A new cooperative optimized channel access for inter-vehicle communication

For future road traffic a variety of applications for increasing security and efficiency are planned. The basis of these services is a communication link between vehicles and infrastructure, or between vehicles. The first generation of services like road pricing and route guidance will be realized using vehicle-infrastructure communication. Future developments aim at integrating inter-vehicle communication to enable cooperative driving, e.g. by harmonizing speed and distance. Existing networks cannot provide the required communication services. Current research is based on the 64 GHz frequency. Protocols from existing packet radio networks cannot be adapted because veh.-veh.-communication implies completely new requirements. This becomes obvious for example in the area of media access protocols (MAC-protocols). It is not possible to distribute the access to the broadcast medium by a central (master) station. In this paper a MAC-protocol is presented-COCAIN (cooperative optimized channel access for inter-vehicle communication). A brief overview on the viewed communication scenario is given and the basics of former channel access protocol approaches are summarized. The protocol approach is presented, results of simulations are briefly discussed and the crucial parameters of this protocol approach are pointed out. The influence of these crucial parameters is considered