Patent ID: 7587205

Claim:
A method for operating a communication system for a mobile radio telephone system, which comprises the following steps: providing a network unit with an overall area; stipulating at least one subscriber area within its overall area, and allocating at least one subscriber number in the subscriber area, wherein the overall area incorporates at least one radio cell that transmits a signal containing coordinates to a mobile user unit within the system, a calculation is performed to determine whether the transmitted coordinates for the radio cell lie within the stipulated subscriber area, the subscriber area is stipulated by a user unit, and the subscriber area is stipulated by a) checking a first and second code, wherein the first code signals whether the user unit is authorized in the subscriber area, and the second code signals whether a stipulation has already taken place relative to the subscriber area; b) selecting the radio cells present around the user unit based on signal strengths; c) recording the radio cell currently used for switching; d) determining urban network code and cell code (cell ID) based on the recorded radio cell; e) transmitting the urban network code and cell code to a centralized point of the network unit and simultaneously storing address of the centralized point in a subscriber code (SIM); f) determining location and local radius based on a file provided in a centralized point containing all radio cells; g) generating a subscriber file within the centralized point, which is write protected; h) transmitting the location and local radius to the subscriber code module of the user unit; and i) updating the location and local radius stored in the user unit.