Traffic light based time stable geocast (T-TSG) routing for urban VANETs

Vehicular Ad Hoc Networks is a self-organizing, distributed communication network formed by highly Mobile Vehicles. This type of networks is developed as part of Intelligent Transportation Systems (ITS) to bring significant improvement to the transportation systems. One of the main goal of ITS, is to increase safety on road and reduce traffic congestion. Safety application requires messages to be sent to all nodes which belong to a particular geographical region. This message must be available to all the vehicles which enter the Geographical Region within a certain Time Period. Also, there are wide varieties of scenarios in VANETs to communicate. In urban environment, there are many streets, intersections, avenues etc. Hence, Driver has many options to reach his destination. In Highway environment, vehicles stay in the same road as there are only few entrances and exits. From a routing perspective, there are different options to forward information in an urban environment depending upon the behavior of traffic lights whereas in highway, most of the same set of vehicles may be used to forward information. In this paper, we have proposed a novel time stable geocast routing protocol nameed as traffic light based time stable geocast (T-TSG) routing protocol for informing vehicles after an accident in urban vehicular environment. T-TSG is a three phase routing approach based on traffic light behavior. It has better message delivery rate, negligible network load for life time management and lower end-to-end delay performance under simulated urban environment.