Path loss prediction using a modified 2D finite-difference time-domain approach for a below to above ground channel

To effectively deploy wireless sensor networks (WSNs) for monitoring and assessing the condition of local water distribution networks, a propagation Path Loss (PL) Model is required that describes the power loss versus distance relationship between a sensor node located below ground in a fire hydrant (FH) chamber and a wireless node located above ground. The general method is to build an empirical PL model based on the experimental results. However, with this approach, extensive field measurements considering different scenarios have to be carried out. This is both time consuming and site specific. On the other hand, constructing a full 3D electromagnetic (EM) model can be both complex and computational infeasible for a large scale problem. In this paper, based on the field measurement results, we present our modified 2D Finite-Difference Time-Domain (FDTD) PL simulation model for the FH scenario that addresses the highlighted problems.