An uplink quality information collecting unit transmits, when there is no uplink data transmission from a terminal station for a predetermined time, dummy data to a base station that is currently connected to the terminal station, and collects uplink-quality information that is generated by transmitting the dummy data to the base station. Said backrest has a front face that supports the back of a seat occupant. The beacon signal may be swept through an angle and may be utilized along with reference system information to determine the direction andor distance between the two or more wireless devices.