The Research And Improvement Of Algorithm On GPSR Routing Protocol In Vehicular Ad Hoc Network

Vehicular Ad Hoc Network (VANET), which has broad prospects for development and application, is an important part of the Intelligent Transportation Systems. The routing protocol is one of the key technologies in VANET, largely determining the performance of the communication system in VANET. VANET draws higher demand in the routing protocol because of the fact that the vehicle nodes are limited to move into a tubular shape in the road; the mobile node is moving too fast; the network topology changes frequently, and the relationship between the nodes is unstable. Aiming at dealing with the GPSR problems of the routing cutting off and routing redundancy in VANET, the paper proposes a program to improve the GPSR routing protocol, which combines the neighbor-relation-based prediction and the direction-based forwarding strategy.Firstly, the paper introduces the node moving model and the routing protocols in VANET, analyzes the overall performance of the routing protocols based on the topology and the routing protocols based on location, and focus on an intense research of the GPSR routing protocol. Secondly, on the complexity of vehicles moving in the road and for the study of the moving model of the vehicles in the road, the paper proposes Dynamic Micro Car-Load Model Based on Actual Road Topology, including the static road network topology map and micro-moving model of the vehicle in traffic rules. The establishment of the static road network topology scene is based on TIGER which is a real geographic information database, and then encodes to generate a real road network scene and simulates it in SUMO. Thirdly, it analyzes the defects of GPSR in VANET, and proposes a program combining the neighbor-relation-based prediction and the direction-based forwarding strategy to improve the validity and reliability to select the next hop neighbor node and to reduce the routing cutting off and routing redundancy of the GPSR in VANET. Finally, combined with the movement locus obtained from the SUMO in the static road network topology scene, the paper conducts simulation experiments on the improved GPSR routing protocol in NS2and analyzes its performances. The results of the performances show that the improved GPSR protocol has a lower packet loss and less delay time in the VANET than the traditional GPSR.