Marcos Augusto M. Vieira

Federal University of Minas Gerais | UFMG · Departamento de Ciência da Computação

This paper presents the novel routing protocol called Underwater Greedy Geographic Routing by Network Embedding (UW-GRE) for underwater wireless networks. Geographic routing is a promising network routing protocol strategy for wireless networks because it is stateless. However, this routing strategy faces various problems in the underwater environm...

Public outdoor surveillance cameras often have limited metadata describing their properties. Frequently, a public camera’s precise position, orientation, focal length, and image center are unknown; these attributes are necessary to precisely pinpoint the location of events seen in the camera. In this article, we ask: what is the minimal information...

Este artigo apresenta o protocolo CodeTSCH, que utiliza a Codificação em Rede (Network Coding) em redes TSCH (Time-Slotted Channel Hoping) para otimizar a entrega de mensagens e diminuir o número de slots utilizados. Esse processo possibilita que duas mensagens sejam combinadas em apenas um pacote, possibilitando uma menor quantidade de mensagens c...

Dual-Radio platforms were proposed to improve the throughput of Wireless Sensor Network applications while conserving energy efficiency. However, current dual-radio protocols do not use all the hardware available. We model this problem as the minimum disjoint parity paths problem. We present the design, implementation and evaluation of SplitPath, a...

Link saturation is a problem in computer networks. We propose a link aggregation solution that is robust and solves this problem. The approach consists of creating a virtual link by combining multiple physical interfaces, summing up their bandwidth. Besides increasing the data transmission throughput, this type of solution enables a fast and clear...

A transmissão e recepção de pacotes em redes sem fio sofre com problemas como interferência, colisões e presença de gargalos, causando o aumento da latência e diminuição da vazão na rede. A alta demanda por um conjunto de enlaces pode tornar a rede ineficiente e, até mesmo, inoperante. As redes TSCH tentam evitar colisões via escalonamento de canai...

O protocolo QUIC é considerado um ambiente de experimentação e uma evolução do protocolo TCP. Aplicações criadas através do QUIC em substituição a tradicional pilha HTTPS tem demonstrado ganhos em desempenho. A técnica de transferência (offload) de carga computacional para o espaço de núcleo é utilizada como otimização em aplicações modernas e traz...

In road traffic networks, famous Braess's Paradox demonstrated that the addition of resources can cause the traffic network performance to decrease. The addition of a new route can cause drivers to use this new road and end up reaching a Nash equilibrium which increases the overall travel time. Unlike previous studies that have investigated the par...

Current Service Function Chaining (SFC) architectures are tailor-made for specific environments and platforms, often relying on SFC support on network devices or specialized frameworkson specialized or modified network devices, either in software or in hardware. Thus, the service plane and the data plane are tightly coupled, id=r2which hindershinde...

O congestionamento de pacotes em uma rede de computadores causa perda de desempenho no sistema. Esta proposta busca melhorar o desempenho das redes de computadores em centro de dados, especialmente em cenários de congestionamento. O protocolo padrão de controle de congestionamento em centro de dados é o Data Center TCP (DCTCP). Este artigo propõe d...

A alocação de núcleos para threads de programas é um problema complexo e de grande custo computacional dentro de ambientes Unix. O escalonador Caladan é uma solução que otimiza na escala dos microssegundos a forma como threads e núcleos são escalonados. O sistema Danian proposto, melhora o algoritmo de escolha de threads para um núcleo a ser escalo...

Underwater wireless sensor networks (UWSNs) can enable many applications in underwater environments. They face many challenges due to the characteristics of these environments and their use of acoustic or optical communications. Here we propose solutions for two existing problems in UWSNs. One of them is CAPTAIN, a cluster-based routing solution fo...

We propose two new computational problems associated with the charging of mobile devices using wireless power transfer via magnetic induction. Algorithms for these problems may enable ubiquitous charging, meaning the user is no longer required to be aware of the devices charging processes. We prove both problems as being NP-Hard and propose three d...

A demanda por suporte a baixa latência em ambientes de alta vazão tem aumentado nosúltimos anos. Sistemas como Shenango permitem que servidores processem pacotes rapidamente, mantendo a eficiência na utilização de CPU através de um algoritmo de detecção de congestionamento e o IOKernel, componente dedicado a orquestrar a alocação de novos núcleos....

