Contextual outlier detection for wireless sensor networks

The quality of dataset measured and collected by wireless sensor networks (WSN) is often affected by noise and error that are inherent to resource-constrained sensor nodes. The affected data points deviating from the normal pattern are termed as outlier(s). However, detected outlier can be a result of the occurrence of an actual event. Outlier detection techniques developed for WSNs perform binary labelling of the data points and does not indicate the context stating whether the outlier is the result of an actual event or the noise/error. This paper proposes a contextual outlier detection framework specifically designed for WSNs named as in-network contextual outlier detection on edge (INCODE). The proposed framework also estimates the degree of outlierness associated with the detected outlier(s) to provide better insight into the measured data point. Algorithms used in INCODE are designed around the edge computing concept to minimize the communication and computational complexities to make it suitable for resource-constrained WSN. The results suggest an impressive 98% accuracy in identifying the context of the outlier(s). The low communication and computational complexity suggest INCODE’s suitability for resource constrained WSNs.