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The purpose of this paper is to describe common methods for evaluating the performance of wireless devices such as wireless sensors in harsh radio environments.

The paper describes how measurements of real‐world propagation environments can be used to support the evaluation process, then presents representative measurement data from multipath environments where sensor networks are likely to be deployed: a fixed‐infrastructure, process‐control environment (here an oil refinery), and a heavy industrial environment (here an automotive assembly plant).

Results on the characterization of multipath in the propagation channel are summarized and how these results may be used in the performance evaluation of sensor networks is discussed.

The paper describes measurement results from environments where little open‐literature data exists on point‐to‐point propagation, specifically high‐multipath environments. These highly reflective scenarios can present difficulties for deployment of sensor networks.

Wireless sensor networks (WSN), as a solution for buried water pipe monitoring, face a new set of challenges compared to traditional application for above-ground infrastructure monitoring. One of the main challenges for underground WSN deployment is the limited range (less than 3 m) at which reliable wireless underground communication can be achieved using radio signal propagation through the soil. To overcome this challenge, the purpose of this paper is to investigate a new approach for wireless underground communication using acoustic signal propagation along a buried water pipe.

An acoustic communication system was developed based on the requirements of low cost (tens of pounds at most), low power supply capacity (in the order of 1 W-h) and miniature (centimetre scale) size for a wireless communication node. The developed system was further tested along a buried steel pipe in poorly graded SAND and a buried medium density polyethylene (MDPE) pipe in well graded SAND.

With predicted acoustic attenuation of 1.3 dB/m and 2.1 dB/m along the buried steel and MDPE pipes, respectively, reliable acoustic communication is possible up to 17 m for the buried steel pipe and 11 m for the buried MDPE pipe.

Although an important first step, more research is needed to validate the acoustic communication system along a wider water distribution pipe network.

This paper shows the possibility of achieving reliable wireless underground communication along a buried water pipe (especially non-metallic material ones) using low-frequency acoustic propagation along the pipe wall.

Wireless communication channel provides a wide area of applications in the field of communication, distributed sensor network and so on. The prominence of the wireless communication channel is because of its robust nature and the sustainability for the precise ranging and the localization. The precision and accuracy of the wireless communication channel largely depend on the localization. The development of the wireless communication channel with improved benefits needs the accurate channel model.

This paper characterizes the tangential path loss model in the WINNER based wireless communication channel model. The measurements taken in the WINNER channel model are compared with the tangential path loss characterized WINNER Channel model.

The model operates well over the varying antenna orientations, measurement condition and the propagation condition. The proposed tangential path loss model is performing well over the various outdoor scenarios.

The proposed characterization shows change in the small-scale parameters (SSP), such as power, delay, angle of arrival and angle of departure as well as the large-scale parameters (LSP), such as RMS delay spread, shadowing, path loss and Ricean factor associated with the model.

This study aims to model and investigate low-loss wave-propagation modes across random media. The objective is to achieve better channel properties for applying radio links through random vegetation (e.g. forest) using a beamforming approach. Thus, obtaining the link between the statistical parameters of the media and the channel properties.

A beamforming approach is used to obtain low-loss propagation across random media constructed of long cylinders, i.e. a simplified two dimensional (2D) model of agroforests. The statistical properties of the eigenmode radio wave propagation are studied following a Monte Carlo method. An error quantity is defined to represent the robustness of an eigenmode, and it is shown that it follows a known Lognormal statistical distribution, thereby providing a base for further statistical investigations.

In this study, it is shown that radio wave propagation eigenmodes exist based on a mathematical model. The algorithm presented can find such modes of propagation that are less affected by the statistical variation of the media than the regular beams used in radio wave communication techniques. It is illustrated that a sufficiently chosen eigenmode waveform is not significantly perturbed by the natural variation of the tree trunk diameters.

As a new approach to obtain low-loss propagation in random media at microwave frequencies, the presented mathematical model can calculate scattering-free wave-propagation eigenmodes. A robustness quantity is defined for a specific eigenmode, considering a 2D simplified statistical forest example. This new robustness quantity is useful for performing computationally low-cost optimization problems to find eigenmodes for more complex vegetation models.

The development of wireless communication techniques has increased the employment of positioning systems, such as GPS. Concerning to this, telecommunication providers predicted that position location (PL) will be an integrated service in the third generation cellular phones. Consequently, in this paper we propose a new method to determine the transmitter/receiver distance, which is based on the transmission of several frames with different frequencies.

The propagation of electromagnetic waves depends on internal factors related to its nature and external factors characterized by the medium in which the wave is propagated. In this work, we propose a method to determine the distance between the transmitter and the receiver by solving a system of non‐linear equations, which depends on the physical model of the medium in which the wave is propagated.

