隨著車載網路 (VANET) 的發展，車輛與基地台間傳輸品質的重要性也與日俱增。當基地台的佈建不夠密集而造成無線訊號強度不足的同時，車輛與基地台間資料傳輸的狀況便成了值得探討的議題。本篇論文提出了單一基地台內資料傳輸成功率(Session completion probability) 的數學模型做為傳輸品質的指標，同時更進一步探討不同的道路環境以及不同的傳輸方式對傳輸成功率的影響。為了使此數學模型更貼近實際的傳輸狀況，我們考慮了傳輸過程中可能會造成的損失以及車輛與基地台連線所花費的時間。最後設計了模擬來驗證所提出的數學模型的正確性，並且觀察模型中各種環境參數對於傳輸成功率所造成的影響。

With increasing popularity of vehicular networks, the need for estimating the quality of networks transmission process is evident. In this thesis, we propose session completion probability models to analyse the quality of vehicular networks. It is the probability that a session of a vehicle can be finished during the network connection time when the vehicle passing through an AP's coverage area. Refer to the transmission process, we consider packet loss and retransmission rate, the DCF technique, and the association delay when the wireless equipment of a vehicle connects to an AP. For the vehicle travel time in an AP's coverage area, we use an estimation method to find the best distribution of the travel time. In the proposed models, we analyse two scenarios and two session transmission methods. Scenarios we analyse are APs in the urban area and the highway scenarios. Also, sessions we evaluate are the random download session for users and the early download session for vehicular network systems. Moreover, we use simulation experiments to validate the proposed analytic model. Finally, we discuss the performances in detail of each figure.

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