121 research outputs found
On providing mobility management in WOBANs: Integration with PMIPv6 and MIH
The Wireless-Optical Broadband Access Network (WOBAN) is a promising access architecture that combines the high performance of optical networks with the ubiquity and convenience of wireless technologies. This article proposes a network-based mobility framework that is specially tailored for WOBANs. The proposed architecture is based on Proxy Mobile IPv6 and IEEE 802.21 mobility management protocols, but it also defines a number of optimizations that enable the seamless handover of mobile nodes. In particular, the hierarchical architecture together with the broadcast-and-select nature of the optical part of the WOBAN are leveraged to: optimize the mobility of users with respect to the overall network resources, both at the wireless access and optical distribution parts, remove the overhead of IP-in-IP tunneling between the PMIPv6 entities, and perform an efficient bicasting during the handover process to minimize packet loss.The authors would like to acknowledge the support of the
EU-funded MEDIEVAL (grant FP7-ICT-2009-5/258053), the
CAM-funded Medianet project (under code S-2009/TIC-1468)
and the MICINN research grant TIN2010-20136-C03.European Community's Seventh Framework ProgramPublicad
Descoberta de serviços independentes do acesso para redes heterogéneas
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
Interworking in heterogeneous wireless networks: comprehensive framework and future trends
Interworking mechanisms are of prime importance
to achieve ubiquitous access and seamless
mobility in heterogeneous wireless networks. In
this article we develop a comprehensive framework
to categorize interworking solutions by
defining a generic set of interworking levels and
its related key interworking mechanisms. The
proposed framework is used to analyze some of
the most relevant interworking solutions being
considered in different standardization bodies.
More specifically, I-WLAN and GAN approaches
for WLAN and cellular integration, solutions
for WiMAX and 3GPP LTE/SAE interworking,
and the forthcoming IEEE 802.21 standard are
discussed from the common point of view provided
by the elaborated framework.Postprint (published version
Middleware de comunicações para a internet móvel futura
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
New concepts for traffic, resource and mobility management in software-defined mobile networks
The evolution of mobile telecommunication networks is accompanied by new demands for the performance, portability, elasticity, and energy efficiency of network functions. Network Function Virtualization (NFV), Software Defined Networking (SDN), and cloud service technologies are claimed to be able to provide most of the capabilities. However, great leap forward will only be achieved if resource, traffic, and mobility management methods of mobile network services can efficiently utilize these technologies. This paper conceptualizes the future requirements of mobile networks and proposes new concepts and solutions in the form of Software-Defined Mobile Networks (SDMN) leveraging SDN, NFV and cloud technologies. We evaluate the proposed solutions through testbed implementations and simulations. The results reveal that our proposed SDMN enhancements supports heterogeneity in wireless networks with performance improvements through programmable interfaces and centralized control
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Heterogeneous Access: Survey and Design Considerations
As voice, multimedia, and data services are converging to IP, there is a need for a new networking architecture to support future innovations and applications. Users are consuming Internet services from multiple devices that have multiple network interfaces such as Wi-Fi, LTE, Bluetooth, and possibly wired LAN. Such diverse network connectivity can be used to increase both reliability and performance by running applications over multiple links, sequentially for seamless user experience, or in parallel for bandwidth and performance enhancements. The existing networking stack, however, offers almost no support for intelligently exploiting such network, device, and location diversity. In this work, we survey recently proposed protocols and architectures that enable heterogeneous networking support. Upon evaluation, we abstract common design patterns and propose a unified networking architecture that makes better use of a heterogeneous dynamic environment, both in terms of networks and devices. The architecture enables mobile nodes to make intelligent decisions about how and when to use each or a combination of networks, based on access policies. With this new architecture, we envision a shift from current applications, which support a single network, location, and device at a time to applications that can support multiple networks, multiple locations, and multiple devices
