Wireless Multimedia Sensor Network Path Monitoring Capability Study

Wireless Multimedia Sensor Networks(WMSNs),developed fromtraditional Wireless Sensor Networks(WSNs), is a novel sensor networkintegrating sensation functions of multimedia information.This WMSNs feelsthe physical world with its sensors, it connects the logical information worldwith the object physical world, changes the way that human recognize thephysical world,and spans a wide spectrum of applications from military toenvironmental monitoring, from medical health to intelligent family.The coverage problem is a key problem and is very important to thetheoretical study and applications in WMSNs, and the path detectability is anindirect measure of the quality of coverage in the networks. By studying thepath detectability of WMSNs, the extent of coverage of a target in themonitoring domain is received, and nodes are re-deployed or added in themonitoring domain in order to ensure the measurement datareliability. Thedissertation studies the detection coverage and the worst and best casecoverage,and then analyzes the path detectability in different coveragestrategy.The thesis includes the following aspects.The research contents and the categories of the path detectability problemare surveyed.The network evaluation metrics are listed and related works arestated.Focusing on the detection coverage, the target does not know the locationof the sensor nodes.Considering the sexual and mobility of sensing area ofmultimedia sensor and analyzing the node sensing area and may sensing area,the delay and non-delay sensing model are established, and then the pathdetectability of WMSNs in different sensing model is studied.Focusing on the worst-case coverage, the target knows the location of thesensor nodes.The appropriate model is established based on the relationshipbetween the sensor sensing range and path detectability,the critical radius ofthe nodes are accessed by analyzing the perception of the upper and lowerbounds of the sensing range,as well as the critical mass and the critical density.A path-finding algorithm is implemented by combining Voronoi diagram and graph search algorithms, the weak region of the WMSNs is found bydiscussing the choice selection of the minimum coverage path under the sensordensity, and a strategy of the coverage enhancement is proposed based on theweak region.Focused on the path detectability under the best-case coverage in wirelessmultimedia sensor networks, a path-finding algorithm is implemented bycombining Delaunay triangulation and graph search algorithms. According tothe perception of directional characteristics of multimedia nodes,we analyzethe restrictive relationship between node properties and path detectability byusing centroid replaced fan perception model.The algorithm is simple and easyto be realized, and extensive Simulation with an target and a sensor networkconfirm the validity of the approaches.