On the Channel Activity Detection in LoRaWAN Networks

In this paper, we consider the problem of detecting the channel activity in LoRaWAN networks. To improve the medium access performance, recent implementations of the chipsets for LoRaWAN end nodes are offering a feature called Channel Activity Detection (CAD), as the first step toward the implementation of the Carrier Sense Multiple Access (CSMA) in LoRaWAN networks. The algorithm underlying the CAD is at the moment left undisclosed. In this paper, we propose a possible implementation of the CAD algorithm; we then evaluate its performance in an additive white Gaussian noise (AWGN) channel, and we find the performance being completely satisfactory and matching the one of the undisclosed algorithm. The results we find are encouraging the community to include the CAD feature in open source implementations of a LoRaWAN receiver.