PROBABILISTIC COVERAGE OF WIRELESS SENSOR NETWORKS IN PRESENCE OF SENSOR FAILURE

Abstract

Coverage is one of the most importance performance metric of wireless sensor networks as it shows a well a region of interest is being monitored by deployed network.It is found that the binary sensing range model does not reflect the true sensing characteristics of sensor nodes as it ignores the environmental factors affecting the sensing capabilities of sensor nodes, thus, over estimates the coverage performance. To consider the influence of environmental factors in the sensing characteristics of sensor nodes, Elfes sensing model was proposed which is a probabilistic sensing range model. Further, sensor failure is an important issue and may cause disrupted and declined coverage and connectivity. This work investigates the coverage performance of wireless sensor network spread in a circular region using binary and Elfes sensing range models. The coverage metric obtained using the derived expression using binary sensing range model provides more coverage as compared to the coverage achieved using Elfes sensing range model. We also analysed the impact of various network parameters on the network coverage and found that number of sensor nodes and sensing range have positive impact whereas sensor failure probability and required value of  have negative impact on the -coverage performance of the network.