Patent ID: 7460521

Claim:
A communication system comprising: a private base station apparatus that is configured to connect with an IP network by transmitting and receiving IP packets; a mobile terminal device configured to connect to said IP network by wireless communication through either a public wireless base station or said private base station apparatus; an IP telephone terminal that is configured to talk through said private base station apparatus with said IP network by transmitting and receiving IP packets; and a call connection server configured to connect a call at a predetermined telephone number of said IP telephone terminal to either said IP telephone terminal or said mobile terminal device on the basis of a designation address of said IP telephone terminal which is associated with said predetermined telephone number, said mobile terminal device comprising: a registration information transmitting unit configured to transmit, when connecting with said IP network which can be used for communication with said call connection server, to said call connection server a terminal identifier for identifying said mobile terminal device and a terminal location address for identifying the location of the current private base station apparatus on said IP network with which said mobile terminal device is connected, and said call connection server comprising: a storing unit configured to store said designation address and said terminal identifier in association with said predetermined telephone number; a registration information receiving unit configured to receive said terminal identifier and said terminal location address; an authentication unit configured to authenticate said mobile terminal device on the basis of said terminal identifier which is received and said terminal identifier which is stored in said storing unit; a priority designation address setting unit configured to associate, when said mobile terminal device is authenticated by said authentication unit, said terminal location address as received and said predetermined telephone number, which is stored in said storing unit in association with said terminal identifier, and set said terminal location address as a priority designation address which is given a priority higher than said designation address; and a call connection unit configured to connect said call to said mobile terminal device on the basis of said terminal location address in the case where said priority designation address has been set up.