scholarly journals A Propagation Study of LoRa P2P Links for IoT Applications: The Case of Near-Surface Measurements over Semitropical Rivers

Sensors ◽  
2021 ◽  
Vol 21 (20) ◽  
pp. 6872
Author(s):  
Amado Gutiérrez-Gómez ◽  
Víctor Rangel ◽  
Robert Edwards ◽  
John Davis ◽  
Raúl Aquino ◽  
...  
Keyword(s):  
Path Loss ◽  
Signal Propagation ◽  
Near Surface ◽  
Flood Warning ◽  
Radio Signals ◽  
Surface Measurements ◽  
Considerable Degradation ◽  
Flood Warning Systems ◽  
Point To Point ◽  
Log Normal

Internet of Things (IoT) radio networks are becoming popular in several scenarios for short-range applications (e.g., wearables and home security) and medium-range applications (e.g., shipping container tracking and autonomous farming). They have also been proposed for water monitoring in flood warning systems. IoT communications may use long range (LoRa) radios working in the 915 MHz industrial, scientific and medical (ISM) band. In this research, we study the propagation characteristics of LoRa chirp radio signals close to and over water in a tropical meadow region. We use as a case study the Colima River in Mexico. We develop a novel point-to-point IoT measurement sounding system that does not require decoding of LoRa propriety bursts and provides accurate power versus distance profiles along the riparian zone of a steeply dropping mountain river. We used this system to obtain the measurements reported in this work, which are also analyzed and modeled. The results show that the LoRa signal propagation over water exhibits a log-normal distribution. As a result of the chirp signal processing, two new experimental path loss models are presented. The path loss results show a considerable degradation of the received signal power over water within vegetation and less signal degradation at antenna heights closer to the water surface.

scholarly journals Joint UAV channel modeling and power control for 5G IoT networks

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Xiuhua Fu ◽  
Tian Ding ◽  
Rongqun Peng ◽  
Cong Liu ◽  
Mohamed Cheriet
Keyword(s):  
Energy Efficiency ◽  
Power Control ◽  
Channel Model ◽  
Path Loss ◽  
Channel Modeling ◽  
Signal Propagation ◽  
Spectrum Efficiency ◽  
Propagation Path ◽  
Control Factor ◽  
The Impact

AbstractThis paper studies the communication problem between UAVs and cellular base stations in a 5G IoT scenario where multiple UAVs work together. We are dedicated to the uplink channel modeling and the performance analysis of the uplink transmission. In the channel model, we consider the impact of 3D distance and multi-UAVs reflection on wireless signal propagation. The 3D distance is used to calculate the path loss, which can better reflect the actual path loss. The power control factor is used to adjust the UAV's uplink transmit power to compensate for different propagation path losses, so as to achieve precise power control. This paper proposes a binary exponential power control algorithm suitable for 5G networked UAV transmitters and presents the entire power control process including the open-loop phase and the closed-loop phase. The effects of power control factors on coverage probability, spectrum efficiency and energy efficiency under different 3D distances are simulated and analyzed. The results show that the optimal power control factor can be found from the point of view of energy efficiency.

scholarly journals Wind Energy Meteorology: Insight into Wind Properties in the Turbine-Rotor Layer of the Atmosphere from High-Resolution Doppler Lidar

2013 ◽  
Vol 94 (6) ◽  
pp. 883-902 ◽  
Author(s):  
Robert M. Banta ◽  
Yelena L. Pichugina ◽  
Neil D. Kelley ◽  
R. Michael Hardesty ◽  
W. Alan Brewer
Keyword(s):  
Wind Energy ◽  
Ground Level ◽  
Turbine Rotor ◽  
Energy Industry ◽  
Doppler Lidar ◽  
Near Surface ◽  
Surface Measurements ◽  
Wind Measurements ◽  
Upper Level ◽  
Insight Into

Addressing the need for high-quality wind information aloft in the layer occupied by turbine rotors (~30–150 m above ground level) is one of many significant challenges facing the wind energy industry. Without wind measurements at heights within the rotor sweep of the turbines, characteristics of the flow in this layer are unknown for wind energy and modeling purposes. Since flow in this layer is often decoupled from the surface, near-surface measurements are prone to errant extrapolation to these heights, and the behavior of the near-surface winds may not reflect that of the upper-level flow.

