多接口车载自组网信道分配算法与接入技术的研究

发布时间：2018-08-18 18:55

【摘要】：车载自组网(Vehicular Ad Hoc Network, VANET)是智能交通系统(Intelligent Transport Systems, ITS)的重要组成部分,整个网络的拓扑结构变化频繁,每条通信链路的生存时间很短。在需要保证网络QoS (Quality of Service)的环境下,为车辆节点配备多接口进行多信道通信技术应运而生,成为研究的热点。实现多接口VANET多信道通信的一个重要保障是高效可靠的MAC机制。信道分配问题与信道接入问题是不同MAC机制的主要差异所在。信道分配问题主要负责为不同的车辆节点分配相应的通信信道,消除信道切换所造成的通信链路之间的冲突；接入控制问题则主要负责解决不同车辆节点在接入信道时的时机冲突,实现各车辆节点合理高效的信道接入。研究和完善多接口VANET的MAC层技术具有重要的学术意义和应用价值。本课题主要就是研究多接口VANET多信道通信的信道分配算法和信道接入机制。首先,针对美国联邦通讯委员会(FCC)划分的车载通信信道,分析常用信道分配算法运用在车载自组织网中的不足之处,利用车辆节点间的交互,考虑当前网络状态参数,以各信道性能因子为衡量标准,生成信道切换队列,提出了一种综合考虑通信双方车辆节点信道切换队列的动态信道分配算法(Channel SwitchingQueue-based Channel Allocation, CSQCA)。其次,针对为车辆节点多接口通信分配的信道,分析多接口VANET信道接入所面临的挑战以及考虑所有车辆节点多射频接口通信造成的网络高负载特性,利用时分多址技术与竞争类信道接入技术的优点,提出了一种基于车辆节点多接口状态字的时分竞争信道接入技术(Time-division Competition Channel Access, TCCA)。接着,在上述研究的基础上,搭建NS-2网络性能仿真平台,对仿真模块进行多接口和多信道的扩展。利用仿真平台,对所提出的信道分配算法以及信道接入技术进行性能仿真与评测。仿真结果表明,CSQCA算法实现了多接口VANET环境下多信道通信的信道动态分配,合理的解决了信道分配不合理的情况,显著的改善了网络的性能；TCCA机制能够很好的适应车辆节点多接口并行通信所造成的网络高负载环境,保证了所有车辆节点得到公平的信道接入机会,同时保持了对网络资源的高效利用。最后,本文列出了一些有待解决和完善的问题,需要进一步去研究,从而引出了后续研究改进的方向。
[Abstract]:Vehicle Ad Hoc Network (Vehicular Ad Hoc Network, VANET) is an important part of Intelligent Transportation system (Intelligent Transport Systems, ITS). The topology of the whole network changes frequently and the lifetime of each communication link is very short. Under the need to ensure the network QoS (Quality of Service), the multi-channel communication technology for vehicle nodes with multiple interfaces has emerged as the times require, and has become a hot research topic. An important guarantee for multi-interface VANET multi-channel communication is the efficient and reliable MAC mechanism. Channel assignment problem and channel access problem are the main differences of different MAC mechanisms. The channel assignment problem is mainly responsible for allocating corresponding communication channels to different vehicle nodes to eliminate the conflicts between communication links caused by channel switching. The problem of access control is mainly responsible for solving the timing conflict of different vehicle nodes when accessing the channel, and realizing the reasonable and efficient channel access of each vehicle node. It is of great academic significance and application value to study and perfect the MAC layer technology of multi-interface VANET. The main purpose of this thesis is to study the channel assignment algorithm and channel access mechanism of multi-interface VANET multi-channel communication. Firstly, aiming at the vehicular communication channel partitioned by the Federal Communications Commission (FCC), this paper analyzes the shortcomings of the common channel allocation algorithms used in the vehicular ad hoc network, and considers the current network state parameters by using the interaction between the vehicle nodes. A dynamic channel assignment algorithm (Channel SwitchingQueue-based Channel Allocation, CSQCA).), which considers the channel switching queue of vehicle nodes on both sides of the communication, is proposed based on each channel performance factor. The channel switching queue is generated according to the criterion of each channel performance factor. Secondly, in view of the channel allocation for multi-interface communication of vehicle nodes, the challenges of multi-interface VANET channel access are analyzed, and the characteristics of network high load caused by multi-RF interface communication of all vehicle nodes are considered. Based on the advantages of time-division multiple access (TDMA) and competing channel access technology, a time-division competitive channel access technology (Time-division Competition Channel Access, TCCA).) based on vehicle node multi-interface status word is proposed. Then, on the basis of the above research, the NS-2 network performance simulation platform is built, and the simulation module is extended with multi-interface and multi-channel. The proposed channel allocation algorithm and channel access technology are simulated and evaluated using the simulation platform. The simulation results show that the algorithm realizes the dynamic channel allocation of multi-channel communication under multi-interface VANET environment, reasonably solves the unreasonable channel allocation situation, and improves the performance of the network significantly. The TCCA mechanism can adapt to the network high load environment caused by the vehicle node multi-interface parallel communication, ensure all the vehicle nodes get fair channel access opportunities, and maintain the efficient use of network resources. Finally, this paper lists some problems to be solved and improved, which need to be further studied, thus leading to the direction of further research and improvement.
【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.5

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