在沒有基地台服務的場景下以公共安全為目的之裝置對裝置同步方法

Abstract

在此篇論文中，我們提出了在沒有基地台服務的情況下裝置對裝置同步程序的方法。由於天災發生時造成了基地台故障的情形，在此情形下我們沒有基地台可以去服務裝置做通訊。然而，我們可以透過裝置對裝置通訊技術做裝置對裝置直接通訊和廣播通訊，但目前主要是希望用於傳送公共安全的資訊，包括災情的狀況和救災資訊。做裝置對裝置通訊前必須先使得裝置之間同步，而同步程序的好壞會直接影響到通訊的品質。因此，我們提出了一個裝置對裝置同步程序，其目標為增加裝置對裝置同步區域的範圍與減少每一個裝置身邊不同步的裝置數量。經模擬結果顯示我們成功達到了我們的目標。

In this thesis, we proposed an approach of D2D synchronization procedure for out-of-coverage scenario. When all of the cellular nodes become fail due to public disaster situations, it is likely that some eNBs are unable to serve UEs and in out-of-coverage scenario, but we can use the D2D direct communication or broadcast communication to deliver information about public safety requirement. Synchronization procedure is important factor that affects performance of communication. Therefore, our goals of D2D synchronization approach are to enlarge the synchronization area for D2D communication and reduce the number of asynchronous timing synchronization sources surrounding a device. The simulation results show our goals are achieved successfully.