scholarly journals EMC assassement criteria and interference protection for basic radio services in accordance with ITU-R recommendations

2021 ◽  
Vol 7 ◽  
pp. 1-9
Author(s):  
Anushka Stancheva
Keyword(s):  
Electromagnetic Compatibility ◽  
Radio Communication ◽  
Multiple Sources ◽  
Regulatory Requirements ◽  
Short Term ◽  
Radio Communications ◽  
Satellite Broadcasting ◽  
Mobile Sources ◽  
Radio Communication System ◽  
Receiver Input

The effect of unwanted energy due to one or a combination of several desired and unwanted emissions upon reception in a radio communication system results in performance degradation, misinterpretation or loss of information. Multiple sources of interference may affect the receiver input: services of the same type or other operating in the same frequency band, services operating in adjacent frequency bands, sources generating continuous or short term interferences, fixed or mobile sources, etc. To prevent such interfering situations, a key element is the standardization of appropriate criteria for electromagnetic compatibility (EMC) and interference protection (IPC). The purpose of the studies and analyzes in this article is to systematize the criteria for electromagnetic compatibility for basic radio services based on the Publications of ITU-R. Criteria for four important areas of radio communications covering fixed, fixed satellite, broadcasting and mobile radio services are compared. Contributions are the categorization of the criteria according to the type of interfering signal and the results of the analyses, which show that the regulatory requirements and practical methods for interference protection and EMC for different radio services differ. Detailed criteria for predicting the probability of interference being standardized only for some radio services.

scholarly journals Technique of radio suppression of a radio communication system in a Wі­Fі network from noise­like signals based on the HTTP/3 рrotocol

Connectivity ◽  
2020 ◽  
Vol 145 (3) ◽  
Author(s):  
V. M. Cherevyk ◽  
◽  
A. V. Glushchuk
Keyword(s):  
Data Transmission ◽  
Communication Systems ◽  
Electromagnetic Compatibility ◽  
Power Level ◽  
Pseudorandom Sequence ◽  
Radio Communication ◽  
Electronic Warfare ◽  
Radio Communications ◽  
Pulse Interference ◽  
Radio Communication System

The article presents the results of the analysis of the existing method of radio suppression of radio communication systems in Wi-Fi networks, and conclusions are drawn regarding ways to increase its effectiveness. The method of radio suppression of radio communication systems with noise-like signals was chosen. It contains the implementation of structural obstacles and a scheme for smooth control of their power implemented in the HTTP/3 protocol. This makes it possible to increase the effectiveness of a jamming station with radio suppression of certain radio communication systems and reduce radioelectronic control equipment requirements. For the applied implementation of this technique in a jamming station, it is necessary to predict a reconnaissance tool covering the reception, determination and estimation of the parameters of noise-like signals; structural interference block; unit execution and regulation of the required power level of structural interference. One of the main tasks is to suppress radio communication systems (SRS). However, with the advance of digital technologies in speech and data transmission, noise-signaling (SHP) signals are increasingly being used to improve the noise immunity and latency of SRHs. One way to implement such signals is to modulate the carrier frequency by a pseudorandom sequence. The issue with productive radio suppression (RP) of SRWs with SHPS has been developing quite actively in recent years, and still remains relevant. Based on the features and means of electronic warfare (EWB), the SPS radio communications systems may be muted by the application of high-power shielding, narrowband or pulse interference. But this method does not cover minimization of radiolabeling of EW methods and can lead to electromagnetic compatibility violations.

scholarly journals Influence of Aircraft Power Electronics Processing on Backup VHF Radio Systems

Electronics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 777
Author(s):  
Jan Leuchter ◽  
Radim Bloudicek ◽  
Jan Boril ◽  
Josef Bajer ◽  
Erik Blasch
Keyword(s):  
Power Electronics ◽  
Electromagnetic Interference ◽  
Communication Systems ◽  
Electromagnetic Compatibility ◽  
Intermediate Frequency ◽  
Radio Communication ◽  
Very High Frequency ◽  
Switching Power ◽  
Radio Systems ◽  
The Impact

The paper describes the influence of power electronics, energy processing, and emergency radio systems (ERS) immunity testing on onboard aircraft equipment and ground stations providing air traffic services. The implementation of next-generation power electronics introduces potential hazards for the safety and reliability of aircraft systems, especially the interferences from power electronics with high-power processing. The paper focuses on clearly identifying, experimentally verifying, and quantifiably measuring the effects of power electronics processing using switching modes versus the electromagnetic compatibility (EMC) of emergency radio systems with electromagnetic interference (EMI). EMI can be very critical when switching power radios utilize backup receivers, which are used as aircraft backup systems or airport last-resort systems. The switching power electronics process produces interfering electromagnetic energy to create problems with onboard aircraft radios or instrument landing system (ILS) avionics services. Analyses demonstrate significant threats and risks resulting from interferences between radio and power electronics in airborne systems. Results demonstrate the impact of interferences on intermediate-frequency processing, namely, for very high frequency (VHF) radios. The paper also describes the methodology of testing radio immunity against both weak and strong signals in accordance with recent aviation standards and guidance for military radio communication systems in the VHF band.

