Evaluating LoRa energy efficiency for adaptive networks: From star to mesh topologies

The LoRa technology has emerged as an interesting solution for low power, long range loT applications by proposing multiple 'degrees of freedom' at the physical layer. This flexibility provides either a long range at the cost of a lower data rate or higher throughput at the cost of low sensitivity, so a shorter range. In this paper, we analyze the flexibility of LoRa and propose various strategies to adapt its radio parameters (such as the spreading factor, bandwidth, and transmission power) to different deployment scenarios. We compute the energy consumption of LoRa transceivers using various radio configurations in both star and mesh topologies. Our simulation results show that in a star topology, we can achieve the optimal scaling-up/down strategy of LoRa radio parameters to obtain either a high data rate or a long range while respecting low energy consumption. In mesh networks, energy consumption is optimized by exploiting various radio configurations and the network topology (e.g., the number of hops, the network density, the cell coverage). Finally, we propose a strategy to take advantage of both star and mesh topologies.