Title: Multi-sensor activation for temporally correlated event monitoring with renewable energy sources

Authors: Neeraj Jaggi, Koushik Kar

Addresses: Department of Electrical Engineering and Computer Science, Wichita State University, Wichita, KS 67260, USA. ' Department of Electrical Computer and Systems Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA

Abstract: Future sensor networks would comprise sensing devices with energy-harvesting capabilities from renewable energy sources, such as solar power. This paper focuses on design of efficient algorithms for multi-sensor activation to optimise overall event detection probability in presence of uncertainties in event and recharge processes. We formulate the dynamic multi-sensor activation question in a stochastic optimisation framework, and show that a time-invariant threshold policy, which maintains an appropriately chosen number of sensors active at all times, is optimal in absence of temporal correlations. Moreover, the same energy-balancing time-invariant threshold policy approaches optimality in presence of temporal correlations as well, albeit under certain limiting assumptions. We also analyse the class of correlation-dependent threshold policies and derive the range for energy-balancing thresholds. Through simulations, we compare the proposed time-invariant policy with energy-balancing correlation-dependent policies, and observe that although the latter may perform better, the performance difference is rather small in the cases studied.

Keywords: multi-sensor activation; temporal correlations; energy constraints; energy-harvesting sensor systems; event monitoring; renewable energy; sensor networks; solar power; solar energy; uncertainties; simulation; correlation dependent thresholds; energy balancing thresholds.

DOI: 10.1504/IJSNET.2011.040903

International Journal of Sensor Networks, 2011 Vol.10 No.1/2, pp.42 - 58

Published online: 26 Jun 2011 *

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