Energy Consumption in LoRa IoT: Benefits of Adding Relays to Dense Networks

Abstract

We propose to reduce and balance the energy consumption across nodes in a LoRa network, by allocating only short spreading factors to them. Relays using longer spreading factors forward the transmissions that cannot reach the gateway directly. We find that although relays increasethe network interference and in turn reduce the probability of successful transmissions, they lower one order of magnitude the consumption at the nodes with minimal impact on the overall network consumption for moderately to highly dense deployments. Furthermore, the consumption spread between nodes close and far from the gateway is effectively reduced, making the battery lifetime of the nodes more uniform.