A Traffic-Light-Aware Routing Protocol Based on Street Connectivity for Urban Vehicular Ad Hoc Networks

In urban vehicular ad hoc networks (VANETs), the network topology changes rapidly due to high mobility and uneven distribution of vehicles, thus the street connectivity is hard to estimate. Conventional routing protocols consider the street density as a decisive factor of street connectivity; however, they ignore the vehicle gathered phenomenon induced by traffic lights at the intersections. In this letter, we first explore the effect of traffic lights on vehicle distribution in a street, and then calculate street connectivity based on the distribution and density of vehicles in the middle area of a street. Finally, we propose a street-centric protocol called traffic-light-aware routing protocol based on street connectivity. Simulation results have shown that our protocol can improve the delivery ratio and reduce end-to-end delay for urban VANETs.