Research On The Broadcast Mechanism Of Security Message In IOV

The security emergency message is the most important information that the IOV needs to transmit, it has a very critical role to the safety of vehicles and traffic congestion in intelligent transportation system. However, due to the rapid movement of the network node which is vehicle in the IOV, the network topology changes frequently, and the communication links between the nodes are unstable. These will directly lead to that the security messages can not be forwarded and transmitted in a timely and reliable manner. Based on these problems and practical requirements, a security message broadcast mechanism SMLP based on location prediction is proposed in this paper.The SMLP broadcast algorithm is mainly implemented by V2V communication. The algorithm is divided into three steps. Firstly, the future location information is predicted according to the location and direction of the neighbor nodes. Secondly, the optimal relay node is selected, and finally the relay node broadcast security messages. In the stage of selecting the optimal relay node, the GPSR selects the nearest neighbor node from the destination node as the next hop forwarding node, which will result in an unstable link. The SMLP algorithm overcomes the shortcoming and further considers the continuous connection time between the nodes and the direction of the neighbor nodes and so on. The node connectivity time, direction coefficient and distance coefficient are introduced, and a stability coefficient is defined by weighting the combination of these factors. SMLP selects the neighbor node with the largest stability coefficient as the next hop relay node.In order to verify the validity and applicability of the algorithm, the traffic flow simulation software VanetMobiSim and the network performance simulation software NS2 are used in the paper to carry on the joint simulation under different scenarios, and contrasts the various performance indexes of the SMLP and the GPSR routing protocol. The simulation result shows that SMLP reduces the packet loss rate and average end to end delay in the packet transmission process to a certain extent compared with the GPSR routing protocol, and improves the throughput of the network. So the SMLP can be applied to the transmission of security messages in the traffic system.