车载自组织网络移动模型研究与仿真(任务书,开题报告,论文13000字)
摘 要
在当今社会，人们对汽车的期望已经不止于它们的质量和性能方面了，能否实现车载移动环境下的有效通信是新时代汽车行业的关键技术之一。车载自组织移动网络作为无线自组织网里的一个重要内容，为我们解决了新一代汽车革命所带来的汽车移动通信的一些问题。车载自组织网（VANET）是一种建立在移动车辆上的分布式、自组织的通信网络。VANET中车辆节点的移动特征与普通移动网络的节点有所不同的是，它们的移动不仅在路径上受到了道路和障碍物限制，移动速度也比较快。因此普通的移动网络协议就并不适用于车载移动网络。因为VANET的特殊性，学者们在研究过程中需要注意寻找到更适用于车载环境的无线网络技术。而利用计算机仿真来分析和评价VANET的各层协议的性能是目前大量采用的研究方法。同时，VANET仿真技术也迎来了不少挑战，例如我们需要找到适用于车载环境的移动模型，以在各个层面为仿真提供符合真实情况的节点移动的描述，这便是本文要讨论的主要问题。
文章首先介绍了几种常用的移动模型，并基于各种模型的具体特征不同，将各移动模型分为了两类，分别是随机移动模型和受限的移动模型。在随机移动模型中，移动节点在设定的仿真区域内能够自由移动且不会受到其他因素的制约。而在现实车载场景中，节点的移动并不完全随机，移动过程中会受到环境条件的限制，例如街道和障碍物等等。于是接着介绍了一种比较贴近现实场景的移动受限模型，在本文中主要是指曼哈顿模型。在该模型中，车辆节点移动受到了街道地图制约，甚至节点同一道路上前方车辆的速度都会对节点移动产生限制。
接着介绍了网络仿真工具——NS2软件，并介绍了在该软件下的仿真流程，在NS2中可以为我们提供车辆间通信所需要的各层协议并能够通过仿真对路由协议的性能进行评价。通过开展的仿真实验证明了采用不同的移动模型，在同一种协议下的仿真得到的性能结果也会有所不同。因此在车载网络环境下中对路由协议的性能进行评估时，更应该要选择符合真实车载环境的移动模型，才能得到真实可靠的评估结果。并在文章末尾对未来的车载通信技术以及其移动模型提出了展望。
关键词：车载自组织网络；移动模型；NS2；网络仿真
Abstract
Nowadays, people's expectations for cars are more than their quality and performance. The key technology of the automotive industry in the new era is to realize effective communication between the mobile cars.As an important part of the wireless self-organizing network, VANET has solved the problems of the automobile mobile communication brought by the new generation automobile revolution. VANET is a distributed, self-organizing communication network based on mobile vehicles. Therefore, the movements of vehicle nodes are limited not only by roads and obstacles, but also by moving speed. Because of the particularity of VANET, it is needed to do more suitable research for automotive environment in the wireless network technology’s research process.So that ordinary communicational protocol does not apply to VANET, the use of computer simulation to test and evaluate the various layers protocol of VANET is widely used research methods. VANET simulation technology also brings a lot of challenges, for example, finding a correct definition of mobile model for the vehicle environment to provide a feasible description of the node movement in each level of the simulation.
At the beginning of the article, several common moving models are introduced. Based on the different characteristics of each model, the mobile models are divided into two categories: stochastic mobile model and limited mobile model. In the stochastic mobile model, the mobile node is free to move within the simulation area and is not subject to any restriction. But in the real scene, the movement of the nodes is not completely random.The process of moving will be subject to environmental conditions, such as streets and obstacles and so on. Then we introduce a mobile limited model that is closer to the real scene. In this paper, we mainly refer to the Manhattan model. In this model, the vehicle nodes are constrained by the street map, and even the speed of the front of the vehicle on the same road .
Later, it introduces the network simulation tool, NS2 software, and describes thesimulatio- n process in NS2. It can provide us various layers of the agreement between VANETcommun- ication and can simulate to evaluate the performance of the routing protocol. The simulation experiments shows that the use of different mobile models, the results of same routing protocol performance simulation will be different. Therefore, during the assessment of the performance of the routing protocol in the vehicle network environment, mobile model should be selected more in line with the real vehicle environment in order to get a reliable assessment results. And at the end of the article, I put forward to the prospect of vehicle communication technology and its mobile model.
Key Words：VANET；mobile model；network simulation；NS2
目 录
第1章绪论 1
1.1 研究背景以及意义 1
1.2 国内外的研究现状 2
1.3 本文的研究内容及章节安排 3
第2章车载自组织网络移动模型综述 4
2.1 随机漫步模型 4
2.2 随机路点（Random Waypoint,RWP）模型 5
2.3 随机方向（Random Direction,RD）模型 5
2.4 曼哈顿移动模型(Manhattan Mobility Model) 5
2.5 本章总结 6
第3章网络仿真设计 7
3.1 网络仿真工具介绍及对比分析 7
3.2 仿真设计流程 8
3.3移动模型场景 9
3.4 移动模型性能结果分析 13
3.4.1 移动模型数据处理GAWK 14
3.4.2 gnuplot绘图及结果分析 14
3.5 本章小结 16
第4章总结与展望 18
4.1 本文总结 18
4.2 研究展望 18
参考文献 20
致谢 21 |
