| 摘要 |
<p>PROBLEM TO BE SOLVED: To solve the problem that information can not be normally given or received in a normal communication area and the problem that an on-vehicle equipment reacts in an adjacent traffic lane since the on-vehicle reacts before the communication area due to the increase of an electric field intensity level resulted from a surrounding radio environment such as a tool gate roof in a conventional private narrow band communication system. SOLUTION: The position of an on-vehicle equipment is measured by using a radio wave incoming direction measuring equipment, and when the on-vehicle is present in a communication area, a communication line is established between a passage side antenna and the on-vehicle equipment. Thus, it can prevent an erroneous operation of the on-vehicle equipment due to the increase of an electric field intensity level outside the communication area resulted from a surrounding radio environment so that normal communication is assured.</p> |
