11 research outputs found

    Avaliação de estabilidade de transmissões de vídeo por protocolo de transporte multicaminho

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    Orientador : Prof. Dr. Eduardo Parente RibeiroCoorientador : Prof. Dr. Carlos Marcelo PedrosoDissertação (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduação em Engenharia Elétrica. Defesa: Curitiba, 23/02/2017Inclui referências : p. 70-75Resumo: A evoluc¸a˜ o tecnolo' gica de dispositivos mo' veis e o aumento da disponibilidade de redes IP, criam novas oportunidades para distribuic¸a˜ o de conteu' do multimedia pela Internet. Atualmente os usua' rios teˆ m a possibilidade de acessar filmes, pec¸as de teatros, concertos de mu' sica transmitidos ao vivo ou armazenados sob-demanda. Aplicac¸o˜ es de tempo-real requerem alta qualidade de servic¸o, na˜ o sendo tolerantes a variac¸o˜ es do atraso me' dio por exemplo. Neste contexto, o delay-centric foi proposto para realizar handover entre redes mo' veis no protocolo SCTP. Sua proposta de realizar a troca de caminho utilizando o valor do atraso me' dio suavi- zado mostrou uma melhora significativa quando utilizado em aplicac¸o˜ es de tempo-real. Va' rios autores tem estudado a utilizac¸a˜ o do SCTP padra˜ o, do CMT e do CMT-PF em transmisso˜ es de v'?deo de tempo real. Este trabalho se propoˆ s a estudar a estabilidade de transmisso˜ es de v'?deo HD com diferentes caracter'?sticas de GOP, por protocolos de transporte multicaminho. Simulac¸o˜ es foram realizadas com trac¸ados de v'?deo de caracter'?sticas distintas e foram anali- sados, para fins de comparac¸a˜ o, o comportamento do delay-centric com diferentes histereses, SCTP padra˜ o, CMT e do CMT-PF. Foram utilizados cena' rios com va' rios n'?veis de diversidade e observadas me' tricas de atraso me' dio, Goodput, justic¸a na divisa˜ o do throughput e trhoughput me' dio nas interfaces dos agentes que enviavam e recebiam o v'?deo. Nos cena' rios com dois e treˆ s caminhos completamente disjuntos, os resultados obtidos confirmaram os dados conti- dos na literatura onde o delay-centric, independente da histerese, teve desempenho igual ou superior do CMT e ao CMT-PF. O SCTP Padra˜ o na˜ o se beneficiou da existeˆ ncia de mu' ltiplos caminhos, obtendo o pior desempenho dentre todos os protocolos estudados nos cena' rios com dois e treˆ s caminhos completamente disjuntos. Entretanto, no cena' rio com treˆ s no' s de acesso interligados a dois cores, com duas redes de acesso compartilhando um core, os resul- tados indicaram que o delay-centric sem histerese obteve o melhor desempenho dentre todos os protocolos estudados e o SCTP Padra˜ o mostrou melhor desempenho que o CMT, CMT-PF e delay-centric com histerese de 10ms, 20ms e 30ms. Palavras-chave: SCTP. Delay-centric. Multihoming.Abstract: The mobile devices technological evolution and the increased availability of IP networks, create new opportunities for multimedia content distribution over Internet. Nowadays, users have ac- cess to movies, plays or music concerts live over demand via video streaming over the Internet. Real-time applications require high quality service and are not tolerant to delay variations. The delay-centric was initially proposed to make the handover between mobile networks in SCTP by using the smoothed round trip time and delivering a higher user experience on real-time appli- cations. Other authors have studied the use of CMT and CMT-PF in real-time video streaming. The main objective of this work is to study the stability of HD video streaming, with different GOP characteristics, using multipath transport protocols. Video traces were used in the simu- lations with various path configurations to compare the behavior of delay-centric with different hysteresis, standard SCTP, CMT and CMT-PF. Results were analyzed using the metrics of de- lay, jitter, Goodput, mean throughput and throughput division justice. In scenarios with two or tree disjoint paths, the results confirmed the previous results on the literature that the delay- centric, independent of hysteresis level, have same or better performance when compared to CMT and CMT-PF. The standard SCTP do not take advantage of the multiple disjoint paths, having the worst performance when compared to the other protocols. In scenarios with tree access nodes connected to two cores, with two access networks sharing the same core, the results showed that the delay-centric with no hysteresis 5have the best performance in compa- rison to the other protocols, followed by the standard SCTP that presented better performance than CMT, CMT-PF and delay-centric with 10ms, 20ms, 30ms of hysteresis respectively. Key words: SCTP. Delay-centric. Multihoming

