(12) United States Patent
(io) Patent No.: (45) Date of Patent:
US 7,747,273 B2 Jun. 29, 2010
(54) ASYNCHRONOUS POWER MANAGEMENT METHODS AND SYSTEMS FOR WIRELESS NETWORKS
(75) Inventor: Zi-Tsan Chou, Taipei (TW)
(73) Assignee: Institute for Information Industry,
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 799 days.
(21) Appl.No.: 11/640,402
(22) Filed: Dec. 18, 2006
(65) Prior Publication Data
Asynchronous power management methods and systems for a first station and a second station in a wireless network. The second station dynamically tunes a SRI (Schedule Repetition Interval) value according to residual power status, quality-ofservice requirements, or other considerations. The SRI value is an odd prime number. Once the SRI is determined, the second station sets the number and positions of ABIs (Awake Beacon Intervals)" within an SRI. An ABI-set defined as the positions of ABIs in an SRI forms a cyclic difference set comprising at least two consecutive Bis. The second station transmits a beacon frame within a beacon window. When the first station has recently received the beacon frame from the second station, the first station predicts the awake/sleep schedule of the second station, and transmits data frames to the second station at the ABI of the second station.
24 Claims, 13 Drawing Sheets