本論文探討車載網路(vehicle ad hoc networks, VANETs)中，一部車輛傳遞訊息到它的下游車輛時所需經歷的延遲。過去的相關研究已計算重建網路斷開之恢復延遲(rehealing delay)；然而，它們多半只考慮上游的訊息傳遞。本論文延續我們之前關於下游訊息傳遞端到端延遲(end-to-end delay)的分析與討論，但採用不同的計算方法。這是因為我們之前的計算方法是針對長距離的端到端訊息傳遞;當端到端訊息傳遞為短距離時，則該分析方法將可能有很大的誤差。針對短距離之端到端訊息傳遞，本論文將首先計算修復單一網路斷開的恢復延遲機率分布。由於該計算可能包含數個隨機變數的加總，因此將利用Laplace轉換與其反轉換。數值結果顯示我們的計算是十分準確的。

The delay incurred during which messages are transmitted by a vehicle to its downstream vehicles in a vehicle ad hoc networks (VANETs) is analyzed in this paper. In related works the recovery delay of rebuilding network disconnection has been calculated; however, most of them only consider upstream message transmissions. This work continues our previous research but uses a different analytical method. It is because our previous calculation method, in which the central limit theorem is used, is suitable for long distance message transmissions. When message transmissions are short-distance, previous analysis may lack good accuracy. Therefore, the recovery delay probability distribution for repairing a single network disconnection will first be calculated in this paper. Since the calculations include the sum of random variables, Laplace transform and its inverse transform will be used. Numerical results show that our analysis is very accurate.

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