222 research outputs found

    Seamless Infrastructure independent Multi Homed NEMO Handoff Using Effective and Timely IEEE 802.21 MIH triggers

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    Handoff performance of NEMO BS protocol with existent improvement proposals is still not sufficient for real time and QoS-sensitive applications and further optimizations are needed. When dealing with single homed NEMO, handoff latency and packet loss become irreducible all optimizations included, so that it is impossible to meet requirements of the above applications. Then, How to combine the different Fast handoff approaches remains an open research issue and needs more investigation. In this paper, we propose a new Infrastructure independent handoff approach combining multihoming and intelligent Make-Before-Break Handoff. Based on required Handoff time estimation, L2 and L3 handoffs are initiated using effective and timely MIH triggers, reducing so the anticipation time and increasing the probability of prediction. We extend MIH services to provide tunnel establishment and switching before link break. Thus, the handoff is performed in background with no latency and no packet loss while pingpong scenario is almost avoided. In addition, our proposal saves cost and power consumption by optimizing the time of simultaneous use of multiple interfaces. We provide also NS2 simulation experiments identifying suitable parameter values used for estimation and validating the proposed mode

    Towards seamless inter-technology handovers in vehicular IPv6 communications

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    Network mobility plays an important role in communications when using different access networks while maintaining application sessions. This is the case of vehicular networks used by the emerging Cooperative Intelligent Transport System (C-ITS), where vehicles are constantly moving, changing their access network. Standardization bodies like IETF, and particular proposals in the literature, have already defined mobility mechanisms by using widely used Internet technologies. The usefulness of these mechanisms in vehicular networks is clear when using IPv6, however, its performance suffer from the high mobility of nodes, the fluctuating performance of communication technologies, and the need for a decision mechanism to choose a proper attachment point among the available access networks on roads. For this reason, here we propose an instantiation of the ISO/ETSI reference architecture for vehicular cooperative systems, by deploying a real vehicular network based on IPv6, as well as a mobility service provided by Network Mobility Basic Support (NEMO) and the Multiple Care of Addresses Registration (MCoA) extension. This mobility solution is embedded into a framework that integrates the IEEE 802.21 technology, which provides a greater control over the handover process. The resulting architecture not only provides a seamless handover but also supports the decision making when searching for the most suitable target network. Our experiments reveal that our combined NEMO/MCoA/802.21 system within a vehicular communication stack is able to provide uninterrupted communications during handovers with a dramatic reduction in the time needed by this process.This work has been sponsored by the Spanish Ministry of Economy and Competitiveness through the EDISON project (contract TIN2014-52099-R) and the Spanish Department of Transport (DGT) through the S-CICLO project (contract SPIP2015-01757)

    Simultaneous multi-access in heterogeneous mobile networks

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    The exponential growth of the number of multihomed mobile devices is changing the way how we connect to the Internet. Unfortunately, it is not yet easily possible to a multihomed device to be simultaneously connected to the network through multiple links. This work enhances the network access of multihomed devices. This enhancement is achieved by using simultaneously all of the mobile devices interfaces, and by individually routing each data flow through the most adequate technology. The proposed solution is only deployed at the network core and it does not depend on the mobile devices, i.e., it’s transparent to the mobile devices. This work gives the necessary tools to reuse the already deployed technologies like WiFi or 3G/LTE. Moreover, it is also possible to extend the network by using femtocells which support multi access technologies. This work is also integrated with IEEE 802.21 standard to improve the handover mechanisms in the network. Additionally, we also propose an integration with a broker that can manage all the data flows individually. The proposed solution improves the quality of service of the users while not overloading the operator infrastructure. Evaluation results, obtained from the developed prototype, evidence that the overhead for using the proposed solution is very small when compared to the advantages.O crescimento exponencial do número de equipamentos móveis com múltiplas tecnologias de acesso à rede está a mudar a maneira como nos ligamos à Internet. Infelizmente, ainda não é possível usar simultaneamente todas as interfaces de rede de um equipamento móvel. Este trabalho melhora o acesso à rede a partir de dispositivos móveis com múltiplas interfaces de rede. Para alcançar esta melhoria todas as interfaces de rede dos dispositivos móveis podem ser usadas simultaneamente, e os fluxos de tráfego são encaminhados individualmente através da tecnologia mais conveniente. A solução proposta apenas é instalada na rede core, ou seja, é transparente para os equipamentos móveis. Este trabalho desenvolveu as ferramentas necessárias para reutilizar as tecnologias existentes que já estão disponíveis em larga escala, como o WiFi ou o 3G/LTE. É também possível usar femto-­células com suporte a múltiplas tecnologias de acesso para expandir mais rapidamente a rede. Este trabalho criou também uma integração com a norma IEEE 802.21 para melhorar os processos de handover. Adicionalmente propomos a integração com um broker externo para uma melhor gestão dos fluxos de tráfego. A solução proposta melhora a qualidade de serviço dos utilizadores sem sobrecarregar a infra-­estrutura do operador. Os resultados obtidos a partir dos testes realizados ao protótipo desenvolvido mostram que o impacto na performance ao usar esta solução é extremamente reduzido quando comparado com as suas vantagens

