scholarly journals Unmanned Aerial Vehicle Propagation Channel over Vegetation and Lake Areas: First- and Second-Order Statistical Analysis

Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 65
Author(s):  
Deyvid L. Leite ◽  
Pablo Javier Alsina ◽  
Millena M. de Medeiros Campos ◽  
Vicente A. de Sousa ◽  
Alvaro A. M. de Medeiros
Keyword(s):  
Secure Communication ◽  
Large Scale ◽  
Communication Channel ◽  
Channel Model ◽  
Path Loss ◽  
Doppler Frequency ◽  
Unmanned Aircraft ◽  
Small Scale ◽  
Log Normal

The use of unmanned aerial vehicles (UAV) to provide services such as the Internet, goods delivery, and air taxis has become a reality in recent years. The use of these aircraft requires a secure communication between the control station and the UAV, which demands the characterization of the communication channel. This paper aims to present a measurement setup using an unmanned aircraft to acquire data for the characterization of the radio frequency channel in a propagation environment with particular vegetation (Caatinga) and a lake. This paper presents the following contributions: identification of the communication channel model that best describes the characteristics of communication; characterization of the effects of large-scale fading, such as path loss and log-normal shadowing; characterization of small-scale fading (multipath and Doppler); and estimation of the aircraft speed from the identified Doppler frequency.

Characterization of path loss model for wireless communication channel modelling

2020 ◽  
Vol 54 (3) ◽  
pp. 343-364
Author(s):  
Nandakishor Sirdeshpande ◽  
Vishwanath Udupi
Keyword(s):  
Wireless Communication ◽  
Communication Channel ◽  
Channel Model ◽  
Path Loss ◽  
Small Scale ◽  
Delay Spread ◽  
Loss Model ◽  
Content Type ◽  
Path Loss Model ◽  
Scale Parameters

PurposeWireless 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.Design/methodology/approachThis 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.FindingsThe 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.Originality/valueThe 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.

scholarly journals Millimeter-Wave Channel Measurement at 73GHz and 81GHz

2021 ◽  
Author(s):  
Changyu Guo
Keyword(s):  
Large Scale ◽  
High Capacity ◽  
Path Loss ◽  
Directional Antennas ◽  
Line Of Sight ◽  
Small Scale ◽  
Wave Channel ◽  
Narrowband Signal ◽  
Loss Models ◽  
Log Normal

The abundant spectrum available at mmWave band can provide high capacity, high throughput, and low latency. In this thesis, we present experimental measurements for 73 and 81 GHz mmWave bands. Wideband propagation measurements were performed at the Boise Airport concourse C area and tarmac for both line-of-sight (LOS) and non-line-of sight (NLOS) scenarios. Power delay profiles were recorded and analyzed with close-in free space reference path loss models and floating intercept path loss models. In addition, building material attenuation at 28, 73, and 91 GHz is presented. Measurements at 73 GHz for wideband and narrowband signal are performed with directional antennas. Moreover, wideband spatial fading measurements were performed at the Boise State University Micron Engineering Building and Boise Airport. The power delay profiles are recorded and analyzed with Rayleigh, Ricean, and log-normal models. Large scale path loss parameters at the airport, material attenuation and small scale fading parameters were computed. The results can help researchers and network designers in simulation and design of mmWave wireless networks.

scholarly journals Spatial characterization of propagation channels for terahertz band

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Bilal Aghoutane ◽  
Mohammed El Ghzaoui ◽  
Hanan El Faylali
Keyword(s):  
Communication Systems ◽  
Indoor Environment ◽  
Channel Model ◽  
Path Loss ◽  
Propagation Loss ◽  
Terahertz Band ◽  
Indoor Scenarios ◽  
Transmission Windows ◽  
Sv Channel

AbstractThe aim of this work consists in characterizing the Terahertz (THz) propagation channel in an indoor environment, in order to propose a channel model for THz bands. We first described a propagation loss model by taking into account the attenuation of the channel as a function of distance and frequency. The impulse response of the channel is then described by a set of rays, characterized by their amplitude, their delay and their phase. Apart from the frequency selective nature, path loss in THz band is also an others issue associated with THz communication systems. This work based on the conventional Saleh-Valenzuela (SV) model which is intended for indoor scenarios. In this paper, we have introduced random variables as Line of sight (LOS) component, and then merging it with the SV channel model to adopt it to the THz context. From simulation, we noted an important effect when the distance between the transmitter and the receiver change. This effect produces variations in frequency loss. The simulations carried out from this model show that to enhance the performance of THz system it is recommended to transmit information over transmission windows instead over the whole band.