Segurança de dados tornou-se um fator crucial no contexto de redes de computadores. Entre 2015 e 2020, estima-se que o prejuízo causado pelo roubo de informações na Internet seja de R$ 26 trilhões. Nesse cenário, Sistemas de Detecção de Intrusão (SDIs) são elementos essenciais na busca de ameaças. Contudo, SDIs são instalados em máquinas convencion...

While most networks have long lifetimes, temporary network infrastructure is often useful for special events, pop-up retail, or disaster response. An instant IoT network is one that is rapidly constructed, used for a few days, then dismantled. We consider the synthesis of instant IoT networks in urban settings. This synthesis problem must satisfy c...

We propose two new computational problems associated with the charging of mobile devices using wireless power transfer via magnetic induction. Algorithms for these problems may enable ubiquitous charging, meaning the user is no longer required to be aware of the devices charging processes. We prove both problems as being NP-Hard and propose three d...

Underwater wireless sensor networks (UWSNs) can enable many applications in underwater environments. They face many challenges due to the characteristics of these environments and their use of acoustic or optical communications. Here we propose solutions for two existing problems in UWSNs. One of them is CAPTAIN, a cluster-based routing solution th...

Recently, power line communication (PLC) is receiving attention from academic and industry researchers worldwide. In particular, PLC systems have been largely investigated as a medium for transmitting control signals, diagnostic information, or data measured by sensors in Smart Grid. However, PLC systems face several challenges, such as multipath e...

In this paper, we propose a blockchain-based cold chain technology for vaccine cooling track. The COVID-19 pandemic has caused the death of millions of people. An important step towards ending the pandemic is vaccination. Vaccines must be kept under control temperature during the whole process, from fabrication to the hands of the health profession...

The novel Underwater Wireless Sensor Network (UWSN) can contribute to monitor and explore aquatic environments. But, communicating in these environments is still hard and has many challenges. For example, optical and electromagnetic waves deteriorate from high-attenuation. Moreover, acoustic communication has a large packet error rate and low throu...

Newer applications for Wireless Sensor Networks, such as for video and audio applications, require higher data rates compared to traditional low data rate sensor network applications. Platforms with two radios were proposed to address these new classes of applications: each radio can send data on different routes to achieve high data rates and ener...

AODV (Ad hoc On‐Demand Distance Vector) is a well‐known routing protocol for wireless networks. Recently, Time Slotted Channel Hopping (TSCH) was proposed as a MAC layer protocol, specified in the IEEE 802.15.4e standard. As MAC layer protocols can impact the performance of protocols in the layers above, we examine the performance of AODV over TSCH...

Software-Defined Networks, in its essence, is the separation of the data and control planes of switching devices. The OpenFlow (OF) protocol is the most popular SDN protocol today, being available in many switches. This is due to the low implementation cost as well as the potential for innovative solutions in the network. Although OF is being used...

Underwater wireless acoustic networks (UWANs) take advantage of acoustic communication to enable many distinct applications. The peculiar features of underwater acoustic channels, such as long propagation delay, high bit error rates, and severely limited bandwidth, make the use of medium access control (MAC) solutions designed for terrestrial radio...

Software is often used for Network Functions (NFs) -- such as firewalls, NAT, deep packet inspection, and encryption -- that are applied to traffic in the network. The community has hoped that NFV would enable rapid development of new NFs and leverage commodity computing infrastructure. However, the challenge for researchers and operators has been...

This paper describes the first Geometric Greedy Router using the Quantum-dot Cellular Automata (QCA) paradigm based on a spanning-tree of the network. This type of router is a revolution for communications as it works without IP address lookups. It uses only local information and can be employed in numerous communication devices. When combined with...

Serverless é um novo paradigma para computação em nuvem. Neste paradigma usuários apenas implementam o núcleo da aplicação sem preocupar com a infraestrutura. Processamento de funções ocorre em servidores com CPUs x86_x64 utilizando virtualização. Essa abordagem não é eficiente, gera atrasos de processamento e sobrecarrega recursos, aumentando o cu...

