JIE JIANG, ZHEN SONG, HEYING ZHANG AND WENHUA DOU
School of Computer Science, National University of Defense Technology, Changsha, P.R.China, E-mail:{ jiangjie,songzhen} @nudt.edu.cn

Reducing power consumption to extend network lifetime is one of the most important challenges in designing wireless sensor networks. One promising approach to reduce energy consumption is node scheduling, which keeps only a subset of sensor nodes active and puts others into low-powered sleep status. However, most of previous work on node scheduling considers only sensing coverage. In this paper, we consider the sensing coverage and communication connectivity simultaneously and address the issue of constructing a minimal connected cover set in wireless sensor network. We propose a centralized, Voronoi tessellation (CVT) based algorithm to select the minimum number of active sensor nodes needed to cover the region of interest (ROI) completely. The constructed sensor set is connected when sensor node's communication radius is at least twice of its sensing radius. For other situations where the CVT algorithm alone cannot maintain the network connectivity, we design a Steiner minimum tree (SMT) based algorithm to ensure the network connectivity. Finally, we evaluate the performance of the proposed algorithms through numerical experiments.