| Vehicular Ad hoc network is an important part of intelligent transportation system. It provides a mobile communication platform for vehicle nodes and plays an important role in regard to enhance traffic efficiency, pre-accident, driver assistance and automotive entertainment. Vehicular Ad hoc network is a special mobile ad hoc networks apply in inter-vehicle communication. They have something in common, but there are many peculiarities such as node speed faster, more frequent changes in the network topology, limited bandwidth, susceptible to interference and so on. These peculiarities seriously affected the normal data packet transmission efficiency, leading to the original routing protocol can not play its due role in VANET directly. Therefore, in order to guarantee the data packets can be transmitted reliably and quickly, how to design efficient and adaptive routing protocol which adapted to the characteristics of VANET has always been a hot and difficult problem in VANET research area.This paper describes the characteristics and applications of vehicular ad hoc network and compares some representative routing protocols. Then it analyzes the current most popular location-based VANET routing algorithm — greedy perimeter stateless routing GPSR (Greedy Perimeter Stateless Routing) algorithm which is applied to the city scene, and points out the flaws of the routing algorithm, proposes a improved GPSR routing algorithm. The improved algorithm not only regard the distance from the neighbor node to the destination node as the only condition to select the next hop, but also taking into account whether the neighbor nodes and the transmit direction of the data packets is consistent and so on, so that the transmission of the data packets can have a better performance both in distance and direction. Simulation results show that the improved GPSR routing algorithm can reduce the packet loss rate and end to end delay more effectively compared to the traditional GPSR routing algorithm. |
PDF Full Text Request