Research Papers
Abstract:
This paper analyzes the potential interference to Fixed Satellite Services (FSS), operating in the 10.70–12.2 GHz band, and Broadcasting Satellite Service (BSS), operating in the 12.2–12.7 GHz band, caused by the identification of the 10.0–10.5 GHz band for IMT, enabling mobile services in 5 G and future 6 G technologies in the Americas (ITU Region 2). The interference levels are evaluated using experimental results and Monte Carlo simulations. The results indicate that IMT systems could saturate the low-noise block feeders of FSS and BSS receivers, highlighting the need for interference mitigation strategies.
Published in Wireless Networks: link to the article
Spectrum analysis: assessing interference risks for Ku‑band satellite services resulting from 5G/6G systems operating in X‑band
Agostinho Linhares, Leandro Carísio Fernandes e Luciano Camilo Alexandre
Feasibility of the 6/7 GHz Frequency Band for 5G Urban Macrocells
Agostinho Linhares, Humberto Pontes e Leandro Carísio
Abstract:
The World Radiocommunication Conference 2023 (WRC-23) identified the frequency band 6,425 - 7,125 MHz for the International Mobile Telecommunications (IMT) systems. This paper evaluates the feasibility of using the 6/7 GHz band in urban macrocells, including indoor coverage. For this, it is used computational simulations based on the International Telecom-munication Union (ITU) methodology and input parameters, including Recommendations and Reports, and 3GPP Technical Reports. Both methodology and input parameters were used in studies supporting WRC-23 decisions. The results are consistent with field measurements that evaluated the performance of 5G systems operating in the 6/7 GHz band, suggesting that the use of this band will be important to ensure a balance between capacity and coverage.
Published in the Proceedings of "The 9th IEEE Asia Pacific Conference on Wireless and Mobile 2024": link to the article
Number of events in Monte Carlo simulations for analysis of interference between radiocommunication systems
Leandro Carísio Fernandes, Agostinho Linhares e Luciano Camilo Alexandre
Abstract:
Monte Carlo simulations are widely used in analysis of interference between radiocommunication systems. The method performs n random experiments, each called an event, snapshot, or trial, to estimate the statistics of some parameter of the problem (for instance, the interference level). There is no formalization about the number of events necessary to run a simulation. In practice, this is often done based on the intuition of the analyst about the model. In this paper, we propose how to choose a number of events for Monte Carlo simulations. We address this issue by understanding that the protection criteria for radiocommunication systems are usually related to a quantile of the result, and then calculating the number of events for which it is also possible to estimate a confidence interval for it. Results show that, for a confidence level of 99.9%, it is possible to estimate confidence intervals for p-quantiles for p up to 99.89% with 10000 events.
Published in "JMOe - Journal of Microwave, Optoelectronics and Electromagnetics Applications": link to the article
A Mathematical Formulation for Maximizing Allocative Spectrum Efficiency
Agostinho Linhares, Leonardo Euler de Morais, Leandro Carísio, Luciano Charlita de Freitas e Humberto Pontes
Abstract:
The efficient, rational, and economical use of frequency bands is a goal of spectrum management. Regulators around the world must decide how to most effectively allocate spectrum for national radiocommunication services, considering domestic demands and international regulations. This paper presents a mathematical formulation for optimizing allocative spectrum efficiency using non-linear programming. We propose a closed-form equation to calculate how much spectrum should be allocated to each radiocommunication service to optimize a given utility function. A case study is presented, applying the proposed formulation to the 6 GHz band, where many countries are evaluating how to address the IMT and WiFi spectrum demands.
Published in the Proceedings of "The 9th IEEE Asia Pacific Conference on Wireless and Mobile 2024": link to the article
European Influence on Brazil’s Digital Agenda
Agostinho Linhares, Leonardo Euler de Morais, Humberto Pontes, Raphael Marcerlino e Luciano Freitas
Abstract:
This article presents and analyzes initiatives undertaken by the three branches of government, particularly the Legislative Branch, addressing issues related to Brazil’s Digital Agenda. The main focus is on Digital Services and Markets, including cybersecurity and artificial intelligence. Brazil is facing the possibility of a new wave of regulatory agency creation, commonly referred to as “agencification.” However, when considering the expertise and enforcement powers already established by existing Special Government Agencies, it may be more advantageous, both in terms of efficiency and scope, to expand the mandates of these existing entities rather than establish new agencies. This approach promotes economies of scale and scope, optimizing resources while leveraging accumulated expertise and institutional experience. Furthermore, there is a noticeable trend toward harmonizing Brazilian regulatory proposals with international standards, particularly European ones, similar to what occurred with Brazil’s General Data Protection Law (LGPD) in relation to the General Data Protection Regulation (GDPR).
Published in the Proceedings of CPR LATAM 2024: link to the article