METHOD AND APPARATUS OF PRESERVING POWER OF A REMOTE UNIT INA DISPATCH SYSTEM

摘要

To reduce the power consumption of a remote unit in a dispatch system the remote unit enters a dormant state. A base station (32) transmits a forward link broadcast signal and monitors a common access channel. A first remote unit (10) continually receives and decodes the forward link broadcast signal and determines whether said forward link broadcast signal comprises active signals (106). If the remote unit determines that the forward link broadcast signal comprises no active signals for some a duration T1, the first remote unit enters a dormant mode (148). In the dormant mode the remote unit sporadically receive s and decodes said forward link broadcast signal. If this remote unit or any other remote unit on the same net presses a push to talk button (128, 130), it transmits a message on the common access channel. In response, every remote unit on the net which is in a dormant sta te exits the dormant state and continually monitors the forward link broadcast signal.