Detecting coverage holes in wireless sensor networks

Wireless sensor network coverage completeness is an important Quality of Service measure. It is frequently assumed that events occurring in the sensor field will always be detected. However, this is not necessary the case, particularly if there are holes in the sensor network coverage. This paper introduces a novel method for detection and relative localization of sensor network coverage holes in coordinate-free networks assuming availability of a network communication graph. We identify sensor nodes that bound coverage holes, called ldquohole boundary nodesrdquo, by processing information embedded in a communication graph, which is non-planar in general. We create a hole-equivalent planar graph preserving a number and position of holes. Finally, we build a planar simplicial complex, called maximal simplicial complex, which contains the information regarding coverage holes. The proposed method is applicable for both coordinate-available and coordinate-free networks. Two implementation strategies for hole detection are provided, and they are each analyzed to compare runtime and accuracy. Simulation results show effectiveness of the hole detection algorithms.