Road Safety Based on Efficient Vehicular Broadcast Communications

Nodes in vehicular mobile networks can resolve Internet Protocol (IP) addresses by using the new technologies associated with IP-based next generation wireless networks. Vehicles are often equipped with a global positioning system (GPS) which signals to them their position. Communication protocols based on IP addressing have proved their reliability in wireline networks; geographical ad hoc routing protocols have proved their efficiency in large scale mobile ad hoc networks (MANETs); broadcast protocols have proved their high performance in reliable delivery of warning packets in vehicular ad hoc networks (VANETs). In this paper we discuss a hybrid geocast routing (HGR) protocol that can reliably and efficiently manage safety related communications in large scale VANETs. This protocol combines vehicle-to-road communications using IP addressing, vehicle-to-vehicle communications using single-hop broadcast, and Geocast and cluster-based broadcast communications. The results compare the HGR protocol and other protocols proposed for vehicular communications, which show that the HGR protocol outperforms them and alleviates the broadcast storm problem by minimizing the number of vehicles that forward warning messages, while guaranteeing high delivery ratio with acceptable delay.