51 research outputs found

    Towards a GNU/Linux IEEE 802.21 Implementation

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    Abstract-Multiaccess mobile devices and overlapping wireless network deployments have emerged as a next generation network fixture. To make the most of all available networks, mobile devices should be capable of handing over between heterogeneous networks seamlessly and automatically. At the same time, operators should be able to steer network attachment based on their criteria. Although several cross layer mechanisms have been proposed in recent years, only the Media Independent Handover (MIH) Services framework has advanced in any of the established standardization bodies. This paper presents a blueprint for a GNU/Linux implementation of IEEE 802.21. We review the salient points of the standard, introduce our software implementation architecture, detail information gathering in GNU/Linux, and show how our prototype implementation can be used in practice. In contrast with prior published work, this paper presents a real IEEE 802.21 implementation, not an abstracted or reduced MIH-like framework, tested and empirically evaluated over real heterogeneous networks

    Interoperabilidade e mobilidade na internet do futuro

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    Research on Future Internet has been gaining traction in recent years, with both evolutionary (e.g., Software Defined Networking (SDN)- based architectures) and clean-slate network architectures (e.g., Information Centric Networking (ICN) architectures) being proposed. With each network architectural proposal aiming to provide better solutions for specific Internet utilization requirements, an heterogeneous Future Internet composed by several architectures can be expected, each targeting and optimizing different use case scenarios. Moreover, the increasing number of mobile devices, with increasing capabilities and supporting different connectivity technologies, are changing the patterns of traffic exchanged in the Internet. As such, this thesis focuses on the study of interoperability and mobility in Future Internet architectures, two key requirements that need to be addressed for the widely adoption of these network architectures. The first contribution of this thesis is an interoperability framework that, by enabling resources to be shared among different network architectures, avoids resources to be restricted to a given network architecture and, at the same time, promotes the initial roll out of new network architectures. The second contribution of this thesis consists on the development of enhancements for SDN-based and ICN network architectures through IEEE 802.21 mechanisms to facilitate and optimize the handover procedures on those architectures. The last contribution of this thesis is the definition of an inter-network architecture mobility framework that enables MNs to move across access network supporting different network architectures without losing the reachability to resources being accessed. All the proposed solutions were evaluated with results highlighting the feasibility of such solutions and the impact on the overall communication.A Internet do Futuro tem sido alvo de vários estudos nos últimos anos, com a proposta de arquitecturas de rede seguindo quer abordagens evolutionárias (por exemplo, Redes Definidas por Software (SDN)) quer abordagens disruptivas (por exemplo, Redes Centradas na Informação (ICN)). Cada uma destas arquitecturas de rede visa providenciar melhores soluções relativamente a determinados requisitos de utilização da Internet e, portanto, uma Internet do Futuro heterogénea composta por diversas arquitecturas de rede torna-se uma possibilidade, onde cada uma delas é usada para optimizar diferentes casos de utilização. Para além disso, o aumento do número de dispositivos móveis, com especificações acrescidas e com suporte para diferentes tecnologias de conectividade, está a mudar os padrões do tráfego na Internet. Assim, esta tese foca-se no estudo de aspectos de interoperabilidade e mobilidade em arquitecturas de rede da Internet do Futuro, dois importantes requisitos que necessitam de ser satisfeitos para que a adopção destas arquitecturas de rede seja considerada. A primeira contribuição desta tese é uma solução de interoperabilidade que, uma vez que permite que recursos possam ser partilhados por diferentes arquitecturas de rede, evita que os recursos estejam restringidos a uma determinada arquitectura de rede e, ao mesmo tempo, promove a adopção de novas arquitecturas de rede. A segunda contribuição desta tese consiste no desenvolvimento de extensões para arquitecturas de rede baseadas em SDN ou ICN através dos mecanismos propostos na norma IEEE 802.21 com o objectivo de facilitar e optimizar os processos de mobilidade nessas arquitecturas de rede. Finalmente, a terceira contribuição desta tese é a definição de uma solução de mobilidade envolvendo diferentes arquitecturas de rede que permite a mobilidade de dispositivos móveis entre redes de acesso que suportam diferentes arquitecturas de rede sem que estes percam o acesso aos recursos que estão a ser acedidos. Todas as soluções propostas foram avaliadas com os resultados a demonstrar a viabilidade de cada uma das soluções e o impacto que têm na comunicação.Programa Doutoral em Informátic

