Estimating the Free Region of a Sensor Node

Laxmi Gewali1, Navin Rongratana1, Jan B. Pedersen1
1School of Computer Science, University of Nevada 4505 Maryland Parkway Las Vegas, NV, 89154, USA

Abstract

We consider the problem of relocating a sensor node in its neighborhood so that the connectivity of the network is not altered. In this context, we introduce the notion of \in-free and out-free regions to capture the set of points where the node can be relocated by conserving connectivity. We present a characterization of maximal free-regions that can be used for identifying the position where the node can be moved to increase the reliability of the network connectivity. In addition, we prove that the free-region computation problem has a lower bound \(\Omega(n\log n)\) in the comparison tree model of computation, and also present two approximation algorithms for computing the free region of a sensor node in time \(O(k)\) and \(O(k\log k)\).