一個整合普適計算環境的運作機制之研究---無線感測網路上省電之資料管理技術之研究

Abstract

隨著無線感測網路技術的進步，未來生活環境中，將佈滿感測器，用以監測並蒐集和生活環境相關的資料。此外，感測器間亦會利用無線網路互相連結形成一無線感測網路。然而無線感測網路具有低耗電、不具龐大記憶單元、低無線網路通訊頻寬及硬體運算能力較弱等限制。因無線感測器之限制，使得在無線感測網路上的資料處理、查詢與傳統分散式系統有所不同，且這些限制使得如何在有限的資源內，提供低耗電，有效率之資料處理與查詢成為日漸重要的課題。 本計畫為一為期三年之計畫，探討在無線感測網路下，如何有效率處理使用者的查詢。第一年的工作重點在於設計省電的位置管理(location management)機制，目的在於設計省電的物計位置估計查詢處理方法。具體的工作內容包括(1)研發階層式之位置伺服器(Hierarchical Location Servers)架構；(2)設計處理估計查詢之訊息流程：(3) 研發位置伺服器的移動與複製演算法及(4)設計更新訊息的多重播送(multicast)方法。在第二年裡，我們將著重於感測器讀數的查詢。我們將考慮在使用者能接著某種程度誤差的情形下，如何有效率地收集或查詢感測器的讀數。具體的工作內容包括(1)設計合適的關聯性評估公式；(2)設計感測器群集演算法；(3)設計多代表點群集演算法及(4)設計群集維持(maintenance)機制。在第三年的研究中，我們將探討在大規模的感測網路上如果有效地進行資料傳播(data dissemination)。主要工作內容包括(1)設計角色化階層式資料傳播機制；(2) 設計事件偵測機制之流程；(3) 設計Sink 節點位址註冊機制之流程與(4) 設計資料傳輸機制之流程。近年來，無論工業界或是學術界對於無線感測網路均相當的重視並且投入大量的人力及研究，無線感測網路於農業應用極為適合，我們相信此計畫之執行，將可研發出適用於無線感測網路系統中的資料處理前瞻性技術。

The growing advance in wireless communications and electronics makes the development of low-cost and low-power sensors possible. These sensors are usually small in size and are able to communicate with other sensors in short distances wirelessly. A sensor network consists of a number of sensors which cooperates with one another to accomplish some tasks. Sensors can be deployed either in a random or in a predetermined manner. Since being self-organized, sensors are able to form a sensor network automatically. Due to the characteristics of wireless communication and configuration-free deployment, sensor networks are suitable for various application areas including inventory management, product quality monitoring and disaster area monitoring. This project aims at designing energy-efficient data management schemes in wireless sensor networks. Our primary goals include (1) developing a hierarchical location management architecture, (2) devising approximate query processing schemes, and (3) designing location server moving and replicating algorithms and (4) devising location update mechanism. Next, by exploiting the spatial correlation among sensors, we will (1) develop a similarity measure metric suitable for wireless sensor networks, (2) design a hybrid sensor clustering algorithms, (3) design an algorithm to select multiple representatives for each cluster, and (4) devise a cluster maintenance mechanism. Then, we will develop an energy-efficiency data dissemination scheme on large-scale sensor networks. Our goals includes (1) proposing a role-based data dissemination scheme, designing (2) an event detection scheme, (2) a sink registration scheme and (3) a data forwarding scheme for the proposed data dissemination scheme. In view of the increasing attention on wireless sensor networks, we strongly believe this project is very timely and will deliver results of both theoretical and practical importance.