LoRaWAN Underground to Aboveground Data Transmission Performances for Different Soil Compositions

The aim of this article is to discuss the usability of the long-range (LoRa) transmission technology together with the LoRa wide-area network (LoRaWAN) protocol for underground monitoring activities. In particular, this article focuses on the transmission performances in different soils (i.e., gravel, sand, and clay), for an underground-to-aboveground (UG2AG) communication. The three soils have been chosen in order to test the system behavior in case of pure soil compositions, in order to provide a general result that can be used to evaluate the transmission chances for any kind of soil. The performances of the transmission channel have been tested using an experimental setup for depths up to 50 cm, acquiring the values of the received signal strength indicator (RSSI) and the signal-to-noise ratio (SNR) for every transmission and analyzing the packet loss (PL). Such a kind of system may be crucial in several application scenarios, such as environmental monitoring or smart agriculture, where the real-time, remote acquisition of underground parameters at different depths is required.