    Exploiting the power of multiplicity: a holistic survey of network-layer multipath

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    The Internet is inherently a multipath network: For an underlying network with only a single path, connecting various nodes would have been debilitatingly fragile. Unfortunately, traditional Internet technologies have been designed around the restrictive assumption of a single working path between a source and a destination. The lack of native multipath support constrains network performance even as the underlying network is richly connected and has redundant multiple paths. Computer networks can exploit the power of multiplicity, through which a diverse collection of paths is resource pooled as a single resource, to unlock the inherent redundancy of the Internet. This opens up a new vista of opportunities, promising increased throughput (through concurrent usage of multiple paths) and increased reliability and fault tolerance (through the use of multiple paths in backup/redundant arrangements). There are many emerging trends in networking that signify that the Internet's future will be multipath, including the use of multipath technology in data center computing; the ready availability of multiple heterogeneous radio interfaces in wireless (such as Wi-Fi and cellular) in wireless devices; ubiquity of mobile devices that are multihomed with heterogeneous access networks; and the development and standardization of multipath transport protocols such as multipath TCP. The aim of this paper is to provide a comprehensive survey of the literature on network-layer multipath solutions. We will present a detailed investigation of two important design issues, namely, the control plane problem of how to compute and select the routes and the data plane problem of how to split the flow on the computed paths. The main contribution of this paper is a systematic articulation of the main design issues in network-layer multipath routing along with a broad-ranging survey of the vast literature on network-layer multipathing. We also highlight open issues and identify directions for future work

    Algorithmes d'adressage et routage pour des réseaux fortement mobiles à grande échelle

