Multi-RAT for IoT: The Potential in Combining LoRaWAN and NB-IoT

The broad range of requirements of Internet of Things applications has lead to the development of several dedicated communication technologies, each tailored to meet a specific feature set. A solution combining different wireless technologies in one device, can overcome the disadvantages of any individual technology. The design of such Multiple Radio Access Technology solutions based on the diverse characteristics of the technologies offers interesting opportunities. In this work we analyze the potential of combining LoRaWAN and NB-IoT in a Multi-RAT solution for IoT. To that end we evaluate key IoT node requirements in function of payload size and link quality: (1) energy efficiency, (2) coverage, (3) payload size, (4) latency performance, (5) Quality of Service, and (6) cost efficiency. Our theoretical assessment and experimental validation of these IoT features show the merits of a Multi-RAT solution. Notably, energy consumption in use cases with only sporadic large payload requirements, can be improved by a factor of at least 4 with respect to either single-mode technologies. Moreover, latency-critical messages can get delivered on time and coverage can be extended elegantly where needed.