scholarly journals Deterministic and Empirical Approach for Millimeter-Wave Complex Outdoor Smart Parking Solution Deployments

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4112
Author(s):  
Fidel Alejandro Rodríguez-Corbo ◽  
Leyre Azpilicueta ◽  
Mikel Celaya-Echarri ◽  
Peio Lopez-Iturri ◽  
Ana V. Alejos ◽  
...  
Keyword(s):  
Large Scale ◽  
Radio Channel ◽  
Path Loss ◽  
Ground Level ◽  
Directional Antennas ◽  
Scale Parameters ◽  
Parking Lot ◽  
Smart Parking ◽  
Wireless Communications Systems

The characterization of different vegetation/vehicle densities and their corresponding effects on large-scale channel parameters such as path loss can provide important information during the deployment of wireless communications systems under outdoor conditions. In this work, a deterministic analysis based on ray-launching (RL) simulation and empirical measurements for vehicle-to-infrastructure (V2I) communications for outdoor parking environments and smart parking solutions is presented. The study was carried out at a frequency of 28 GHz using directional antennas, with the transmitter raised above ground level under realistic use case conditions. Different radio channel impairments were weighed in, considering the progressive effect of first, the density of an incremental obstructed barrier of trees, and the effect of different parked vehicle densities within the parking lot. On the basis of these scenarios, large-scale parameters and temporal dispersion characteristics were obtained, and the effect of vegetation/vehicle density changes was assessed. The characterization of propagation impairments that different vegetation/vehicle densities can impose onto the wireless radio channel in the millimeter frequency range was performed. Finally, the results obtained in this research can aid communication deployment in outdoor parking conditions.

scholarly journals Topophilia, Placemaking, and Boundary Work

2022 ◽  
Vol 6 (GROUP) ◽  
pp. 1-33
Author(s):  
Janghee Cho ◽  
Samuel Beck ◽  
Stephen Voida
Keyword(s):  
Large Scale ◽  
Methodological Approach ◽  
Work Practice ◽  
Small Scale ◽  
Work From Home ◽  
Humanistic Geography ◽  
Working From Home ◽  
Long Term Impact

The COVID-19 pandemic fundamentally changed the nature of work by shifting most in-person work to a predominantly remote modality as a way to limit the spread of the coronavirus. In the process, the shift to working-from-home rapidly forced the large-scale adoption of groupware technologies. Although prior empirical research examined the experience of working-from-home within small-scale groups and for targeted kinds of work, the pandemic provides HCI and CSCW researchers with an unprecedented opportunity to understand the psycho-social impacts of a universally mandated work-from-home experience rather than an autonomously chosen one. Drawing on boundary theory and a methodological approach grounded in humanistic geography, we conducted a qualitative analysis of Reddit data drawn from two work-from-home-related subreddits between March 2020 and January 2021. In this paper, we present a characterization of the challenges and solutions discussed within these online communities for adapting work to a hybrid or fully remote modality, managing reconfigured work-life boundaries, and reconstructing the home's sense of place to serve multiple, sometimes conflicting roles. We discuss how these findings suggest an emergent interplay among adapted work practice, reimagined physical (and virtual) spaces, and the establishment and continual re-negotiation of boundaries as a means for anticipating the long-term impact of COVID on future conceptualizations of productivity and work.

scholarly journals Characterization of Path Loss and Large-Scale Fading for Rapid Intervention Team Communication in Underground Parking Garages

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2431 ◽  
Author(s):  
Seppe Van Brandt ◽  
Robbe Van Thielen ◽  
Jo Verhaevert ◽  
Tanja Van Hecke ◽  
Hendrik Rogier
Keyword(s):  
Large Scale ◽  
Path Loss ◽  
Wireless Channel ◽  
Building Structure ◽  
Propagation Channel ◽  
Parking Garage ◽  
High Penetration ◽  
Parking Garages ◽  
Intervention Team

