Road transmission antennas (4a, 4b) are disposed along a road, each
radiating a single cell (E) with electromagnetic waves at the same
frequency and of the same content. A vehicle mounted device (3) receiving
the waves from the road transmission antennas (4a, 4b) performs antenna
pattern diversity reception. When entering a wave blocking area of a large
vehicle, a small vehicle is provided with seamless communications with a
stationary station (FIG. 1).