    SCALABLE AND EFFICIENT VERTICAL HANDOVER DECISION ALGORITHMS IN VEHICULAR NETWORK CONTEXTS

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    A finales de los años noventa, y al comienzo del nuevo milenio, las redes inalámbricas han evolucionado bastante, pasando de ser sólo una tecnología prometedora para convertirse en un requisito para las actividades cotidianas en las sociedades desarrolladas. La infraestructura de transporte también ha evolucionado, ofreciendo comunicación a bordo para mejorar la seguridad vial y el acceso a contenidos de información y entretenimiento. Los requisitos de los usuarios finales se han hecho dependientes de la tecnología, lo que significa que sus necesidades de conectividad han aumentado debido a los diversos requisitos de las aplicaciones que se ejecutan en sus dispositivos móviles, tales como tabletas, teléfonos inteligentes, ordenadores portátiles o incluso ordenadores de abordo (On-Board Units (OBUs)) dentro de los vehículos. Para cumplir con dichos requisitos de conectividad, y teniendo en cuenta las diferentes redes inalámbricas disponibles, es necesario adoptar técnicas de Vertical Handover (VHO) para cambiar de red de forma transparente y sin necesidad de intervención del usuario. El objetivo de esta tesis es desarrollar algoritmos de decisión (Vertical Handover Decision Algorithms (VHDAs)) eficientes y escalables, optimizados para el contexto de las redes vehiculares. En ese sentido se ha propuesto, desarrollado y probado diferentes algoritmos de decisión basados en la infraestructura disponible en las actuales, y probablemente en las futuras, redes inalámbricas y redes vehiculares. Para ello se han combinado diferentes técnicas, métodos computacionales y modelos matemáticos, con el fin de garantizar una conectividad apropiada, y realizando el handover hacia las redes más adecuadas de manera a cumplir tanto con los requisitos de los usuarios como los requisitos de las aplicaciones. Con el fin de evaluar el contexto, se han utilizado diferentes herramientas para obtener información variada, como la disponibilidad de la red, el estado de la red, la geolocalizaciónMárquez Barja, JM. (2012). SCALABLE AND EFFICIENT VERTICAL HANDOVER DECISION ALGORITHMS IN VEHICULAR NETWORK CONTEXTS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/17869Palanci

    EMICOM: Enhanced Media Independent COnnection Manager

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    With the increasing amount of mobile interfaces combining different kinds of access technologies, ranging from Wi-Fi to 3G and LTE, the integration of flexible and mediaindependent link control mechanisms becomes of paramount importance. By employing an abstract way of obtaining access link status information and exercising control over the network interface operations, these control mechanisms become able to optimize device connectivity and network attachment. This paper presents EMICOM, an Enhanced Media Independent COnnection Manager framework where a GNU/Linux Network Manager and Link Service Access Points for the IEEE 802.3 and 802.11 technologies were implemented and integrated through crosslayer Media Independent Handover (MIH) mechanisms from the IEEE 802.21 standard. Through an open-source implementation of the framework, the (MIH) command set capabilities are extended, allowing the support of network association and authentication, as well as Layer 3 services such as IP configuration, providing a generic solution for optimal network connectivity management