An Analysis of The Impact of Short-Term Vacation Rentals on the Hotel Industry

2021 ◽  
pp. 109634802110191
Author(s):  
Jungtae Soh ◽  
Kwanglim Seo
Keyword(s):  
Economic Effect ◽  
Hotel Industry ◽  
Price Difference ◽  
Multiple Sources ◽  
Short Term ◽  
Hotel Performance ◽  
Negative Effect ◽  
Research Gap ◽  
The Impact ◽  
Scholarly Attention

Much scholarly attention has been paid to Airbnb’s influence on the hotel industry. However, extant studies have limitations because they consider only Airbnb while overlooking various other short-term vacation rental players that can also affect performance of hotels. To address this research gap, this study aims to provide a broader understanding of the impacts of short-term vacation rentals by analyzing data obtained from various vacation rental platforms. This study shows that while increase in short-term vacation rentals has an overall negative effect on hotel performance, the economic effect is more significant in the low-end market than in the high-end market. Our findings further reveal that the negative effect is reduced when there is a large price difference between short-term vacation rentals and hotels. By comprehensively examining multiple sources of data on hotels and vacation rentals, this study brings alternative perspectives to the attention of researchers for further investigation of vacation rentals.

scholarly journals Performance of Base Stations in Railway Digital Radio Communication Networks

2021 ◽  
Vol 19 (2) ◽  
pp. 41-48
Author(s):  
Yu. V. Nemtsov ◽  
I. V. Seryogin ◽  
P. I. Volnov
Keyword(s):  
Communication Network ◽  
Communication Networks ◽  
Base Station ◽  
Base Stations ◽  
Radio Communication ◽  
Radio Communications ◽  
Digital Radio ◽  
Cargo Transportation ◽  
Assess Quality

Base station (BS) is a terminal device of a radio communication network, while railway radio communications play an important role in ensuring safety of passenger and cargo transportation.A proposed method for calculating the performance of base stations in railway digital radio communication networks is intended to calculate for the BS the probabilities of being in certain state.BS was decomposed and such functional elements as circuit groups and a radio frequency path were identified, as well as the central module ensuring the exchange of information with elements of this BS and with other BSs. A detailed study of each element has increased accuracy of the proposed method. Following the Markov model, BS is presented as a system in which all possible states are considered. Models for BS with two and three circuit groups have been constructed. The parameters of each functional element of the model can be obtained through observation over a certain period. The solution of the system of equations for each of the models presented in the article will allow obtaining the values of the system being in a certain state. The obtained characteristics can be used to calculate the reliability of the entire radio communication network, and then to assess quality of service provided to the users of this network.Conclusions are made about the possibilities of using the obtained models when designing new railway communication networks and when calculating quality indices of existing ones. The proposed models can be applied not only to railway radio communication networks but also to mobile communication networks of commercial operators. 

scholarly journals Investigation of the technology of mutual navigation and orientation of small space vehicles flying in formation

2019 ◽  
Vol 18 (1) ◽  
pp. 88-93
Author(s):  
A. V. Nebylov ◽  
V. V. Perliouk ◽  
T. S. Leontieva
Keyword(s):  
Video Camera ◽  
Space Vehicles ◽  
Radio Communication ◽  
Small Space ◽  
Modeling Simulation ◽  
Ground Station ◽  
Bench Experiment ◽  
Radio Communication System ◽  
The Cost ◽  
Orbital Constellation

The paper presents the problem of ensuring support of the flight of a group of small spacecraft (microsatellites) taking into account the small mutual distances between them. The purpose of using the orbital constellation specified is to create a radio communication system to control remote objects like unmanned aerial vehicles and ground robots located in hard-to-reach areas of the Earth from the Central ground station. To reduce the cost of microsatellite design, it was decided to rigidly fix the receiving and transmitting antennas on their housings and use the spatial orientation of the entire apparatus for antenna guidance. This seriously complicated the tasks of navigation and orientation of microsatellites in a formation and required the development of a new method for determining the orientation of a single microsatellite. The essence of the method is to process the image obtained by means of a video camera mounted on a nearby microsatellite. We used methods of computer vision. The results of mathematical modeling simulation, as well as the results of full-scale bench experiment confirming the efficiency of the proposed method are presented.

scholarly journals Aplikasi Monitoring Energi SHS Off-Grid Menggunakan Lora

2021 ◽  
Vol 13 (1) ◽  
pp. 26-32
Author(s):  
Satrio Yudho
Keyword(s):  
Internet Of Things ◽  
Long Range ◽  
Spread Spectrum ◽  
Communication System ◽  
Electricity Consumption ◽  
Radio Communication ◽  
Energy Monitoring ◽  
Chirp Spread Spectrum ◽  
Solar Home System ◽  
Radio Communication System

The manner of efficiency and effective of power usage is the main objective in electricity consumption, one major steps to control the usage is by providing a monitoring to aim the power usage data and process it to information needed. Internet of Things benefit in power and electricity has involved sensors to work as data reader continuously.  LoRa or well known as Long Range radio communication system work with chirp spread spectrum which work from 920 to 923 Mhz in Indonesia. This paper presents implementation of LoRa system to support the prototype of energy monitoring in Solar Home System off-grid

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