Comparative Study of LPWAN Technologies on Unlicensed Bands for M2M Communication in the IoT: beyond LoRa and LoRaWAN

Low power wide area networks (LPWAN) are widely used in IoT applications as they offer low power consumption and long-range communication. LoRaWAN and SigFox have taken the top positions in the unlicensed ISM bands, while LTE-M and NB-IoT have emerged within cellular networks. We focus on unlicensed bands operation because of their availability for both private and public use with one's own infrastructure. New technologies have since been developed to overcome limitations of LoRaWAN and SigFox, based on LoRa or other modulation techniques, and are finding their way mainly into the industrial IoT. These include Symphony Link or Ingenu RPMA. To the best of our knowledge, previous works have not been focused on comparing LPWAN technologies in-depth including alternatives to the link and network layers over LoRa other than LoRaWAN. This paper provides a detailed comparative study of these technologies and potential application scenarios. We defend that LoRaWAN is the most suitable for small-scale or public deployments, while Symphony Link provides a robust solution for industrial environments. SigFox is one the most widely deployed networks; and RPMA has the advantage of using the 2.4GHz band, equally regulated in most countries.