| 摘要 |
In order to establish radio communications between an in-vehicle unit mounted on a vehicle and a roadside unit, an on-board antenna is mounted on the vehicle. The on-board antenna is operatively coupled to the in-vehicle unit and has directivity toward a road surface. Further, a stationary antenna means is operatively coupled to the roadside unit. The stationary antenna is provided at approximately center portion of a vehicle lane in a manner to have directivity toward an upward direction. Thus, a very short distance of radio communication can be formed thereby to eliminate a radio wave interference caused by a big vehicle. <IMAGE> |
