| 摘要 |
<P>PROBLEM TO BE SOLVED: To securely inspect an operation state including transmission and reception functions of radio equipment installed on a road. <P>SOLUTION: A free flow system is provided with an antenna 2 arranged so as to form a predetermined communication area three-dimensionally on a toll road, for wirelessly communicating with an on-vehicle unit 6 for receiving radio transmission mounted on a vehicle entering the communication area, a marker beacon 4 installed on an on-road position which does not interfere with passage of the vehicle 5 in the communication area and provided with a radio-communication function equivalent to the on-vehicle unit 6, and a control device for making the marker beacon 4 and the antenna 2 communicating with each other and inspecting a radio function of the antenna 2 in a period when communication with the on-vehicle unit 6 is not established by the antenna 2. <P>COPYRIGHT: (C)2007,JPO&INPIT |
