【正文】 work. We test a simulation, 20 percent of mobile nodes are moved with the speed of fifteen, twenty, twentyfive km/s, and so on. And then we pare some very important parameters. Such as delay time, throughout, jitter and loss packet ratio. Finally, we can get the conclusion that GPSR routing protocol is more suitable for Vehicular Ad Hoc Network .With the reason of GPSR chose the fastest nodes to act as forward nodes, which will cause small average time. At the traffic almost the same, so the throughout is much more bigger than the way of using the routing protocol using AODV. Keywords： Ad hoc work, Vehicular Ad Hoc Network, NS – 2, GPSR 目錄 I 目錄 第一章 前言 ................................................................................................................................. 1 研究背景與意義 ............................................................................................................. 1 國內(nèi)外研究現(xiàn)狀 ............................................................................................................. 2 主要研究工作 ................................................................................................................. 2 論文結(jié)構(gòu) ......................................................................................................................... 3 第二章 車載自組 網(wǎng)現(xiàn)狀 ............................................................................................................. 4 車載自組網(wǎng)概述 .............................................................................................................. 4 車載自組網(wǎng)的特點 ............................................................................................... 4 車載自組網(wǎng)的體系結(jié)構(gòu) ....................................................................................... 6 車 載自組網(wǎng)中的關(guān)鍵技術(shù) ............................................................................................. 7 車載自組網(wǎng)無線接入技術(shù) .................................................................................... 7 GPS 定位技術(shù) ........................................................................................................ 7 車載自組網(wǎng)路由協(xié)議 ........................................................................................... 8 2． 3 車載自組網(wǎng)路由協(xié)議的分類 ...................................................................................... 8 基于拓?fù)涞穆酚蓞f(xié)議 ........................................................................................... 9 基于地理位置路由協(xié)議 ..................................................................................... 10 基于地圖的路由協(xié)議 ......................................................................................... 12 本章小結(jié) ....................................................................................................................... 12 第三章 NS2 模擬與仿真工具 ................................................................................................... 14 車載網(wǎng)算法的 NS2 仿真平臺構(gòu)建 ............................................................................... 14 網(wǎng)絡(luò)仿真的方法和一般過程 ....................................................................................... 15 NS2 的節(jié)點模型 ............................................................................................................ 15 NS2 移動節(jié)點的創(chuàng)建 .................................................................................................... 16 NS2 下無線傳輸?shù)哪芰磕Ｐ? ........................................................................................ 17 NS2 工具介紹 ................................................................................................................ 18 數(shù)據(jù)分析工具 awk 簡介 .................................................................................... 18 動畫演示的工具 NAM....................................................................................... 20 添加 GPSR 路由算法在 NS2 下 .................................................................................. 21 目錄 II 本章小結(jié) ....................................................................................................................... 21 第四章 基于車載網(wǎng) GPSR 的改進算法 ................................................................................... 23 車載網(wǎng) GPSR 算法的不足 ............................................................. 錯誤 !未定義書簽。最后，得到的結(jié)論為：由于 GPSR 算法通過貪心算法，選取的是最遠(yuǎn)的節(jié)點作為轉(zhuǎn)發(fā)中繼，故延時相對于 AODV 算法比較而言，端到端延時更小。其中包括仿真工具 NS2。本文選用 AODV 路由協(xié)議與 GPSR 協(xié)議進行對比分析?，F(xiàn)在交通系統(tǒng)需要解決的問題是怎樣減少交通事故的發(fā)生，堅決這個問題的關(guān)鍵是怎樣提高道路交通環(huán)境的質(zhì)量。摘要 隨著科學(xué)技術(shù)的不斷發(fā)展與進步，人們的生活水平在逐漸的提高，對生活質(zhì)量也有了越來越高的要求，越來越多的家庭開始擁有私家車了。在我看來，如果能夠?qū)崿F(xiàn)車輛間的通信，使得車輛之間能夠迅速、快捷的獲得其他車輛的信息，從而讓駕駛者能快速的做出正確的反應(yīng)，那么就可以很大限度的降低交通事故的 發(fā)生，從而能在一定的程度上緩解道路的擁堵。其中重點分析了 AOD與 GPSR 這二種協(xié)議的原理。模擬了車載網(wǎng)節(jié)點的移動。二種協(xié)議傳送相同的數(shù)據(jù)包，由于 GPSR 協(xié)議延時小，故吞吐量較大，抖動比較小。 基于車載網(wǎng) GPSR 的改進算法 ................................................................................... 23 添加改進代碼在 NS2 下的修改 .................................................................................. 23 本章小結(jié) ....................................................................................................................... 28 第五章 仿真實驗及結(jié)果分析 ................................................................................................... 29 仿真模擬實驗 ............................................................................................................... 29 網(wǎng)絡(luò)仿真場景拓?fù)湓O(shè)置 ..................................................................................... 29 仿真參數(shù)比較 ..................................................................................................... 33 實驗結(jié)果分析 ............................................................................................................... 34 端到端的延時 ..................................................................................................... 35 吞吐量的比較 ..................................................................................................... 36 抖動率的比較 ..............................