Browsing by Author "Cavalcanti, Carlos Frederico Marcelo da Cunha"

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    An architectural framework for providing QoS in IP differentiated services networks.
    (2001) Trimintzios, Panos; Andrikopoulos, Ilias; Pavlou, George; Cavalcanti, Carlos Frederico Marcelo da Cunha; Georgatsos, Panos; Griffin, David; Jacquenet, C.; Goderis, D.; T'Joens, Y.; Georgiadis, Leonidas; Egan, R.; Memenios, G.
    As the Internet evolves, a key consideration is support for services with guaranteed quality of service (QoS). The proposed differentiated services (DiffServ) framework, which supports aggregate traffic classes, is seen as the key technology to achieve this. DiffServ currently concentrates on control/data plane mechanisms to support QoS but also recognises the need for management plane aspects through the bandwidth broker (BB). In this paper we propose a model and architectural framework for supporting end-to-end QoS in the Internet through a combination of both management and control/data plane aspects. Within the network we consider control mechanisms for traffic engineering (TE) based both on explicitly routed paths and on pure node-by-node layer 3 routing. Management aspects include customer interfacing for service level specification (SLS) negotiation, network dimensioning, traffic forecasting and dynamic resource and routing management. All these are policy-driven in order to allow for the specification of high-level management directives. Many of the functional blocks of our architectural model are also features of BBs, the main difference being that a BB is seen as driven purely by customer requests whereas, in our approach, TE functions are continually aiming at optimising the network configuration and its performance. As such, we substantiate the notion of the BB and propose an integrated management and control architecture that will allow providers to offer both qualitative and quantitative QoS-based services while optimising the use of underlying network resources
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    Blockchain é tudo que você precisa : a integração e comunicação descentralizada dos sistemas da Indústria 4.0.
    (2022) Garrocho, Charles Tim Batista; Oliveira, Ricardo Augusto Rabelo; Cavalcanti, Carlos Frederico Marcelo da Cunha; Oliveira, Ricardo Augusto Rabelo; Cavalcanti, Carlos Frederico Marcelo da Cunha; Loureiro, Antônio Alfredo Ferreira; Greve, Fabíola Gonçalves Pereira.; Silva, Jorge Miguel Sá; Correia, Luiz Henrique Andrade
    A Internet Industrial das Coisas é um novo marco que exigirá novos paradigmas e investimentos na indústria. Nesse contexto, os sistemas ciber-físicos são considerados a ponte para a quarta revolução industrial. Um exemplo disso é apresentado por diversos trabalhos recentes que aplicam novas tecnologias de hardware e software que permitem uma maior integração vertical dos sistemas de automação de processos industriais. Tais trabalhos geralmente possuem abordagens centralizadas e adicionam novos elementos na infraestrutura de rede que podem afetar as restrições de tempo na comunicação de processos industrias. Buscando uma decentralização na integração e comunicação entre dispositivos e sistemas industriais, o blockchain vem sendo amplamente aplicado, tornando os processos industriais mais seguros, automáticos, rastreáveis, imutáveis, e auditáveis. Entretanto, a utilização de tecnologias relacionadas a blockchain para o controle de processos também pode sofrer com problemas temporais que podem afetar os prazos de processos sensíveis ao tempo. Portanto, tornar a integração e comunicação dos processos industriais decentralizados que atendam os requisitos rigorosos de sistemas sensíveis ao tempo é um importante desafio que deve ser superado para o avanço da Indústria 4.0. Para enfrentar e superar esse desafio, é apresentado nessa tese diferentes arquiteturas de integração baseada em blockchain dos sistemas de automação de processos industriais. Essas arquiteturas aplicam contratos inteligentes baseados em blockchain como middleware na comunicação entre máquinas e dispositivos de monitoramento de chão de fábrica, permitindo uma decentralização do controle e o monitoramento de dispositivos industriais sem afetar os processos sensíveis ao tempo. Como provas de conceito, foram desenvolvidos sistemas de automação industrial baseado nas arquiteturas e implantados em dispositivos controladores sensíveis ao tempo. As avaliações de desempenho das provas de conceito permitiram a análise de viabilidade e o comportamento das arquiteturas propostas. Além disso, as discussões dessas experiências resultaram no desenvolvimento de metodologias e modelos que podem contribuir significamente no projeto, desenvolvimento, implantação e monitoramento de sistemas industriais baseados em tecnologias blockchain.
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    Engineering the multi-service internet : MPLS and IP-based techniques.
    (2001) Trimintzios, Panos; Georgiadis, Leonidas; Pavlou, George; Griffin, David; Cavalcanti, Carlos Frederico Marcelo da Cunha; Georgatsos, Panos; Jacquenet, C.
