Wireless communication system between roadside base station and vehicles are expected to become basic infrastructures for the ITS (Intelligent Transport Systems), since various kinds of information including vehicle control signals, navigation information and multimedia information etc for the safety and comfortable drive should be supplied timely to the vehicles running on the road. CRL Yokosuka (Yokosuka Radio Communications Research Centre, Communications Research Laboratory, MPT Japan) has intensively set up millimeter-wave test facilities in order to accelerate research activities on the ITS wireless communications. In this paper, the road-vehicle communications test facilities based on the Radio On Fiber (ROF) transmission system and micro-cell network system along a road in the YRP (Yokosuka Research Park) are introduced. In these facilities, millimeter-wave frequency bands of 36-37GHz as the experimental band are used. A control station is located on the 3rd floor of a research building and 12 antenna poles for the roadside base stations are put up in the equal interval of 20 meters along an about 200 meters straight line road. Optical fiber cables are installed in the state of a star connection between the Control Station (CS) and each roadside Local Base Station (LBS). Propagation characteristics between the roadside antenna and a vehicle are presented and overall transmission system including optical fiber cable section and air section are also mentioned in this paper.
Samenvatting