Long Range Low Power Wireless Communication Technologies for the IoT

The Internet of Things addresses a huge set of possible application domains, requiring both short- and long-range communication technologies. When long distances are present, a number of proprietary and standard solutions for Low Power Wide Area Networks are already available. Among them, LoRaWAN and NB-IoT are candidate technologies supported by many network operators. LoRaWAN is one of the first technologies defined to operate in unlicensed bands. Its simple access protocol is designed to avoid complexity and costs while maximising the transmission range. The proprietary modulation used is very robust with respect to the interferers present in the shared bands used. NB-IoT is a new radio access technology targeting a large set of use cases for massive machine-type communications standardised by the 3GPP. NB-IoT has been enhanced in terms of coverage and power saving capabilities while reducing the complexity at the same time. In this thesis, first, many typical applications that may benefit from these technologies are presented, with a focus on the performance metrics and the definition of the scenario and traffic pattern. Secondly, the LoRaWAN technology is assessed both experimentally and through simulations, to characterise it from the link-level and system-level viewpoint, with the target of estimating the capacity of a LoRaWAN gateway and a multi-gateway network to serve a large area. Then, this thesis provides an overview of NB-IoT, together with a mathematical model of the network able to predict the maximum performance in a given scenario with a specific configuration of some design parameters. This model is used to study how these parameters affect the overall performance and how the optimal configuration may be chosen according to arbitrary criteria. Finally, some projects and practical activities are presented to prove the need for these standards, and to share the know-how that was developed during these studies.