Tone generating apparatus for a cellular telephone simulates those tones normally sensed by a user of a conventional land-line telephone. The cellular telephone is adapted to communicate with a base station via a service provider which provides different types of service, such as HOME service, ROAM service,...http://www.google.com/patents/US5960363?utm_source=gb-gplus-sharePatent US5960363 - Tone generating apparatus for a cellular telephone to simulate tones normally sensed by a user of a land-line telephone
