Abstract
ITS (Intelligent Transportation System) is the most promising method to maximise the efficiency on existing highways. The major tool that enables ITS schemes is radio communication, either existing commercial system or non existing dedicated radio systems. The subject of communication architecture for AVHS has been considered by many in the literature. Normally, the length of communication link in vehicle-to-vehicle is relatively short but it suffers from multipath fading and interference. The communication scheme in AVHS needs an extremely high reliability and a very short communication cycle. The objective of this paper is to assess the reliability and bandwidth efficiency of various communication schemes.