Programa de Pós-Graduação em Engenharia Elétrica - PPGEE/ITEC
URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/2314
O Programa de Pós-Graduação em Engenharia Elétrica (PPGEE) do Instituto de Tecnologia (ITEC) da Universidade Federal do Pará (UFPA) foi o primeiro e é considerado o melhor programa de pós-graduação em Engenharia Elétrica da Região Amazônica. As atividades acadêmicas regulares dos cursos de mestrado e doutorado são desenvolvidas principalmente nas Faculdades de Engenharia Elétrica e Engenharia de Computação, supervisionadas pela Coordenação do Programa de Pós-Graduação em Engenharia Elétrica (CPPGEE).
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Item Acesso aberto (Open Access) Alocação de dois níveis para uma arquitetura h-cran baseada em offloading(Universidade Federal do Pará, 2019-01-24) GONÇALVES, Mariane de Paula da Silva; BARROS, Fabrício José Brito; http://lattes.cnpq.br/9758585938727609; CARDOSO, Diego Lisboa; http://lattes.cnpq.br/0507944343674734The accelerated data and apps growth represents significant challenges to the next generation of mobile networks. Amongst them, it is highlighted the necessity for a co-existence of new and old patterns during the transition of architectures. Thus, this paper has investigated solutions for offloading into a hybrid architecture, also known as H-CRAN (Heterogeneous Cloud Radio Access Network Architecture), that centralizes processing and searches a better use of the network resources. The strategy of optimization was analyzed through the evolutive algorithm PSO (Particle Swarm Optimization), in order to find a suboptimal solution to the allocation of two levels (TLA) in the H-CRAN architecture and another one based on FIFO (First In, First Out), for benchmarking purposes. SNR (Noise Interference Signal) average, Maximum Bit Rate, the number of users with or without connections and number of connections in RRHs and macro were used as performance measurements. Through the results, it was noticed an improvement of approximately 60% in the Maximum Bit Rate when compared to the traditional approach, enabling a better service to the users.Item Acesso aberto (Open Access) Análise de heurísticas de implantação de hetnets densas(Universidade Federal do Pará, 2017-02-24) ARAÚJO, Welton Vasconcelos; CARDOSO, Diego Lisboa; http://lattes.cnpq.br/0507944343674734The growth of traffic in mobile networks demands a search for new technologies that can bring evolutions to the sector in question. Technologies such as heterogeneous networks (HetNets) and C-RAN (Centralized Radio Access Networks) appear as prominent solutions to this demand. However, without proper planning in the deployment of these networks, problems such as deployment cost, interference, energy efficiency and subsequent network management can lead to project unfeasibility. In this sense, this work investigates how to plan a heterogeneous network, through several heuristics in the implementation of HetNets, which will be explained later. These algorithms are evaluated in scenarios that illustrate real environments, in addition to analyzing several metrics to perform the appropriate performance evaluation of each approach. The planning of the use of centralized networks is also addressed, with a comparison with the Distributed Radio Access Network (D-RAN) model in order to show in which situations one is less costly than other. With the results, it is possible to perceive that the change in the size of the network (numbers of connected users) directly influences the results, as well as having a good indication of which technology to use in a given situation.Item Acesso aberto (Open Access) Análise e classificação de severidade de COVID-19 usando aprendizado de máquina(Universidade Federal do Pará, 2022-08-16) LIMA, Marco Antonio Loureiro; CARDOSO, Diego Lisboa; http://lattes.cnpq.br/0507944343674734In the last years, with the alarming growth of COVID-19 cases, a highly contagious viral disease, new forms of diagnosis and control for this sickness have become necessary to the spread decreases until the population is effectively vaccinated. In this context, Artificial Intelligence (AI) and its subfields appear as possible alternatives to help and provides a response to combat the virus. Some Machine Learning (ML) methods are shown as an answer to control this disease, these methods can perform an analysis based on a set of symptoms presented by the patient and consequently indicating the diagnosis, as well as streamline the treatment process. To achieve this goal in this paper, three models that uses ML methods to predict COVID-19 severity on different degrees are proposed, unlike other works whose purpose was to diagnose only the presence or absence of COVID-19, this paper aims to improve the classification of the patient’s disease state. The results in each of these models are evaluated through the metrics established in this work. Furthermore, there are distinct suggestions to improve the analysis and make predictions with greater accuracy..Item Acesso aberto (Open Access) Uma análise