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    After successfully connecting machines and people later (world wide web), the new era of In-ternet is about connecting things. Due to increasing demands in terms of addresses, mobility, scalability, security and other new unattended challenges, the evolution of current Internet archi-tecture is subject to major debate worldwide. The Internet Architecture Board (IAB) workshop on Routing and Addressing report described the serious scalability problems faced by large backbone operators in terms of routing and addressing, illustrated by the unsustainable growth of the Default Free Zone (DFZ) routing tables. Some proposals tackled the scalability and IP semantics overload issues with two different approaches: evolutionary approach (backward com-patibility) or a revolutionary approach. Several design objectives (technical or high-level) guided researchers in their proposals. Mobility is definitely one of the main challenges.Inter-Vehicle Communication (IVC) attracts considerable attention from the research com-munity and the industry for its potential in providing Intelligent Transportation Systems (ITS) and passengers services. Vehicular Ad-Hoc Networks (VANETs) are emerging as a class of wire-less network, formed between moving vehicles equipped with wireless interfaces (cellular and WiFi) employing heterogeneous communication systems. A VANET is a form of mobile ad-hoc network that provides IVC among nearby vehicles and may involve the use of a nearby fixed equipment on the roadside. The impact of Internet-based vehicular services (infotainment) are quickly developing. Some of these applications, driver assistance services or traffic reports, have been there for a while. But market-enabling applications may also be an argument in favor of a more convenient journey. Such use cases are viewed as a motivation to further adoption of the ITS standards developed within IEEE, ETSI, and ISO.This thesis focuses on applying Future Internet paradigm to vehicle-to-Internet communica-tions in an attempt to define the solution space of Future Vehicular Internet. We first introduce two possible vehicle-to-Internet use cases and great enablers for IP based services : eHealth and Fully-electric Vehicles. We show how to integrate those use cases into IPv6 enabled networks. We further focus on the mobility architectures and determine the fundamental components of a mobility architecture. We then classify those approaches into centralized and distributed to show the current trends in terms of network mobility extension, an essential component to vehicular networking. We eventually analyze the performance of these proposals. In order to define an identifier namespace for vehicular communications, we introduce the Vehicle Identification Numbers are possible candidates. We then propose a conversion algorithm that preserves the VIN characteristics while mapping it onto usable IPv6 networking objects (ad-dresses, prefixes, and Mobile Node Identifiers). We make use of this result to extend LISP-MN protocol with the support of our VIN6 addressing architecture. We also apply those results to group IP-based communications, when the cluster head is in charge of a group of followers.Cette thèse a pour objectif de faire avancer l'état de l'art des communications basée sur Internet Protocol version 6 (IPv6) dans le domaine des réseaux véhiculaires, et ce dans le cadre des évolutions récentes de IP, notamment l'avènement du Future Internet. Le Future Internet (F.I.) définit un ensemble d'approches pour faire évoluer l'Internet actuel , en particulier l'émergence d'un Internet mobile exigeant en ressources. Les acteurs de ce domaine définissent les contraintes inhérentes aux approches utilisées historiquement dans l'évolution de l'architecture d'Internet et tentent d'y remédier soit de manière évolutive soit par une rupture technologique (révolutionnaire). Un des problèmes au centre de cette nouvelle évolution d'Internet est la question du nommage et de l'adressage dans le réseau. Nous avons entrepris dans cette thèse l'étude de ce problème, dans le cadre restreint des communications véhiculaires Internet.Dans ce contexte, l'état de l'art du Future Internet a mis en avant les distinctions des approches révolutionnaires comparées aux propositions évolutives basées sur IPv6. Les réseaux véhiculaires étant d'ores-et-déjà dotés de piles protocolaires comprenant une extension IPv6, nous avons entamé une approche évolutive visant à intégrer les réseaux véhiculaires au Future Internet. Une première proposition a été de convertir un identifiant présent dans le monde automobile (VIN, Numéro d'Identification de Véhicule) en un lot d'adresses réseau propres à chaque véhicule (qui est donc propriétaire de son adressage issu de son identifiant). Cette proposition étant centrée sur le véhicule, nous avons ensuite intégré ces communications basés dans une architecture globale Future Internet basée sur IPv6 (protocole LISP). En particulier, et avec l'adressage VIN, nous avons défini un espace d'adressage indépendant des fournisseurs d'accès à Internet où le constructeur automobile devient acteur économique fournissant des services IPv6 à sa flotte de véhicules conjointement avec les opérateurs réseau dont il dépend pour transporter son trafic IP. Nous nous sommes ensuite intéressés à l'entourage proche du véhicule afin de définir un nouveau mode de communication inter-véhiculaire à Internet: le V2V2I (Angl. Vehicle-to-Vehicle-to-Infrastructure). Jusqu'à présent, les modes de transmission de données à Internet dans le monde du véhicule consistaient en des topologies V2I, à savoir véhicule à Internet, où le véhicule accède à l'infrastructure directement sans intermédiaire. Dans le cadre des communications véhiculaires à Internet, nous proposons une taxonomie des méthodes existantes dans l'état de l'art. Les techniques du Future Internet étant récentes, nous avons étendu notre taxonomie par une nouvelle approche basée sur la séparation de l'adressage topologique dans le cluster de celui de l'infrastructure. Le leader du cluster s'occupe d'affecter les adresses (de son VIN) et de gérer le routage à l'intérieur de son cluster. La dernière contribution consiste en la comparaison des performances des protocoles de gestion de mobilité, notamment pour les réseaux de véhicules et des communications de type vehicule-à-Internet. Dans ce cadre, nous avons proposé une classification des protocoles de gestion de mobilité selon leur déploiement: centralisé (basé réseau ou host) et distribué. Nous avons ensuite évalué les performances en modélisant les durées de configurations et de reconfigurations des différents protocoles concernés

    Desempenho de SCTP em terminais multi-abrigados para transporte de tráfego VoIP em cenários com perdas

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    Resumo: A multiplicidade de meios de acesso e sua popularização estimula a exploração de sistemas multi-abrigados, que são sistemas com mais de uma porta disponível para acessar a internet. Esta característica pode trazer ganhos à resiliência da conexão e à qualidade de serviços. Serviços multimídia podem ser beneficiados pelo uso mais adequado das rotas disponíveis em sistemas multi-abrigados. O SCTP (Stream Control Transmission Protocol) é um protocolo de transporte que suporta conexões multi-abrigadas, e por esse motivo vem sendo alvo de estudos envolvendo otimização do uso de caminhos para elhoria de qualidade de serviços multimídia. Este trabalho estuda o desempenho do SCTP juntamente com um mecanismo de troca automática de rotas baseado em atraso (delay-centric) para o transporte de tráfego VoIP (Voice over IP) em terminais multi-abrigados. Os cenários simulados envolvem atrasos e perdas variáveis. Dois parâmetros que apresentam forte influência sobre o comportamento do SCTP, o PMR (Path.Max.Retrans) e o RTOmax (Valor máximo do Retransmission TimeOut), têm seus valores variados com o objetivo de investigar sua influência na qualidade de chamadas VoIP. A métrica de desempenho utilizada é o MOS (Mean Opinion Score) estimado a partir do E-model. Os resultados indicam que abordagens mais agressivas, representadas por menores valores para os parâmetros estudados, proporcionam uma melhor qualidade nas chamadas VoIP