A comunicação óptica sem fio (OWC) tem se mostrado como uma das tecnologias de comunicação complementares à radiofrequência que pode solucionar o problema de falta de espectro. Além disso, novas aplicações como Internet das Coisas e rede sensores sem fio podem se beneficiar do OWC. Com o aumento de dispositivos conectados, a eficiência de uso do ca...

In this work, we study the localization problem considering two Wireless Sensor Network (WSN) metrics commonly used for distance estimation. In this sense, we use Bayesian filters to combine odometry and distance estimations provided by the WSN devices. Our strategies aim at a general application and can be used for both indoor and outdoor environm...

Network monitoring is essential to tasks ranging from planning to troubleshooting. Unfortunately, comprehensive real-time monitoring of complex networks with large traffic volume is challenging. In particular, tracking of time-dependent metrics, such as round-trip latency or transmission rate requires maintaining state and this is hard to scale. We...

Although widespread in the market, the wireless power transfer devices following the Qi Standard suffer from limited transmission range and link instability. Previous works often address these issues by proposing improvements for both transmitting and receiving sides, which disposes of the Qi interoperability and ease of purchasing. This article pr...

Software-defined networking (SDN) has provided a new paradigm for network management by allowing a central controller to program the underlying switches directly. However, OpenFlow, the de facto standard API for communicating with the switches, has limited visibility into the network headers, hindering innovations in the data plane and overloading...

Public cameras often have limited metadata describing their attributes. A key missing attribute is the precise location of the camera, using which it is possible to precisely pinpoint the location of events seen in the camera. In this paper, we explore the following question: under what conditions is it possible to estimate the location of a camera...

This study describes the first Gray‐code adder architecture, without the need to transform the Gray code into binary code, using the quantum‐dot cellular automata (QCA). This device is a widely used resource for machine communications, counters, and encoders. QCA is a possible alternative to the current integrated circuit [complementary metal oxide...

Advances in optimization and constraint satisfaction techniques, together with the availability of elastic computing resources, have spurred interest in large-scale network verification and synthesis. Motivated by this, we consider the top-down synthesis of ad-hoc IoT networks for disaster response and search and rescue operations. This synthesis p...

Extended Berkeley Packet Filter (eBPF) is an instruction set and an execution environment inside the Linux kernel. It enables modification, interaction, and kernel programmability at runtime. eBPF can be used to program the eXpress Data Path (XDP), a kernel network layer that processes packets closer to the NIC for fast packet processing. Developer...

Underwater sensor networks are used to collect data from aquatic environments. Nodes from these networks usually communicate via acoustic or optical transmissions due to the poor performance of radiofrequency communication in these environments. Acoustic transmissions achieve longer distances than optical ones, but also consume more energy and have...

Wireless networks show several challenges not found in wired networks, due to the dynamics of data transmission. Besides, home wireless networks are managed by non-technical people, and providers do not implement full management services because of the difficulties of manually managing thousands of devices. Thus, automatic management mechanisms are...

The use of two radios per node increases the energy efficiency of wireless sensor networks. Given that data collection is one of the most important functions in wireless sensor networks, this paper presents and compares two new data collection protocols for wireless sensor networks with two radios, DCTP-A and DCTP-I. DCTP-A builds the collection tr...

It is important for Quantum-dot Cellular Automata (QCA) systems to reliably communicate with other circuits. In this work, we detail a circuit designed in QCA that corrects single byte errors. The circuit implements a Reed–Solomon code and was designed using principles from Cellular Automata (CA) theory. We present an encoder and a decoder that are...

The IEEE 802.11ac standard enables a higher transmission speed than the previous IEEE standards because it allows the network frequency spectrum to be divided into communication channels of different bandwidths, varying from 20MHz to 160MHz. In this paper, we introduce the Variable Rate and Variable Bandwidth Scheduling Problem (VRBSP), which is a...

Wireless Networks have become ubiquitous to support the growing demand from mobile users, and other devices, like in the Internet of Things (IoT). This article proposes a Software-Defined Wireless Networking architecture specialized in 802.11 Wireless LANs, called Ethanol, which provides a more fine-grained control. Ethanol is the first wireless SD...