    Descoberta de serviços independentes do acesso para redes heterogéneas

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    Mestrado em Engenharia de Computadores e TelemáticaA recente proliferação de nós móveis com múltiplas interfaces sem fios e a constituição de ambientes heterogéneos possibilitaram a criação de cenários complexos onde os operadores de rede necessitam de disponibilizar conectividade para diferentes tipos de redes de acesso. Assim, a norma IEEE 802.21 foi especificada de forma a facilitar e optimizar os procedimentos de handover entre diferentes tecnologias de acesso sem perda de conectividade. Para cumprir o seu propósito, a norma disponibiliza serviços chamados Media Independent Handover e que permitem o controlo e a obtenção de informação de diferentes ligações. A configuração estática destes serviços por parte do nó móvel torna-se ineficiente devido aos múltiplos cenários possíveis. Desta forma, o nó móvel deve descobrir nós da rede que providenciem serviços de mobilidade e as suas capacidade de uma forma dinâmica. Nesta dissertação, um conjunto de mecanismos para descoberta de serviços de handover independentes do acesso são analisados, implementados e avaliados em termos de duração e quantidade de informação trocada. Um novo mecanismo de descoberta de entidades locais é também proposto e avaliado, demonstrando que a sua utilização aumenta o desempenho e requer a troca de menos quantidade de informação.The recent proliferation of mobile nodes with multiple wireless interfaces, in addition to the creation of heterogeneous environments, created complex scenarios where network operators need to provide connectivity for di erent kinds of access networks. Therefore, the IEEE 802.21 standard has been speci ed to facilitate and optimize handover procedures between di erent access technologies in a seamless way. To ful l its purpose, it provides Media Independent Handover services which allow the control and gathering of information from di erent links. The static con guration of these services by the MN becomes ine cient due to the amount of possible scenarios. Thus, the MN must discover the network-supporting nodes and their capabilities in a dynamic way. In this work, a series of proposed Media Independent Handover discovery procedures are analyzed, implemented and evaluated in terms of duration and amount of exchanged information. In addition, a novel discovery procedure for local entities is proposed and evaluated, showing that its deployment increases the performance and requires less information exchanged

    Securing Handover in Wireless IP Networks

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    In wireless and mobile networks, handover is a complex process that involves multiple layers of protocol and security executions. With the growing popularity of real time communication services such as Voice of IP, a great challenge faced by handover nowadays comes from the impact of security implementations that can cause performance degradation especially for mobile devices with limited resources. Given the existing networks with heterogeneous wireless access technologies, one essential research question that needs be addressed is how to achieve a balance between security and performance during the handover. The variations of security policy and agreement among different services and network vendors make the topic challenging even more, due to the involvement of commercial and social factors. In order to understand the problems and challenges in this field, we study the properties of handover as well as state of the art security schemes to assist handover in wireless IP networks. Based on our analysis, we define a two-phase model to identify the key procedures of handover security in wireless and mobile networks. Through the model we analyze the performance impact from existing security schemes in terms of handover completion time, throughput, and Quality of Services (QoS). As our endeavor of seeking a balance between handover security and performance, we propose the local administrative domain as a security enhanced localized domain to promote the handover performance. To evaluate the performance improvement in local administrative domain, we implement the security protocols adopted by our proposal in the ns-2 simulation environment and analyze the measurement results based on our simulation test

    A framework for supporting network continuity in vehicular IPv6 communications

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    The appearance of recent standards about cooperative ITS architectures towards a reference communication stack has been an inflection point in the research about vehicular networks. The ISO Communication Access for Land Mobiles (CALM) and the ETSI European ITS communication architecture have paved the way towards real and interoperable vehicular cooperative systems. Within these convergent proposals, IPv6 communications are recognized as a key component to enable traffic efficiency and infotainment applications. The proper operation of these applications and the achievement of value-added ITS services require an uninterrupted network connectivity. This paper addresses this problem by proposing a novel communication stack to support the provision of continuous and secure IPv6 vehicular communications. The solution follows the ISO/ETSI guidelines for the development of cooperative ITS systems and is based on standardized technologies such as Network Mobility (NEMO) protocol to provide an integral management of IPv6mobility. The solution integrates IEEE 802.21 media independent handover services for optimizing the handover process. While the support to the handover optimization offered by the proposed ITS communication stack is demonstrated through a mobility use case, a real testbed supporting most of the communications features is developed to validate and assess the real performance of the stack design.This work has been sponsored by the European Seventh Framework Program, through the ITSSv6 (contract 270519) and FOTsis (contract 270447) projects; the Ministry of Science and Innovation, through the Walkie-Talkie project (TIN2011-27543-C03); and the Seneca Foundation, by means of the GERM program (04552/GERM/06)
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