Geocast Based on Traffic Light and RSU for Data Dissemination in Vehicular Ad Hoc Networks

Geocast is used to disseminate safety and non-safety information in specific regions. To reach routing protocols with low delay and high reliability, RSU and traffic lights are introduced to improve the efficiency of transmission in this paper. Firstly, we determined Geocast Region (GR). Most of existing geocast protocols directly select a circular or rectangular area as GR. Considering irregular road conditions, we combined state of traffic lights and road to determine GR, and gives high priority to vehicles that having big probability to reach event area. Secondly, we determined the Forwarding Region (FR). We took the opposite direction of the event lane as the FR. Finally, the source vehicle geocasts messages to other vehicles and the nearest RSU. There are two simulation indicators, namely the delivery ratio and delay. Simulation shows that GTR has a good performance in both the data reach and the delay.