Sensor Node Failure Affecting Coverage of WSNs: An Overview

Abstract

A Wireless Sensor Network (WSN) is an extreme form of ad-hoc networking in which a large number of sensor nodes are distributed over a huge area functioning autonomously. Their function is to monitor the physical and environmental conditions like temperature, sound, pressure etc in their surroundings [1]. These sensors sense the phenomenon, and convert into an electrical output and transmit data or gather data from different locations and then send it to the main location. The one important thing that is responsible for the degradation of the performance of a WSN is the node failure. There are many reasons due to which the sensor nodes may undergo an unexpected failure. The failure of a single node results into the failure of the whole network in the cluster-based topologies. Hence, the detection of the failure-prone nodes is important. In a WSN with randomly deployed sensor nodes (non-structured deployment) too, the failure of any node will affect the network coverage. In this paper, we present a study of the node failure in WSNs. The reasons for failure, the methods to detect faulty nodes are discussed initially, followed by the sensor node failure affecting the coverage of a randomly deployed WSN.  The objective of the work presented in the paper is to study the node failure problem at the theoretical level and find out how it be tackled in real-time scenarios to improve the performance of a WSN.