Patent ID: 7079841

Claim:
An apparatus for performing a handover between at least two mobile communication systems in a mobile communication network, the two mobile communication systems adapting mutually independent communication methods, and the network including a mobile communication terminal using the mobile communication systems, said apparatus comprising: a first mobile communication system for transmitting a first handover notification message to the mobile communication terminal, and generating a second handover notification message upon receiving a handover preparation message from the mobile communication terminal; a second mobile communication system for transmitting a page message to the mobile communication terminal upon receiving the second handover notification message from the first mobile communication system, transmitting a channel assignment message upon receiving a prescribed page response message, and forming a call path; and the mobile communication terminal having first and second communication modules respectively communicating with the first and second mobile communication systems, wherein the first communication module generates a drive command for the second communication module upon receiving the first handover notification message from the first mobile communication system, and transmits the handover preparation message to the first mobile communication system upon receiving a prescribed drive-response signal, and the second communication module transmits the drive-response signal to the first communication module upon receiving the drive command from the first communication module, transmits the page response message upon receiving the page message from the second mobile communication system, and enters a call connection state upon receiving the channel assignment message from the second mobile communication system.