Wireless Sensor Network Coverage And Control

With the development of sensor technology, micro-electromechanical systems, modern networking and wireless communication technology, wireless sensor network have emerged. Wireless sensor network is composed of the micro-sensor nodes which are energy limited and have sensing, computing and communicating capabilities through self-organized manner. Network coverage is the core issue of wireless sensor network. In wireless sensor network of high-density deployment, network coverage control technology through density control, node scheduling and other means to reduce the number of active nodes and let the redundant nodes work in turn without affecting the performance of network coverage, so as to extend the network life time. Network coverage control algorithm will have a direct impact on the network monitoring quality and survival time.In this paper a variety of typical coverage control algorithms for wireless sensor network are introduced and analyzed. On the basis of the analysis, a coverage guarantee sensing radius adjustment algorithm is proposed. In the algorithm, a node adjust its sensing radius as small as possible under the premise of ensuring network coverage, only according to the location and sensing radius information of its neighbor nodes. Under the target network model, the effects of coverage control and energy consumption of the algorithm are simulated and analyzed. Simulation results demonstrate that the algorithm act well on the network coverage control. It greatly reduced the network coverage redundancy degree without affecting the performance of network coverage. On energy consumption, the average energy consumption of coverage region of the network is reduced much lower than the original after the sensing radius adjustment. Considering the sensor node in the sleep state uses less energy, a node scheduling algorithm NSASR based on sensing radius adjustment is proposed in this paper in order to further extend the network survive time. In NSASR algorithm, the node whose sensing radius is adjusted to zero can turn into sleep state in order to save energy. In this paper, NSASR algorithm is realized combining with GPSR routing protocol and simulation experiments are made. Simulation result prove that NSASR algorithm has better performance than DiTian algorithm in the number of active nodes, redundant coverage degree control, and network survival time. Finally, as the expansion of NSASR, a K coverage algorithm is proposed. We also provide the corresponding control scheme for the issue that partial region has high degree of coverage redundancy in the K coverage algorithm.