Abstract：In wireless sensor networks,the random deployment of sensor nodes causes the overlap of sensing areas and hence leads to the redundancy of sensing area.With regard to the applications which require a partial coverage of target scenario,how to activate as few nodes as possible to meet the partial coverage requirement and to guarantee the network connectivity is a difficult problem.In this paper,the target scenario is divided into several areas.In each area,the sensing nodes are selected based on the maximum independent set,and then a tree structure is constructed across all the areas to collect data.First,the sensing area and the redundancy of sensing area are calculated by using the gird model,and the maximum independent set is computed accordingly.Then few nodes are added or deleted by considering the redundancy of sensing area and the coverage contribution in order to meet the monitoring requirement.Finally,a small number of sensing nodes are activated to achieve partial coverage.Furthermore,all the sensing nodes in different areas are combined together to construct a tree to connect the sink and all areas for data collection.For those areas which cannot join the tree,some supplement transmission nodes are activated to guarantee the connectivity.Except for the sensing nodes and the supplement transmission nodes,other nodes turn to sleep state so as to save energy and prolong the network lifetime.Simulation results show that,compared with other approaches,this scheme selects fewer nodes to meet the partial coverage requirement and thus reduces the energy consumption.
2020, Vol. 41 
