Reliable virtual sensing for wireless sensor networks

Abstract

Several "energy-hungry" sensors such as gas detectors, radar, and cameras have excessive energy dissipation. Virtual sensing is a technique which "breaks the downward spiral" between energy expenditure and events-miss probabilities. The idea is to deactivate main sensors and utilize a set of energyfriendly HW & SW components instead. However, reliability of such systems composed of virtual and real sensors should be as high as possible. In this article, a novel approach is proposed to improve the virtual sensing reliability. An ontology on sensorenvironment relationships is utilized to automatically generate rules before deployment to switch between real and virtual sensors. We illustrate the general approach by a case study: we show how reliable virtual sensing reduces the energy consumption and event-miss probabilities of object tracking applications. Seismic sensors and a dynamic time-warping algorithm shape the virtual object tracking sensor. We validate the precision of such virtual sensors over several experiments. A series of experiments with a network of TelosB sensor nodes show that virtual sensors have much less energy consumption than a Doppler μ-radar (main) sensor. Finally, we evaluate event-miss probabilities and lifetime extension by using the WSNet simulator.1 978-1-4799-8055-0/15/$31.00 ©2015 IEEE

Improving Energy Efficiency in QoS-Constrained Wireless Sensor Networks

“…The run-time evaluation of the sensor selection rules could result in a highly dynamic selection of the most reliable sensor. A more detailed overview of the ontology-based decision-making algorithm is given in [8]. In the sequel, an object tracking mechanism is discussed as well as how virtual sensing can be beneficial in this field.…”

“…The strategy is to develop ideas mainly for energy efficiency and then refine such ideas to improve the QoS parameters. Three detailed examples are given in order to support the proposed strategy [7][8][9].…”