técnico-econômica para implantação de arquiteturas centralizadas de redes de telefonia móveis(Universidade Federal do Pará, 2018-03-06) SOUZA, Daniel da Silva; CARDOSO, Diego Lisboa; http://lattes.cnpq.br/0507944343674734Upon the the challenges proposed by the fifth generation of mobile networks, the architecture of C-RAN (Centralized Radio Acess Network) has gained space by supporting high-capacity ultra-densas networks of next generation and offering economies. This dissertation proposes a TCO (Total Cost of Ownership) for C-RAN, CAPEX (Capital Expenditure), OPEX (Operational Expenditure) and these are the fundamental criteria in the field of investment assessment and projection. It is soon presented with a higher level of detailing as to the investment aspects, which are of great relevance to the architectural landscape of mobile communication networks. In this way, this work is conducted in order to evaluate the economic context of the implementation of a centralized architecture, based mainly on the financial aspects that service operators need to plan before deploying a new Mobile Access Network. The proposed model is used in a case study where the total cost of implementation and operation of the distributed and centralized architectures is compared taking into account several specific scenarios. The results point to an economy in the centralized scenarios and highlight the most relevant economic aspects in the planning of C-RAN.Item Acesso aberto (Open Access) Estratégias de planejamento de Smart Grids: uma abordagem baseada em meta-heurísticas e simulação(Universidade Federal do Pará, 2017-05-15) SANTOS, Ederson Costa dos; CARDOSO, Diego Lisboa; http://lattes.cnpq.br/0507944343674734Currently, the Electric Power System undergoes major modifications, which focus on various levels and sub-levels of the generation, transmission and distribution subsystems, all of which are based on Smart Grids logic. This concept is characterized by the inclusion of new digital technologies in the electrical system, with the purpose of bringing security, speed, monitoring, among many other benefits. For the full development of Smart Grids, a lot still needs to be done in several areas of research. In this line, this work presents simulations of a Smart Grid planning model, characterizing it from protocols, which are trends for this type of network. For this, we also analyzed an optimization method, which uses intelligent algorithms to optimize devices in a Smart Grid. The proposed solution is based on the optimized allocation of equipment in acommunication network, which uses as its physical transmission medium its own electrical wiring, Power Line Communitation technology. In this network are inserted Smart Grid applications defined through IEC 61850. Thus, with this proposed model, simulations were performed in the Network Simulator-3 discrete event software. The results show a significant decrease in the quantity of equipment, maintaining the quality levels to the applications.Item Acesso aberto (Open Access) Heurística para provisionamento dinâmico de recursos de hardware em redes híbridas de acesso via rádio considerando o efeito de maré(Universidade Federal do Pará, 2020-03-06) FALCÃO, Igor Wenner Silva; CARDOSO, Diego Lisboa; http://lattes.cnpq.br/0507944343674734The increase in the volume of services and applications, in addition to the accelerated growth in wireless access demands, represent significant challenges for the fifth generation of mobile networks, the 5G network. This increase in the volume of applications is a reflection of the growing number of devices connecting to the network, consuming data expansively, generating high data load. Another point of great impact is the large-scale daily migration of people in urban centers, causing the so-called Tide Effect. This promotes the space-time fluctuation of traffic throughout the day, making it difficult to control and manage the network (low efficiency in the use of hardware resources, load imbalance, underutilization and idleness of resources). Based on these indications and considering the knowledge of the service operators, data from the movement of users in New York City were extracted through an LBSN (Location-Based Social Network). Considering the expected high traffic demand for 5G and the problems arising from the Tidal Effect, this dissertation proposes a heuristic with two approaches to provisioning hardware resources (one based on the aggregate throughput and the other on the number of connected users). The results show that the network provisioning met the traffic variability of the scenario used, reducing the Probability of Blocking by 3.7%, maximizing the efficiency of the Base Band Unit (BBU) and quantifying the Small Cells (SCs) necessary to meet user demand.Item Acesso aberto (Open Access) Implantação de sistema fotovoltaico de baixo custo em arquitetura de rádio centralizada(Universidade Federal do Pará, 2020-01-31) SARAIVA, Paline Alves; CARDOSO, Diego Lisboa; http://lattes.cnpq.br/0507944343674734The growing demand for higher data rates and