    IP Differentiated Services (DiffServ) is seen as the framework to support quality of service (QoS) in the Internet in a scalable fashion, turning it to a global multiservice network. In this context, integrated service/network management and traffic control mechanisms are of paramount importance for service provisioning and network operation, aiming to satisfy the QoS requirements of contacted services while optimizing the use of underlying network resources. In this paper, after briefly introducing an architectural framework for integrated service/network management and control, we concentrate in its traffic engineering aspects comparing and contrasting two different approaches: MPLS-based explicit routed paths and IP-based hop-by-hop routing. We consider relatively longterm network dimensioning based on the requirements of contracted services and subsequent dynamic route and resource management that react in shorter time scales to statistical traffic fluctuations and varying network conditions.
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    IoT registration and authentication in smart city applications with blockchain.
    (2021) Ferreira, Célio Márcio Soares; Garrocho, Charles Tim Batista; Oliveira, Ricardo Augusto Rabelo; Silva, Jorge Sá; Cavalcanti, Carlos Frederico Marcelo da Cunha
    The advent of 5G will bring a massive adoption of IoT devices across our society. IoT Applications (IoT Apps) will be the primary data collection base. This scenario leads to unprecedented scalability and security challenges, with one of the first areas for these applications being Smart Cities (SC). IoT devices in new network paradigms, such as Edge Computing and Fog Computing, will collect data from urban environments, providing real-time management information. One of these challenges is ensuring that the data sent from Edge Computing are reliable. Blockchain has been a technology that has gained the spotlight in recent years, due to its robust security in fintech and cryptocurrencies. Its strong encryption and distributed and decentralized network make it potential for this challenge. Using Blockchain with IoT makes it possible for SC applications to have security information distributed, which makes it possible to shield against Distributed Denial of Service (DDOS). IoT devices in an SC can have a long life, which increases the chance of having security holes caused by outdated firmware. Adding a layer of identification and verification of attributes and signature of messages coming from IoT devices by Smart Contracts can bring confidence in the content. SC Apps that extract data from legacy and outdated appliances, installed in inaccessible, unknown, and often untrusted urban environments can benefit from this work. Our work’s main contribution is the development of API Gateways to be used in IoT devices and network gateway to sign, identify, and authorize messages. For this, keys and essential characteristics of the devices previously registered in Blockchain are used. We will discuss the importance of this implementation while considering the SC and present a testbed that is composed of Blockchain Ethereum and real IoT devices. We analyze the transfer time, memory, and CPU impacts during the sending and processing of these messages. The messages are signed, identified, and validated by our API Gateways and only then collected for an IoT data management application.
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    Uma metodologia heurística baseada em grasp, VND e VNS para a resiolução do problema de dimensionamento em redes IP.
    (2004) Cavalcanti, Carlos Frederico Marcelo da Cunha; Souza, Marcone Jamilson Freitas; Souza, Fernanda Sumika Hojo de; Coelho, Viviane de Souza
    O presente trabalho apresenta uma proposta de formulação e implementação de algoritmos baseados nas técnicas de otimização GRASP (Greed Randomized Search Procedure), VND (Variable Neighborhood Descent) e VNS (Variable Neighborhood Search) para satisfazer a nova geração da Internet, que implementa Qualidade de Serviço e Engenharia de Tráfego. Este contexto surgiu da crescente expansão da Internet e da necessidade de satisfazer a novos requisitos impostos por aplicações mais complexas, tais como transmissões em tempo real, exigindo que caminhos explícitos entre um nó de entrada da rede e um ou mais nós de saída sejam computados. Esta tarefa é também chamada de dimensionamento da rede. Resultados computacionais são apresentados, comprovando que é possível prover uma melhora no dimensionamento da rede através das técnicas propostas.
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    Qualidade de serviço IP : nasce uma nova internet.
    (2000) Cavalcanti, Carlos Frederico Marcelo da Cunha; Loureiro, Antônio Alfredo Ferreira; Fernandes, Antônio Otávio; Nogueira, José Marcos Silva
    Por causa do rápido crescimento do tráfego em aplicações de tempo real, as redes de computadores requerem mais funções do que anteriormente oferecidas no passado. Na presente geração da Intemet, constata-se a grande demanda por aplicações comércio eletrônico, de voz e de multimídia. É essencial que a rede suporte diferentes níveis de Qualidade de Serviço (QoS) e cada nível seja associado a um usuário ou a um grupo de usuários distintos. Em resposta ao crescimento da demanda por QoS na Intemet, a Internet Engineering Task Force estabeleceu dois grupos de trabalho denominados DiffServ and IntServ. Este artigo apresenta os principais conceitos e soluções propostas por ambos para prover Qualidade de Serviço, estendendo a arquitetura TCP/IP.
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    Real-time systems implications in the blockchain-based vertical integration of industry 4.0.
    (2020) Silva, Mateus Coelho; Ferreira, Célio Márcio Soares; Cavalcanti, Carlos Frederico Marcelo da Cunha; Oliveira, Ricardo Augusto Rabelo
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    Simulação de roteamento em redes IP com QoS.
