A Reliable Multihop Broadcasting In Vanet

Abstract

Broadcasting of messages, especially for safety applications, is one of the fundamental services in vehicular ad-hoc networks (VANETs). These services typically require delivering the information to all vehicles traveling over a geographical area, with high reliability and low delay. At the same time the number of relaying hops must be minimized to avoid the broadcast storm problem. Broadcasting in VANET is very di erent from routing in mobile ad hoc networks (MANET) due to several reasons such as network topology, mobility patterns, high speed of the nodes, di erent trafic patterns etc. These di erences imply that conventional ad hoc routing protocols are not appropriate in VANETs for most vehicular broadcast applications. During my M.Tech thesis study, I propose a reliable solution for the broadcasting in VANET designed for the optimum performance of public-safety related applications. Also the broadcasting may be used in many other applications. The protocol is based on slotted p-persistence[17] and RTS/CTS handshake scheme of UMB protocol[16] which guarantees the successful reception of a broadcasting message. At the time of broadcasting it becomes essential to select a node who should be the next relayer otherwise it may lead to broadcast storm problem. While the RTS/CTS scheme makes the protocol reliable and takes care of the hiddennode problem, the next broadcaster is selected using p-persistence algorithm. Simulation results show that the proposed protocol performed better in terms of bytes usage, success rate and propagation time when compared with slotted p-persistence and UMB protocol. iii