Patent ID: 7248870

Claim:
A communicative base station switching system of a portable terminal for switching a communicative base station while in motion comprising: a base station memory section for storing base station position data; a base station position comparing section for receiving position data from a global positioning system of a mobile body and obtaining and comparing the distances of a plurality of neighbor base stations from the portable terminal by using the received position data as the position data of the portable terminal; and a base station frequency switching section for switching the communicative base station of the portable terminal to one of the plurality of neighbor base stations based only on which of the plurality of neighbor base stations is closest to the portable terminal according to the result of comparison in the base station position comparing section, wherein the base station position memory section stores latitude and longitude positions the plurality of neighbor base stations; and wherein the base station frequency switching section switches the communicative base station of the portable terminal to said one of the plurality of neighbor base stations, without measuring a received power level from any of the plurality of neighbor base stations, thereby reducing a time and burden on the base station frequency switching section.