Comparison of reliable broadcasting protocols for vehicular ad-hoc networks

Reliable broadcasting in vehicular ad hoc networks is one of the keys to success for services and applications on intelligent transportation system. Many reliable broadcasting protocols have been proposed but none of them has been evaluated in realistic scenario. In this paper, we discuss and evaluate these reliable broadcasting protocols on VANET. First, we separate mechanisms of the protocols into three main modules, which are preferred node selection algorithm, waiting timeout calculation and beaconing mechanism. These modules are employed on the reliable broadcasting protocols. Then, we evaluate performance of the protocols by simulation. To be more realistic, in our simulation, multiple broadcast messages are concurrently generated on highway and urban scenarios. None of the previous works we found in the literature uses more than one broadcast message on their simulation. From simulation result, we found a problem on the preferred node selection algorithm, the waiting timeout calculation and the beaconing mechanism of some protocols, which can lead to broadcast storm problem and inefficient operation.