Abstract: A method and apparatus for changing the mobile identification number of a cellular telephone unit to reflect a local network planning area number, including a cellular telephone unit having a microprocessor and associated data storage. The microprocessor is programmed to interrogate the cellular telephone unit to obtain the local system identification number. The network planning area number corresponding to the system identification number is included as a part of the mobile identification number such that the cellular telephone unit appears as a local unit to enable calls to be pre-validated by the local cellular system.

Abstract: A method and apparatus for locating and communicating with vehicles is provided, including at least one mobile cellular unit connected to at least one microprocessor and installed within a vehicle. The microprocessor interrogates the mobile cellular unit to obtain location information from an overhead message stream transmitted from cellular telephone transmitter sites. The location is displayed on a display located in the vehicle or the microprocessor periodically instructs the mobile cellular unit to initiate a call to a host controller and, upon receipt of transmitting instructions from the host controller, transmits the location information for display on a screen connected to the host controller.