交通號誌在城市環境中對車用網路路由協定之影響及協定之設計

Abstract

車用網路 (Vehicular Ad hoc Network，簡稱VANET) 是近年最熱門的研究領域之一。車用網路可歸類為移動隨意網路(MANET)的一種，但其中幾項特性與移動隨意網路有著極大的差異。因此許多研究便針對車用網路的環境特性來設計協定，而路由協定也是廣為研究的一部份。 從已發表的車用網路路由協定相關論文可以得到協定設計的方向，都是朝著以路口為基礎的路由來發展其協定的設計。相對於先前其他的研究，我們發現「交通號誌」完全沒有拿來被討論過。然而交通號誌在城市環境中扮演者重要角色：影響拓撲分佈的主因之一。因此，我們想設計出更適合在這樣的網路環境中所使用的路由協定，來提升網路連線的機率、時間及可靠度。 根據模擬結果與其他已發表的車用網路路由協定比較，我們所提出的路由方 法在UDP的應用上有著相對低的封包延遲、在相同時間內有著較高的送達率;在TCP的應用上，有著相對高的吞吐量。 我們提出了一個新的車用網路路由協定，其適用於城市環境下。並且更考慮城市環境的特性對網路的影響，設計出更適合此環境的路由協定。我們的路由協定從模擬結果也可發現有著較好的效能。

Vehicular ad hoc network (VANET) is one of the most popular research areas in recent years. It can be regarded as one type of MANET but with some great differences. Many researches propose new protocols in accordance with these features, and routing protocols are also one part of them. From the previous proposed works, we can get the routing protocol design guide. Most of them are intersection based routing. Contrast to the previous works, we find out that the traffic light has never been discussed before. However, traffic light plays an important role in urban area. It affects the vehicles distribution and the network topology. So we want to design a routing protocol which is more suitable for such kind of scenario and improve the connected probability, connection time and reliability. The simulation results show that our routing protocol outperforms than other protocols. We achieve shorter average delay, higher delivery ratio in certain time and higher TCP throughput. We proposed a new VANET routing protocol which is suitable for urban area. We consider the characteristics of this kind of environments and design a routing protocol which performs better than other existing routing protocols.