Currently, there are about 3.6 billion people in the world without any kind of Internet access. Parallel to this, we have the connectivity as a funda-mental part for insertion of the individual in a globalized society. Thus, with the understanding of Internet access as a basic right of citizenship, the con-cept of community networks arises. This network is characterized by low cost, minimal complexity, ease of deployment and expansion, as well as the active participation of the beneficiary community in its development. This study in-tends to describe the process of implementation of a community network with application of wireless mesh network using the LibreMesh free platform in the community of Boa Vista do Acarain Para.

Information-Centric Network (ICN) has been an emerging network paradigm for Future Internet based on a host-to-content approach. In this model, both router and users devices are able to store content. One of the key features of ICN is in-network content caching, reducing bandwidth consumption, server load and even enhancing QoE of end-users. ICN behavior is determined by a 3-tuple, which are routing, content insertion and content replacement. Besides, Routing algorithms influence content insertion performance and, which in turn, influences in replacement policies performance. Furthermore, it is proven that content insertion policies influence routing performance and there is no work regarded to analyze the impact of replacement algorithms in content insertion. Therefore this paper proposed a new caching metric called Replacement Ratio and a dynamic content insertion strategy named RatioCache to prove that content replacement, which is strongly bounded to caching system, also influence the caching process. Our results improved up to 110% cache hit ratio, and reduced up to 30% server load and latency up to 10%, thus RatioCache performance shows replacement policies influence caching policies and enhances network performance.

Information-Centric Networking (ICN) is one of the most promising model for dealing with the cern of the current Internet scenario, that is content. In this model, either routers or user devices in the network are capable of storing content in cache, where a client device pull a content by expressing an interest of the desired content name. One of the most sucessfull implementation of ICN is Content-Centric Networking (CCN) proposed by PARC. In CCN, the forwarding strategy pushes interest packets torwards a content server through a route determined by the Shortest-Path Route (SPR) strategy. However, SPR cannot fully exploit the network caching benefits, because the caching process only happens within the path without considering cache saturation level. Therefore, we propose Least Cache Routing (LCR) cache-aware strategy. Besides being based on SPR, LCR is constantly looking for the least saturated paths. The results shows that, a slight improvement on forwarding strategy is capable of improving LCE and LCD cache decision policies. Our results shows 150% and 53% performance gain on cache hit probability when LCR is jointly running with, respectively, LCE and LCD on Torus network.

Information Centric Networks (ICN) has been a new network paradigm and it has attracted a lot of attention recently. In this new model, contents are retrieved by their name, not by IP address, shifting from host-to-host to a host-to-content approach. In networking-caching plays a very important role in ICN, which enables routers to cache content in the path between a user and the permanent server, for instance. These intermediate nodes use a caching scheme to decide whether to store a content or not. However, most of the current caching schemes are only-one-criterion based and, given the dynamics of the network, this only one criterion may not be suitable, resulting in both low network hit ratio and performance. Therefore, we designed a MultiCriteria Caching Decision scheme for ICN, which not only considers one criterion for caching decision, but it aggregates three of them to better distribute content over the network and provide user’s requests. Our results got a much higher cache hit ratio than the other evaluated schemes and a reasonable download time.

The user experience on watching live video sequences transmitted over a Flying Ad-Hoc Networks (FANETs) must be considered to drop packets in overloaded queues, in scenarios with high buffer overflow and packet loss rate. In this paper, we introduce a context-aware adaptation mechanism to manage overloaded buffers. More specifically, we propose a utility function to compute the dropping probability of each packet in overloaded queues based on video context information, such as frame importance, packet deadline, and sensing relevance. In this way, the proposed mechanism drops the packet that adds the minimum video distortion. Simulation evaluation shows that the proposed adaptation mechanism provides real-time multimedia dissemination with QoE support in a multi-hop, multi-flow, and mobile network environments.

O tempo de ajuste em redes de comutação de rajadas ópticas (OBS) pode ser estimado de forma aleatória ou através de cálculos. Este artigo propõe alternativas para o cálculo do tempo de ajuste em redes OBS, buscando minimizar a probabilidade de bloqueio das rajadas. Para validar a proposta foram realizadas simulações utilizando a plataforma NS-2 (Network Simulator) com diferentes topologias e cenários. Os resultados mostram que o cálculo do tempo de ajuste através de uma distribuição exponencial apresenta os melhores resultados.

O GLASS (GMPLS Lightwave Agile Switching Simulator) é uma ferramenta de simulação para Redes Ópticas de Nova Geração, livre e de código aberto, desenvolvida em Java. Este artigo visa apresentar uma nova funcionalidade no simulador para facilitar o re-roteamento dinâmico de LSPs (Label Switched Paths) em cenários de redes GMPLS, baseado no protocolo de sinalização RSVP-TE.

