I-AODV: Infrastructure based Ad Hoc On-demand Distance Vector routing protocol for Vehicular Ad Hoc Networks

Researchers are showing more and more interest in the Vehicular Ad Hoc Networks (VANETs) as it is found the most suitable mean for road safety, effective monitoring and control of traffic and global connectivity at all times as desired currently and in the future ahead. VANETs do not face the energy resource constraint which makes them suitable for larger coverage and network life time. However, due to higher vehicle speeds, persistent issues regarding network topology arises leading to frequent link failures, stale routes, end to end delay and higher packet loss ratios. In this paper, performance of Ad Hoc On-demand Distance Vector (AODV) routing protocol has been optimized by introducing fixed roadside wireless nodes for data transmission in a VANET environment. The concept is based on the presence of such wireless nodes along the road sides in major cities in the world. The word infrastructure is used because these fixed nodes contribute in providing paths available most of the time; thereby a way of tackling the dynamic network topologies and link failures. Additional directional antennas are employed at the fixed wireless nodes to achieve Line Of Sight (LOS) communication between them. Significant improvements are shown based on key performance metrics of hop count, route discovery time, network control traffic, end to end delay, media access delay, data dropped and throughput.