better quality of Internet services has resulted in high investments in mobile network infrastructure by operators. In this context, Centralized Radio Architecture (CRA) is a promising solution that relies on centralizing, sharing, and better allocating network resources, resulting in reduced deployment and operation costs when adequately planned. While the benefits of CRA are numerous, this cost reduction can also be enhanced through the adoption of alternative energy sources. One of the options for this, it is Growing demand for higher data rates and better quality of Internet services has resulted in high investments in mobile network infrastructure by operators. In this context, Centralized Radio Architecture (CRA) is a promising solution that relies on centralizing, sharing, and better allocating network resources, resulting in reduced deployment and operation costs when adequately planned. While the benefits of CRA are numerous, this cost reduction can also be enhanced through the adoption of alternative energy sources. One of the options for this equipment through optimization approaches, considering the energy demand of CRA, represents a challenge to be overcome. To this end, this work proposes a strategy to minimize the cost of imple- menting a photovoltaic system by reducing the number of inverters, formulated as an Integer Linear Programming (ILP) problem, to further reduce costs related to CRA. From the results, it is evident that the proposed optimization technique, implied in the average reduction of the Total Cost of Ownership (TCO) of the photovoltaic system in about 0.02 million reais, as well as in the environmental sustainability through the reduction of carbon dioxide emissions (CO2) in the atmosphere.Item Acesso aberto (Open Access) Mapeamento otimizado entre RRH-BBU visando o balanceamento de carga em arquitetura C-RAN utilizando inteligência computacional(Universidade Federal do Pará, 2018-12-20) PAIXÃO, Ermínio Augusto Ramos da; CARDOSO, Diego Lisboa; http://lattes.cnpq.br/0507944343674734The Cloud Radio Access Network (C-RAN) is an architecture proposition for next-generation mobile networks (5G), aimed at centralized management and processing, collaborative radio and real-time cloud computing. Such features enable this architecture to dynamically adjust the connections between Remote Radio Heads (RRHs) and Baseband Units (BBUs). However, if this feature is neglected, network problems such as blocked call and poor connection may occur. This work addresses this issue and proposes an optimized mapping model between RRH-BBU, seeking a fairer and more efficient balancing. In this sense, the Key Performance Indicator (KPI) of blocked calls was used to measure Quality of Service (QoS) metrics. In order to minimize them, an algorithm by Particle Swarm (PSO) was developed. A literature scenario composed of 19 RRHs distributed in a geographical area was used, which can be mapped in a BBU pool that manages two BBUs that have three sectors each. The initial configuration generated, on average, 80 blocked calls. Results obtained indicate a reduction of up to 100% of blocked calls and a more egalitarian load distribution among the BBUs. In addition, realistic scenarios with different user profiles were implemented, demonstrating that such factors directly impact the load generated by the BBUs and, consequently, affect their balancing. In order to verify the proposed formulation, in Network Simulator (NS-3) the same scenario used in the modeling was implemented, through the comparison of optimized and non-optimized scenarios, in order to the impact of serving more users in the network, where satisfactory results were obtained.Item Acesso aberto (Open Access) Meta-heurística para mapeamento BBU-RRH e balanceamento de carga entre BBUs, aplicada a redes de acesso centralizado(Universidade Federal do Pará, 2022-08-19) CUNHA, Rita de Cássia Porfírio da; CARDOSO, Diego Lisboa; http://lattes.cnpq.br/0507944343674734The growing demand for information access, generated by multimedia applications, is one of the challenges of the new generation of mobile networks. The fifth generation (5G) aims to meet increasingly stringent user requirements, such as latencies and low power consumption. One of the proposed architectures to supply the demands that arise with 5G and to support this traffic is the Cloud Radio Access Network (C-RAN), which centralizes processing power to solve the load imbalance, allocate resources accordingly based on network demand. This architecture proposes resource sharing while addressing processing scalability issues. Recently, metaheuristic optimization algorithms have been widely used to solve problems of this nature. Meta-heuristic algorithms are used because they are more powerful than conventional methods, which are to on formal logic or mathematical programming, in addition to the fact that the time required for execution is less than the exact algorithms’ one. In this context, the objective of this study is to develop an optimized resource allocation model that performs load balancing