Energy-Efficient Methods to Maximize Network Lifetime in Wireless Sensor Networks with Adjustable Sensing Ranges

we study the target coverage problem for wireless sensor networks where every sensor node is capable of adjusting its sensing range. Our aim is to increase the network lifetime by increasing the number of cover sets as many as possible. A cover set is a subset of all sensor nodes that can cover every target node. Instead of keeping all the sensor nodes active at once, network lifetime can be extended by generating a number of cover sets that will monitor the network in turn. We develop two polynomial time algorithms that utilize an efficient contribution formula on circular lists of sensor nodes for building a variety of cover sets. Our proposed algorithms find maximum number of cover sets and consume as low energy as possible for each sensor node. Our simulation results exhibit that the proposed algorithms outperform existing ARSC [1] algorithm in terms of number of cover sets while conserving significant amount of energy among the sensor nodes. Keywordswireless sensor networks; target coverage; adjustable sensing range;