黃政吉Huang, Jeng-Ji蘇雯琪Su, Wun-Ci2019-09-032012-7-182019-09-032012http://etds.lib.ntnu.edu.tw/cgi-bin/gs32/gsweb.cgi?o=dstdcdr&s=id=%22GN0699750161%22.&%22.id.&http://rportal.lib.ntnu.edu.tw:80/handle/20.500.12235/95854車載網路（VANET）為智慧型運輸系統（Intelligent Transportation System, ITS）之應用的發展關鍵，其中用於提升行車安全的車輛安全應用最為重要。安全應用之運作方式，是由發生事故之車輛不斷地利用訊號廣播，以達到警告周遭車輛之目的。本論文以高速公路為探討環境，分析因車流密度造成網路不完全連接而導致的訊息傳送延遲，除了使用雙向車道之環境特性以減少網路修復時間，並以更為精準之機率密度計算方式，討論其網路修復時間，以提供數值化之車輛隨意網路延遲解析。模擬結果顯示，本論文提出之分析作法與模擬結果高度相符，不但修正過去文獻使用之分析方式於低密度環境下產生之錯誤結果，並且也大幅改善延遲分析之準確度。The development of VANET is crucial for the applications of Intelligent Transportation System (ITS) to, e.g., improving safety of driving. That is, warning messages can periodically be broadcast to inform neighboring vehicles when an emergency event occurs. In this thesis, we analyze the transmission delay of warning messages resulting from the disconnected network when traffic density is low on a bidirectional highway. When a disconnection occurs, vehicles moving in the opposite direction help to restore the connectivity of VANET. We provide accurate analysis to calculate the re-healing time, the average time during which a disconnected VANET can be restored. Simulation result shows that our analysis achieves very accurate results.車載隨意網路專用短距離通訊網路連接性安全訊息路間單元VANETsDSRCnetwork connectivitysafety messageroadside units (RSUs)