Wireless Underground Communications in Sewer and Stormwater Overflow Monitoring: Radio Waves through Soil and Asphalt Medium Storm drains and sanitary sewers are prone to backups and overflows due to extra amount wastewater entering the pipes. To prevent that, it is imperative to efficiently monitor the urban underground infrastructure. The combination of sensors system and wireless underground communication system can be used to realize urban underground IoT applications, e.g., storm water and wastewater overflow monitoring systems. The aim of this article is to establish a feasibility of the use of wireless underground communications techniques, and wave propagation through the subsurface soil and asphalt layers, in an underground pavement system for storm water and sewer overflow monitoring application. In this paper, the path loss analysis of wireless underground communications in urban underground IoT for wastewater monitoring has been presented. The dielectric properties of asphalt, subgrade aggregates, and soil are considered in the path loss analysis for the path loss prediction in an underground sewer overflow and wastewater monitoring system design. It has been shown that underground transmitter was able to communicate through thick asphalt (10 cm) and soil layers (20 cm) for a long range of up to 4 km.

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.