Improving safety message dissemination in IEEE 802.11e based VANETs using direction oriented controlled repetition technique

Broadcasting in vehicular ad hoc networks (VANETs) has become an active area of research. VANET applications are inherently broadcast-oriented and require the underlying communication protocols to be reliable and scalable. On the other hand, the conventional broadcast mechanism may lead to the so called broadcast storm problem, a scenario in which there is a high level of contention and an excessive number of broadcast packets suffer from collision. In this paper, we propose direction oriented and stochastic controlled repletion techniques in an IEEE802.11e-based VANET to overcome the broadcast storm problem in a two dimensional highway. The adequacy of the proposed techniques has been evaluated by a simulation. The results of this simulation show that the performance of VANET improves by setting proper parameters and controlling the number of repetition per priority class. Further, controlling the storm problem by direction oriented technique can highly improve the performance of VANET for broadcasting of safety messages.