    Estudio de la movilidad en redes de siguiente generación

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    El continuo avance de las redes de telecomunicaciones nos proporciona cada vez más facilidades en todos los ámbitos de nuestra vida. En este caso, nos hemos centrado en el estudio de la movilidad en Redes de Siguiente Generación. Una parte del presente proyecto se ha realizado en colaboración con Deutsche Telekom AG, durante una estancia de seis meses trabajando como colaboradora en sus laboratorios con emplazamiento en Berlín. El principal objetivo de este proyecto ha sido realizar un estudio sobre los diferentes estándares y tecnologías que facilitan la movilidad en Redes de Siguiente Generación. Por ello, en la primera parte se han estudiado los diferentes grupos de trabajo centrados en este aspecto, así como se ha recabado información sobre productos y soluciones disponibles en el mercado, para obtener una visión global de la situación actual. Como se puede comprobar más adelante, esta primera parte es la más extensa de todo el documento. Esto se debe a que es, probablemente, la parte más importante del trabajo, ya que contiene el estudio de los mecanismos que más tarde nos servirán para dar una solución teórica a los distintos escenarios que se plantean. En la segunda parte del proyecto, nos hemos centrado en desarrollar varios escenarios de interés en sistemas de Redes de Siguiente Generación y aportar, de forma posterior, posibles soluciones teóricas. Para finalizar, se han expuesto las conclusiones extraídas como resultado del trabajo y los aspectos que se podrán tratar sobre el mismo en un futuro próximo.Ingeniería de Telecomunicació

    Global connectivity architecture of mobile personal devices

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. 193-207).The Internet's architecture, designed in the days of large, stationary computers tended by technically savvy and accountable administrators, fails to meet the demands of the emerging ubiquitous computing era. Nontechnical users now routinely own multiple personal devices, many of them mobile, and need to share information securely among them using interactive, delay-sensitive applications.Unmanaged Internet Architecture (UIA) is a novel, incrementally deployable network architecture for modern personal devices, which reconsiders three architectural cornerstones: naming, routing, and transport. UIA augments the Internet's global name system with a personal name system, enabling users to build personal administrative groups easily and intuitively, to establish secure bindings between his devices and with other users' devices, and to name his devices and his friends much like using a cell phone's address book. To connect personal devices reliably, even while mobile, behind NATs or firewalls, or connected via isolated ad hoc networks, UIA gives each device a persistent, location-independent identity, and builds an overlay routing service atop IP to resolve and route among these identities. Finally, to support today's interactive applications built using concurrent transactions and delay-sensitive media streams, UIA introduces a new structured stream transport abstraction, which solves the efficiency and responsiveness problems of TCP streams and the functionality limitations of UDP datagrams. Preliminary protocol designs and implementations demonstrate UIA's features and benefits. A personal naming prototype supports easy and portable group management, allowing use of personal names alongside global names in unmodified Internet applications. A prototype overlay router leverages the naming layer's social network to provide efficient ad hoc connectivity in restricted but important common-case scenarios.(cont) Simulations of more general routing protocols--one inspired by distributed hash tables, one based on recent compact routing theory--explore promising generalizations to UIA's overlay routing. A library-based prototype of UIA's structured stream transport enables incremental deployment in either OS infrastructure or applications, and demonstrates the responsiveness benefits of the new transport abstraction via dynamic prioritization of interactive web downloads. Finally, an exposition and experimental evaluation of NAT traversal techniques provides insight into routing optimizations useful in UIA and elsewhere.by Bryan Alexander Ford.Ph.D

    Improved planning and resource management in next generation green mobile communication networks

