Browse Prior Art Database

RESELECT PROCEDURE FOR REDUCED PORTABLE BATTERY DRAIN

IP.com Disclosure Number: IPCOM000007350D
Original Publication Date: 1995-Mar-01
Included in the Prior Art Database: 2002-Mar-18
Document File: 2 page(s) / 86K

Publishing Venue

Motorola

Related People

Garty Hess: AUTHOR

Abstract

The requirement to stay connected to the best control channel during idle periods (called "reselec- tion") can dominate portable battery life. Presently, reselection involves signal quality estimator (SQE) monitoring of the current control channel and one neighbor cell control channel once per two frame periods. Seven foreground cycles are required to obtain a credible SQE estimate of the best neigh- boring control channel. Assuming 12 neighbor cells are monitored and the foregouund membership is limited to 3 members, the "response time" for the current approach is roughly 56 frames (4 frames per foreground cycle times 7 cycles per foreground esti- mate times 2 frames per measurement; 1 frame occu- pying 90 ms), about 5 seconds. Since typical lognormal shadowing decorrelation times are 15 sec- onds. it would not be advisable to reselect at a slower rate.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 50% of the total text.

Page 1 of 2

MO-LA Technical Developments Volume 24 March 1995

@

RESELECT PROCEDURE FOR REDUCED PORTABLE BATTERY DRAIN

by Garty Hess

  The requirement to stay connected to the best control channel during idle periods (called "reselec- tion") can dominate portable battery life. Presently, reselection involves signal quality estimator (SQE) monitoring of the current control channel and one neighbor cell control channel once per two frame periods. Seven foreground cycles are required to obtain a credible SQE estimate of the best neigh- boring control channel. Assuming 12 neighbor cells are monitored and the foregouund membership is limited to 3 members, the "response time" for the current approach is roughly 56 frames (4 frames per foreground cycle times 7 cycles per foreground esti- mate times 2 frames per measurement; 1 frame occu- pying 90 ms), about 5 seconds. Since typical lognormal shadowing decorrelation times are 15 sec- onds. it would not be advisable to reselect at a slower rate.

  An alternative is to adopt a "switch and stay" strategy for interconnect-only portables. That is, one would select a best control channel and stay with it unless and until its SQE indication dropped below some minimum acceptable criteria. This would cut the measurement load in half To be viable, the port- able would need to be programmed to do a "burst" reselect whenever the current control channel fell below the minimum acceptable criteria. Also, in the

event a page is received or a call is initiated, the portable should burst reselect. Approximately 1.5 sec- onds would be required to do this (12 neighbors to examine times 3 measurements to make...