    (2004) Cavalcanti, Carlos Frederico Marcelo da Cunha; Nascimento, Ricardo Alonso dos Santos; Borges, Daniel Prata Leite
    The costumer demands for multimedia and realtime applications are rising up the Internet into a new level of guarantees of QoS. This article explains the key steps to provide an effective schema of how to implement QoS routing based on Diffserv and MPLS and explains how to simulate it using the classical NS-2 simulator.
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    System-level partitioning with uncertainty.
    (1999) Albuquerque, Jones; Coelho Júnior, Claudionor José Nunes; Cavalcanti, Carlos Frederico Marcelo da Cunha; Silva Júnior, Diógenes Cecílio da; Fernandes, Antônio Otávio
    Several models and algorithms have been proposed in the past to generate HW/SW components for system-level designs. However, they were focused on a single designer who had a throughout knowledge of the design. In other words, the decision trade-offs were simplified to a stand-alone developer who did not have to consider individual skills, concurrent development for portions of the design, risk analysis for time-to-market development, nor team load and assignment. In this paper, we propose a design management approach associated with a partitioning methodology to deal with the concurrent design problems of system-level specifications. This methodology allows one to incorporate the uncertainties related to development at the very early stages of the design, and to follow up during the development of a final product.
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    Using Blockchain and Low Power in Smart Cities to internet of thigs applications : a Fog Computing approach.
    (2022) Ferreira, Célio Márcio Soares; Oliveira, Ricardo Augusto Rabelo; Silva, Jorge Sá; Oliveira, Ricardo Augusto Rabelo; Aquino, André Luiz Lins de; Cavalcanti, Carlos Frederico Marcelo da Cunha; Ramos Filho, Heitor Soares; Correia, Luiz Henrique Andrade; Silva, Saul Emanuel Delabrida; Silva, Jorge Miguel Sá
    With the advent and popularization of Internet of Things (IoT) devices, new possibilities for applications that use data extracted from the things we use in everyday life arise. Cars, wearables, health sensors, and home appliances will generate unprecedented amounts of data and bring insights that will revolutionize our daily routines. A potential scenario significantly impacted is Smart Cities (SC), which uses devices spread out on a large scale in an urban environment to extract traffic, weather, and equipment maintenance data to obtain insights acting on city management and disaster prevention. The network infrastructure currently available for these network applications uses proprietary communication technologies and is dependent on mobile phone companies. Their systems are proprietary, centralized, isolated from other databases, and constantly exposed to Single Point of Failure (SPOF). IoT applications are still primarily embryonic and do not provide reliable verification of the data source at the edge, as in the case of IoT devices, often with outdated firmware. Our work investigates the use in SC of a composition of Low Power Wide Area Networks (LPWAN) and the popular Personal Area Networks (PAN), independence of mobile network providers, and Low Power consumption. For this, we used development kits with LoRa and BLE to verify the feasibility and possible problems in this integration, and we evaluated the scalability of LoRa using a simulator. Security gaps in IoT Apps in Smart Cities mainly come from the difficulty of knowing and trusting edge devices. The problem of standardizing and updating these devices during their lifetime justifies our search for using tools that support transparency, scalability, reliability, resilience, and implicit requirements of decentralized Blockchain networks that support Smart Contracts. For this, we present a network architecture using Fog Computing and Smart Contracts Blockchain, which, through API gateways, authorizes and authenticates edge communication from IoT devices previously known by their metadata and firmware. To provide standard and link data from Blockchain with existing Web datasets, we use and add new components to ontologies that model Ethereum entities. This approach allows us to use the semantic web for data consumption and linking, which exposes data from Ethereum networks in soft-realtime through middleware. This work investigates the potential use of Fog Computing in SC in Low Power networks, strategies to identify and authenticate IoT devices at the edges using Blockchain and Smart Contract, and consumption and data link of Blockchain with the current web using the Semantic web. The set of these resources used in Fog computing allows searching for a composition of independent SC network infrastructures, Low Power, with reliable information coming from the edges and integrable with other pre-existing data sets. As the main results, we show the limits of the LoRa network, using a simulator in single-gateway and multi-gateway scenarios. We present scenarios of mixed use of traditional using Blockchain as authentication and validation background, by API gateway in Fog Computing architecture, and we present the times in transactions per second of this approach considering signatures and validation of payloads using Ethereum Blockchain. We present a middleware to expose Ethereum data in soft-realtime using ontologies that model Ethereum in the literature and extended by our EthExtras ontology, providing classes and properties for links and queries.The main advances of this work are the models using the Fog Computing paradigm for Smart Cities, where we present its use as a mixing point of LoRa and BLE and the Blockchain API Gateway to validate data from IoT devices. In addition to our Middleware for extracting and consuming Ethereum data in soft real-time using our EthExtras and EthOn vocabulary.