CUHK electronic theses & dissertations collection

An active sensor network is a wireless network comprising a large number of mobile sensor nodes. This dissertation deals with a general model of active sensor network, heterogeneous sensor network, where sensor nodes may have different sensing ranges. The deployment problem aims at relocating a large set of sensor nodes from arbitrary locations to give a connected, hole-free and locally maximized sensing coverage of the entire network.The major contribution of this dissertation lies in four aspects. First, it is the first work that solves the deployment problem for optimal deterministic coverage of heterogeneous sensor networks, while most existing works limit their problems on stochastic coverage and homogeneous sensing model. Second, this work envisages the use of a generalized Voronoi diagram, the power diagram, as a novel solution to geometrically analyse and visualise the coverage of a heterogeneous sensor network. Third, it an original work that applies circle packing on sensor network deployment, and analyses and proves a number of geometrical properties of circle packing. Fourth, all methods provided in this dissertation are based on localized and distributed computation; no centralized processor or common data fusion platform is assumed to exist.This dissertation gives an algorithm to solve the self-deployment problem. It is composed three parts. In the first part, the logical topology of the sensor network is constructed as triangulation by three distributed protocols: localized Delaunay triangulation, redundant boundary edge pruning and local edge swapping. Second, the sensor nodes self-deploy to new locations that are calculated using a circle packing algorithm. The dissertation shows that the homomorphism between Voronoi and power diagrams is necessary and sufficient for the equivalences of power Delaunay triangles to Delaunay triangles. This result allows the network to preserve a unit Delaunay triangulation by localized re-triangulations among a small number of nodes. Third, the sensor nodes further relocate themselves based on a virtual force approach to eliminate all existing coverage holes and redundant overlaps.This dissertation studies the problem of active sensor network deployment. It focuses on self-deployment, localized and distributed computation and coverage maximization of heterogeneous sensor networks.Lam, Miu Ling."February 2008."Adviser: Yun-hui Liu.Source: Dissertation Abstracts International, Volume: 70-03, Section: B, page: 1757.Thesis (Ph.D.)--Chinese University of Hong Kong, 2008.Includes bibliographical references (p. 152-158).Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.Abstracts in English and Chinese.School code: 1307