  LoRaWAN exhibits several characteristics that can lead to an unfair
distribution of the Data Extracted Rate (DER) among nodes. Firstly, the capture
effect leads to a strong signal suppressing a weaker signal at the gateway and
secondly, the spreading codes used are not perfectly orthogonal, causing packet
loss if an interfering signal is strong enough. In these conditions, nodes
experiencing higher attenuation are less likely to see their packets received
correctly. We develop FADR, a Fair Adaptive Data Rate algorithm for LoRaWAN
that exploits the different Spreading Factors (SFs) and Transmission Powers
(TPs) settings available in LoRa to achieve a fair Data Extraction Rate among
all nodes while at the same time avoiding excessively high TPs. Simulations
show that FADR, in highly congested cells, achieves 300% higher fairness than
the minimum airtime allocation approach and 22% higher fairness than Brechts
approach, while consuming almost 22% lower energy.
