Patent ID: 6950676
Filing Date: 2005-09-27
Classification: H04W

Abstract:
1. A portable telephone apparatus for roaming between a first portable telephone system and a second portable telephone system, comprising: reception means for receiving a message transmitted from a base station in one of the first portable telephone system and the second portable telephone system; judging means for judging whether a received message has a format which is common to each of the first and the second portable telephone systems or is unique to one of the first and the second portable telephone systems; first processing means for storing therein program code which is common to each of the first and the second portable telephone systems, and for processing the received message by performing a procedure which is common to each of the first and the second portable telephone systems when the message has the format which is common to each of the first and the second portable telephone systems, and second processing means for storing therein program code which is unique to each of the first and the second portable telephone systems, and for processing the received message by performing a procedure which is unique to one of the first and the second portable telephone systems when the message has the format which is unique to one of the first and the second portable telephone systems.