Wireless local area network supporting multiple slot times

1. A method for operating a Basic Service Set (BSS)/Independent Basic Service Set (IBSS) of a Wireless Local Area Network (WLAN) that services a plurality of WLAN devices (STAs), wherein at least one STA of the plurality of STAs supports multiple slot times, the method comprising:

initiating operation of the BSS/IBSS of the WLAN using a short slot time;

determining that operation of the BSS/IBSS requires use of a long slot time, wherein the long slot time is longer than the short slot time; and

altering operation of at least one of the plurality of STAs to be consistent with the long slot time by:

using the long slot time;

setting a local Long Slot Termination Time (LSTT);

when a Target Beacon Transition Time (TBTT) is before the local LSTT, transmitting a beacon that indicates that the long slot time is to be used and that includes the local LSTT; and

when the TBTT is after the local LSTT, transmitting a beacon that indicates that the short slot time is to be used.

2. The method of claim 1 , further comprising by a STA of the plurality of STAs:

receiving a beacon from another STA of the plurality of STAs, wherein the beacon includes a remote LSTT;

when the remote LSTT precedes the local LSTT, ignoring the remote LSTT; and

when the remote LSTT is later than the local LSTT, writing the remote LSTT as the local LSTT.

3. The method of claim 1 , further comprising, when a Timing Synchronization Function (TSF) of the BSS/IBSS is later than the LSTT, reverting to use of the short slot time.

4. The method of claim 1 , wherein determining that operation of the BSS/IBSS requires use of a long slot time comprises identifying a STA that associates with the BSS/IBSS and that requires operation with the long slot time.

5. The method of claim 1 , wherein determining that operation of the BSS/IBSS requires use of a long slot time comprises:

identifying a co-channel BSS that requires operation with the long slot time; and

determining that a service area of the co-channel BSS overlaps with a service area of BSS/IBSS.

6. The method of claim 1 , further comprising:

receiving a beacon from a co-channel BSS/IBSS STA that includes a remote LSTT and a Timing Synchronization Function (TSF);

normalizing the remote LSTT based upon the TSF to produce a normalized remote LSTT;

when the normalized remote LSTT precedes the local LSTT, ignoring the remote LSTT; and

when the remote LSTT is later than the local LSTT, writing the normalized remote LSTT as the local LSTT.

7. The method of claim 6 , wherein the beacon further comprises an indication that the long slot time is to be used.

8. The method of claim 1 , wherein determining that operation of the BSS/IBSS requires use of a long slot time comprises identifying a co-channel IBSS that requires operation with the long slot time.

9. The method of claim 1 , wherein setting the local LSTT includes setting the local LSTT to the sum of a Target Beacon Transition Time (TBTT) and a Minimum Long Slot Epoch (MLSE).

10. A method for operating a WALN device (STA) of an Independent Basic Service Set (IBSS) of a Wireless Local Area Network (WLAN), wherein the STA supports multiple slot times, the method comprising:

operating the STA using a short slot time;

determining that operation of the BSS/IBSS requires use of a long slot time, wherein the long slot time is longer than the short slot time; and

altering operation to be consistent with the long slot time by:

using the long slot time;

setting a local Long Slot Termination Time (LSTT);

when a Target Beacon Transition Time (TBTT) is before the local LSTT, transmitting a beacon that indicates that the long slot time is to be used and that includes the local LSTT; and

when the TBTT is after the local LSTT, transmitting a beacon that indicates that the short slot time is to be used.

11. The method of claim 10 , further comprising:

receiving a beacon from another STA of the IBSS, wherein the beacon includes a remote LSTT;

when the remote LSTT precedes the local LSTT, ignoring the remote LSTT; and

when the remote LSTT is later than the local LSTT, writing the remote LSTT as the local LSTT.

12. The method of claim 10 , further comprising, when a Timing Synchronization Function (TSF) of the IBSS is later than the LSTT, reverting to use of the short slot time.

13. The method of claim 10 , determining that operation of the IBSS requires use of a long slot time comprises identifying a STA that associates with the IBSS and that requires operation with the long slot time.

14. The method of claim 10 , wherein determining that operation of the IBSS requires use of a long slot time comprises:

identifying a co-channel BSS/IBSS that requires operation with the long slot time; and

determining that a service area of the co-channel BSS/IBSS overlaps with a service area of BSS/IBSS.

15. The method of claim 10 , further comprising:

receiving a beacon from a co-channel BSS/IBSS STA that includes a remote LSTT and a Timing Synchronization Function (TSF);

normalizing the remote LSTT based upon the TSF to produce a normalized remote LSTT;

when the normalized remote LSTT precedes the local LSTT, ignoring the remote LSTT; and

when the remote LSTT is later than the local LSTT, writing the normalized remote LSTT as the local LSTT.