ASSESSMENT OF THE ELECTROMAGNETIC ENVIRONMENT AND RADIO MONITORING OF SIGNAL PROPAGATION AND RECEPTION CONDITIONS

2020 ◽  
Author(s):  
С.В. КИЗИМА ◽  
Е.Г. РУДЕНКОВА
Keyword(s):  
Frequency Spectrum ◽  
Electromagnetic Compatibility ◽  
Measurement Data ◽  
Signal Propagation ◽  
Radio Sources ◽  
Electromagnetic Environment ◽  
Radio Monitoring ◽  
Radio Frequency Spectrum ◽  
Radio Signals ◽  
Problematic Situations

Рассматривается технология комплексного радиомониторинга излучений в заданной географической точке. Полученные результаты сопоставляются с разрешенными уровнями излучений. Технология направлена на решение задач оценки условий распространения и приема радиосигналов, планирования использования радиочастотного спектра (РЧС), выявления помех и других проблемных ситуаций, связанных с обеспечением электромагнитной совместимости ( ЭМС) действующих и перспективных радиосредств. The article describes the technology of complex radio monitoring of emissions from multiple radio sources. The measurement data are compared with the permitted emission levels. The application of the technology helps to assess the conditions for the propagation and reception of radio signals, planning the use of the radio frequency spectrum, identifying interference and other problematic situations related to electromagnetic compatibility of existing and promising radio facilities.

scholarly journals Topology Control Using Distributed Power Management Algorithm for Mobile Ad Hoc Networks

2009 ◽  
Vol 5 (4) ◽  
pp. 128
Author(s):  
Nuraj Pradhan ◽  
Tarek Saadawi
Keyword(s):  
Ad Hoc ◽  
Dynamic Network ◽  
Path Loss ◽  
Packet Delay ◽  
Management Algorithm ◽  
Physical Channel ◽  
Strongly Connected ◽  
Node Connectivity ◽  
Hoc Networks ◽  
Log Normal

In order to be strongly connected in the network, a node may increase its power indiscriminately causing interference. Since interference is one of the major problems in wireless network, the proposed algorithm will co-operatively reduce inter-node interference in the network. Further, uni-directional links are a major source of interference as most of the routing protocol only utilizes bi-directional links. The algorithm will attempt to prevent such links or if required convert them into bi-directional links. We will show that the proposed algorithm provides strongly connected and more reliable network over dynamic physical channel modeled by log-distance path loss model, log-normal shadowing model and rayleigh fading model. It stabilizes node connectivity over the dynamic network and environment and even, to a certain extent, prevent node from being completely disconnected from the network. For the selected simulation environment, we will show that the proposed algorithm provides a shorter packet delay, improves the network throughput by as much as 37%, decreases the routing overhead and reduces interference.

scholarly journals Simulation of mineral dust aerosol with piecewise log-normal approximation (PLA) in CanAM4-PAM

2011 ◽  
Vol 11 (9) ◽  
pp. 26477-26520
Author(s):  
Y. Peng ◽  
K. von Salzen ◽  
J. Li
Keyword(s):  
Climate Model ◽  
Normal Approximation ◽  
Global Climate ◽  
Global Climate Model ◽  
Dust Aerosol ◽  
Radiative Properties ◽  
Fourth Generation ◽  
Surface Measurements ◽  
Log Normal ◽  
Year 2000

Abstract. A new size-resolved dust scheme based on the numerical method of piecewise log-normal approximation (PLA) was developed and implemented in the fourth generation of the Canadian Atmospheric Global Climate Model with the PLA Aerosol Module (CanAM4-PAM). The total simulated annual mean dust burden is 37.8 mg m−2 for year 2000, which is consistent with estimates from other models. Results from simulations are compared with multiple surface measurements near and away from dust source regions, validating the generation, transport and deposition of dust in the model. Most discrepancies between model results and surface measurements are due to unresolved aerosol processes. Radiative properties of dust aerosol are derived from approximated parameters in two size modes using Mie theory. The simulated aerosol optical depth (AOD) is compared with several satellite observations and shows good agreements. The model yields a dust AOD of 0.042 and total AOD of 0.126 for the year 2000. The simulated aerosol direct radiative forcings (ADRF) of dust and total aerosol over ocean are −1.24 W m−2 and −4.76 W m−2 respectively, which show good consistency with satellite estimates for the year 2001.

Sign in / Sign up

Export Citation Format

Share Document