车载网中路由选择算法的研究与改进

发布时间：2018-03-25 14:29

本文选题：车载网络　切入点：AODV协议　出处：《江南大学》2017年硕士论文

【摘要】：近年来,车载网作为现代智慧交通系统的重要组成部分越来越引起人们关注,它通过车辆与车辆之间以及车辆与基站之间的交互,实现二者的动态通信,在现代交通管理、交通信息查询、缓解交通堵塞以及预防交通事故发生等方面有很大的应用前景。车载网是一种特殊的移动自组织网络,相较于传统的移动自组织网络,车载网有着车辆节点高速移动性以及网络拓扑结构剧烈变化性等特点。因此,如何提高车载网中数据转发的效率成为了研究的重点。从目前来看,车载网的研究重点是网络协议。在车载网中,车辆节点是高速移动的,这样就导致了网络拓扑结构的剧烈变化,在加上建筑物的阻挡以及无线信道的不稳定性,因此车载网的链路是极不稳定的,链路极易断裂。针对以上不足,本文提出了一种基于链路稳定度的AODV路由协议,协议的改进分别在路由发现过程和路由选择过程。在路由发现过程中根据车辆节点的移动方向计算转发角,选择在转发角范围内的节点进行广播,用来减少网络中的广播冗余;在路径建立的过程中,通过车辆节点的移动速度和方向计算节点剩余生存时间和到目的节点的投影长度,并将二者综合作为节点稳定度,选择稳定度较高的节点进行数据转发,很大程度上解决了链路容易断裂的问题,使网络的服务质量大大提高。此外根据车载网本身的特点,选择稳定的链路并不能完全解决链路断裂的问题,所以本文在此基础上又对链路断裂后的路由修复机制进行了改进,提出了源路由与本地修复相结合的方式,并且在本地修复时通过选择上下游节点中较稳定的节点发起本地修复过程的方法,避免二次断裂的发生。源路由修复和本地修复的选择是通过判断断裂处的位置决定的,本地修复是通过比较断裂处上下游节点的稳定性参数决定的,通过对路由修复机制的改进,使网络中数据包的传递更加高效稳定。最后对真实的城市车辆场景进行实况模拟,将上述改进的协议应用在真实场景产生的车载网中,分析城市道路中车辆链接的情况。
[Abstract]:In recent years, as an important part of modern intelligent transportation system, vehicle network has attracted more and more attention. Through the interaction between vehicle and vehicle and between vehicle and base station, it realizes the dynamic communication between vehicle and base station and realizes the modern traffic management. Traffic information query, traffic congestion relief and traffic accident prevention have great application prospects. Vehicle network is a special mobile ad hoc network, compared with the traditional mobile ad hoc network. Vehicle network has the characteristics of high-speed mobility of vehicle nodes and dramatic changes in network topology. Therefore, how to improve the efficiency of data forwarding in vehicular networks has become the focus of research. The research focus of vehicular network is network protocol. In vehicular network, vehicle nodes are moving at high speed, which leads to drastic changes in network topology, in addition to building blocking and wireless channel instability. Therefore, the link of vehicular network is extremely unstable, and the link is easy to break. In view of the above shortcomings, a AODV routing protocol based on link stability is proposed in this paper. In the process of routing discovery, the forwarding angle is calculated according to the moving direction of the vehicle node, and the node in the range of forwarding angle is selected to broadcast, which is used to reduce the broadcast redundancy in the network. In the course of path establishment, the residual survival time and projection length to the destination node are calculated by the moving speed and direction of the vehicle node, and the nodes with high stability are selected to transmit the data. To a large extent, the problem of easy link breakage is solved and the quality of service of the network is greatly improved. In addition, according to the characteristics of the vehicular network, the problem of link breakage cannot be completely solved by selecting a stable link. On this basis, this paper improves the route repair mechanism after link break, and puts forward the combination of source routing and local repair. In order to avoid the occurrence of secondary breakage, the selection of source route repair and local repair is determined by judging the location of the fracture, by selecting the more stable nodes in the upstream and downstream nodes to initiate the local repair process. The local restoration is determined by comparing the stability parameters of the upstream and downstream nodes at the fracture location. Through the improvement of the routing repair mechanism, the transmission of data packets in the network is more efficient and stable. Finally, the real urban vehicle scene is simulated. The improved protocol is applied to the vehicle network generated by the real scene to analyze the situation of the vehicle link in the urban road.
【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.5;U495

【参考文献】