Supporting a large number of devices in wireless communications
A method for receiving a backoff value at a wireless station is presented. A traffic indication map is received at the station, wherein a backoff number is implicitly assigned to the station based on a position of the station within the traffic indication map. The backoff value is determined by multiplying the backoff number by a predetermined time value.
1. A method comprising:
receiving a time value at a station;
receiving a traffic indication map (TIM) element at the station, the TIM element indicating a positive indication for a group of stations having traffic that is pending;
determining an offset for the station as a function of a position of the station within the group of stations; and
determining a medium access backoff time for the station based on the determined offset and the received time value.
2. The method of claim 1 , wherein the time value is a fixed value.
3. The method of claim 1 , wherein the time value is received at the station via a beacon or a short beacon.
4. The method of claim 1 , further comprising:
setting a backoff timer at the station with the medium access backoff time; and
attempting to send a communication by the station after the backoff timer has expired.
5. The method of claim 1 , wherein the medium access backoff time is a slot time.
6. The method of claim 1 , further comprising signaling the medium access backoff time using at least one of a beacon or a short beacon.
7. The method of claim 1 , wherein the position is associated with the positive indication in the TIM element.
8. The method of claim 1 , wherein the position is an index of an association identifier (AID) of the station.
9. The method of claim 1 , further comprising determining a slot in which the station is configured to contend for the medium based on the medium access backoff time for the station.
10. The method of claim 1 , wherein the station is a STA.
11. A station comprising:
a processor and a transceiver communicatively coupled to:
receive a time value at a station;
receive a traffic indication map (TIM) element at the station, the TIM element indicating a positive indication for a group of stations having traffic that is pending;
determine an offset for the station as a function of the position of the station within the group of stations; and
determine a medium access backoff time for the station based on the determined offset and the received time value.
12. The station of claim 11 , wherein the time value is a fixed value.
13. The station of claim 11 , wherein the time value is received at the station via a beacon or a short beacon.
14. The station of claim 11 , the processor and a transceiver communicatively coupled to further:
set a backoff timer at the station with the medium access backoff time; and
attempt to send a communication by the station after the backoff timer has expired.
15. The station of claim 11 , wherein the medium access backoff time is a slot time.
16. The station of claim 11 , the processor and a transceiver communicatively coupled to further signal the medium access backoff time using at least one of a beacon or a short beacon.
17. The station of claim 11 , wherein the position is associated with the positive indication in the TIM element.
18. The station of claim 11 , wherein the position is an index of an association identifier (AID) of the station.
19. The station of claim 11 , the processor and a transceiver communicatively coupled to further determine a slot in which the station is configured to contend for the medium based on the medium access backoff time for the station.
20. The station of claim 11 , wherein the station is a STA.