The Research On Routing Optimization For VANET Based On Location Information

Vehicular Ad Hoc Networks(VANET)is an application of Mobile Ad Hoc Networks.However,vehicles move quickly and their moving directions change frequently,and their moving paths are also limited by the real roads,which make the topology of VANET change fast,the links of VANET unstable,and the probability of link broken high.Consequently,it is still a hot topic that how to choose the most stable route between the source node and the destination node to improve the reliability of data transmissions and reduce the transmission delay.Based on the characteristics of the VANET,we propose a direction preferable and link estimated routing algorithm,which makes full use of the information of the vehicle position,direction,and speed that are provided by the vehicle positioning and auxiliary RF systems.Then we design a packet forwarding mechanism which is suitable for VANET.First,we divide the vehicles into ordinary nodes and crossroad nodes based on their positions.For ordinary nodes,they are grouped according to their moving direction,which ensures that the vehicles within the same group are generally moving towards the same direction.Furthermore,the proposed protocol adopts the strategy that combines the estimated link expiration time with routing hops,based on which we can select the most suitable route in the same group;For the crossroad nodes,we use the maximum cosine value rule to select forwarding nodes which move to the same direction with the destination node.Finally,the algorithm was simulated by NS3 software,and implemented in the agricultural projects IOT.The results show that it has a good effort.Compared to the GPSR-AGF and A-STAR routing protocol,the simulation results show that the proposed routing algorithm can successfully improve the data throughput,and reduce the end to end transmission delay and route control overhead.