Vehicle-mounted communication system, portable machine, and vehicle-mounted machine

Abstract

Provided are a vehicle-mounted communication system with which a vehicle-mounted machine is able to continue receiving a wireless signal even if the signal is interrupted. When an ID signal, indicating identification information (ID) corresponding to a vehicle, and more than M (where M is a natural number) data signals, indicating control content, are caused to be included in a wireless signal by the portable machine, and the portable machine transmits the wireless signal, the portable machine adds the ID signal into the wireless signal each time M data signals have been transmitted, and continues to transmit the wireless signal. Meanwhile, each time the vehicle-mounted machine receives the ID signal included in the wireless signal, the vehicle-mounted machine verifies the identification information the received ID signal against identification information stored in a ROM, and continues to receive the wireless signal when there is a match.