(19) United States
(12) Patent Application Publication (io) Pub. No.: US 2002/0173303 Al
Shibutani (43) Pub. Date: Nov. 21,2002
(54) WIRELESS COMMUNICATION SYSTEM
(75) Inventor: Akira Shibutani, Sunnyvale, CA (US)
Brinks Hofer Gilson & Lione
P.O. Box 10395
Chicago, IL 60610 (US)
(73) Assignee: DoCoMo Communications Laboratories USA, Inc.
(21) Appl. No.: 09/858,706
(22) Filed: May 16, 2001
Publication Classification (51) Int. CI.7 II04Q 7/20
The present invention provides a wireless communication system that comprises a plurality ol communication networks operating with different communication parameters and protocols and at least one communication terminal having multiple communication modules each adapted to operate with specific communication parameters and protocol for access to at least one corresponding communication network operating with the same communication parameters and protocol. A module in the communication terminal is activated to prepare for communication with the corresponding network when it is expected likely that the communication terminal is heading to access the corresponding network. The activated module is deactivated when the same is expected unlikely. The communication terminal is usually battery-powered. Since modules are deactivated when not necessary, the battery life can be prolonged.