Patent ID: 7826846

Claim:
A handover method for a dual band/dual mode mobile communication terminal including an asynchronous Radio Frequency (RF) device for performing asynchronous communication and a synchronous RF device for performing synchronous communication and being capable of performing wireless communication with a asynchronous mobile communication network and a synchronous mobile communication network, comprising: the first step of setting an initial mobile communication network connection to the asynchronous mobile communication network and connecting to the asynchronous mobile communication network when power is applied; the second step of activating the synchronous RF device and setting up a connection to the synchronous mobile communication network when the intensity of a signal from the asynchronous mobile communication network is equal to or lower than a first predetermined reference value; the third step of determining whether the intensity of a signal from the asynchronous mobile communication network is equal to or lower than a second predetermined reference value previously set for the handover; the fourth step of activating the connection to the synchronous mobile communication network set up at the second step if the intensity of the signal from the asynchronous mobile communication network is determined to be equal to or lower than the second predetermined reference value at the third step; and the fifth step of releasing the connection to the asynchronous mobile communication network, wherein the first step comprises: an asynchronous activation step of activating the asynchronous RF device when power is applied; a connection request step of requesting a connection to the asynchronous mobile communication network via the asynchronous RF device; a connection performance step of the asynchronous mobile communication network making location registration based on the connection request with a Home Location Register (HLR) of the asynchronous mobile communication network and transmitting a response message to the location registration to the mobile communication terminal; and a connection completion step of the mobile communication terminal receiving the response at the connection performance step, transmitting a connection setup completion message to the mobile communication network, and receiving a response.