Este artigo apresenta uma proposta de gerenciamento dinâmico de Qualidade de Serviço (QoS), em redes ópticas que utilizam o paradigma de comutação de rajadas ópticas (OBS) baseadas no GMPLS. Nessa proposta, agentes de monitoração são utilizados para verificar a qualidade de serviço oferecida às classes de rajadas e executar mecanismos reativos para garantir níveis absolutos de desempenho e, através da engenharia de tráfego do GMPLS, oferecer recursos ociosos a fluxos cujo nível de serviço não esteja sendo obedecido. Resultados de simulação mostram que a proposta é capaz de reduzir a probabilidade de bloqueio dos fluxos de rajadas na ocorrência de quebras de contexto.

One of the main problems faced by ad hoc networks is providing specific quality of service guarantees for multimedia applications, mainly due to factors such as radio signal fading and node mobility. Since mesh networks are a special type of ad hoc network, they inherit these networks’ problems. This paper’s main goal is to present OLSR-MD, an extension to OLSR (Optimized Link State Routing), to provide quality of service based on link delay measurements. An evaluation of OLSR-MD in a mesh network to be deployed at the Federal University of Pará, by means of ns2 (version 2.30) simulations, showed that this protocol performed better than other OLSR-based alternatives studied in the simulations.

Wireless mesh networks (WMNs) can be utilized in various applications. However, they lack standards, leading to several issues that need to be addressed to ensure the proper functioning of these networks. Among these issues, routing is the primary focus of this paper. Therefore, we propose the use of multiple metrics with the proactive Optimized Link State Routing (OLSR) protocol to provide quality of service routing. Although it has been demonstrated that routing with multiple metrics is an NP-complete problem, we illustrate how the techniques of Analytic Hierarchy Process (AHP) and Pruning can be combined to facilitate multiple-metric routing, delivering the best available routes based on the metrics considered. A performance study of the metrics included in the proposal is also conducted using the NS simulator.

O padrão 802.11x para redes sem fio tem sido amplamente adotado por corporações e instituições para suas atividades diárias, visto que o aumento de produtividade, proporcionado pela mobilidade e flexibilidade oferecidas por esses novos dispositivos sem fio, tem trazido grandes vantagens operacionais. No entanto, existem questões de segurança importantes que devem ser levadas em consideração ao utilizar essa nova tecnologia. Com o objetivo de fornecer mais uma fonte de referência para técnicos e pesquisadores, este projeto investiga as vulnerabilidades de segurança, assim como as formas e ferramentas de ataques presentes nas redes sem fio atuais.

O GLASS (GMPLS Lightwave Agile Switching Simulator) é uma ferramenta de simulação para Redes Ópticas de Nova Geração, livre e de código aberto, desenvolvida em Java. Este artigo visa apresentar uma nova funcionalidade no simulador para facilitar o re-roteamento dinâmico de LSPs (Label Switched Paths) em cenários de redes GMPLS, baseado no protocolo de sinalização RSVP-TE.

We conduct a comparative analysis of two proposals for establishing a facilities-based metropolitan network to serve the education and research community in the city of Belém do Pará in Brazil, utilizing the “do-it-yourself” (DIY) model for building infrastructure, and benefiting around a dozen research and education institutions. The first alternative involves constructing a fiber optic network using Gigabit Ethernet technology. The second option employs a metropolitan wireless network based on the IEEE 802.16 standard, examining the feasibility of this technology in a context with the unique characteristics of the Amazon region. In both cases, we demonstrate that the capital cost for each institution is feasible, and that the total cost in the medium term is lower than the recurring costs associated with maintaining the traditional model reliant on telecommunications provider services.

Este artigo compara dois protocolos de roteamento, reativo (AODV) e pró-ativo (OLSR), em uma rede Mesh por meio de simulações no Network Simulator 2.29, analisando o desempenho da rede em conexões simultâneas de dados e voz, em um cenário amazônico. Os resultados demonstram um melhor comportamento da rede com o AODV.

The necessity of wireless networks already has been felt a long time ago in sight of limitations imposed by the wired networks, mainly related to the increasing necessity of flexibility of the current network projects. In association to this necessity, also is observable a crescent demand for data transmissions that supply the current multimedia applications requirements, just as a larger bandwidth and a greater number of users attended on larger distances. In this context, the wireless metropolitan area networks are one solution that allies the flexibility, common in wireless networks, with the possibility of reaching a greater number of users. This paper investigates the Standard 802.16 and analyses its use for Belém-PA.