Patent ID: 7069020

Claim:
An asynchronous mobile communication terminal, comprising: a real time clock circuit for generating time information; a memory for storing a time difference table including time difference information between areas; and a central processing unit for reading a time difference from the time difference table when a user of the terminal moves from a first area to a second area and controlling the real time clock circuit; wherein the time difference table comprises a first columnar portion for storing area information for various first areas, a second columnar portion for storing area information for various second areas, and a third columnar portion for storing time differences between respective pairs of first and second areas, wherein the area information for the various first and second areas are received from various base stations corresponding to the first or second areas; wherein the central processing unit reads a time difference for a pair of first and second areas by referring to the area information for the pair as stored in the first and second columnar portions.