There are a wireless access network comprising a radio network gateway apparatus (101), radio access network control apparatus (102a), (102b) and a base stations (103a), (103b) and a terminal (104) accommodated in the wireless access network and when the terminal (104) enters into a new cell B, a packet data is transmitted from the source radio access network control apparatus (102a) to the target radio access network control apparatus (102b). Further, when the terminal (104) switches the radio access network control apparatus (102) with which the terminal (104) communicates, the target radio access network control apparatus (102b) switches a transmission line of a data to be transmitted to the terminal (104) from a wireless data to a packet data in the source radio access network control apparatus (102a), and from the source packet data to a target packet data in a synchronized manner at each timing. This reduces traffic which occurs when switching a radio access network control apparatus to be communicated while the terminal moves between cells and prevent packet interruption in a wireless access network providing packet transmission service.