Radio server, mobile unit, and recording medium

摘要

A radio server (1) is provided which enables a packet destine for a mobile unit (3) to be surely routed to the mobile unit (3) even when the mobile unit (3) moves and a communication zone is changed. The radio server (1) establishes communications between itself and the mobile unit (3) using radio communications via one of a plurality of base station radios (2-n). The radio server (1) comprises a mobile unit searcher (1d) for analyzing the packet destined for the mobile unit (3) and searching the mobile unit (3) based on a destination address of the analyzed packet; a search request transmitter (1e) for transmitting a search request including the destination address; and a search reply receiver (1f) for receiving a search reply transmitted in response to the search request and determining one base station radio, to which the packet is to be transmitted, in accordance with an identifier of the one base station radio which is contained in the search reply. The radio server (1) broadcasts a search request including the address of the mobile unit to all the base station radios (2-n), and transmits the packet destined for the mobile unit (3) via one base station radio which has sent back a reply to the search request.