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)

This application is a continuation of U.S. patent application Ser. No. 11/054,811, filed Feb. 10, 2005, which claims the benefit of U.S. Provisional Application 60/543,462 filed Feb. 10, 2004, which is incorporated by reference as if fully set forth.

The present invention relates to WWANs/WLANs and more particularly to a method and apparatus for reducing the battery consumption of WTRUs in a WLAN/WWAN network.

WLAN networks currently in use typically provide for an access point (AP) to send information about queued packets for WTRUs when WTRUs are in sleep state. WTRUs enter into a sleep state by sending a message to the AP and receiving a confirmation from the AP. This is performed at a much lower frequency for WTRUs that are not in an active session for a longer period of time.

However, there are no techniques or apparatus presently in use in WTRUs to reduce battery consumption during an active session for every application independent of the nature of application.

The present invention is characterized by a “power save” feature for WTRUs. This “power save” feature can be used by all or some WTRUs in the system. A WTRU can inform an AP about its “power save” feature either during association or any time after the association. The AP sends packets to “power save” enabled WTRUs after indicating this information to the WTRU. This method is employed by the WTRU for reducing battery consumption during an active session. The AP transmits the WTRU information regarding packets in a queue for that WTRU, (optionally when the packets are to be decoded), thereby enabling the WTRUs to enter or remain in the OFF mode until the next transmission of the packet information, (if there are no packets for the WTRU), or the intended arrival time. The OFF mode is defined as the mode in which a WTRU listens to a beacon and remains in AWAKE mode between two beacons if there are queued packets for the WTRU, but goes into sleep state if there are no queued packets indicated in the beacon for the WTRU until the next Beacon. The WTRU enters OFF mode from AWAKE mode by default after every beacon if the beacon indicates no queued packet for the WTRU.

Although the features and elements of the present invention are described in the preferred embodiments in particular combinations, each feature or element can be used alone without the other features and elements of the preferred embodiments or in various combinations with or without other features and elements of the present invention.

FIG. 1 shows a method 10 implemented by WLAN network comprising an AP 12 such as a multiport wireless AP and a WTRU 14 capable of communicating with the AP 12.