    Towards a GNU/Linux IEEE 802.21 Implementation

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    Abstract-Multiaccess mobile devices and overlapping wireless network deployments have emerged as a next generation network fixture. To make the most of all available networks, mobile devices should be capable of handing over between heterogeneous networks seamlessly and automatically. At the same time, operators should be able to steer network attachment based on their criteria. Although several cross layer mechanisms have been proposed in recent years, only the Media Independent Handover (MIH) Services framework has advanced in any of the established standardization bodies. This paper presents a blueprint for a GNU/Linux implementation of IEEE 802.21. We review the salient points of the standard, introduce our software implementation architecture, detail information gathering in GNU/Linux, and show how our prototype implementation can be used in practice. In contrast with prior published work, this paper presents a real IEEE 802.21 implementation, not an abstracted or reduced MIH-like framework, tested and empirically evaluated over real heterogeneous networks

    Middleware de comunicações para a internet móvel futura

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    Doutoramento em Informática (MAP-I)A evolução constante em novas tecnologias que providenciam suporte à forma como os nossos dispositivos se ligam, bem como a forma como utilizamos diferentes capacidades e serviços on-line, criou um conjunto sem precedentes de novos desafios que motivam o desenvolvimento de uma recente área de investigação, denominada de Internet Futura. Nesta nova área de investigação, novos aspectos arquiteturais estão ser desenvolvidos, os quais, através da re-estruturação de componentes nucleares subjacentesa que compõem a Internet, progride-a de uma forma capaz de não são fazer face a estes novos desafios, mas também de a preparar para os desafios de amanhã. Aspectos chave pertencendo a este conjunto de desafios são os ambientes de rede heterogéneos compostos por diferentes tipos de redes de acesso, a cada vez maior mudança do tráfego peer-to-peer (P2P) como o tipo de tráfego mais utilizado na Internet, a orquestração de cenários da Internet das Coisas (IoT) que exploram mecanismos de interação Maquinaa-Maquina (M2M), e a utilização de mechanismos centrados na informação (ICN). Esta tese apresenta uma nova arquitetura capaz de simultaneamente fazer face a estes desafios, evoluindo os procedimentos de conectividade e entidades envolvidas, através da adição de uma camada de middleware, que age como um mecanismo de gestão de controlo avançado. Este mecanismo de gestão de controlo aproxima as entidades de alto nível (tais como serviços, aplicações, entidades de gestão de mobilidade, operações de encaminhamento, etc.) com as componentes das camadas de baixo nível (por exemplo, camadas de ligação, sensores e atuadores), permitindo uma otimização conjunta dos procedimentos de ligação subjacentes. Os resultados obtidos não só sublinham a flexibilidade dos mecanismos que compoem a arquitetura, mas também a sua capacidade de providenciar aumentos de performance quando comparados com outras soluÇÕes de funcionamento especÍfico, enquanto permite um maior leque de cenáios e aplicações.The constant evolution in new technologies that support the way our devices are able to connect, as well the way we use available on-line services and capabilities, has created a set of unprecedented new challenges that motivated the development of a recent research trend known as the Future Internet. In this research trend, new architectural aspects are being developed which, through the restructure of underlying core aspects composing the Internet, reshapes it in a way capable of not only facing these new challenges, but also preparing it to tackle tomorrow’s new set of complex issues. Key aspects belonging to this set of challenges are heterogeneous networking environments composed by di↵erent kinds of wireless access networks, the evergrowing change from peer-to-peer (P2P) to video as the most used kind of traffic in the Internet, the orchestration of Internet of Things (IoT) scenarios exploiting Machine-to-Machine (M2M) interactions, and the usage of Information-Centric Networking (ICN). This thesis presents a novel framework able to simultaneous tackle these challenges, empowering connectivity procedures and entities with a middleware acting as an advanced control management mechanism. This control management mechanism brings together both high-level entities (such as application services, mobility management entities, routing operations, etc.) with the lower layer components (e.g., link layers, sensor devices, actuators), allowing for a joint optimization of the underlying connectivity and operational procedures. Results highlight not only the flexibility of the mechanisms composing the framework, but also their ability in providing performance increases when compared with other specific purpose solutions, while allowing a wider range of scenarios and deployment possibilities

