A first wireless node transmits a control signal to be propagated to each of a plurality of wireless links linked up between a plurality of wireless nodes that forms a backhaul network. Each of second wireless nodes that is different from the first wireless node selects, for a transmission route of a data signal, a wireless link corresponding to one of different routes in an upstream direction toward the first wireless node among the linked up wireless links, based on an indicator indicative of a radio wave propagation quality of one or more wireless links through which a plurality of the control signals received from different routes are propagated.