Research On VANET’s Routing Algorithm Based On GPSR

Vehicular ad hoc networks have the characteristics of frequent network topology changes, and uneven density of vehicle nodes, which makes the end to end routing path has a short survival time.These features make the routing in mobile ad hoc networks can not be directly applied to vehicular ad hoc networks.Typical based on location routing is GPSR protocol, it is more suitable for urban vehicular network routing protocol, but studies show GPSR in urban environments with large packet loss rate, information of neighbor nodes and slow, in urban environmental performance is poor, so we study on routing stage is based on the improved GPSR routing protocol.The general ideas to improve city electronic map based path planning, this type of routing protocols assume that vehicles are equipped with navigation system and electronic map which can obtain their location and urban road structure information.When the vehicle node transmits the data, the vehicle node generally uses the Dijkstra algorithm to plan well to pass through the road section and the intersection and the planning information in the data package. The intermediate node only needs to be forwarded to the destination node according to the planned path.And improvement ideas is the dynamic route choice, this kind of routing protocols use the idea of GPSR protocol, vehicle node when sending packets does not perform path planning but directly using greedy forwarding, relay nodes in the forwarding process of path selection.In this paper, a new routing protocol is proposed.This protocol mainly has three characteristics,first, the intersection node is introduced to avoid the local optimum. Second a method of detection of road connectivity is proposed. Third improved GPSR protocol based on road connectivity. The new routing protocol is always a priority. Can avoid the local optimal situation, in the case of ideal traffic flow can reach the destination node in the best way, in the case of the vehicle flow is not ideal can be adjusted in a timely manner. At the end of this paper, the NS2 simulation software is used to simulate the new routing protocol, and the experiment proves that it is more suitable for the urban environment.