無線廣播系統下主動式的資料接收器的設計與評估

在無線資訊系統中，廣播磁碟技術已經變成一個熱門的資料散播的方式。然而，當有些因素，如週期性的斷線發生時，廣播的策略就需要告訴行動通訊使用者一個合適的存取廣播資料的方法。本篇論文中，我們提出一個新索引架構AMI (access mode Indicator)，使用者可以根據回復時間(turnaround time)決定連線(active)與睡眠(sleep)的時間週期。我們的目標是發展一種利益導向(benefit-oriented)的資料擷取協定，讓行動通訊使用者在有限的回復時間(turnaround time)內能夠在消耗少量電源的情況下，取得對行動使用者而言更多有價值的資料。經由實驗評估與驗證，我們提出的AMI索引架構各方面的效能優於適用於廣播環境的改良式廣播索引架構，特別在等待時間(waiting time)的節省比率更高達75%。因此，運用我們的方法使用者不但能利用更少的電力得到更多有價值的資料，而且等待時間的減少代表能得到更快速查詢結果回應，那麼使用者可以將節省下來的時間用來處理其它的應用。

關鍵字

行動資料管理；行動計算；資料庫管理系統；資料廣播；無線資訊系統

並列摘要

Broadcast disk technology has become a popular method for data dissemination in wireless information systems. However, when the factors such as intentional periodic disconnection are involved, a broadcast strategy needs to actively tell the mobile host (MH) a suitable access mode for retrieving the broadcast data. In this paper, we propose a new broadcast indexing structure AMI (Access Mode Indicator) such that mobile client can decide his active and sleep time period by his turnaround time. Our goal is to develop a retrieval protocol so that a mobile host can retrieve more valuable broadcast information by consuming less power of a mobile device at a turnaround time. By performance evaluation shows that AMI substantially outperforms the traditional indexes (enhanced for wireless broadcast) and especially gets 75% saving on waiting time. Since，apply our approach mobile client can retrieve more valuable broadcast information by consuming less power. The decreasing waiting time represents mobile clients can get query results more quickly and then they can have more time to do other applications.