    Media independent handovers : network selection for mobile IP nodes in heterogeneous wireless networks

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    Includes abstract.Includes bibliographical references (p. 79-82).In Next Generation Networks (NGN), also known as 4G, Beyond 3G, Converged, Integrated and Interworked Network, user node mobility in wireless and wired environments will seamlessly cross disparate network boundaries. The effort to offer ubiquitous computing, providing access to services anywhere and anytime, strongly encourages the ability to roam across the different existing and future networks. Literature shows investigation of concepts such as Always Best Connected (ABC) when heterogeneous networks co-exist , which will work or compete with other schemes like Home Network Default (HND), Compatibility and Network Operator Agreements (CNOA) to guide network selection or access . With the variety of available networks, the mobile node may be faced with having to decide which network to connect to. We concentrate on the network selection aspects of these envisaged mobile, overlay and integrated environment in heterogeneous networks. The standard developments by the IEEE802.21 Working group and the IETF Networking group form the base of our approach that seeks to see mobility across heterogeneous networks a reality. We propose an IEEE802.21 Media Independent Handover Function (MIHF) based network discovery and network selection, leading to a handover. The selection may be further assisted by an MIHF capable Broker Node that is Third party to the Network Providers to provide a central yet distributed database of the available networks as encountered by the Mobile Node, to cater for Nodes with no prior knowledge of networks and software repository. A Mobile Node (MN) in our solution uses 802.21 communication messages to obtain information about foreign networks encountered before selecting the networks to connect to. Our evaluation through simulations, shows that network selection in heterogeneous wireless networks environment for the appropriately equipped devices is greatly enhanced by the use of the Media Independent Handover Protocol. In scenarios where the mobile node has no prior knowledge of the encountered different network architectures, the use of a Broker node can, for an optimal number of available networks also greatly enhance the mobile node’s network selection by reducing the delay associated and the packet losses incurred

    Distribuição de vídeo para grupos de utilizadores em redes móveis heterogéneas19

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    The evolutions veri ed in mobile devices capabilities (storage capacity, screen resolution, processor, etc.) over the last years led to a signi cant change in mobile user behavior, with the consumption and creation of multimedia content becoming more common, in particular video tra c. Consequently, mobile operator networks, despite being the target of architectural evolutions and improvements over several parameters (such as capacity, transmission and reception performance, amongst others), also increasingly become more frequently challenged by performance aspects associated to the nature of video tra c, whether by the demanding requirements associated to that service, or by its volume increase in such networks. This Thesis proposes modi cations to the mobile architecture towards a more e cient video broadcasting, de ning and developing mechanisms applicable to the network, or to the mobile terminal. Particularly, heterogeneous networks multicast IP mobility supported scenarios are focused, emphasizing their application over di erent access technologies. The suggested changes are applicable to mobile or static user scenarios, whether it performs the role of receiver or source of the video tra c. Similarly, the de ned mechanisms propose solutions targeting operators with di erent video broadcasting goals, or whose networks have di erent characteristics. The pursued methodology combined an experimental evaluation executed over physical testbeds, with the mathematical evaluation using network simulation, allowing the veri cation of its impact on the optimization of video reception in mobile terminalsA evolução veri cada nas características dos dispositivos moveis (capacidade de armazenamento, resolução do ecrã, processador, etc.) durante os últimos anos levou a uma alteração signi cativa nos comportamentos dos utilizadores, sendo agora comum o consumo e produção de conteúdos multimédia envolvendo terminais móveis, em particular o tráfego vídeo. Consequentemente, as redes de operador móvel, embora tendo também sido alvo constante de evoluções arquitecturais e melhorias em vários parâmetros (tais como capacidade, ritmo de transmissão/recepção, entre outros), vêemse cada vez mais frequentemente desa adas por aspectos de desempenho associados à natureza do tráfego de vídeo, seja pela exigência de requisitos associados a esse serviço, quer pelo aumento do volume do mesmo nesse tipo de redes. Esta Tese propôe alterações à arquitetura móvel para a disseminação de vídeo mais e ciente, de nindo e desenvolvendo mecanismos aplicáveis à rede, ou ao utilizador móvel. Em particular, são focados cenários suportados por IP multicast em redes móveis heterogéneas, isto é, com ênfase na aplicação destes mecanismos sobre diferentes tecnologias de acesso. As alterações sugeridas aplicam-se a cenários de utilizador estático ou móvel, sendo este a fonte ou receptor do tráfego vídeo. Da mesma forma, são propostas soluções tendo em vista operadores com diferentes objectivos de disseminação de vídeo, ou cujas redes têm diferentes características. A metodologia utilizada combinou a avaliação experimental em testbeds físicas com a avaliação matemática em simulações de redes, e permitiu veri car o impacto sobre a optimização da recepção de vídeo em terminais móveisPrograma Doutoral em Telecomunicaçõe

