A Reliable Method for Disseminating Safety Information in Vehicular Ad Hoc Networks Considering Fragmentation Problem

Many of applications in vehicular ad hoc networks (VANET) are based on dissemination of information, so broadcasting is a fundamental service in these networks. Broadcasting is a difficult task since vehicular networks often lack continuous end-to-end connectivity and have large variations in node densities. In this paper we present a method that improves the reception rates of broadcast messages by overcoming problem of connectivity gaps. In our method, every forwarder of message when facing a gap sends small messages periodically. These methods are used to understand entrance of a new vehicle that can be selected as the next forwarder of message. We have evaluated the performance of proposed protocol in NS2 under various network conditions.