Patent ID: 7103023

Claim:
A radio communication control station, for communicating with a radio communication terminal that roams among sub-networks, comprising: a packet receiver for receiving an IP packet destined for a radio communication terminal subscribing to one of sub-networks constituting a composite radio communication network; a paging controller for causing one of the sub-networks to page the radio communication terminal; a location information receiver for receiving location information on a current location of the radio communication terminal from the radio communication terminal; a retriever for retrieving candidates of sub-networks that is employed by the radio communication terminal on the basis of the location information on the radio communication; and a packet transmitter for modifying the IP packet, which has been already received by the packet receiver, to be matched with the selected sub-network when an connection environment is established between the sub-network selected by the roaming radio communication terminal for its use and the radio communication terminal, the packet transmitter transmitting the modified IP packet to the radio communication terminal.