Efficient power management in wireless local area networks

• US 7,603,146 B2
• Filed: 01/12/2005
• Issued: 10/13/2009
• Est. Priority Date: 01/12/2004
• Status: Active Grant

• Current Assignee: Red Hat, Inc. (International Business Machines Corporation)
• Original Assignee: Avaya Incorporated
• Inventors: Benveniste, Mathilde
• Primary Examiner(s): Corsaro, Nick
• Assistant Examiner(s): Ajayi, Joel
• Application Number:
  US11/034,024
• Publication Number:
  US 20050152324A1
• Time in Patent Office: 1,735 Days
• Field of Search: None
• US Class Current: 455/574
• CPC Class Codes: H04W 28/10 Flow control between communication endpoints
• CPC Class Codes: H04W 28/14 using intermediate storage
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/34 TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading
• CPC Class Codes: H04W 52/44 in connection with interruption of transmission
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method of providing power management in a Wireless Local Area Network (WLAN) is presented. The method includes receiving a Traffic Indication Map (TIM) at a station, indicating the presence of buffered frames, associated with any AC, for the station at an Access Point (AP). The method further includes sending, by the station, one of an uplink data frame if one is buffered, and a null frame to retrieve the buffered frames from said AP. The station remains awake to receive frames from the AP until a downlink frame is received containing an indication that it is the last frame to be transmitted in the service period. The method may further include determining at the end of service period whether there are more frames remaining buffered for the station at the AP.

Claims

1. A method of deriving a schedule in a Wireless Local Area Network (WLAN) comprising:

adopting a basic service interval;

determining whether the service interval in the Traffic Specification (TSPEC) is a multiple of said basic service interval;

when said service interval is a multiple of said basic service interval then accepting said TSPEC;

when said service interval is not a multiple of said basic service interval then denying said TSPEC;

slotting channel time into time schedule channels repeating at fixed time intervals equal to the basic service interval; and

assigning an time schedule channel to a TSPEC based on the service interval contained in said TSPEC and the service intervals of other TSPECs already assigned said channel.

2. The method of claim 1 wherein said denying a scheduled APSD TSPEC further comprises use of Unscheduled APSD.

3. The method of claim 1 wherein said schedule is used for one of APSD and polling.