Na última década, o interesse em torno da Comunicação por Luz Visível (VLC) aumentou consideravelmente, devido a fatores como a crescente demanda por recursos sem fio na Internet e às vantagens oferecidas pela transmissão de dados através da luz visível. Entretanto, a utilização da luz como meio de comunicação apresenta diversos desafios como inter...

Monitoramento de tráfego é uma ferramenta importante em engenharia de tráfego, permitindo que gerentes de rede possam detectar ataques e comportamentos anormais da rede. O paradigma de SDN prove uma nova alternativa para fazer isso, separando o plano de dados e controle e os permitindo ser programáveis. Neste trabalho é proposto a implementação de...

Os problemas de localização de controladores buscam posicionar espacialmente os controladores de uma rede definida por software (SDN) e escolher os enlaces que atenderão os mesmos. Esses problemas são NP-Difícil. Neste trabalho, é proposta uma nova formulação focada em redes de longa distância baseada na minimização dos custos financeiros de manute...

Comunicação por Luz Visível (VLC) apresenta diversos desafios como interferência e bloqueios criados por obstáculos. Ao mesmo tempo, vários ambientes oferecem uma rica infraestrutura de fontes de luz, que podem ser utilizadas para auxiliar na comunicação fim-a-fim. Neste trabalho, D-VLC um protocolo de roteamento dinâmico. D-VLC reage às interrupçõ...

A RFC 7665 propõe uma arquitetura de referência para encadeamento de funções de rede (Service Function Chaining, SFC) que decompõe as funcionalidades de SFC em um conjunto de elementos especializados. Entretanto, essa abordagem é dependente da infraestrutura de redes e requer comunicação entre as funções de rede (Service Functions, SFs) e os elemen...

O uso de dois rádios por nó aumenta a eficiência energética das redes de sensores. Dado que a coleta de dados é uma das funções mais importantes em redes de sensores, este artigo apresenta e compara dois novos protocolos de coleta de dados para redes de sensores sem fios com dois rádios. Os protocolos foram implementados no TinyOS e avaliados exper...

A demanda por redes sem fio tem crescido nos últimos anos, isto implica em uma maior necessidade de melhoria em seu desempenho. O padrão IEEE 802.11ac permite utilizar canais com largura de banda maiores que 20 MHz. Porém, os pontos de acesso alocam a largura de banda do canal estaticamente, independente das configurações dos clientes. Isso leva a...

Visible Light Communication (VLC) presents several challenges, such as interference and blockages created by obstacles. At the same time, several environments offer a rich infrastructure of light sources, which can be used to aid end-to-end communication. In this work, we present DYRP-VLC, a dynamic routing protocol. DYRP-VLC reacts to communicatio...

High latency, low transmission rate and the presence of limited computational devices are characteristics present in scenarios of underwater communications. Despite the existence of concrete works on underwater wireless sensor networks (UWSNs), there is a gap in the interoperability of these networks and the traditional Internet networks. Indeed, c...

Energy is often a critical resource for underwater sensor networks. Underwater nodes usually have their life restricted to the initial charge of their battery, since recharging them may be impractical. This fact directly impacts sensing and monitoring applications, where a set of nodes is expected to cover and sense some region as long as possible....

Many applications in Wireless Sensor Networks (WSNs) require collecting massive data in a coordinated approach. To that end, a many-to-one (convergecast) communication pattern is used in tree-based WSNs. However, traffic near the sink node usually becomes the network bottleneck. In this work, we propose an extension to the 802.15.4 standard for ena...

LED‐to‐LED communication, in which an LED is used as both transmitter and receiver, is an ubiquitous technology that presents important advantages such as low‐cost devices and security enhancement. We investigate the performance of Visible Light LED‐to‐LED communication under realistic conditions. We analyze the impact on transmission performance i...

This manuscript presents a novel approach based on hybrid optimization techniques for planning Wireless Local Area Networks in two stages: i) network structure design for access point (AP) placement and channel assignment and ii) channel assignment enhancement. We consider two objective functions: network load balance and signal-to-interference-plu...