Radio Link System Research Articles

Estimation of some Radio Propagation Parameters using Measurements of Surface Meteorological Variables in Ede, Southwest Nigeria

A data acquisition system that utilised the open-source Arduino platform was developed to take real-time ground measurements of primary radio climatological variables of pressure, temperature, and relative humidity at Ede, a tropical station in southwest Nigeria (7.7349^{o} N, 4.4439^{o} E). Surface radio refractivity was deduced from these variables and used to estimate refractivity gradients at 100 m and 1000 m heights from the exponential reference atmosphere model for terrestrial propagation. Secondary radio propagation parameters such as refractivity gradients, the effective-earth-radius-factor, k, and geoclimatic factor, K, essential parameters for quick application in the planning and design of line-of-sight radio link systems, were also deduced. Data acquired from the device were compared to those obtained from the Re-Analyses (ERA-5) satellite database of the European Centre for Medium-Range Weather Forecast (ECMWF) 2020/2021. Aside from logging data on a micro secure digital (SD) card, measurements were displayed on a liquid crystal display (LCD). The peripheral Arduino-compatible meteorological sensors were connected to the analog inputs of the ATMega328 in the Arduino independent development environment (IDE), and the unit was powered by a 12 V battery charged by a 50-watt solar module. Results showed that slightly higher values of the ERA-5 data characterise the dry months from November to March, while the wet months displayed higher values of the Arduino-derived measured data. The accuracies of the data collected were compared using Mean Percentage Error (MPE) performance indicator. The interpretation is that the mean difference between the Arduino inferred measurements and the ERA-5 data is less than 10%, which is an indication of the measurement accuracy.

A test of general relativity with ESA’s JUICE mission

The ESA’s JUICE mission is planned for launch in April 2023. After a 8.3-year interplanetary cruise it will reach the Jovian system in mid 2031. The mission is devoted to the study of Jupiter and three of the Galilean moons (Europa, Callisto and Ganymede). The 3GM (Geodesy and Geophysics of Jupiter and the Galilean Moons) radio-science package onboard the spacecraft comprises a Ka-band Transponder (KaT) that will enable a highly stable two-way coherent Ka/Ka link to study the gravity fields of the three Jovian satellites and their internal structure, and an Ultra Stable Oscillator (USO) to probe the atmosphere of Jupiter and the ionospheres of the three moons. The KaT can be used together with the onboard Deep Space Transponder (DST), enabling a full multi-frequency radio link system capable to suppress the dispersive noise, due to solar plasma and ionospheric effects, at nearly all solar elongation angles. The cruise phase of the mission provides three opportunities to perform classical tests of general relativity by measuring the relativistic time-delay and the frequency shift experienced by radio signals during superior solar conjunctions. A similar experiment, performed by Cassini in 2002, provided the most accurate measurement of the post-Newtonian parameter γ so far, with an accuracy of 2.3×10-5. The MORE experiment onboard the ESA/JAXA BepiColombo mission to Mercury is expected to improve the result obtained by Cassini up to a factor of 10 while orbiting the planet. Less significant improvements are expected in the cruise phase. The advanced radio-tracking system of JUICE and the favorable dynamical environment experienced in the outer solar system make a repetition of the Cassini and BepiColombo cruise experiments quite significant. In this work, we show the results of numerical simulations of JUICE superior conjunction experiments. We have found that 3GM can estimate γ with an accuracy at the level of 4.8×10-7, which represents a constraint on the value of γ 50 times tighter than the one obtained by Cassini and about four times better than the expected result from BepiColombo at the end of the mission.

Rework the Radio Link Budget for 5G and Beyond

The 5th generation of mobile communication system (5G) enables the use of millimeter wave frequency bands and beamforming with narrow-beam directional antennas for mobile communication. Accurate estimation of radio link budget which enables direct assessment of achievable cell range or maximum throughput and facilitates network parametrization before deployment is one of the most challenging problems in radio network planning. In contrast to traditional cellular systems, where omni-directional or sectoral antennas are deployed with half-power beam-width much larger than angular spread of the radio channel, the beam-width of antenna arrays assumed for 5G in sub-6GHz and millimeter wave bands can be comparable to or smaller than channel angular spread in scattering environment. Since the effective antenna pattern is determined jointly by the nominal antenna pattern and channel angular spread, it is no longer appropriate to use nominal pattern in radio link budget analysis or system level simulations. Simplified approach, where nominal pattern is assumed for all typical propagation conditions, results in overestimation of the signal power in serving links and underestimation of interference, which in consequence gives erroneous estimation of link budget and leads to unsatisfactory network design and deployment. To avoid inaccurate calculation of link budget while maintaining simplicity it is proposed to modify the simplified approach by using effective antenna patterns. On the other hand, effective antenna pattern can be further optimized by matching its half-power beam-width to the angular spread of the radio channel. It is demonstrated via simulations how to rework the radio link budget for accurate estimation of system performance in high bands for 5G and beyond, along with benefits of effective antenna pattern optimization.

