車聯網(Vehicular Ad-Hoc Networks)是連接具有移動性拓撲結構的移動車輛的隨意網絡，也因為這樣在連接性方面穩定性會比較低，借助網路(Internet)使得道路上的車輛可以與其他已連接上網路的車輛進行通信，藉由這種方法來分享彼此的車況來達到安全且有效率的駕駛，車對車(V2V)與車對基礎設施(V2I)是其主要的架構，當中也有許多問題值得探討。 但是，在某些道路上因為地形或建築物的關係而導致有視線遮蔽(Non line of sight)的情況，這會造成較大的封包遺失率從而導致封包接收率較低，因此我們在這篇論文提出了一個解決方法，透過高車(Tall Vehicle)來提高天線的高度從而改善傳播的效能，讓高車使用AODV (Ad hoc On-Demand Distance Vector Routing)進行群播將資訊傳給群內其他的車輛，使用不同的速度並加入Fading環境更加嚴峻，來比較有無使用高車傳播的差異，藉此證明高車可以明顯的優化在NLOS狀況下的傳播。 ;Vehicular Ad-Hoc Networks is an organizational network that connects mobile vehicles with mobile topology. Because of this, the stability of connectivity is relatively low. With the help of the Internet, vehicles on the road can communicate with other ones. Vehicles connected to the Internet communicate to achieve safe and efficient driving by sharing each other’s conditions. Vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) are the main architectures. There are many issues about V2V and V2I worth discussing. However, on some roads, due to the trees or buildings, there is a Non-line of sight (NLOS) situation, which will cause a large packet loss rate and lead to a lower packet reception rate. So in this thesis, we propose a solution to increase the height of the antenna through the Tall Vehicle to improve the propagation efficiency. The Tall Vehicle multicasts information with AODV (Ad hoc On-Demand Distance Vector Routing) to communicate with other vehicles in the group. By using different speeds and the addition of the Fading channel to make the environment worse, we can compare the difference between using tall-vehicle and not using it to prove that the tall-vehicle can obviously optimize the propagation under NLOS conditions.