16. The method of claim 15 , wherein the beacon further comprises an indication that the long slot time is to be used.

17. The method of claim 10 , wherein determining that operation of the IBSS requires use of a long slot time comprises identifying a co-channel IBSS that requires operation with the long slot time.

18. The method of claim 10 , wherein setting the local LSTT includes setting the local LSTT to the sum of a Target Beacon Transition Time (TBTT) and a Minimum Long Slot Epoch (MLSE).

19. A method for operating a WALN device (STA) of a Basic Service Set (BSS)/Independent Basic Service Set (IBSS) of a Wireless Local Area Network (WLAN), wherein the STA supports multiple slot times, the method comprising:

operating the STA using a short slot time;

determining that operation of the BSS/IBSS requires use of a long slot time, wherein the long slot time is longer than the short slot time;

receiving a beacon from another STA of the BSS/IBSS, wherein the beacon includes a remote Local Long Slot Termination Time (LSTT);

when the remote LSTT precedes the local LSTT, ignoring the remote LSTT; and

when the remote LSTT is later than the local LSTT, writing the remote LSTT as the local LSTT.

20. The method of claim 19 , wherein the beacon further comprises an indication that the long slot time is to be used.

21. The method of claim 19 , determining that operation of the BSS/IBSS requires use of a long slot time comprises identifying a STA that associates with the BSS/IBSS and that requires operation with the long slot time.

22. The method of claim 19 , wherein determining that operation of the BSS/IBSS requires use of a long slot time comprises:

identifying a co-channel BSS that requires operation with the long slot time; and

determining that a service area of the co-channel BSS overlaps with a service area of BSS/IBSS.

23. The method of claim 19 , further comprising:

receiving a beacon from a co-channel BSS/IBSS STA that includes a remote LSTT and a Timing Synchronization Function (TSF);

normalizing the remote LSTT based upon the TSF to produce a normalized remote LSTT;

when the normalized remote LSTT precedes the local LSTT, ignoring the remote LSTT; and

when the remote LSTT is later than the local LSTT, writing the normalized remote LSTT as the local LSTT.

24. The method of claim 23 , wherein the beacon further comprises an indication that the long slot time is to be used.

25. The method of claim 19 , wherein determining that operation of the BSS/IBSS requires use of a long slot time comprises identifying a co-channel IBSS that requires operation with the long slot time.

26. A Wireless Local Area Network (WLAN) device (STA) that supports multiple slot times, the STA comprising:

a Radio Frequency (RF) interface that supports communications with at least one other STA of the WLAN;

a processor operably coupled to the RF interface; and

wherein the RF interface and the processor cooperatively operate to:

commence operations using a short slot time;

determine that operation requires use of a long slot time, wherein the long slot time is longer than the short slot time by:

using the long slot time;

setting a local Long Slot Termination Time (LSTT);

when a Target Beacon Transition Time TBTT) is before the local LSTT, transmitting a beacon that indicates that the long slot time is to be used and that includes the local LSTT; and

when the TBTT is after the local LSTT, transmitting a beacon that indicates that the short slot time is to be used.

27. The STA of claim 26 , wherein the RF interface and the processor cooperatively operate further to:

receive a beacon from another STA, wherein the beacon includes a remote LSTT;

when the remote LSTT precedes the local LSTT, ignore the remote LSTT; and

when the remote LSTT is later than the local LSTT, write the remote LSTT as the local LSTT.

28. The STA of claim 26 , wherein the RF interface and the processor cooperatively operate further to:

receive a beacon from a foreign co-channel STA that includes a remote LSTT and a Timing Synchronization Function (TSF);

normalize the remote LSTT based upon the TSF to produce a normalized remote LSTT;

when the normalized remote LSTT precedes the local LSTT, ignore the remote LSTT; and

when the remote LSTT is later than the local LSTT, write the normalized remote LSTT as the local LSTT.

29. The STA of claim 26 , wherein the STA is a wireless terminal.

30. The STA of claim 26 , wherein the STA is an Access Point (AP).

31. A Wireless Local Area Network (WLAN) device (STA) that supports multiple slot times, the STA comprising:

a Radio Frequency (RF) interface that supports communications with at least one other STA of the WLAN;

a processor operably coupled to the RF interface; and

wherein the RF interface and the processor cooperatively operate to:

commence operations using a short slot time;

determine that operation requires use of a long slot time, wherein the long slot time is longer than the short slot time by:

using the long slot time;

receiving a beacon from another STA, wherein the beacon includes a remote Local Long Slot Termination Time (LSTT);

when the remote LSTT precedes the local LSTT, ignoring the remote LSTT; and

when the remote LSTT is later than the local LSTT, writing the remote LSTT as the local LSTT.

32. The STA of claim 31 , wherein the STA is a wireless terminal.

33. The STA of claim 31 , wherein the STA is a Access Point (AP).