An adaptive energy-efficient area coverage algorithm for wireless sensor networks

The connected dominating set (CDS) concept has recently emerged as a promising approach to the area coverage in wireless sensor network (WSN). However, the major problem affecting the performance of the existing CDS-based coverage protocols is that they aim at maximizing the number of sleep nodes to save more energy. This places a heavy load on the active sensors (dominators) for handling a large number of neighbors. The rapid exhaustion of the active sensors may disconnect the network topology and leave the area uncovered. Therefore, to make a good trade-off between the network connectivity, coverage, and lifetime, a proper number of sensors must be activated. This paper presents a degree-constrained minimum-weight extension of the CDS problem called DCDS to model the area coverage in WSNs. The proper choice of the degree-constraint of DCDS balances the network load on the active sensors and significantly improves the network coverage and lifetime. A learning automata-based heuristic named as LAEEC is proposed for finding a near optimal solution to the proxy equivalent DCDS problem in WSN. The computational complexity of the proposed algorithm to find a optimal solution of the area coverage problem is approximated. Several simulation experiments are conducted to show the superiority of the proposed area coverage protocol over the existing CDS-based methods in terms of the control message overhead, percentage of covered area, residual energy, number of active nodes (CDS size), and network lifetime. (C) 2013 Elsevier B.V. All rights reserved.