SERVER, MOBILE COMMUNICATION TERMINAL, RADIO DEVICE, COMMUNICATION METHOD FOR COMMUNICATION SYSTEM, AND COMMUNICATION SYSTEM

摘要

A server for enabling a terminal to change the communication network in a communication system from a mobile communication network to a packet communication network and vice versa while continuing the communication through the mobile communication network. The server, installed in a packet network for relaying a packet from first to second terminals comprises a session managing section where stored are a first address of a first terminal allocated to a first session representing the status of the connection between the server and a terminal and a second address of the first terminal allocated to a second session representing the status of the connection between the server and the first terminal, a receiving section for receiving a packet containing user data from the second terminal, a switching section for switching the session from the first session of the packet addressed to the first address and containing the user data to the second session of the packet addressed to the second address and containing the user data, and a transmitting section for transmitting the packet by use of the second session selected by the switching section.