between Baseband Units (BBUs) and Remote Radio Heads (RRHs), based on the Particle Swarm Optimization (PSO) method. For this purpose, a variation of the PSO algorithm, the Discrete Particle Swarm Optimization (DPSO) was used, to optimize the proposed objective function. Results indicated a point to superior performance of this objective function in comparison to the adopted benchmarking, both in high and low traffic densities.Item Acesso aberto (Open Access) Mitigação de interferência em redes de próxima geração utilizando técnicas de clusterização e inteligência computacional(Universidade Federal do Pará, 2016-12-16) TORRES, Fábio de Oliveira; CARDOSO, Diego Lisboa; http://lattes.cnpq.br/0507944343674734Due to the success of broadband networks and the growing use of smartphones, mobile operators are in search to offer the same standard of wired network services, such as speed and stability, to wireless users and thus new technologies have emerged, among them there are the Small Cells. These are small radio base stations that in relation to the macrocells present a much lower cost, however, offer a smaller space of coverage. Therefore, in a scenario where a large amount of this equipment will be installed, usually called DenseNets or dense networks, and this implementation is not carried out based on a suitable planning, numerous problems can arise, among them the co-channel interference, that in some situations, makes any type of information exchange impossible. For this reason, the model proposed in this thesis intends to assist the project analysts and solution architects in the planning of dense networks, offering, based on the information about the locations of the Small Cells, which frequency bands are appropriate for the use of each one, that so the new applications, supported by smartphones, do not suffer a degradation of signal to the point that their functions are not executed and there is an increase in the quality of the services that are offered to the users of these networks. In the tests carried out, the model showed an improvement in the traffic in more than 80% of the Small Cells, reduced the value of the delay of the switched packets and also collaborated to reduce the number of discarded packets. Nevertheless, we also analyzed the performance of the battery modules of mobile devices when the model was employed and it was noticed that it did not increase the battery consumption of these devices.Item Acesso aberto (Open Access) Orquestração de recursos multicamadas para arquiteturas de próxima geração(Universidade Federal do Pará, 2024-11-29) PAIXÃO, Ermínio Augusto Ramos da; CARDOSO, Diego Lisboa; http://lattes.cnpq.br/0507944343674734Due to the significant increase in data traffic and the large number of devices using Internet Protocol (IP), operators and researchers are seeking solutions to meet the growing demand. One of the most attractive solutions is Heterogeneous Cloud Radio Access Networks (H-CRAN), which has the capability to address current generation problems and bring various improvements, such as centralized processing and greater energy efficiency. The central challenge lies in the complexity of managing and optimizing these resources efficiently, especially in highdemand scenarios with dense device populations. However, the orchestration of resources such as radio, mapping between radio and BaseBand Unit (BBU), and load balancing in the BBU pool remains critically important. This thesis presents a framework aimed at reconfiguring the mobile network in areas affected by the variability of tidal effect traffic, ensuring high availability, energy savings, and improved data processing efficiency. The results obtained were compared with other approaches in the literature and demonstrated that the proposed framework optimizes the resources of the Peak Remote Radio Head (PRRH) and the BBU without compromising the user’s minimum QoS. The findings highlight a reduction of up to 9% in the number of active antennas over a 24-hour period and emphasize that the proposed solution consumes up to 14% less energy than the primary reference in this thesis.Item Acesso aberto (Open Access) Otimização da alocação de recursos em datacenters hierarquicamente distribuídos(Universidade Federal do Pará, 2018-12-19) VIEIRA, Rafael Fogarolli; CARDOSO, Diego Lisboa; http://lattes.cnpq.br/0507944343674734The rapidly increasing volume of services and applications, in addition to the high wireless access demand, are significant challenges for the next generation of mobile networks. The growth in the volume of applications is the reflection of the quantity of “things” that are being connected to the network and generating a huge data traffic. A new paradigm that is gaining recognition in the field of wireless networks, and is also responsible for part of this growth in the volume of services and applications, is the Internet of Things. The high amount of data that is generated by connecting those devices to the network will require significant computational resources to be processed and stored. A prominent approach