  In recent years, we have witnessed the rapid development of LoRa technology,
together with extensive studies trying to understand its performance in various
application settings. In contrast to measurements performed in large outdoor
areas, limited number of attempts have been made to understand the
characterization and performance of LoRa technology in indoor environments. In
this paper, we present a comprehensive study of LoRa technology in multi-floor
buildings. Specifically, we investigate the large-scale fading characteristic,
temporal fading characteristic, coverage and energy consumption of LoRa
technology in four different types of buildings. Moreover, we find that the
energy consumption using different parameter settings can vary up to 145 times.
These results indicate the importance of parameter selection and enabling LoRa
adaptive data rate feature in energy-limited applications. We hope the results
in this paper can help both academia and industry understand the performance of
LoRa technology in multi-floor buildings to facilitate developing practical
indoor applications.
