Patent ID: 7634293

Claim:
A mobile communication system including a first radio access network, a second radio access network different from the first radio access network, and a core network, wherein the first radio access network comprises a first base station configured to communicate with a first mobile station and a first extension transmission/reception server configured to connect to the first base station; the second radio access network comprises a second base station configured to communicate with a second mobile station; the core network comprises a mobile switching center; the first base station receives mobile station control data from the first mobile station and transmits the mobile station control data to the second mobile station via the mobile switching center and the second base station; the mobile switching center notifies the first base station of a first address, which indicates an address of the first extension transmission/reception server and notifies the first extension transmission/reception server of a second address, which indicates an address of the second base station; the first base station receives user data from the first mobile station and transmits the user data to the first extension transmission/reception server, without going through the mobile switching center, based on the first address provided by the mobile switching center; the first extension transmission/reception server receives the user data from the first base station, without going through the mobile switching center, and transmits the user data to the second base station, without going through the mobile switching center, based on the second address provided by the mobile switching center; and the second base station receives the user data from the first extension transmission/reception server, without going through the mobile switching center, and transmits the user data to the second mobile station.