Patent ID: 8817788

Claim:
A wireless communication terminal which determines, before a handover, whether a wireless base station as a handover candidate belongs to the same subnet as that of the currently connected wireless base station, comprising: an address acquisition unit which acquires, via a wireless communication interface unit, a layer 2 address of a wireless communication interface of a new wireless base station different from a currently connected wireless base station; a presence confirmation request generation unit which generates a presence confirmation request message by designating the acquired layer 2 address as a destination address, and one of a broadcast address and a multicast address as a layer 3 address; a presence confirmation request transmitting unit which transmits, via the currently connected wireless base station, the presence confirmation request message specifically to the new base station, whose IP address is unknown to the terminal, by using the layer 2 address and the layer 3 address; a presence confirmation response receiving unit which receives a presence confirmation response message for the presence confirmation request message; and a subnet determination unit which, when said presence confirmation response receiving unit has received the presence confirmation response message replied from the new wireless base station in response to a match between the destination address and the layer 2 address, determines that the new wireless base station belongs to the same subnet as that of the currently connected wireless base station, and when said presence confirmation response receiving unit has not received the presence confirmation response message, determines that the new wireless base station belongs to a subnet different from that of the currently connected wireless base station.