Dianne Scherly Varela Medeiros

New digital television standards are emerging to meet the demand for new services from TV broadcasters, as well as to support new high-resolution audio and video formats available on the market. In Brazil, the Brazilian Digital TV System (SBTVD) Forum defines the standard to be adopted. Among the currently available physical layer technologies, the Advanced Television Systems Committee (ATSC) 3.0 standard offers great flexibility in operating modes, depending on the broadcasters’ requirements and propagation conditions, for both fixed and mobile reception. This allows the system to be configured to balance robustness and transmission efficiency. This paper presents the performance test results in various mobile reception scenarios in the city of Rio de Janeiro, using an ATSC 3.0 signal with a transmission rate of 32.3 Mbps in a $2\times 2$ Multiple-Input Multiple-Output (MIMO) configuration. The results showed a reception success rate of 53.6%, with an increase in reception errors for Carrier-to-Noise Ratio (C/N) lower than 26 dB. Furthermore, reception errors were detected with greater intensity when the received signal level was below -70 dBm. Although the overall success rate was around 50%, the complementary metrics (C/N threshold, RSSI, and PLP0 error behavior) were consistent with theoretical expectations, demonstrating that ATSC 3.0 performs effectively under real urban mobility conditions at high spectral efficiency. ATSC 3.0 thus proved effective in broadcast transmission, meeting the needs for ultra-high-definition (UHD) audio and video broadcasting.

O aumento no número de veículos autônomos desafia as operadoras de telecomunicações e a gestão pública, exigindo soluções que garantam a segurança e a fluidez do trânsito, e que suportem a demanda heterogênea das aplicações de rede. Neste cenário, os Sistemas de Transporte Inteligentes (Intelligent Transportation Systems ITS), integrados às redes 5G, desempenham papel fundamental na gestão do trânsito e na locomoção dos usuários. O planejamento de trajetórias emerge como uma solução para os desafios da mobilidade urbana no ecossistema de veículos conectados, garantindo trajetos que respeitem as leis de trânsito e os requisitos das aplicações de rede executadas pelos veículos. Este artigo propõe a estratégia de Planejamento de Trajetória Orientada a Qualidade de Serviço (Quality of Service-Oriented Path Planning - QoS-OPP), que considera dados históricos da qualidade do canal para definir a melhor trajetória que atende à QoS exigida pelas aplicações. A proposta é avaliada em um estudo de caso em um bairro de Niterói/RJ por meio de simulações que refletem as leis de trânsito locais e a rede 5G que atende à região. Os resultados mostram um aumento de até 19% na vazão, enquanto reduz o atraso em até 54%.

A Qualidade de Serviço (QoS) é mandatória em redes móveis de próxima geração (além do 5G e 6G) para suportar serviços de banda larga móvel aprimorada (eMBB), comunicação ultraconfiável de baixa latência (URLLC) e comunicação massiva entre máquinas (mMTC) em uma Rede de Acesso via Rádio Aberta (Open RAN). Contudo, a complexidade na gestão dessas redes aumenta a probabilidade de erros de configuração que implicam degradação da QoS. Este artigo propõe um sistema baseado em intenções, no qual os operadores controlam a alocação de recursos por meio expressões em linguagem natural, traduzidas em políticas de rede para controle dinâmico de largura de banda. O sistema é validado em um ambiente emulado, medidores OpenFlow e filas de tráfego. Os resultados mostram a alocação eficiente de recursos e conformidade com os Acordos de Nível de Serviço (SLAs), garantindo a QoS e a priorização do tráfego para fluxos.

Data security in the Internet of Things (IoT) is crucial for protecting both the devices and the data they transmit over the network. Nevertheless, security is often overlooked in this context, leaving systems vulnerable to cyberattacks that can compromise information confidentiality and integrity. This work focuses on a use case of an environment remote monitoring system for disaster prevention, in which information must be confidential and intact. The AES (Advanced Encryption Standard) and Speck cryptographic algorithm families are evaluated in both traditional and memory-optimized implementations, targeting data confidentiality. The algorithms are assessed through practical experiments on two resource-constrained hardware platforms. Transmission throughput, estimated energy consumption, execution time, and memory usage are evaluated. Results show that the Speck family executes more quickly, has lower estimated energy consumption, and occupies less memory space than AES in both platforms.

The Flying Ad-hoc Networks (FANETs) enhance the coverage capacity in cellular networks by forwarding data in multiple hops using Unmanned Aerial Vehicles (UAVs). Nevertheless, unlike classic ad-hoc networks, FANETs have specific characteristics, such as free movement in three dimensions and very high-speed nodes. These characteristics lead to a more complex and dynamic mobility pattern compared to other ad-hoc networks, generating more frequent topology changes. This paper proposes the Greedy Weighted Perimeter Routing Protocol (GWPRP), which aims to improve networking performance. GWPRP is a location-aware and greedy cross-layer routing protocol based on a classic protocol for vehicular networks, the Greedy Perimeter Stateless Routing (GPSR). Following a similar greedy strategy, GWPRP forwards packets based only on local information obtained from neighbors, which considers link and network layer information, local link stability, and node location. We assess the protocol in a simulated environment, comparing its performance with GPSR and Energy Efficient Hello Ad-hoc On-Demand Distance Vector (EE HELLO AODV), a variant of AODV for FANETs. The results show that GWPRP achieves a higher packet delivery ratio with smaller control overhead and lower average end-to-end delay and jitter.

The COVID-19 pandemic has highlighted the necessity for agile health services that enable reliable and secure information exchange, but achieving proper, private, and secure sharing of EMRs remains a challenge due to diverse data formats and fragmented records across multiple data silos, resulting in hindered coordination between healthcare teams, potential medical errors, and delays in patient care. While centralized EMR systems pose privacy risks and data format diversity complicates interoperability, blockchain technology offers a promising solution by providing decentralized storage, ensuring data integrity, enhancing access control, eliminating intermediaries, and increasing efficiency in healthcare. By focusing on a Brazilian case study, this paper explores the significance of EMR standards, security challenges, and blockchain-based approaches to promote interoperability and secure data sharing in the healthcare industry.