Enhanced IEEE Power Save in Ad Hoc Wireless Mode

• US 20080125190A1
• Filed: 11/21/2007
• Published: 05/29/2008
• Est. Priority Date: 11/28/2006
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell World Trade Limited (Marvell Technology Group Limited)
• Inventors: Lee, Robert, Chow, Long, Luo, Xiaohua, Huang, Frank, Jan, James
• Granted Patent: US 9,332,496 B2
• Time in Patent Office: Days
• US Class Current: 455/574
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

In accordance with the invention, a method, system and apparatus for saving power consumed by a station in an ad hoc wireless network are presented. The method comprises transmitting or receiving a signal by a station in the ad hoc wireless network during a beacon interval. The station enters a power saving doze state immediately following the transmission or reception of the signal and prior to the end of the beacon interval. Additionally or alternatively, the station may enter power saving doze state following a timed period, according to a counter, or according to a periodic pattern.

Claims

1. A method for saving power consumed by a station in an ad hoc wireless network, the method comprising:

transmitting or receiving a signal by the station in the ad hoc wireless network during a beacon interval; and

entering a power saving doze state by the station immediately following the transmission or reception of the signal during the beacon interval and prior to an end of the beacon interval.

2. The method of claim 1, wherein an announcement traffic identification message (ATIM) window occurs at a beginning of the beacon interval.

3. The method of claim 2, further comprising:

detecting a level of activity for the station after the ATIM window of the beacon interval.

4. The method of claim 3, wherein the station enters the power saving doze state when no activity is detected after the ATIM window of the beacon interval.

5. The method of claim 1, wherein a station in power saving doze state cannot transmit or receive signals.

6. The method of claim 1, wherein the ad hoc wireless network is an independent basic service set (IBBS).

7. A method for saving power consumed by a station in an ad hoc wireless network wherein the station transmits or receives signals during a beacon interval, the method comprising:

timing a period of the beacon interval following an announcement traffic identification message (ATIM) window;

determining whether the station is active during the timed period; and

immediately entering a power saving doze state by the station, prior to the end of the beacon interval, if the station is inactive during the timed period.

8. The method of claim 7, further comprising:

adjusting duration of the timed period.

9. The method of claim 7, wherein an ATIM window occurs at the beginning of the beacon interval.

10. The method of claim 7, wherein a station in doze state cannot transmit or receive signals.

11. The method of claim 7, wherein the ad hoc wireless network is an independent basic service set (IBBS).

12. A method for saving power by a station in an ad hoc wireless network, the method comprising:

transmitting a beacon at a beginning of a beacon interval;

determining whether an announcement traffic identification message (ATIM) has been transmitted or received in the beacon interval after transmission of the beacon;

incrementing a counter each time, after the beacon is transmitted, no ATIM has been received or transmitted in the beacon interval; and

causing the station to enter a power saving doze state or remain awake based on a comparison of the counter with a nap threshold.

13. The method of claim 12, wherein causing the station to enter a power saving doze state or remain awake based on a comparison of the counter with a nap threshold comprises;

if the counter is less than the nap threshold, causing the station to remain awake and incrementing the counter, or if the counter is equal to the nap threshold, causing the station to enter the power saving doze state immediately following the transmission or reception of the signal during the beacon interval and prior to the end of the beacon interval.

14. The method of claim 12, wherein causing the station to enter a power saving doze state or remain awake based on a comparison of the counter with a nap threshold comprises;

if the counter is less than the nap threshold, causing the station to enter the power saving doze state immediately following the transmission or reception of the signal during the beacon interval and prior to the end of the beacon interval, and if the counter is equal to the nap threshold, causing the station to remain awake.

15. A system for saving power consumed by a station in an ad hoc wireless network, the system comprising:

a transceiver for transmitting a beacon at the beginning of a beacon interval and transmitting or receiving announcement traffic identification messages (ATIM);

a monitor for detecting whether an ATIM has been transmitted or received within the beacon interval after transmission of the beacon; and

means for causing the station to enter a power saving doze state immediately following the transmission or reception of a signal during the beacon interval and prior to the end of the beacon interval when no activity is detected after the ATIM window of the beacon interval.

16. The system of claim 15, further comprising:

a counter for counting inactive beacon intervals; and

a comparator for determining when the counter has reached a nap threshold, and causing the station to remain awake and increment the counter, or if the counter has reached a nap threshold, causing the station to enter a power saving doze state immediately following the transmission or reception of the signal during the beacon interval and prior to the end of the beacon interval.

17. A system for saving power consumed by a station in an ad hoc wireless network, the system comprising:

a transceiver for transmitting or receiving a signal by the station in the ad hoc network during the beacon interval; and

a monitor for detecting a level of activity for the station after an ATIM window of the beacon interval,

a timer for timing and causing the station to enter a power saving doze state immediately following the transmission or reception of a signal during the beacon interval and prior to the end of the beacon interval.