LoRaWAN multi-hop uplink extension.

Abstract The coverage of a LoRaWAN network in a city is greatly hampered by the harsh propagation environment. Sensors are sometimes placed under the ground or in places with strong electromagnetic attenuation. Also, for users who have a contract with a network operator, installing another gateway to improve coverage of blind spots is not an option. In other cases, there is no or very weak connectivity (e.g. basements). In the present work, we design and implement a multi-hop uplink solution compatible with the LoRaWAN specification, which can act as an extension to already deployed gateways. End nodes transmit data messages to intermediate nodes, which relay them to gateways by choosing routes based on a simplified version of Destination-Sequenced Distance Vector (DSDV) routing. The routing protocol was successfully implemented and was assessed using a linear and bottleneck topology, where the Packet Reception Rate (PRR) and throughput were measured. On the bottleneck topology it was observed that the PRR of each node did not significantly vary. On the linear topology we observed that the throughput and PRR did not decrease considerably with the increase of hops.