The parameters of the model may vary when the link conditions change. As a result, the positioning system must update the model in real time. Following these constraints, a MATLAB simulation to calculate the distance in a satellite‐earth link has been completed. We have shown that scattering phenomena can be used to estimate the transmitter/receiver distance in a radio frequency link. Moreover, any electromagnetic communication in which scattering appears could be considered in the same way.

We have explained a new method to develop a complete PL service. Some of the advantages of this system are that there are no measures in absolute time and that it is not necessary to synchronize the receiving antennas, unlike many current commercial systems.

Network coverage is crucial for the adoption of advanced Smart Home applications. The commonly used log-based path loss model is not able to accurately estimate WiFi signal strength in different houses, as it does not fully consider the impact of building morphology. To better describe the propagation of WiFi signals and achieve higher estimation accuracy, this paper studies the basic building morphology characteristics of houses.

A new path loss model based on a decision tree was proposed after measuring the WiFi signal strength passing through multiple housing units. Three types of regression models were tested and compared.

The findings demonstrate that the log-based path loss model fits small houses well, while the newly proposed nonlinear path loss model performs better in large houses (area larger than 125 m2 and area-to-perimeter ratio larger than 2.5). The impact of building design on path loss has been proven and specifically quantified in the model.

Proposed an improved model to estimate indoor network coverage. Quantify the impacts of building morphology on indoor WiFi signal strength. Improve WiFi signal strength estimation to support Smart Home applications.

The purpose of this paper is to provide a brief introduction of the finite difference based parabolic equation (PE) modeling to the advanced engineering students and academic researchers.

A three-dimensional parabolic equation (3DPE) model is developed from the ground up for modeling wave propagation in the tunnel via a rectangular waveguide structure. A discussion of vector wave equations from Maxwell’s equations followed by the paraxial approximations and finite difference implementation is presented for the beginners. The obtained simulation results are compared with the analytical solution.

It is shown that the alternating direction implicit finite difference method (FDM) is more efficient in terms of accuracy, computational time and memory than the explicit FDM. The reader interested in maximum details of individual contributions such as the latest achievements in PE modeling until 2021, basic PE derivation, PE formulation’s approximations, finite difference discretization and implementation of 3DPE, can learn from this paper.

For the purpose of this paper, a simple 3DPE formulation is presented. For simplicity, a rectangular waveguide structure is discretized with the finite difference approach as a design problem. Future work could use the PE based FDM to study the possibility of utilization of meteorological techniques, including the effects of backward traveling waves as well as making comparisons with the experimental data.

The proposed work is directly applicable to typical problems in the field of tunnel propagation modeling for both national commercial and military applications.

The purpose of this paper is to investigate the effect of snow on the radio link performance of wireless sensor nodes in Indian Himalayan conditions and to propose empirical path loss models for radio wave propagation.

At the remote test site, one source and three listening wireless sensor nodes were deployed at frequency of 433 MHz. The path loss models are derived from experimental data collected during the period of snowfall and clear weather conditions. Linear, exponential, second and third-order polynomials path loss models have been investigated along with experimental data.

With the help of curve fitting and goodness-of-fit tests, it is found that path loss can be modelled through third-order polynomial equation during the snowfall period. However, if sensor is buried, the acceptable path loss model is exponential. Similarly, for unified modelling requirement, exponential path loss model over linear can be a preferred choice.

Results show that path loss can be estimated priori for deciding optimum transmission energy in wireless sensor network. Presented work is usable in extending the lifetime of health monitoring devices buried in snowy environment.

The purpose of this study is to understand the effects of building components of a growing concrete structure and different building materials such as glass and steel on Wi-Fi signals propagation in a construction site. Wireless local area networks are considered effective tools to link the islands-of-communication in construction. Still, designing a Wi-Fi network that can grow with a new construction requires that one understands the performance of propagation of electromagnetic signals transmitted at 2.4 GHz.

This paper reviews the theoretical behavior of electromagnetic signals when signal attenuation is caused by various construction materials changing their strengths, directions and possibly leading to total absorption. The authors used a typical building layout to conduct experimental work to measure the effect of common building features and communication technologies on signal strengths.

The measured data not only confirmed the theory-based predictions but also demonstrated the complexity of predicting signal propagation when obstructions inhibit the line-of-sight “travel” of electromagnetic signals.

Different to other papers, the experiments were conducted outside a concrete building mimicking the situation where the transmitter is set up at the site office.

This book is intended to be a comprehensive work of reference on the subject of radio aids to civil aviation. It is not written for the circuit designer or routine operator requiring detailed information on existing aids but rather for the system designer and operational planner. To this end it gives systems information required by the radio engineer or operational specialist. The inclusion at an early stage of some one hundred and fifteen pages devoted to the basic principles of radio propagation, radar, etc., assists those having a nodding acquaintance only with radio engineering to a better understanding of the later sections of the book; besides presenting a number of nomograms, graphs, and formulae directly useful to the systems designer.