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    In upcoming years, mobile communication networks will experience a disruptive reinventing process through the deployment of post 5th Generation (5G) mobile networks. Profound impacts are expected on network planning processes, maintenance and operations, on mobile services, subscribers with major changes in their data consumption and generation behaviours, as well as on devices itself, with a myriad of different equipment communicating over such networks. Post 5G will be characterized by a profound transformation of several aspects: processes, technology, economic, social, but also environmental aspects, with energy efficiency and carbon neutrality playing an important role. It will represent a network of networks: where different types of access networks will coexist, an increasing diversity of devices of different nature, massive cloud computing utilization and subscribers with unprecedented data-consuming behaviours. All at greater throughput and quality of service, as unseen in previous generations. The present research work uses 5G new radio (NR) latest release as baseline for developing the research activities, with future networks post 5G NR in focus. Two approaches were followed: i) method re-engineering, to propose new mechanisms and overcome existing or predictably existing limitations and ii) concept design and innovation, to propose and present innovative methods or mechanisms to enhance and improve the design, planning, operation, maintenance and optimization of 5G networks. Four main research areas were addressed, focusing on optimization and enhancement of 5G NR future networks, the usage of edge virtualized functions, subscriber’s behavior towards the generation of data and a carbon sequestering model aiming to achieve carbon neutrality. Several contributions have been made and demonstrated, either through models of methodologies that will, on each of the research areas, provide significant improvements and enhancements from the planning phase to the operational phase, always focusing on optimizing resource management. All the contributions are retro compatible with 5G NR and can also be applied to what starts being foreseen as future mobile networks. From the subscriber’s perspective and the ultimate goal of providing the best quality of experience possible, still considering the mobile network operator’s (MNO) perspective, the different proposed or developed approaches resulted in optimization methods for the numerous problems identified throughout the work. Overall, all of such contributed individually but aggregately as a whole to improve and enhance globally future mobile networks. Therefore, an answer to the main question was provided: how to further optimize a next-generation network - developed with optimization in mind - making it even more efficient while, simultaneously, becoming neutral concerning carbon emissions. The developed model for MNOs which aimed to achieve carbon neutrality through CO2 sequestration together with the subscriber’s behaviour model - topics still not deeply focused nowadays – are two of the main contributions of this thesis and of utmost importance for post-5G networks.Nos próximos anos espera-se que as redes de comunicações móveis se reinventem para lá da 5ª Geração (5G), com impactos profundos ao nível da forma como são planeadas, mantidas e operacionalizadas, ao nível do comportamento dos subscritores de serviços móveis, e através de uma miríade de dispositivos a comunicar através das mesmas. Estas redes serão profundamente transformadoras em termos tecnológicos, económicos, sociais, mas também ambientais, sendo a eficiência energética e a neutralidade carbónica aspetos que sofrem uma profunda melhoria. Paradoxalmente, numa rede em que coexistirão diferentes tipos de redes de acesso, mais dispositivos, utilização massiva de sistema de computação em nuvem, e subscritores com comportamentos de consumo de serviços inéditos nas gerações anteriores. O trabalho desenvolvido utiliza como base a release mais recente das redes 5G NR (New Radio), sendo o principal focus as redes pós-5G. Foi adotada uma abordagem de "reengenharia de métodos” (com o objetivo de propor mecanismos para resolver limitações existentes ou previsíveis) e de “inovação e design de conceitos”, em que são apresentadas técnicas e metodologias inovadoras, com o principal objetivo de contribuir para um desenho e operação otimizadas desta geração de redes celulares. Quatro grandes áreas de investigação foram endereçadas, contribuindo individualmente para um todo: melhorias e otimização generalizada de redes pós-5G, a utilização de virtualização de funções de rede, a análise comportamental dos subscritores no respeitante à geração e consumo de tráfego e finalmente, um modelo de sequestro de carbono com o objetivo de compensar as emissões produzidas por esse tipo de redes que se prevê ser massiva, almejando atingir a neutralidade carbónica. Como resultado deste trabalho, foram feitas e demonstradas várias contribuições, através de modelos ou metodologias, representando em cada área de investigação melhorias e otimizações, que, todas contribuindo para o mesmo objetivo, tiveram em consideração a retro compatibilidade e aplicabilidade ao que se prevê que sejam as futuras redes pós 5G. Focando sempre na perspetiva do subscritor da melhor experiência possível, mas também no lado do operador de serviço móvel – que pretende otimizar as suas redes, reduzir custos e maximizar o nível de qualidade de serviço prestado - as diferentes abordagens que foram desenvolvidas ou propostas, tiveram como resultado a resolução ou otimização dos diferentes problemas identificados, contribuindo de forma agregada para a melhoria do sistema no seu todo, respondendo à questão principal de como otimizar ainda mais uma rede desenvolvida para ser extremamente eficiente, tornando-a, simultaneamente, neutra em termos de emissões de carbono. Das principais contribuições deste trabalho relevam-se precisamente o modelo de compensação das emissões de CO2, com vista à neutralidade carbónica e um modelo de análise comportamental dos subscritores, dois temas ainda pouco explorados e extremamente importantes em contexto de redes futuras pós-5G
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