IDENTIFYING FAULTY NODES IN WIRELESS SENSOR NETWORKS

Abstract

A Wireless Sensor Network (WSN) is a distributed system populated by a base station and a number of wireless sensor nodes. The main task of the sensor nodes in a WSN is to monitor the environment, collect data, and eventually transfer the sensed data to the base station. For reliable monitoring, the sensor nodes must be in close proximity to the physical events. The sensor nodes are tiny devices that operate on a frugal energy budget and may fail dua to, among other causes, power depletion, catastrophic events, and external damages. When the location and the state (faulty or fault-free) of each sensors in the network is known, the faulty sensors can be repaired/recharged or new sensors could be added to the affected areas so as to maintain accurate monitoring. The main contribution of this work is to provide energy-efficient means to identify the location of the faulty sensor nodes in the WSN. Consider a WSN populated by n wireless sensor nodes which are arranged in a two-dimensional grid of size [Formula: see text]. Let q and k denote the number of fault-free and faulty nodes in the WSN, respectively. The task of identifying the faulty nodes and reporting the location of these faulty sensors to the base station can be completed in O(α + r2) time slots and none of the sensors need to awake for more than O( log log α) time slots, where α = min (q,k) and r is the transmission range of the sensor nodes.