Natural or generated signals for indoor location systems? An evaluation in terms of sensitivity and specificity

In this paper, we perform an evaluation of natural and generated signals features, in order to help designers and researchers of indoor location systems to decide which signal and feature is more suitable to estimate the user indoor location, considering the accuracy in terms of sensitivity and specificity. Four signals were considered in our experiments due their ubiquity into the indoor environments; two of them were signals available everywhere (earth magnetic-field and indoor light) and two were generated signals for information communication (Wi-Fi and Bluetooth). Temporal and spectral features were considered to develop a classification model of the indoor places, so that the room in which the user is located could be predicted.