Research On Coverage-Enhancing Algorithm For Wireless Multimedia Sensor Networks

Wireless Multimedia Sensor Networks (WMSNs) is composed of the video, audio, image sensor node which has the ability of computation, storage and communications; it forms the distributed perceptive networks by self-organizing and has the ability of perceiving, collecting, processing and transmitting the multimedia information by cooperation in the area of covering. WMSN not only strengthen the applications of traditional sensor network, but also has wide application prospects in military, civil and commercial field.Coverage control and network deployment is the basic problems in researching Wireless Multimedia Sensor Networks, and it not only reflects the physical world perception scope by the network, but directly affects the whole network of service quality. In traditional sensor network, covering control and deploy technology has accumulated more research achievements, but most studies focused on the Disk sensing model which is designed by node coverage method in planar for the entire sensor. In recent years, with the emergence of multimedia sensor network, the perception of node has perspective and direction, and covering control method has not using coverage for Wireless Multimedia Sensor Networks, it is urgent to design new sensing model and covering control method.Because of the deployment of the randomness of sensor network, after the node of Wireless multimedia sensor network deploy randomly, it is apt to cause the network of unreasonable, and cannot deploy completely covering or maximize cover the entire area. For example, it forms blind hydrophobic because the distribution of node is too focused, or it forms overlap area because the distribution of node is too evacuation. Therefore, in the initial deployment to sensor network, it needs to adopt enhancement, strategies to improve the network covering quality and then optimize network service quality.The node of Wireless Multimedia Sensor Networks has the characteristic of direction and mobility. Therefore, the coverage-enhancing algorithm in the traditional wireless sensor network has not used in Wireless Multimedia Sensor Networks. Because the nodes of sensors network deploy irrational and uneven after initial deployment, this thesis hypothesis sensor node exist between gravity or the virtual repulsion force, it makes the node distribution reasonable and uniform by the different virtual force which adjust the position of sensor node, preventing the node of sensor network deploy too close or sparse after initial deployment. It achieves the maximum coverage by adjusting the work direction of directional sensor node through particle swarm optimization algorithm, and it maximizes coverage with the least mount of sensor nodes. Through the experimental simulation, in a random deploying way, we compared the initial deployment and based on virtual force and the particle swarm optimization coverage, and we analyses the performance influence by the radius of a sensor node and the node number. Through experiments, it showed that the algorithm based on virtual force and particle swarm algorithm has very good effects in the cover enhancement algorithm enhancing the network coverage.