Figueiredo, AlexandreLuís, MiguelZÚQUETE, ANDRÉ2023-02-092023-02-092022-07FIGUEIREDO, Alexandre; LUÍS, Miguel; ZÚQUETE, André –A fair channel hopping scheme for LoRa Networks with multiple single-channel gateways. Sensors. eISSN 1424-8220. Vol. 22, N.º 14 (2022), pp. 1-19.http://hdl.handle.net/10400.21/15535LoRa is one of the most prominent LPWAN technologies due to its suitable characteristics for supporting large-scale IoT networks, as it offers long-range communications at low power consumption. The latter is granted mainly because end-nodes transmit directly to the gateways and no energy is spent in multi-hop transmissions. LoRaWAN gateways can successfully receive simultaneous transmissions on multiple channels. However, such gateways can be costly when compared to simpler single-channel LoRa transceivers, and at the same time they are configured to operate with pure-ALOHA, the well-known and fragile channel access scheme used in LoRaWAN. This work presents a fair, control-based channel hopping-based medium access scheme for LoRa networks with multiple single-channel gateways. Compared with the pure-ALOHA used in LoRaWAN, the protocol proposed here achieves higher goodput and fairness levels because each device can choose its most appropriate channel to transmit at a higher rate and spending less energy. Several simulation results considering different network densities and different numbers of single-channel LoRa gateways show that our proposal is able to achieve a packet delivery ratio (PDR) of around 18% for a network size of 2000 end-nodes and one gateway, and a PDR of almost 50% when four LoRa gateways are considered, compared to 2% and 6%, respectively, achieved by the pure-ALOHA approachengLow power wide-area networksLarge-scale LoRa networksSingle-channel LoRa gatewaysjournal article10.3390/s221452601424-8220