WAVE/DSRC電子收費系統在預約區之分析與驗證

Abstract

智慧型運輸系統(Intelligent Transportation System，簡稱ITS)是整合資訊、通訊與管理等軟硬體設施之交通運輸系統，其能提升用路安全與交通服務之品質，而目前在高速公路所使用之電子收費系統(Electronic-Toll-Collection System，簡稱ETC)亦是ITS中重要的應用之一，根據其架構之類型可區分成單一車道與多車道自由流，而後者架構之電子收費系統為目前世界各國發展之趨勢。在我們設計之WAVE/DSRC電子收費系統，其將通訊之區域細分成預約區與交易區，車輛進入預約區時會向控制頻道(Control Channel, CCH)發出預約之請求，一旦請求成功便會分配一服務頻道(Service Channel, SCH)給予車輛，並在進入交易區後使用該服務頻道完成交易扣款之程序。在本篇論文中，我們針對車輛在預約區能成功預約到頻道之機率做數學分析，並計算預約區長度與預約成功之機率。最後使用Estinet 7.0進行實驗模擬，並與我們已建立之數學模型做比對，結果顯示兩者之數據相當接近，以此佐證我們所提出的數學分析具有一定之準確性。

Intelligent Transport System (ITS) is a traffic system which combines with information, communication, management, software and hardware devices, and the main purpose is to enhance the road-safety and quality of traffic service. One of important applications in ITS is Electronic Toll Collection (ETC). In accordance with the architectures, ETC system can be divided into two types, which are Single-Lane Free-Flow (SLFF) and Multi-Lanes Free-Flow (MLFF), and the latter architecture is the main worldwide trend for development. In our proposed system, the ETC area is divided into reservation zone and transaction zone. A vehicle will send request message on control channel (CCH) when it enters reservation zone. Once the request message is sent successfully, then the system will allocate a service channel (SCH) to this vehicle. After that, the vehicle will use this SCH for transaction process. In the thesis, we propose a mathematical analysis for computing the probability that a vehicle reserves a CCH successfully. Finally, we conducted simulation experiments by Estinet 7.0 simulator to show the feasibility of the proposed ETC system. We also compared simulation results with the analysis results to show the correctness of the proposed mathematical model.