An unmanned mobile vehicle M acquires the line quality of a wireless communication line to each of the corresponding base stations having been measured by each mobile station and transmits the line quality to a control station 30. The control station 30 acquires the line quality of a wireless communication line to each of the corresponding mobile stations having been measured by each base station and transmits the line quality to the unmanned mobile vehicle M. When the same communication data is transmitted using two or more wireless communication lines in combination between the control station 30 and the unmanned mobile vehicle M, the transmitting side of the communication data selects two or more wireless communication lines that are used for the transmission of the communication data, on the basis of the line quality of each wireless communication line having been measured by each base station or each mobile station on the receiving side of the communication data.