本文選題：VANET + 路由協(xié)議��； 參考：《吉林大學》2017年碩士論文

【摘要】：VANET(Vehicular Ad-hoc Network)作為無線網(wǎng)絡領域的熱門話題,目標是在車輛與車輛或者車輛與路邊設施之間完成通信,而完成通信的路徑則是由路由算法決定的。由于車輛通常是高速移動的狀態(tài),傳統(tǒng)靜態(tài)網(wǎng)絡的路由算法已經(jīng)完全不適用于VANET。因此,在VANET中提出新算法以完成數(shù)據(jù)的有效傳輸是解決問題的關鍵�；诋斍把芯楷F(xiàn)狀提出一個適合復雜交通環(huán)境的路由算法仍面臨許多挑戰(zhàn)。首先,車輛移動速度快,導致車輛之間的通信鏈路可靠性較差。其次,在VANET中,由于車輛的移動而導致網(wǎng)絡拓撲結(jié)構(gòu)的不斷變化,使得車輛之間的單跳通信鏈路無法維持遠距離多跳數(shù)據(jù)的傳輸。第三,車輛之間的通信必須在其通信范圍內(nèi),車輛間這種機會性的通信使得遠距離數(shù)據(jù)傳輸?shù)貌坏娇煽勘Ｕ喜⑶視r延較長。針對VANET的特點,基于地理位置的路由比較適用于VANET環(huán)境。然而目前的路由方案主要考慮車輛的地理位置和運行方向等,忽視了交通道路對于車輛行駛的限制,以及駕駛員對于路徑選擇的偏好等因素。由于在實際交通環(huán)境中,車輛并不是漫無目的的隨機運動,而是沿著交通道路從一個始發(fā)地到目的地。因此,道路受限對發(fā)掘車輛軌跡信息有關鍵的作用。如果獲得車輛行駛軌跡,便等同于得到了VANET節(jié)點之間數(shù)據(jù)轉(zhuǎn)發(fā)的時機。本文結(jié)合道路受限因素提出一種基于GPSR的VANET路由改進方案,用來更有效地找到數(shù)據(jù)轉(zhuǎn)發(fā)的路徑。本文通過分析數(shù)據(jù)轉(zhuǎn)發(fā)過程中通信鏈路斷裂的原因,利用路徑約束提出路由算法的啟發(fā)式規(guī)則,總結(jié)車輛軌跡的規(guī)律性并建立運動模型,通過判斷下一跳轉(zhuǎn)發(fā)車輛是否位于交通路口處提出不同的路由選擇策略。本文利用NS2對實驗結(jié)果進行驗證。首先在NS2中基于GPSR源碼進行改進,利用C++代碼實現(xiàn)新路由策略的邏輯機制,將改進后的代碼在NS2目錄下重新編譯。然后利用SUMO模擬車流信息,最后將車流信息嵌入到NS2的Tcl腳本中,對生成的trace文件進行整理分析。針對分組投遞率、端到端時延及吞吐量等指標對本文方案與GPSR協(xié)議進行比較,結(jié)果顯示本方案的實效性和高效性均有提高。
[Abstract]:As a hot topic in wireless network field, VANET (vehicle Ad-hoc Network) aims to complete communication between vehicle and vehicle or vehicle and roadside facilities, and the path to complete communication is determined by routing algorithm. Because the vehicle is usually moving at high speed, the traditional routing algorithm of static network is no longer suitable for VANET. Therefore, the key to solve the problem is to propose a new algorithm in VANET to complete the effective transmission of data. Based on the current research situation, it is still facing many challenges to propose a routing algorithm suitable for complex traffic environment. First of all, the fast moving speed of vehicles leads to poor reliability of communication links between vehicles. Secondly, in VANET, because of the moving of vehicles, the network topology changes continuously, which makes the single hop communication link between vehicles unable to maintain the transmission of long-distance multi-hop data. Thirdly, the communication between vehicles must be within the range of their communication. This kind of opportunistic communication between vehicles makes the long-distance data transmission not reliable and the delay is longer. In view of the characteristics of VANET, geographical location based routing comparison is suitable for VANET environment. However, the current routing scheme mainly considers the location and direction of the vehicle, neglects the restriction of the traffic road to the vehicle, and the preference of the driver for the route choice and so on. Because in the actual traffic environment, the vehicle is not aimless random motion, but along the traffic road from a place of origin to the destination. Therefore, road restriction plays a key role in excavating vehicle track information. If the vehicle track is obtained, it is equal to the time of data forwarding between VANET nodes. In this paper, we propose an improved VANET routing scheme based on GPSR, which is used to find the path of data forwarding more effectively. In this paper, by analyzing the reason of communication link breakage in the process of data forwarding, the heuristic rules of routing algorithm are proposed by using path constraints, and the regularity of vehicle trajectory is summarized and the motion model is established. Different routing strategies are proposed to determine whether the next hop forwarding vehicle is located at a traffic junction. NS2 is used to verify the experimental results. In NS2, the source code is improved based on GPSR, and C code is used to implement the logic mechanism of the new routing strategy. The improved code is recompiled in the NS2 directory. Then, the traffic information is simulated by sumo, and the traffic information is embedded into the TCL script of NS2, and the generated trace file is analyzed. The proposed scheme is compared with the GPSR protocol in terms of packet delivery rate, end-to-end delay and throughput. The results show that the effectiveness and efficiency of the proposed scheme are improved.
【學位授予單位】：吉林大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：U495;TN929.5

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相關碩士學位論文 前2條

1 張建偉;VANET環(huán)境下基于路徑優(yōu)先級的交叉口自適應控制[D];大連理工大學;2015年

2 龐亮;VANET環(huán)境下基于道路受限的路由方案研究[D];吉林大學;2017年

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本文編號：2074006