Method and system for reducing battery consumption in wireless transmit/receive units (WTRUs) employed in a wireless local area network/wireless wide area network (WLAN/WWAN)

• US 20050190710A1
• Filed: 02/10/2005
• Published: 09/01/2005
• Est. Priority Date: 02/10/2004
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Zeira, Eldad, Chandra, Arty
• Granted Patent: US 7,474,887 B2
• Time in Patent Office: Days
• US Class Current: 370/311
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Method and system for reducing battery consumption during an active session wherein an access point (AP) transmits a wireless transmit/receive unit (WTRU) a packet information regarding packets in a queue waiting for transmission to the WTRU and when the packets are to be decoded, whereby enabling the WTRU to enter or remain in an OFF mode in accordance with the packet information. The AP does not send the packets to the WTRU until the AP informs the WTRU about the packet.

Claims

1. A method for saving battery life of wireless transmit/receive units (WTRUs) communicating with an access point (AP), comprising:

the AP;

creating a queue of packets intended for a WTRU, the WTRU configured to implement a power saving mechanism;

transmitting packet information regarding the queue of packets waiting for transmission to the WTRU in a scheduled transmission;

the WTRU;

receiving the packet information in the scheduled transmission; and

entering into an OFF mode or an AWAKE mode in accordance with the packet information, whereby the WTRU enters the AWAKE mode only when it is indicated in the packet information that there is a packet queued for transmission for the WTRU at the AP, otherwise the WTRU enters the OFF mode.

2. The method of claim 1 wherein the WTRU transmits an indication to the AP that the WTRU will implement the battery saving mechanism while the WTRU is associated with the AP, whereby the WTRU may enter a OFF mode or an AWAKE mode in accordance with the packet information.

3. The method of claim 2 wherein the AP transmits parameters necessary for implementing the battery saving mechanism including the number of beacons (n) within an OFF mode and the packet type in which the queued packet information is sent.

4. The method of claim 2 wherein the indication is transmitted to the AP during initial association.

5. The method of claim 2 wherein the indication is transmitted to the AP after initial association.

6. The method of claim 5 wherein the indication is transmitted when a level of battery life falls below a predetermined threshold.

7. The method of claim 1 wherein the battery saving mechanism is implemented automatically as a default.

8. The method of claim 1 wherein the packet information is transmitted with a beacon frame.

9. The method of claim 1 wherein the packet information is transmitted with a special packet designed for signaling queue information which is transmitted in accordance with a predetermined schedule.

10. The method of claim 9 wherein the special packet is transmitted periodically.

11. The method of claim 9 wherein the special packet is transmitted non-periodically whereby timing of transmission of the special packet is informed to the WTRU in advance.

12. The method of claim 1 wherein the packet information is transmitted in a header attached to a packet transmitted to the WTRU.

13. The method of claim 1 wherein the AP withholds transmission of the packets to the WTRU until the WTRU is informed about the packets queued at the AP.

14. The method of claim 1 wherein the WTRU enters an OFF mode after receiving the schedule of transmission of the packets and setting a timer in accordance with the schedule and enters an AWAKE mode when the timer expires.

15. The method of claim 14 wherein the WTRU stays in the AWAKE mode to receive all the packets from the AP.

16. The method of claim 14 wherein the WTRU stays in the AWAKE mode only during the time interval indicated that data is transmitted to the WTRU in the packet information.

17. The method of claim 1 further comprising:

the WTRU, to avoid conflicts, withholding sending of packets intended for the AP when the packet information indicates that there is at least one packet in the AP'"'"'s queue intended for the WTRU and the packet at the WTRU is not time critical.

18. The method of claim 1 wherein the AP stores the packets in a buffer. for the WTRU whereby the AP withholds transmission of the packet information.

19. The method of claim 18 wherein the amount of time that the AP withholds sending the packet information depends on the quality of service requirement for that application and the buffer limit for the application and/or WTRU.

20. The method of claim 1, wherein the packet information includes at least one of the number of queued packet for a WTRU, location of the packet, WTRU identity, identity of WTRUs that should remain in awake mode and queued traffic information such as traffic type and the exact time or the time interval in which the packet is sent to the WTRU.

21. A system for saving battery life in a wireless receive/transmit unit (WTRU) communicating with an access point (AP) a wireless network, comprising:

the AP comprising means for sending a packet information regarding a queue of packets waiting for transmission to the WTRU in a scheduled transmission; and

the WTRU comprising;

means for receiving the packet information in the scheduled transmission; and

means for implementing a battery saving mechanism whereby entering into an OFF mode or an AWAKE mode in accordance with the packet information.

22. The system of claim 21 wherein the WTRU transmits an indication to the AP that the WTRU will implement the battery saving mechanism while the WTRU is associated with the AP, whereby the WTRU may enter an OFF mode or an AWAKE mode in accordance with the packet information.

23. The system of claim 22 wherein the AP transmits parameters necessary for implementing the battery saving mechanism including the number of beacons (n) within an OFF mode and the packet type in which the queued packet information is sent.

24. The system of claim 22 wherein the indication is transmitted to the AP during initial association.

25. The system of claim 22 wherein the indication is transmitted to the AP after initial association.

26. The system of claim 21 wherein the battery saving mechanism is implemented automatically as a default.

27. The system of claim 21 wherein the packet information is transmitted with a Beacon frame.

28. The system of claim 21 wherein the packet information is transmitted with a special packet designed for signaling queue information which is transmitted in accordance with a predetermined schedule.

29. The system of claim 28 wherein the special packet is transmitted periodically.

30. The system of claim 28 wherein the special packet is transmitted non-periodically whereby timing of transmission of the special packet is informed to the WTRU in advance.

31. The system of claim 21 wherein the packet information is transmitted in a header attached to a packet transmitted to the WTRU.

32. The system of claim 21 wherein the AP withholds transmission of the packets to the WTRU until the WTRU is informed about the packets queued at the AP.

33. The system of claim 21 wherein the WTRU enters a OFF mode after receiving the schedule of transmission of the packets and setting a timer in accordance with the schedule and enters an AWAKE mode when the timer expires.

34. The system of claim 33 wherein the WTRU stays in the AWAKE mode to receive all the packets from the AP.

35. The system of claim 33 wherein the WTRU stays in the AWAKE mode only during the time interval indicated that data is transmitted to the WTRU in the packet information.

36. The system of claim 21 wherein the WTRU, in order to avoid conflicts, withholds sending of packets intended for the AP when the packet information indicates that there is at least one packet in the AP'"'"'s queue intended for the WTRU and the packets at the WTRU are not time critical.

37. The system of claim 21 wherein an AP stores the packets in a buffer for a WTRU whereby the AP withholds transmission of the packet information.

38. The system of claim 37 wherein the amount of time that the AP withholds sending the packet information depends on the quality of service requirement for that application and the buffer limit for the application and/or WTRU.

39. The system of claim 21, wherein the packet information includes at least one of the number of queued packet for a WTRU, location of the packet, WTRU identity, identity of WTRUs that should remain in awake mode and queued traffic information such as traffic type and the exact time or the time interval in which the packet is sent to the WTRU.

40. The system of claim 21 wherein the wireless network is one of a wireless local area network (WLAN) and a wireless wide area network (WWAN).