在城市環境下交通號誌對網路建設佈局之影響

Abstract

近幾年，車用網路 (Vehicular Ad hoc Network，簡稱VANET)愈來愈被廣泛討論。應用層面也愈加深廣。例如在緊急訊息的傳送，實際路況的估測，商店街廣告訊息的廣播接收，車與車及車與公共網路建設之間的傳送，這幾個研究議題也時常被加以討論。車用網路之快速的拓樸變換，時常造成連接的中斷。另外有一重要特性，即交通號誌造成車子在道路上分佈的變化，則為本篇論文的重要關鍵。 網路建設的佈局，若是在有交通號誌的情況下，考慮紅綠燈的特性，則與以往為了可同與橫向及縱向的車輛連接，只單純佈建在十字路口有所不同。本篇論文即探討在有交通號誌的情況下，網路建設的佈局該如何作轉換，能達到更大的效益，增加整個網路的連接機率。也探討在對稱與不規則的網路拓樸中，此佈建對策應有如何的相應調整。根據模擬結果可以發現，我們所提出的公共網路建設佈局對策相較於傳統的十字路口佈建法，無論是在格狀或不規則的拓樸中，都有更好的連接機率。

In recently years, vehicular ad hoc network (VANET) is more and more popular in network research area. There are many applications in this field. Like the waining message dissmination Disseminatio, real time traffic estimation, shopping street commercial information broadcasting, and vehicle-to-vehicle and vehicle-to-RSU communication. The fast changing topology will lead intermittent network connection. Furthemore, the keypoints of our work, the characteristics traffic lights will let different vehicles distribution on the roads. The RSUs placement strategy, if with traffic lights, we consider its characteristics to offer a new placement strategy that is different from the originally placing at intersections. We research how to advance the the RSUs placement strategy to improve the mobile nodes coverage connectivity ratio. We also investigate how to adjust the placement strategy in symmetric and irregular topology respectivity. From the simulation results, we can find the RSUs placement strategy we offered has better performance than just place RSUs at intersections whether in grid or irregular topology.