Practical limitations for deployment of LoRa gateways

In this paper, we discuss the upcoming network stack LoRaWAN and its underlying modulation technology LoRa, which is an implementation of a LPWAN (Low Power Wide Area Network) and consider practical limitations that can occur when restricted Machine-to-Machine (M2M) data agreements for the connection of LoRa gateways to a cellular network are involved. We provide a theoretical estimate of the maximum possible communication range of a LoRa link depending on output power and spreading factor and illustrate a LoRa-transceiver's contrary behaviour of energy consumption and range versus the achievable data rate by means of current consumption and RF output power measurement results for different combinations of modulation parameters. Our analysis of the data overhead introduced by LoRa gateways identifies that the amount of generated backhaul network traffic can cause substantial costs for IoT service providers in case of cellular-connected gateways or limit the number of supported sensor nodes.