Rain attenuation and worst month statistics verification and modeling for 5G radio link system at 26 GHz in Malaysia

AbstractThe explosive daily dependence on wireless communication services necessitates the research to establish ultrawideband communication systems with ultrahigh bit rate transmission capabilities. The advent of the fifth‐generation (5G) microwave link transmitting at millimeter‐wave (mm‐wave) frequency band is a promising technology to accommodate the escalating demand for wireless services. In this frequency band, however, the behavior of the transmission channel and its climatic properties are a major concern. This is of particular importance in tropical regions where the climate is mainly rainy with large raindrop size and high rainfall rate that may interact destructively with the propagating signal and cause total attenuation for the signal. International Telecommunication Union (ITU) introduced a global rain attenuation model to characterize the effect of rain on the propagating signal at a wideband of frequencies. The validity of this model in tropical regions is still an open question for research. In this paper, real measurements are conducted at Universiti Teknologi Malaysia (UTM), Johor Bahru, Malaysia, to investigate the impact of rain on the propagation of mm‐waves at 26 GHz over the microwave 5G radio link system. Rainfall rate and rain attenuation data sets are collected for one year at one sample per min sampling rate. Both data sets are used to estimate signal propagation conditions in comparison to the ITU model prediction. From the presented results, it is found that at 0.01% percentage of time and rainfall rate of about 120 mm/hr, the propagated signal would experience 26.2 dB losses per kilometer traveled. In addition, there is a significant deviation between the empirical estimation of the worst month parameters and the ITU worst month parameter prediction. Similarly, rainfall rate and rain attenuation estimated through the ITU model imposes a large deviation as compared with the measurements. Furthermore, more accurate empirical worst month parameters are proposed that yielded more accurate estimation of the worst month rainfall and rain attenuation predictions in comparison to the ITU model predictions.

Radio link system solutions for mobile platforms operatingin sea environment

Abstract In this paper radio link system solutions operating in 300 MHz — 3000 MHz range and sea environment were described. Solutions with more than one frequency and wave propagation models for horizontal not more than 50 km and far range were described. In the paper the results of actions taken design and construction solutions adopted were presented, aimed to contribute to ensure the reliability of the system, among other things, by implementing mechanisms for collecting and processing information. This solutions allow resources management to automatically adjust the transmission parameters configuration to the bitrate and range requirements. Available configurations can be extended with active part and electronic beam steering with one or more beams. The paper describes antenna systems ability of transmission parameters adaptation to get the range required.

Real Measurement Study for Rain Rate and Rain Attenuation Conducted Over 26 GHz Microwave 5G Link System in Malaysia

In this paper, real measurements were conducted to investigate the impact of rain on the propagation of millimeter waves at 26 GHz. The measurements were accomplished using a microwave fifth generation radio link system with 1.3 km path length implemented at Universiti Teknologi Malaysia Johor Bahru, Malaysia. The implemented system consisted of Ericsson CN500 mini E-link, radio unit, rain gauge, and data logger. The measurements were attained and logged daily for a continuous year, with 1-min time intervals. Next, the MATLAB software was used to process and analyze the annual rain rate and rain attenuation, including for the worst month. From the analyzed results, it was found that at 0.01% percentage of time, the rain rate was 120 mm/hr; while the specific rain attenuation was 26.2 dB/km and the total rain attenuation over 1.3 km was 34 dB. In addition, the statistics acquired from the measurements for the worst month were lower than what was predicted by the international telecommunication union (ITU) model; around 51% and 34% for the rain rate and rain attenuation, respectively. The average percentage of error calculated between the measurements and predicted results for the rain rate and rain attenuation were 143% and 159%, respectively. Thus, it can be concluded that the statistics for the worst month in Malaysia is lower than what was predicted by the ITU model.

