Research On V2V Multi-hop Broadcast Of VANETs

The information distribution of VANETs is an important topic that many researchers focus on, multi-hop broadcast as the principal means of information distribution has became the core technologies to forward the information to a further and greater area. Since the topology of VANETs changes frequently, which resulting in the reliability of information transmission is poor, in addition, the bandwidth of VANETs is limited, it is also a problem of information transmission which must be considered in the designing of a multi-hop broadcast protocol. It is critical to optimize the network topology, maximize the throughput of network information, improve network resource utilization, reduce latency,improve the security of information transmission reliability and timeliness, these are the problems in the process of designing a multi-hop broadcast protocol will encounter. There is no buildings which will block the transmission of information, so the network topology of car nodes render randomly, while because of the tall building in the city area, the network topology of nodes show regular, it is particularly important to design a broadcast protocol can apply to a variety of environments.Traditional broadcast protocols are inflexibility, this paper presents a region-based adaptive broadcast protocol to forward packet of safety information(Self-Adaption Area-Grouping Based Broadcast Protocol of Safety Message, SABP).First, this paper analysis the relay node selection problem, using the method of solving convex hull points set to select the relay nodes, and make special processing of the algorithm, so that it can be better to solve the problem of the relay node selection.And then presents the design of a relay node broadcasting strategy, in order to prevent a large number of nodes send information at the same time, it may cause the loss of broadcast messages, SABP defines that the nodes after decentralized processing the convex hull points immediately repeated broadcast and other neighboring nodes which haven’t been selected for a period of time after the broadcast.Finally, SABP protocol broadcasts information dynamically changes based on the distribution of nodes around the car, the experimental results show that, SABP protocol can achieve better network performance indicators both in urban environment and rural environment.