An Improved GPSR Routing Strategy in VANET

As a special type of mobile Ad hoc network, VANET has increasingly become an attractive technology in terms of safety driving and comfortable network services provided to vehicular users. However, high mobility of vehicular nodes in VANET makes network topology changing frequently, and this makes route unavailability and causes high data packet loss. Therefore, many researchers have focused on proposing or improving VANET routing protocols in order to provide more efficient and reliable routing solutions. In this paper, taking vehicle density, moving direction and speed into consideration, a new routing strategy based on GPSR routing protocol is proposed. Compared with the existed ones, it has three differences: 1) The special Hello Packet is designed with the functionality of setting precisely one-hop neighboring vehicles within the transmission range of the current node; 2) Set priority on the current vehicle\´s one-hop neighbors and select the next hop forwarder that may not be closest to the destination, the distance and velocity are taken into consideration. 3) Take the "Quorum" as a buffer and reforward the data packet to solve the local maximum problem. VanetMobiSim is used to build the simulation scenario and the performance of the proposed routing strategy is compared with GPSR and AODV on network simulator NS2. The results indicate that the improved GPSR routing strategy presented in the paper has better performance on packet delivery ratio, routing overhead.