    IEEE 802.21 in heterogeneous handover environments

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    Mestrado em Engenharia de Computadores e TelemáticaO desenvolvimento das capacidades tecnológicas dos terminais móveis, e das infra-estruturas que os suportam, potenciam novos cenários onde estes dispositivos munidos com interfaces de diferentes tecnologias vagueiam entre diferentes ambientes de conectividade. É assim necessário providenciar meios que facilitem a gestão de mobilidade, permitindo ao terminal ligar-se da melhor forma (i.e., optando pela melhor tecnologia) em qualquer altura. A norma IEEE 802.21 está a ser desenvolvida pelo Institute of Electrical and Electronics Engineers (IEEE) com o intuito de providenciar mecanismos e serviços que facilitem e optimizem handovers de forma independente da tecnologia. A norma 802.21 especifica assim um conjunto de mecanismos que potenciarão cenários como o descrito acima, tendo em conta a motivação e requerimentos apresentados por arquitecturas de redes futuras, como as redes de quarta geração (4G). Esta dissertação apresenta uma análise extensiva da norma IEEE 802.21, introduzindo um conjunto de simulações desenvolvidas para estudar o impacto da utilização de mecanismos 802.21 em handovers controlados por rede, numa rede de acesso mista composta por tecnologias 802.11 e 3G. Os resultados obtidos permitiram verificar a aplicabilidade destes conceitos a ambientes de próxima geração, motivando também uma descrição do desenho de integração de mecanismos 802.21 a arquitecturas de redes de quarta geração. ABSTRACT: The development of the technological capabilities of mobile terminals, and the infra-structures that support them, enable new scenarios where these devices using different technology interfaces roam in different connectivity environments. This creates a need for providing the means that facilitate mobility management, allowing the terminal to connect in the best way possible (i.e., by choosing the best technology) at any time. The IEEE 802.21 standard is being developed by the Institute of Electrical and Electronics Engineers (IEEE) to provide mechanisms and services supporting Media Independent Handovers. The 802.21 standard specifies a set of mechanisms that enable scenarios like the one described above, considering the motivation and requirements presented by future network architectures, such as the ones from fourth generation networks (4G). This thesis presents an extensive analysis of the IEEE 802.21 standard, introducing a set of simulations developed for studying the impact of using 802.21 mechanisms in network controlled handovers, in a mixed access network composed of 802.11 and 3G technologies. The obtained results allow the verification of the applicability of these concepts into next generation environments, also motivating the description of the design for integration of 802.21 mechanisms to fourth generation networks

    Control mechanisms for mobile terminals in heterogeneous access technology environments