Real-Time Analysis for Remote Operations Centers

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper IPTC 16999, ’Remote Real-Time Analysis - A Game Changer for Remote Operations Centers,’ by Erland Saeverhagen, Arve Thorsen, Jan Ove Dagestad, Nic Spanovic, and Kate Cannon, SPE, Baker Hughes, prepared for the 2013 International Petroleum Technology Conference, Beijing, 26-28 March. The paper has not been peer reviewed. Drilling completion, production, and general surveillance are all areas that benefit greatly from remote real-time analysis. However, several challenges to remote services exist, including communications issues, fear of job loss, and working outside one’s comfort zone. What is considered an important development goal for a business might be regarded as a threat to an individual, leading to reduced development within remote services. Remote-Operations Business Model A remote-operations business model removes geographic location and physical distance in all phases of oilfield-service delivery. It reduces the cost of delivering services, increases geographic reach, and improves safety. Remote operations, in essence, are real-time workflows that integrate personnel at rigsites and at assembly and maintenance and overhaul (AMO) facilities; at remote operations centers; or at real-time operational centers (RTOCs) anywhere in the world. Remote operations are the acquisition of sensor data from rigsite equipment and instruments, and the transmission and processing of those data from remote locations. Monitoring, alarm, or advisory services are delivered in real time with global delivery models, increasing the capability to move work from the point of service to another lo cation, where it can be performed more safely, more quickly, and at a lower cost. Infrastructure, while critical, is only an enabler. The true sources of efficiency and competitive advantage come from the organizational redeployment of the workforce and the re-engineering of workflows. Providing on-demand expertise enables service providers to deploy new technology faster and deliver high-end services in areas with few local qualified resources. Customers also benefit from bundled services, which require the integration of different disciplines and expertise that may be in short supply. The Digital Oil Field Improved connectivity through radio link, fiber optics, and satellite systems has opened a new world of opportunities for operation optimization. Real-time operations monitoring occurs from any office, accessing data streams through Web portals. New downhole tools and software have been developed on the basis of these new abilities, and new service levels have resulted, leading to new and interesting jobs, improved well placement, high service quality, and reduced non-productive time (NPT).

항공기 RF 장비들의 신호 간섭 방지를 위한 필터 설계

This paper presents method to suppress signal interference by using the filter in the RF output stage of the radiation equipment as a way to avoid interference between the RF(Radio Frequency) equipment mounted on aircraft. Especially filter design to suppress harmonics of the radiation equipment and testing method to verify the filter`s performance is presented. Filter was installed at RF output stage of U/VHF radio in order to prevent interference between U/VHF(Ultra/Very High Frequency) radio and data link system. Filter design and testing method in this paper will be able to give help in the design of aircraft equipments as a tool that can be used to establish measures for problem of interference in the aircraft.

A Compact Analytical Design of Dual-Loop 18 GHz Frequency Synthesizer to Enhance Signal Reliability in Digital Millimeter Radio Link System

A Compact Analytical Design of Dual-Loop 18 GHz Frequency Synthesizer to Enhance Signal Reliability in Digital Millimeter Radio Link System

A Compact Analytical Design of Dual-Loop 18 GHz Frequency Synthesizer to Enhance Signal Reliability in Digital Millimeter Radio Link System

In this paper a high resolution dual-loop 17.7–19.7 GHz frequency synthesizer is presented which is compatible with ITU-R (F.595-6) standards. The investigations of phase noise and spur frequency contents are discussed in detail. The simulated and measured phase noise and spur frequency contents are similar to one another. Phase noise of –81 dBc/Hz in 17.7 GHz at 10 KHz offset frequency is measured by (HP8560) series Spectrum analyzer and it matches with predicted measurements.

ＭＵレーダによる下部成層圏風速の観測 成層圏無線中継システムのための環境評価

Height, seasonal, and short-period variations of lower stratospheric winds around 20km altitude, where aircraft for the stratospheric radio link system will fly, are analyzed based on the wind data obtained by the MU (middle and upper atmosphere) radar for three years. While the stratospheric jet stream was found to be weak enough in summer, it turned to be fairly strong in winter even at the so-called ‘zero-wind’ height of around 20km, sometime exceeding 40m/s over a period of two days. Random wind fluctuations of the order of 1m/s was found to exist in thin turbulent layers of 50-100m thickness.

Capacity of time-space switched cellular radio link systems for metropolitan area networks

Capacity of time-space switched cellular radio link systems for metropolitan area networks

4. A range of metal-ceramic travelling wave tubes from 100 mW to 100 W, using a common vacuum envelope

This paper describes the construction, processing and testing of a range of small metal-ceramic packaged travelling wave tubes (TWTs). The construction was originally developed for TWTs for use as the output amplifier in radio-link communications systems. These operate over relatively narrow band-widths at output power levels between 5 and 22 W. However, the construction has since proved suitable for broadband low noise TWTs for military applications, and for CW power levels of up to 100 W CW in C-band. It has proved possible to cover frequencies from 3.6 to 18 GHz at power levels from a few mW upwards. At present there are some 30 types in the range, with the majority of piece-parts used in the construction remaining common throughout the range, regardless of frequency or power output. Automated helix winding and measuring systems allow rapid response to new requirements by modifications to the helix parameters without major changes to any of the other piece-parts.

Components for Microwave Integrated Circuits with Evanescent-Mode Resonators

The electrical performance of active microwave components for radio link systems, which have been realized utilizing evanescent-mode resonators, is described. This waveguide-below-cutoff technique is shown to be an alternative to the techniques established before now.

Planning 13-GHz TV Relay Systems

Considerable study has been done in recent years by propagation analysts in regard to the effects of precipitation loss in the 10-13 GHz region. This paper assembles this work, relating it it to earlier propagation estimating rules. These rules are presented in conjunction with practical problems of planning radio link systems in the 13-GHz band, for specific performance objectives.