Comparison of Flooding Techniques for Safety Applications in VANETs

In this paper, we study safety applications in Vehicular Ad hoc Networks (VANETs). More specifically we concentrate on emergency situations after a car crash in a platoon of vehicles which have wireless transmission capabilities. In order to avoid multiple collisions, vehicles should exchange emergency information as quickly as possible. To extend the area in which the emergency information is sent, they must relay it. In this article, we study various techniques to disseminate emergency data within a platoon of cars. We examine three different techniques : the pure flooding, the multipoint relay (MPR) diffusion mechanism of OLSR [1] and a geographic aware flooding technique as described in [2]. Different realistic scenarios are considered; we scrutinize various parameters such as vehicle density, and background traffic load.