R-ALOHA protocol for SS inter-vehicle communication network using head spacing information

The purpose of the studies is to improve the safety of road traffic systems and the smooth control of the traffic flow by providing information to vehicles. This paper assumes that the vehicles incidentally close to each other, form and manage a locally autonomous decentralized dynamic network. An R-ALOHA (reservation-ALOHA) protocol for the spread spectrum (SS) inter-vehicle communication network using head spacing information is proposed which improve the conventional slot reservation methods. Since the near-far problem in SS communication is one reason for the degradation of system performance, this proposed scheme is shown to improve the efficiency of communication. The performance of the proposed system in the environment where vehicles are assumed to run freely on a highway is verified by computer simulation. It is shown that inter-vehicle communication can be smoothly carried out between one vehicle and the surrounding vehicles using the propose method.