A Global Topology Based Broadcast Algorithm for VANETs

Abstract

Multi-hop broadcast communication has been increasingly used to disseminate safety applications for Vehicular Ad hoc Network (VANET), which requires high reliability and low latency. However existing broadcast algorithms are unable to achieve these goals well, because they only employ local topology information to determine relays and the messages are just delivered by vehicles. In this paper, we propose the global topology based broadcast (GTB) algorithm which has the aid of the base station (BS) to obtain the global information. First, the BS constructs the global topology periodically. Second, we formulate an optimization problem to select the cluster heads (CHs). In order to solve this problem, we develop the cluster head selection algorithm (CHSA), in which the BS employs to select vehicles with optimal locations as CHs. Finally, the BS and CHs assist with the broadcast of the message. Compared with existing broadcast algorithms, the GTB shows the better performance both in urban and freeway scenarios in simulations.