A Preliminary Study of UG2AG Link Quality in LoRabased Wireless Underground Sensor Networks A reliable communication channel between the underground sensor nodes and aboveground devices is vital and mostly desirable for data collection, relay and upload for the wireless underground sensor networks (WUSNs). In particular, the analysis of the undergroundtoaboveground (UG2AG) link quality is crucial for the practical realization and deployment of WUSNs. Recently, LoRa, as one of the lowpower widearea networks (LPWANs) technologies, has attracted substantial attentions for its unique advantages such as the low power consumption and longrange capability. However, to the best of our knowledge, its performance has not yet been quantitatively analyzed for LoRabased WUSNs. In this paper, a preliminary evaluation of the LoRaxe2x80x99s capability of serving a UG2AG channel are presented at various burial depths in two challenging media, i.e., attenuative soils and water. We experimentally analyze the influence of various physical layer (PHY) parameters, e.g., spreading factor (SF), bandwidth (BW), and coding rate (CR) on the LoRaxe2x80x99s propagation performance in the field. The results reveal that the reliable UG2AG communication link (without packet loss) can be established at an internode distance greater than 50m when the LoRa device is buried 0.4m deep, even in soils with relatively high volumetric water content (VWC). Our field results successfully verify the theoretical model for the UG2AG channel. These results may have a significant impact on the deployment of LoRabased WUSNs with the potential applications in underground utilities monitoring.

Experimental Evaluation on NBIoT and LoRaWAN for Industrial and IoT Applications Low power and longrange communications are essential features of the Internet of Things (IoT) paradigm that is becoming widespread across a spectrum of industrial applications. In this paper, we present performance evaluation of the most promising longrange communication technologies, namely LoRaWAN and NBIoT. We present accurate infield measurements using a monitoring application as a testbench for a fair comparison in terms of energy efficiency and lifetime. Experimental results highlight that NBIoT payload length does not impact on transmission energy. Thus, applications that implement buffering and caching techniques are favored. On the other hand, LoRaWAN consumes 10xc3x97 less energy to transmit a payload equivalent to that of NBIoT, thereby allowing longer enddevice lifetime.