme using a modulo N backoff scheme providing a modulo N backoff;

and

said channel access scheme further providing traffic prioritization.

22. The article of claim 21, wherein said traffic prioritization is accomplished by using an AIFS interval defined on a per-class basis.

23. The article of claim 21, wherein one slot difference in AIFS intervals correspond to N-value difference in backoff counters in said modulo N backoff scheme.

24. The article of claim 21, wherein said modulo N backoff is aligned with an EDCF algorithm.

25. The article of claim 21, wherein said AIFS interval replaced a DFIS interval.

26. The article of claim 22, wherein decrementing a backoff counter takes place at the beginning of a foreign transmission period.

27. The article of claim 22, wherein a contention window associated with said channel access scheme has a window range of <

0,3>

and said modulo N is modulo 4 ensuring strict-priority precedence of real-time traffic over non-real time packets.

28. The article of claim 22, wherein said access scheme using a modulo N backoff scheme providing a modulo N backoff with prioritization comprises:

(a) setting b=random(0, CW);

(b) waiting AIFS after medium busy;

(c) transmitting one slot burst if b<

N, and if b=0 transmitting a packet;

if b≠

0, wait one slot, set b=b−

1 and, if slot is idle, repeat until b=0;

if slot is not idle, return to step (b); and

(d) waiting one slot if b≧

N, and, if slot is idle, setting b=b−

N and repeating until b<

N;

if slot is not idle, determine if b=0 and if so, transmit packet;

if b≠

0, wait one slot, set b=b−

1 and, if slot idle, repeat until b=0;

if slot is not idle return to step (b).

29. The article of claim 22, wherein the number of backoff slots in said access scheme using a modulo N backoff scheme is expressed as:

MBL_k,N=[k/N]+1+(k mod N)

where,

k=a drawn random backoff counter,

N=modulo number.

in a wireless communication environment, protection-capable and non-protection-capable Management Frames, said protection-capable Management Frames being protected.

44. The article of claim 21, wherein said wireless network is a wireless local area network (WLAN).

30. A system, comprising:

said system capable of prioritizing traffic access to a wireless network,

a channel access scheme which provides access to said wireless network;

said channel access scheme using a modulo N backoff scheme providing a modulo N backoff; and

said prioritization is accomplished by using an AIFS interval defined on a per-class basis and wherein said AIFS intervals correspond to N-value difference in backoff counters in said modulo N backoff scheme.

31. The system of claim 30, wherein said modulo N backoff is aligned with an EDCF algorithm.

32. The system of claim 30, wherein said AIFS interval replaced a DFIS interval.

33. The system of claim 30, wherein decrementing a backoff counter takes place at the beginning of a foreign transmission period.

34. The system of claim 30, wherein a contention window associated with said channel access scheme has a window range of <

0,3>

and said modulo N is modulo 4 ensuring strict-priority precedence of real-time traffic over non-real time packets.

35. The system of claim 30, wherein said access scheme using a modulo N backoff scheme providing a modulo N backoff with prioritization comprises:

(a) setting b=random(0, CW);

(b) waiting AIFS after medium busy;

(c) transmitting one slot burst if b<

N, and if b=0 transmitting a packet;

if b≠

0, wait one slot, set b=b−

1 and, if slot is idle, repeat until b=0;

if slot is not idle, return to step (b); and

(d) waiting one slot if b≧

N, and, if slot is idle, setting b=b −

N and repeating until b<

N;

if slot is not idle, determine if b=0 and if so, transmit packet;

if b≠

0, wait one slot, set b=b−

1 and, if slot idle, repeat until b=0;

if slot is not idle return to step (b).

36. The system of claim 30, wherein the number of backoff slots in said access scheme using a modulo N backoff scheme is expressed as:

MBL_k,N=[k/N]+1+(k mod N)

where,

k=a drawn random backoff counter,

N=modulo number.

45. The system of claim 30, wherein said wireless network is a wireless local area network (WLAN).

37. Computer-executable instructions stored on a computer-readable storage medium for providing a Quality of Service (QoS) service prioritization to a wireless station in a wireless network, said computer-executable instructions comprising:

providing a channel access scheme using a modulo N backoff scheme providing a modulo N backoff; and

prioritizing traffic seeking access to said wireless network by using an AIFS interval defined on a per-class basis, wherein one slot difference in said AIFS intervals correspond to N-value difference in backoff counters in said modulo N backoff scheme.

38. The computer-executable instructions stored on a computer-readable storage medium of claim 37, wherein decrementing a backoff counter takes place at the beginning of a foreign transmission period.

39. The computer-executable instructions stored on a computer-readable storage medium of claim 37, wherein a contention window associated with said channel access scheme has a window range of <

0,3>

and said modulo N is modulo 4 ensuring strict-priority precedence of real-time traffic over non-real time packets.

40. The computer-executable instructions stored on a computer-readable storage medium of claim 37, wherein said access scheme using a modulo N backoff scheme providing a modulo N backoff with prioritization comprises:

(a) setting b=random(0, CW);

(b) waiting AIFS after medium busy;

(c) transmitting one slot burst if b<

N, and if b=0 transmitting a packet;

if b≠

0, wait one slot, set b=b−

1 and, if slot is idle, repeat until b=0;

if slot is not idle, return to step (b); and

(d) waiting one slot if b≧

N, and, if slot is idle, setting b=b −

N and repeating until b<

N;

if slot is not idle, determine if b=0 and if so, transmit packet;

if b≠

0, wait one slot, set b=b−

1 and, if slot idle, repeat until b=0;

if slot is not idle return to step (b).

41. The computer-executable instructions stored on a computer-readable storage medium of claim 37, wherein the number of backoff slots in said access scheme using a modulo N backoff scheme is expressed as:

MBL_k,N=[k/N]+1+(k mod N)

where,

k=a drawn random backoff counter,

N=modulo number.

46. The computer-executable instructions stored on a computer-readable storage medium of claim 37, wherein said wireless network is a wireless local area network (WLAN).