Cellular telephone unit with prioritized frequency acquisition

摘要

A cellular telephone unit includes selective carrier signal acquisition. Priority of acquisition is given to carrier signals associated with home system identification codes (SIDs), then to any carrier signal associated with a non-excluded SID. Any attempt to dial an emergency call (e.g., a 911 call) overrides any lockout of excluded SIDs. A display such as "roam" and "no service" lights is used selectively to indicate to the user the availability of home and/or non-excluded carrier signals.