This paper reports the characterization of the 2.45-GHz-ISM-band radio wave propagation channel. Specifically, measurements were performed in an underground parking garage, with the aim of optimizing breadcrumb systems for a Rapid Intervention Team application. The effects of the high penetration loss and large reflections by the concrete reinforced building structure on the path loss and the large-scale fading were studied. Based on the analysis of the wireless channel, critical points for reliable communication between members of a Rapid Intervention Team were identified. In particular, attention was paid to dealing with large, spatially confined signal losses due to shadowing, the anticipation of corner losses and the ability of the system to operate on multiple floors.

Establishment of Testing Methodology for Forge Welded Tubular Products

2012 ◽  
Author(s):  
Ganesan S. Marimuthu ◽  
Per Thomas Moe ◽  
Bjarne Salberg ◽  
Jan Inge Audestad
Keyword(s):  
Material Flow ◽  
Large Scale ◽  
Flow Behavior ◽  
Treatment Options ◽  
Full Scale ◽  
International Standards ◽  
Small Scale ◽  
Test Plan ◽  
Welding Machine

A state-of-the-art small-scale solid state forge welding machine has been fabricated for checking weldability by Shielded Active Gas Forge Welding (SAG-FW) of tubular products applicable predominantly for, but not limited to offshore Industries. Effective, fast and inexpensive welding and testing of joints make this small-scale method suitable for evaluating weldability of a material before starting regular qualification and fabrication in a full-scale welding machine normally located in spool base or offshore. The small-scale machine provides a complete package for pre-qualification studies, including assessment of welding conditions, material flow behavior, heat treatment options. However, there are considerable challenges relating to application of international standards of testing as well as interpretation and use of results in the context of large-scale welding. In this paper results from small-scale welding and weld characterization of an API 5L X65 quality are presented. First, a detailed test plan for analyzing the weld is outlined. This procedure is subsequently applied for checking the welds to be produced in the full-scale machine. Short-comings in using the small-scale process as well as the possible remedies are discussed in detail.

scholarly journals Experimental Characterization of Ultra-Wideband Channel Parameter Measurements in an Underground Mine

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
B. Nkakanou ◽  
G. Y. Delisle ◽  
N. Hakem
Keyword(s):  
Underground Mining ◽  
Path Loss ◽  
Measurement Procedure ◽  
Ultra Wideband ◽  
Small Scale ◽  
Scale Parameters ◽  
Channel Parameter ◽  
Channel Parameters ◽  
Uwb Channel

Experimental results for an ultra-wideband (UWB) channel parameters in an underground mining environment over a frequency range of 3 GHz to 10 GHz are reported. The measurements were taken both in LOS and NLOS cases in two different size mine galleries. In the NLOS case, results were acquired for different corridor obstruction angles. The results were obtained during an extensive measurement campaign in the UWB frequency, and the measurement procedure allows both the large- and small-scale parameters such as the path loss exponent, coherence bandwidth, and so forth, to be quantified. The capacity of the UWB channel as a function of the physical depth of the mine gallery has also been recorded for comparison purposes.

scholarly journals Experimental Characterization and Correlation Analysis of Indoor Channels at 15 GHz

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Xin Zhou ◽  
Zhangdui Zhong ◽  
Bei Zhang ◽  
Ruisi He ◽  
Ke Guan ◽  
...  
Keyword(s):  
Large Scale ◽  
Small Scale ◽  
Delay Spread ◽  
Experimental Characterization ◽  
Wireless System ◽  
Normal Distributions ◽  
Indoor Radio ◽  
Log Normal ◽  
Wireless System Design ◽  
Correlation Properties

The indoor radio channels at 15 GHz are investigated based on measurements. The large- and small-scale fading behaviors as well as the delay dispersion characteristics are discussed. It is found that the large-scale fading, RiceanK-factor, and delay spread can be described by log-normal distributions. Furthermore, both autocorrelation and cross correlation properties of the above parameters are analyzed and modeled. These parameters characterize fading and delay behaviors as well as their mutual dependency and can be used as empirical values for future wireless system design and simulation in 15 GHz short-range indoor channels.

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