Correcting time displayed on mobile telephone to local conditions by using country, operator, and location area codes received from local network to obtain correction from tables in telephone memory

摘要

A mobile telephone in any country keeps radio contact with a base station (8) within a network comprising Base Station Controllers (101), Mobile Services Switching Centers and stored data (104). The mobile telephone derives codes for the country (5), operator (6) and location area (7) from the stored data (104) in the network and uses them to derive a correction (22) from a memory (12) and apply it to GMT (24)