Use of cellular digital packet data (CDPD) communications to convey system identification list data to roaming cellular subscriber stations

摘要

An analog cellular voice telephone system and subscriber stations associated therewith are controlled to conserve power and to provide alternate service carriers. Acquisition of all of the service carriers is facilitated through the use of system identification numbers (SIDS) associated with each service carrier. A roaming subscriber will tune to a cellular digital packet data (CDPD) frequency to obtain a list of service carriers operating within that geographical area. Based upon a comparison with a preferred SID list stored in the subscriber station, an available service carrier will be selected by the subscriber station, and registration with the selected service carrier will take place. Usually, analog voice communication is suspended until the selection process takes place.