| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a road side radio communication system solving problems of unnecessary radio wave generated by reflecting the radio wave irradiated from an antenna of a roadside radio device to adjacent buildings, installations, road surfaces, and ceilings and erroneous communication of an on-vehicle device outside a prescribed communication range in road-vehicle communications of DSRC(dedicated short range communications) system. SOLUTION: The road side radio device 68 of the DSRC system including an antenna 23 for forming a new erroneous communication preventing electric field 24 covering over an unnecessary radio wave region 26 leaking the unnecessary radio wave by using a feature that the on-vehicle device 28 of the DSRC system does not communicate with radio waves of different frequency channels and radio waves of the same frequency channel with the strength of the synchronized radio wave or less as long as the electric field strength in an electric field range already establishing synchronization is stabilized at a sufficient strength for holding synchronization.</p> |
