Motorola Corporation

Daniel T Buhmann

Michael D Kotzin

Christopher N Kurby

R Travis Jones

Bradley B Bakke

A system for rapidly acquiring a time reference for the location determination of a wireless communication device. The system includes a wireless communication device (,), a GPS satellite (,) and a communication satellite (,). The method comprises the steps of acquiring a communication satellite signal (,) and using the finite frame time to establish a course time reference. Once the course time reference is established, an absolute device time is determined by the wireless communication device, which as a result is synchronized to the absolute time of the communication satellite (,) to within ten milliseconds. The absolute device time is then used to synchronize the GPS portion of the wireless communication device with the GPS satellite system.

Method and apparatus for GPS time determination

A method for system acquisition for a subscriber unit (112) in a satellite communication system (100) maximizes life of a battery (320) of a battery-powered subscriber unit. A receiver (304) of the subscriber unit is energized only when ring bursts are expected from satellites in the system, serving to minimize consumption of battery power. During just two scans, the subscriber unit acquires enough information to enable it to identify the best beam for monitoring for a ring alert and to predict the nearby beams most likely to carry a ring alert targeted for the subscriber unit. From the received information, the subscriber unit can also perform necessary processes such as passive geolocation. The subscriber unit then enters a low-power standby mode, energizing the receiver only long enough to detect the best beam to scan for a ring alert targeted for the subscriber unit.

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Hainesville, IL, United States of America

Daniel T Buhmann