Patent ID: 7864730

Claim:
A method of controlling a multi-mode multi-band mobile communication terminal for handover, the multi-mode multi-band mobile communication terminal being provided with an asynchronous modem unit and a synchronous modem unit and being configured to receive signals from a synchronous mobile communication system during use of service provided by an asynchronous mobile communication system in a mobile communication network in which the asynchronous and synchronous mobile communication systems coexist, the method comprising: a first step of, as the multi-mode multi-band mobile communication terminal using the service provided by the asynchronous mobile communication system moves into a synchronous area, the asynchronous modem unit of the multi-mode multi-band mobile communication terminal receiving a dummy pilot signal from the synchronous mobile communication system wherein the dummy pilot signal has the same frequency as that used in the asynchronous mobile communication system, driving the synchronous modem unit of the multi-mode multi-band mobile communication terminal, searching for a cell in which to perform a handover, notifying the asynchronous mobile communication system of results of the search for the cell in which to perform the handover, and transmitting a channel assignment message to the synchronous modem unit when a handover command has been received from the asynchronous mobile communication system; a second step of switching a vocoder and turning off the asynchronous modem unit; and a third step of the synchronous modem unit achieving synchronization with the synchronous mobile communication system, the third step comprising steps of: the synchronous modem unit changing to a traffic state; the synchronous modem unit transmitting a reverse traffic signal to a base station of the synchronous mobile communication system; and the synchronous modem unit notifying the synchronous mobile communication system that the handover has been completed.