A radio network can select a route of minimum path loss among entire relay routes and can set the relay route so as to satisfactorily resist interference. The radio network has a core node connected to a wired network, relay nodes each relaying at least one of a down-link data packet transmitted from the core node and an up-link data packet directed toward the core node, and a terminal station capable of transmission and reception of data packets with both the core node and the relay node. The relay node has total path loss optimized to be minimum between relay nodes included in a relay route of the data packet or between the relay node and the core node or both.