Patent ID: 6765920
Filing Date: 2004-07-20
Classification: H04L,H04W,Y10S

Abstract:
A network address converting apparatus for converting a source address or a destination address included in data transmitted between an external host server connected to the Internet and a mobile terminal within a radio communication network system, the radio communication network system including a plurality of subnetworks, each including at least one mobile terminal and at least one wireless server connected via radio communication to the at least one mobile terminal, the mobile terminal being movable among the plurality of subnetworks, each wireless server storing and managing the Internet IP address of a wireless server which controls a subnetwork in which one or more mobile terminals, for which the wireless server serves as the home server, are currently located, wherein:the network address converting apparatus is provided for each wireless server; and the network address converting apparatus operates in such a manner that: when an inquiry signal about the current location of a particular mobile terminal is sent from an external host server to a home server of the particular mobile terminal, if the network address converting apparatus receives the inquiry signal, it notifies the external host server of the Internet IP address of the wireless server which controls a subnetwork in which the particular mobile terminals is currently located; when an assignment request signal requesting assignment of an Internet IP address to the particular mobile terminal is received from the external host server, the network address converting apparatus selects one of available IP addresses in a subnetwork including the network address converting apparatus and assigns the selected Internet IP address to the particular mobile terminal and notifies the external host server of the assigned Internet IP address; and when data addressed to the assigned Internet IP address is received from the external host server, the network address converting apparatus converts the destination of the received data to an address of the particular mobile terminal defined in the subnetwork in which the particular mobile terminal is currently located.