Energy Efficient Area Monitoring Using Information Coverage in Wireless Sensor Networks

Abstract

In this paper, we are concerned with enarea [1], [2]. Energy is consumed in the sensor nodes ergy efficient area monitoring using information cov-for the purpose of sensing as well as communication. erage in wireless sensor networks, where collaboration Several studies in the literature have addressed the isamong multiple sensors can enable accurate sensing sue of minimizing the energy spent for the purpose of of a point in a given area-to-monitor even if that communication (e.g., energy efficient routing [3]). In point falls outside the physical coverage of all the sen-this paper, we address the energy spent for the pursors. We refer to any set of sensors that can collecpose of sensing, focusing on energy efficient algorithms tively sense all points in the entire area-to-monitor for scheduling the sensing activity of sensor nodes usas a full area information cover. We first propose a ing Information Coverage [4], instead of the often used low-complexity heuristic algorithm to obtain full area physical coverage. information covers. Using these covers, we then obSensor nodes in the network have the task of senstain the optimum schedule for activating the sensing ing/monitoring an area-to-sense/monitor and sending activity of various sensors that maximizes the sensing the sensed information to a sink. Not all nodes in the lifetime. The scheduling of sensor activity using the network may be needed to adequately cover (sense) optimum schedules obtained using the proposed algo-the entire area-to-monitor. By intelligently switchrithm is shown to achieve significantly longer sensing ing the redundant sensor nodes to low power operalifetimes compared to those achieved using physical tion, the energy spent in sensing can be reduced, and coverage. Relaxing the full area coverage requirement hence the overall lifetime of the network can be into a partial area coverage (e.g., 95% of area coverage creased. Redundant nodes can be deactivated as long as adequate instead of 100% area coverage) further as the area-to-monitor remains adequately covered by enhances the lifetime. the other nodes, and activated when needed for ade-