to handling such large amount of data is the use of Cloud Computing, which uses datacenters for storage and data processing. However, traditional Cloud Computing, which has centralized resources, is not able to handle the high volume of data and the strict latency and Quality of Service requirements. Thus, to address such adversities, a new emerging concept known as Edge Cloud Computing has been proposed as an extension of the traditional Cloud Computing, bringing computational resources to the edge of the network and thereby creating a hierarchy of datacenters. In this way, the stricter requirements from services and applications, such as obtaining near-instant user experience, can be satisfied. In this work, a mathematical formulation for the dimensioning and provisioning of a hierarchy of DCs is proposed. According to the obtained results, the hierarchy of DCs provisioned and dimensioned using the proposed model can be better when compared to the others, being able to allocate 99% of the set of applications that were used in the tests and to decrease the data flow in the backhaul links that is generated by the high number of applications the would circulate through the network. The analysis highlight the necessity of bringing computational resources to the network’s edge in addition to an efficient applications allocation strategy in order to guarantee a better network performance.Item Acesso aberto (Open Access) Otimização Energética em Redes B5G Utilizando RSMA.(Universidade Federal do Pará, 2024-02-29) SANTOS, Albert Einstein Coutinho dos.; CARDOSO, Diego Lisboa; http://lattes.cnpq.br/0507944343674734Next-generation wireless communication networks demand extremely high requirements with the increase in data traffic, user transmission rates, decrease in minimum transmission delay, and a massive number of wireless devices per unit area. To meet these demands, network densification, the development of new access technologies, and resource management are necessary. However, challenges associated with interference and resource allocation emerge as significant obstacles. Power allocation is identified as crucial to mitigate interference, ensure specific quality requirements for different services, and enhance spectral efficiency. This work applies a multi-objective algorithm for power allocation in a scenario that employs the Rate Splitting Multiple Access (RSMA) concept, an emerging alternative for next-generation networks. RSMA involves splitting messages into private and common parts, allowing adaptation of the amount of signal sent in an overlapping channel. Evaluation metrics include spectral efficiency, specifically the minimum rate among users, the Sum Rate (SR), and energy efficiency. The average results obtained are compared with NOMA (Non-Orthogonal Multiple Access), indicating gains of 11% in spectral efficiency and 2% in energy efficiency with the implementation of RSMA in the simulated scenario.Item Acesso aberto (Open Access) Sistemas fotovoltaicos aplicados em redes móveis heterogêneas(Universidade Federal do Pará, 2016-05-22) SOUZA, Marcela Alves de; COSTA, João Crisóstomo Weyl Albuquerque; http://lattes.cnpq.br/9622051867672434; CARDOSO, Diego Lisboa; http://lattes.cnpq.br/0507944343674734Mobile telecommunications operators are facing continuous challenges in increasing the capacity and coverage of the network in a way that can meet the growing demand from the users for better quality of service and experience in high-speed mobile applications. These frequent improvements have been followed by an unprecedented rise in the consmption of electric energy caused by the densification of heterogeneous mobile networks (HetNet – Heterogenous Network) through small cells. As a result, there has been an increase in the number of devices in backhaul mobile technologies which are needed to connect all the base stations by means of the access layer in the network core. Although they can be regarded as an efficient energy strategy, the small cells lead to a considerable increase in the energy consumption of HetNet, owing to the expansion of backhaul and this threatens to undermine its benefits and incurs extra energy costs for the mobile network operators. It is proposed that this problem can be overcome by exploiting renewable eneergy sources, in particular the photovoltaic system. This is expected to diversify the energy matrix and reduce the volume of CO2 emissions, as well as being more viable in technical and economic terms than conventional sources of energy supply. Thus the aim of this research study is to make a techno-economic assessment of the feasibility of acquiring, installing, and operating photovoltaic systems in the context of heterogeneous mobile networks while taking account of the energy consumption of both the fronthaul and backhaul radio networks. On the basis of the results, evidence was found of the financial viability of adopting photovoltaic frameworks, as well as the environmental sustainability that can be achieved through a considerable reduction of CO2 emissions in the atmosphere.