US 8,014,369 B2Granted

Adaptive power management methods and systems for wireless networks

AssigneeInstitute for Information Industry

InventorZi-Tsan Chou

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Abstract

Adaptive power management methods and systems for a first station and a second station in a wireless network. Each station operating in the power-saving (PS) mode adaptively determines a “listen interval” (LI) according to residual power state, quality-of-service requirements, or other considerations. The LI is composed of a “normal beacon interval” (NBI) followed by the combination of “beacon-window-only beacon intervals” (BBIs) and “sleep beacon intervals” (SBIs). The LI value is one or a prime number which is larger than two, and the positions of the NBI and BBIs in an LI form a cyclic difference set. Each station broadcasts a beacon frame comprising at least information about “the remaining number of BIs (RBI)” within a beacon window. Once the first station correctly receives 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 NBI of the second station.

Claims17

Dependent claims

An adaptive power management method for use in a first station and a second station in an ad hoc wireless local area network, in which the second station enters an NBI (Normal Beacon Interval) every certain number of BIs (Beacon Intervals) for power saving and data reception, where the certain number of consecutive BIs is called an LI (Listen Interval), comprising:

determining the length of LI (in units of BI) which is one or a prime number that is larger than two, wherein the BIs in the LI are denoted as 0th, 1st, 2nd, . . . , and (n−1)th BIs, respectively, where n is the value of LI, and setting the 0th BI in the LI as the NBI, wherein the NBI comprises an AW (ATIM Window) comprising a BW (Beacon Window), where a station transmits its beacon frame within the BW, transmits and receives ATIM frames within the AW, returns an ATIM ACK (acknowledgement) to a specific station transmitting the ATIM frame and remains awake after the AW ends to wait for the reception of data frames when receiving an ATIM frame within the AW, and returns a data ACK if a data frame is received;
determining the number of BBIs (Beacon-Window-Only Beacon Intervals) and determining the positions of the NBI and BBIs in the LI to form a cyclic difference set, in which each of the BBIs comprises a BW (Beacon Window), and the second station broadcasts a beacon frame within the BW of every BBI, and enters a doze state in the BBI after the end of the BW, the beacon frame comprises a station identification and an RBI (Remaining number of BIs) representing the remaining number of BIs between the BBI and the NBI, wherein the beacon frame is transmitted in the BBI;
and
the first station receiving the beacon frame from the second station in the ad hoc wireless local area network, recording the RBI corresponding to the second station, predicting the NBI of the second station according to the RBI, and transmitting a data frame to the second station at the NBI of the second station in the ad hoc wireless local area network.

1 more element

An adaptive power management system for an ad hoc wireless local area network, comprising:

a second station entering an NBI (Normal Beacon Interval) every certain number of BIs (Beacon Intervals) for power saving and data reception, where the certain number of consecutive BIs is called an LI (Listen Interval), determining the length of LI (in units of BI) which is one or a prime number that is larger than two, wherein the BIs in the LI are denoted as 0th, 1st, 2nd, . . . , and (n−1)th BIs, respectively, where n is the value of LI, and setting the 0th BI in the LI as the NBI, wherein the NBI comprises an AW (ATIM Window) comprising a BW (Beacon Window), where a station transmits and receives beacon frames its beacon frame within the BW, transmits and receives ATIM frames within the AW, returns an ATIM ACK (acknowledgement) to a specific station transmitting the ATIM frame and remains awake after the AW ends to wait for the reception of data frames when receiving an ATIM frame within the AW, and returns a data ACK if a data frame is received;
determining the number of BBIs (Beacon-Window-Only Beacon Intervals) and determining the positions of the NBI and BBIs in the LI to form a cyclic difference set, in which each of the BBIs comprises a BW (Beacon Window), and the second station broadcasts a beacon frame within the BW of every BBI, and enters a doze state in the BBI after the end of the BW, the beacon frame comprises a station identification and an RBI (Remaining number of BIs) representing the remaining number of BIs between the BBI and the NBI, wherein the beacon frame is transmitted in the BBI;
and
a first station receiving the beacon frame from the second station in the ad hoc wireless local area network, recording the RBI corresponding to the second station, predicting the NBI of the second station according to the RBI, and transmitting a data frame to the second station at the NBI of the second station in the ad hoc wireless local area network.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 11/640,196Filed 18 Dec 2006
Priority: TW 95118974 A29 May 2006
Published: US 2007/0275748 A129 Nov 2007
Granted: 6 Sep 2011
Term ends: Not estimatedThe source records don’t support an estimate.

Classification3 codes

H04W 52/343
TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading: taking into account loading or…
H04W 52/265
Using transmission rate or quality of service QoS [Quality of Service]: taking into account the quality of service QoS
H04W
Wireless communication networks