Radio telecommunication apparatus

A radio telecommunication subscriber unit for use in a radio telecommunication system, wherein said radio telecommunication system encompasses a plurality of service areas each having one or more base units which transmits a signal including a system identifier identifying a service area, said radio telecommunication subscriber unit comprising:

• storing means for storing a system identifier corresponding to a home service area of said radio telecommunication subscriber unit;
• receiving means for receiving a system identifier transmitted from a base unit;
• input means, operable by a subscriber, for inputting a system identifier corresponding to a service area of said radio telecommunication system;
• comparing means for comparing the received system identifier and the subscriber-input system identifier;
• and
• supplying means responsive to said comparing means for supplying the subscriber-input system identifier to said storing means when the received system identifier corresponds to the subscriber-input system identifier to designate the service area corresponding to the subscriber - input system identifier as a home service area.

A method of identifying a home area for a radio telecommunication subscriber unit operating in a radio telecommunication system, wherein the radio telecommunication system encompasses a plurality of service areas each having one or more base units which transmits a signal including a system identifier identifying a service area, the method comprising the steps of:

• storing a system identifier corresponding to a home service area of said radio telecommunication subscriber unit in a memory device;
• receiving a system identifier transmitted from a base unit;
• inputting a system identifier corresponding to a service area of said radio telecommunication system;
• comparing the received system identifier and the input system identifier;
• and
• supplying the input system identifier to said memory device when the received system identifier corresponds to the input system identifier to designate the service area corresponding to the input system identifier as a home service area for said radio telecommunication subscriber unit.

A radio telecommunication system having a plurality of service areas, said radio telecommunication system comprising:

• at least one base unit in each of said service areas transmitting a signal including a system identifier identifying a service area in which said respective base units are located;
• a radio telecommunication subscriber unit comprising:
• storing means for storing a system identifier corresponding to a home service area of said radio telecommunication subscriber unit;
• input means, operable by a subscriber, for inputting a system identifier corresponding to a service area of said radio telecommunication system;
• and
• supplying means for supplying the subscriber-input system identifier to said storing means to designate the service area corresponding to the subscriber-input system identifier as a home service area.