A Position Based Speed Adaptive Dissemination approach for Vehicular Ad hoc Networks

Vehicular Ad hoc Networks (VANETs) being a vital component of Intelligent Transport System (ITS), is getting due attention from the research community. VANET are self-organized networks, offering a variety of services, comprising not only the safety of drivers and commuters but also provides them travel comfort, while they are on the wheels. But due to some inherent characteristics of VANETs, information dissemination is a big challenge in both dense and sparse environments. Simple broadcasting in the dense traffic environment leads to redundancy of packets, channel access contentions, and packet collisions. This results in a broadcast storm problem. On the contrary, when the traffic density is very low, information dissemination is affected by network partition and network fragmentation. To deal with such issues, we propose a Position Based Speed Adaptive Dissemination (PBSAD) approach, where relay nodes for rebroadcast are selected considering the geographical position of vehicular nodes, irrespective of their direction of movement. The speed of the message sending vehicle is taken into consideration while evaluating the time slots for rebroadcasting nodes. The approach avoids periodic beaconing to gather 1-hop information. Further, this approach ensures information dissemination in a sparse environment as well by using the store, carry, and forwarding concept in which vehicles moving in either direction can act as relay nodes. To validate the proposed approach, a comparative analysis of the PBSAD approach is done with few state of art schemes based on parameters like message delivery ratio, delay, and the number of collisions. The simulation results reveal that PBSAD performs efficiently.