Patent ID: 7133384

Claim:
A method of supporting hand-off determination for guaranteeing mobility of a dual-mode terminal in a mixed communication network in which a synchronous and an asynchronous network system coexist, the dual-mode terminal being capable of accessing both the synchronous and the asynchronous network system, comprising the steps of: (a) transmitting information of terminal capability operable in both the synchronous and the asynchronous network system to the mixed communication network, irrespective of which network system a present service area belongs to, at the side of the dual-mode terminal; and (b) constructing information on adjacent cells, which are selectively included based on the received terminal capability information, of the dual-mode terminal, and providing the dual-mode terminal with the constructed adjacent cell information, at the side of the mixed communication network; wherein said step (a) inserts information of terminal capability operable in the asynchronous network system in an originating message including a protocol revision number, if the dual-mode terminal is operative in service area of the synchronous network system; and wherein, in said step (b), a controller installed in the synchronous network system checks, based on the received terminal capability information, whether or not the dual-mode terminal can access the asynchronous network system, and sends the information on adjacent cells of the asynchronous network system to the dual-mode terminal, if accessible.