Wireless sensor networks are expanding across nearly all aspects of social and economic activity. Their deployment now spans almost all available environments, including, in some cases, off-planet applications. Applications may range from near-ground, underground, undersea, indoor–outdoor, and on- and in-body, to name a few deployment environments. Each channel model exhibits its own physical representation and statistical distributions. In this work, we categorize and re-evaluate the various propagation models published in the open literature while, at the same time, we contribute critical updates needed due to the rapid expansion of the wireless sensor network discipline. Our work includes various results, based on simulation and/or analytical formulas, that advocate for and evaluate our classification and findings. Unlike prior reviews that treat environments in isolation, this article introduces a unified analytical and simulation framework for a cross-environment comparison, with updated parameterizations aligned with modern WSN deployments. The innovation lies in the consistent cross-environment evaluation of propagation mechanisms, updated parameterizations aligned with modern WSN deployments, and the identification of feasibility and trade-off boundaries across heterogeneous media.

In the work at hand, we contribute a system study of a full-coverage antenna array for applications ranging from wireless communication base station transceivers to aerospace applications. There are two main objectives in the road toward achieving active, electronically scanned array antennas: the passage from mechanical to electronic steering and the subsequent accommodation of a large number of simultaneously active, independent beams and respective Tx-Rx chains. The first objective comes with the unwanted introduction of scanning losses, which degrade the system’s performance. This problem is solved in the current work by employing a toroidal array antenna and scanning the beam by exploiting the double curvature of the host surface. Furthermore, the second issue, of signal path routing complexity, is also resolved by the contributed 2D, hierarchical (exhibiting both horizontal and vertical organization) beam-forming network. The stated results successfully validate our contribution.