低成本感測網路覆蓋保證佈置法

Abstract

感測網路(Sensor Networks)環境技術應用已日益成熟，為能提供感測網路佈置(Deployment)擁有最佳覆蓋率(Coverage)與節省降低成本，有效且快速之感測網路佈置法已成為一項基本但極為重要的研究議題。針對無線感測網路佈置，以往研究中大部份都是採用隨機佈置(Random Deployment)、圖形理論(Graphic Theory)佈置法或先決式(Deterministic)佈置法等方式進行佈置感測網路環境，相關佈置法不多且無法應用於大型感測網路環境下。大多數佈置法若保證單一層覆蓋(1-covered)時，則其時間複雜度(Time Complexity)差異不大，但若需保證k層覆蓋(k-covered)時，其佈置成本與時間複雜度(Deployment Costs and Time Complexity)將成為相當重要之考量議題。針對佈建成本與效率，本論文提出九個因子(Factors)評估所建置之感測網路，並且提出兩個簡易覆蓋保證方式進行各種地形佈置，其中包括慢速起始法(Slow-Start Method)與方型圍繞法(Square-Encircled Method)。透過本論文所提之方法，感測網路之佈置則不需再經過先前分析(Pre-Analysis)或進行大量計算即可有效避開障礙物，達到保證k層覆蓋之成效。本論文並探討利用三種不同覆蓋大小之感測器(Sensors)結合所設計之兩種佈置方式，實驗結果證明可以達到最小重疊(Minimum Overlapping)感測區域佈置進而降低佈置成本與時間複雜度。One of the fundamental issues in the wireless sensor networks is the deployment problem. In past researches, three deployment methods are widely used, which are the random deployment, the computed deployment and the deployment by graphic theory. All of them have high time complexity and unsuitable for the k-covered sensor deployment. To effectively evaluate the performance of wireless sensor networks, this study firstly concludes nine evaluation factors. Furthermore, to achieve scalable and efficient deployment, this study proposes two novel topology deployment methods, which are the slow-start and square-encircled methods. Without the necessity of pre-analyzing unknown environments, the proposed deployment methods successfully prove a k-covered scenario with minimal overlapping area using three different power capabilities of sensors. Finally, the simulation results reveal the efficiency and effectiveness of the proposed deployment schemes.