Simulation System And Optimize Algorithm For Sensor Sleeping/Wake Scheduling

Wireless Senor Networks (WSNs) are usually deployed to monitor complex dy-namic environment, which has brought challenges for the network systems with re-spect to high adaptability and self-organizing. In order to maximize the lifetime of a sensor network system, the mechanism of node sleep/wake scheduling is usually used to save energy. That is, only a set of sensor nodes are selected to be in active status while maintaining sensing coverage and network connectivity. Besides, a convenient simulation system is designed to study node sleep/wake scheduling for sensor net-works.A simulator system for node sleep/wake scheduling is designed and the schedul-ing scheme is proposed in this paper. The system is based on multi-thread model to simulate via communicating among nodes. It can simulate varieties of working processes of a WSN that includes the communication, sensing, node move and sleep scheduling. The system is implemented on the Java platform which works efficiently by the thread poll technology and memory sharing model to control the communica-tion among nodes. Further, users can define the commands and messages which are designed by interpreter pattern. A coverage-guaranteed distributed sleep/wake sche-duling scheme is presented with the purpose of prolonging network lifetime while gu-aranteeing network coverage. Our scheme divides sensor nodes into clusters based on sensing coverage metrics and allows more than one node in each cluster to keep active simultaneously via a dynamic node selection mechanism. Further, a dynamic refusal scheme is presented to overcome the deadlock problem during cluster merging process, which has not been specially investigated before. The simulation results illu-strate that our scheme outperforms some other existed algorithms in terms of coverage guarantee, algorithm efficiency and energy conservation.