Today’s advanced simulators facilitate thorough studies on Vehicular Ad-hoc NETworks (VANETs). However the choice of the physical layer and the mobility models in such simulators is a crucial issue that greatly impacts the results. Realistic simulation of routing protocols in VANETs is still an open question. Indeed, only a few works address routing protocols comparison performed under realistic conditions. This paper compares common reactive, pro-active, hybrid and geographic routing protocols by using a simulation platform integrating a realistic physical layer and mobility models.
It also presents and analyzes several reactive protocols enhancements propositions dedicated to the VANETs context such as multi-path routing, but also protocols tuning which allows it to adapt faster. They have all received a lot of attention and are typically proposed to increase the reliability of data transmission. This paper study the behavior of each protocol in different situations and analized their advantages and drawbacks. Results presented in this paper gives an important explanation on the contradictory results found in similar works. Finally, our realistic simulations show that reactive protocols are the best suited for VANETs, and more especially the DYMO protocol.