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    Internet is evolving to become mobile and ubiquitous. As a consequence, there is a trend towards a diversification of the access technologies, as it can be seen with the recent appearance of wireless technologies such as WiFi or UMTS and the future deployment of WiMAX. Following these new opportunities, multi-technology terminals able to connect to the Internet through different technologies are appearing in the market. In this scenario, users start to demand new solutions able to use these new technologies in a transparent way from the user point of view. Foreseeing this demand, the IEEE started developing the specification IEEE 802.21, which enables multi-technology terminals to handover from one technology to another in a transparent way for the user. This specification has not yet being finished, and its deployment requires from the research community to analyze how to integrate it in current networks, how to achieve maximum benefit from its possibilities, and how to configure its parameters. In this thesis we propose control mechanisms for IP terminals to i) support efficient handovers in multi-technology environments applying the 802.21 framework and ii) allow the use of several interfaces and/or multiple providers by the terminals to improve the failure robustness of their communications. These mechanisms are focused in the terminal, although we also provide details on how to integrate IEEE 802.21 into nowadays operator's networks. The contributions of this thesis are threefold. In the first place the integration of 802.21 into terminals has been studied, focusing on the configuration of the parameters required to decide when to perform a handover in the case when the handover is initiated by the terminal. This analysis has also been done taking into account variables such as the terminal speed and the delay of the links. In the second place, we have studied how to introduce the Network Controlled Handover concept, using 802.21, into the network, including the possibility of the handover being initiated by the network. We have analyzed which are the main benefits of this approach and proposed and validated an implementation of this concept in 802.21. In third place we have analyzed a protocol, REAP, under development in the IETF, which allows terminals to detect and recover from failures in the links used in their communications. We have focused in the analytical characterization of the time required to detect a failure, since this parameter is crucial for the application's behavior. The applications should be able to cope with a failure without being disrupted by it. Through the analytical study performed, the REAP protocol can be properly configured to achieve a target recovery time. All the proposed mechanisms have been validated through simulation, using several tools such as OPNET, OMNET++ and MatlabLas tecnologías de acceso están evolucionando hacia un perfil móvil y ubicuo. Así mismo se está produciendo una diversificación en las tecnologías de acceso disponibles, con la proliferación de tecnologías inalámbricas como WiFi o UMTS y el despliegue próximo de WiMAX. Con la diversificación en el acceso aparecen también los primeros terminales multi-tecnología, capaces de utilizar diferentes redes simultáneamente. En este escenario, los usuarios empiezan a demandar soluciones y servicios capaces de utilizar estas tecnologías de forma transparente al usuario. Anticipándose a esta demanda, el IEEE comenzó la estandarización de la especificación 802.21 que permitirá a terminales multi-tecnología la posibilidad de realizar traspasos transparentes entre diferentes redes de acceso. Dicha especificación todavía no ha sido completada y su despliegue requiere la investigación de cómo integrarla en las redes actuales, cómo obtener el máximo beneficio de las posibilidades que presenta, así como de la configuración de sus parámetros. En la presente Tesis Doctoral proponemos una arquitectura que dota a terminales IP de mecanismos de control para i) soportar movilidad eficiente en entornos multi-tecnología en el marco de 802.21 y ii) permitir el uso de múltiples interfaces y/o proveedores con el objetivo de mejorar la robustez ante fallos en las comunicaciones. Dicha arquitectura se centra en el terminal aunque también se aportan detalles de cómo introducir las modificaciones requeridas por IEEE 802.21 en las redes de los operadores. Las contribuciones realizadas son varias. En primer lugar se ha estudiado la integración de IEEE 802.21 en un terminal, centrándonos en la configuración de los parámetros utilizados para determinar el momento del traspaso cuando éste es iniciado por el terminal. En segundo lugar se estudió cómo introducir, usando IEEE 802.21, el concepto de traspaso controlado por la red incluyendo la posibilidad de que la propia red sea la iniciadora del traspaso, analizando sus beneficios y aportando una propuesta de implementación dentro de IEEE 802.21. En tercer lugar analizamos un protocolo, REAP, que se está desarrollando dentro del IETF para permitir, desde los terminales, la detección y recuperación frente a fallos en los enlaces usados en sus comunicaciones. Dentro de este bloque nos centramos en la caracterización analítica del tiempo requerido para detectar un fallo ya que este parámetro es de vital importancia para el funcionamiento de las aplicaciones, que deben poder sobrevivir a un fallo sin verse completamente interrumpidas por él. Con el estudio analítico realizado es posible configurar REAP para alcanzar un tiempo determinado de recuperación ante fallo. Todos los mecanismos propuestos han sido validados mediante simulación empleando diversas herramientas como OPNET, OMNET++ y Matla
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