Minimum connected cover of a query region in heterogeneous wireless sensor networks

Wireless sensor networks are composed of a large number of tiny sensors that have limited resources and yet must form a connected network. The main challenge in the design of sensor networks is the limited battery power of the sensors and the difficulty of replacing and/or recharging these batteries due to the nature of the monitored field. Thus, it is necessary that the sensors be densely deployed and energy-efficient protocols be designed to maximize the network lifetime while meeting the specific application requirements in terms of coverage and connectivity. Given a query over a sensor network the minimum connected sensor cover problem is to select a minimum, or nearly minimum, set of sensors such that the selected sensors cover the query region and form a connected network. In this paper, we propose a new distributed algorithm to find the minimum connected cover of the queried region for heterogeneous sensors, each with arbitrary sensing and transmission radii and different energy levels. Each sensor node in the network determines whether to sense the queried region according to its minimum-weight coverage cost. We provide performance metrics to analyze the performance of our approach and the simulation results show that our approach clearly improves the network lifetime over existing algorithms. (C) 2012 Elsevier Inc. All rights reserved.