车辆自组织网络中基于Beaconless的路由协议和车辆接入机制的研究

发布时间：2018-03-16 05:24

本文选题：车辆自组织网络　切入点：可靠性传输　出处：《西安电子科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着科技的发展,无线网络的应用越来越广泛。车辆自组织网络(Vehicular Ad Hoc Network,VANET)将无线网络应用于交通方向,是发展智能交通和智慧城市的重要部分。对于VANET中的安全性和非安全性应用实现,可靠的数据传输都起到关键性的作用,而数据的传输离不开可靠的传输协议和接入协议。因此,VANET的数据可靠性传输问题受到了汽车厂商、高校和研究所的广泛关注,并且在近几年来取得了一定的成果。作为移动自组织网络(Mobile Ad Hoc Network,MANET)的一个分支,车辆自组织网络即具有MANET的普遍特性,也具有自身独有的特性。普遍性体现在网络的无中心、自组织、自管理和多跳转发等。VANET的独特性体现在其节点为运动的车辆并且节点的运动是有迹可循的,该特性带来了数据可靠性传输的挑战。在网络中,快速运动的节点会引起高动态的拓扑,从而引起间歇性链接且严重影响协议性能,因此设计一个高性能的路由协议对于数据的可靠性传输非常重要。基于beaconless的协议采用接收节点之间的竞争来选择最佳的下一跳,不仅可以提高网络传输可靠性且不采用beacon信息从而降低网络开销。当多个车辆对路设发起请求信息时,路设对车辆的服务顺序规则对于网络整体的性能有严重的影响,因此设计一个适应于动态场景的接入服务机制是很有必要的。本文针对车辆自组织网络中数据可靠性传输存在的挑战,提出了基于beaconless的路由协议SLBF。该协议在现有的基于beaconless协议的基础上,定义了自适应性的转发区域,考虑贪婪转发、链路质量和节点业务方面设计等待时间算法,并且采用了重传机制从而来提高网络中数据包的可靠性传输。通过在NS-2上进行仿真,并且与经典的GPSR协议和BLR协议进行了对比,仿真结果表明SLBF在投递率、时延和平均跳数方面都有一定的提高。当有多个车辆向路设请求服务时,路设对于多个请求的服务规则会影响网络的服务质量。本文针对该问题提出了基于内容完整性和内容重要性的接入机制。在内容完整性方面采用了一定的条件预先判断请求内容是否可被完整服务,根据判断的结果结合请求内容重要性计算得到一个服务优先级,最后采用简单的资源分配机制来对符合要求的请求进行服务。该机制还可以在V2V通信的辅助下进一步的提高网络的整体性能。
[Abstract]:With the development of science and technology, wireless network is more and more widely used. Vehicle Ad Hoc Network (VANET) applies wireless network to traffic direction. It is an important part of the development of intelligent transportation and intelligent city. Reliable data transmission plays a key role in the implementation of security and non-security applications in VANET. The transmission of data can not be separated from reliable transmission protocols and access protocols. Therefore, the problem of data reliability transmission in VANET has been widely concerned by automobile manufacturers, universities and research institutes. As a branch of Mobile Ad Hoc Network (Manet), the vehicle Ad Hoc network has both the universal and unique characteristics of MANET. The uniqueness of .VANET, such as self-organization, self-management and multi-jump transmission, is reflected in the fact that its nodes are moving vehicles and that the movement of nodes is traceable, which brings challenges to the reliable transmission of data. Fast moving nodes can cause highly dynamic topologies, causing intermittent links and seriously affecting protocol performance. Therefore, it is very important to design a high-performance routing protocol for the reliable transmission of data. The protocol based on beaconless uses the competition between the receiving nodes to select the best next hop. It can not only improve the reliability of network transmission, but also reduce network overhead by not using beacon information. When more than one vehicle initiates requests for information, the service sequence rules of vehicles have a serious impact on the performance of the network as a whole. Therefore, it is necessary to design an access service mechanism suitable for dynamic scenarios. In this paper, a routing protocol based on beaconless is proposed. Based on the existing beaconless protocol, the adaptive forwarding region is defined, and the waiting time algorithm is designed in terms of greedy forwarding, link quality and node service. The retransmission mechanism is used to improve the reliable transmission of data packets in the network. The simulation results on NS-2 are compared with the classical GPSR protocol and BLR protocol. The simulation results show that the SLBF is delivering rate. The delay and the average number of hops are improved. When more than one vehicle requests service, The routing rules for multiple requests will affect the quality of service of the network. In this paper, an access mechanism based on content integrity and content importance is proposed. First determine whether the request content can be fully serviced, A service priority is calculated based on the results of the judgment combined with the importance of the request content. Finally, a simple resource allocation mechanism is used to service the requests that meet the requirements. This mechanism can further improve the overall performance of the network with the assistance of V2V communication.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN929.5;U495

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