Seamless Handover with Buffer Prediction for Wireless Networks Based on IEEE 802.21
[[abstract]]Future generations of wireless networks will place great demands on the performance of radio access technology and the real-time multimedia applications provided by these new wireless environments. During the mobility between heterogeneous wireless networks, the quality of multimedia services for users depends heavily on seamless handover which should be provided by the middleware of IP to MAC protocol stack. IEEE 802.21 is designed for this reason which provided the basic platform for seamless handover between heterogeneous wireless networks. In this paper, a dynamically adjusted buffer component with algorithm for prediction of the buffer size is proposed to enhance the functionality of IEEE 802.21. The mechanism of proposed scheme included Service Specific Layer which decides the opportunity of handover, and adjusted Buffer which stores the temporal streaming data for applications between handover. The services and communication flows among service specific layer, buffer and IEEE 802.21 Media Independent Handover function are described and analyzed. According to analysis of the connection process and simulation, buffer prediction and pre-allocation could indeed reduce the influence of handover between heterogeneous wireless networks.[[conferencetype]]國際[[conferencelocation]]Busan, Kore
Network-Assisted Handover for Heterogeneous Wireless Networks using IEEE 802.21
The IEEE 802.21 is a standard for enabling handover in heterogeneous wireless networks. Published in January 2009, it defines protocols and messages for mobile-to-node and node-to-node communication in a technology-neutral and flexible manner. The need arises because of the widespread diffusion of different technologies for wireless communications (e.g., WiFi, WiMAX, LTE) coexisting in the same geographical area. Even though the number of multi-radio multi-technology mobile devices is increasing significantly, there are no open solutions in the market to enable efficient inter-technology handover.
As is often the case with communication standards, the structure of the required components, the procedures, and the algorithms are left unspecified by the IEEE 802.21 standard so as to promote competion by differentiation of equipment capabilities and services. The contribution of this thesis is two-fold: i) a design and an implemenation of the Media Independent Information Service (MIIS) server; and, ii) a solution to enable network-assisted handover using the IEEE 802.21 standard, aimed at reducing the handover latency and the energy consumption of mobile devices due to scanning.
The MIIS server has been fully implemented in C++ under Linux. In order to perform testbed evaluations, all the required components have been implemented, as well, within an open source framework for IEEE 802.21 called ODTONE. Modifications to the latter have been performed for optimization and fine tuning, and for extending those functional modules needed but not fully implemented.
For a realistic evaluation, Linux-based embedded COTS devices have been used, equipped with multiple IEEE 802.11a and IEEE 802.11g wireless network interface cards. This has required additional development for kernel/user space binding and hardware control.
Testbed results are reported to show the effectiveness of the proposed solution, also proving the MIIS server scalability
Acesso banda larga sem fios em ambientes heterogéneos de próxima geração
Doutoramento em Engenharia InformáticaO acesso ubíquo à Internet é um dos principais desafios para os operadores
de telecomunicações na próxima década. O número de utilizadores da Internet
está a crescer exponencialmente e o paradigma de acesso "always connected,
anytime, anywhere" é um requisito fundamental para as redes móveis de
próxima geração. A tecnologia WiMAX, juntamente com o LTE, foi
recentemente reconhecida pelo ITU como uma das tecnologias de acesso
compatíveis com os requisitos do 4G. Ainda assim, esta tecnologia de acesso
não está completamente preparada para ambientes de próxima geração,
principalmente devido à falta de mecanismos de cross-layer para integração de
QoS e mobilidade. Adicionalmente, para além das tecnologias WiMAX e LTE,
as tecnologias de acesso rádio UMTS/HSPA e Wi-Fi continuarão a ter um
impacto significativo nas comunicações móveis durante os próximos anos.
Deste modo, é fundamental garantir a coexistência das várias tecnologias de
acesso rádio em termos de QoS e mobilidade, permitindo assim a entrega de
serviços multimédia de tempo real em redes móveis.
Para garantir a entrega de serviços multimédia a utilizadores WiMAX, esta
Tese propõe um gestor cross-layer WiMAX integrado com uma arquitectura de
QoS fim-a-fim. A arquitectura apresentada permite o controlo de QoS e a
comunicação bidireccional entre o sistema WiMAX e as entidades das
camadas superiores. Para além disso, o gestor de cross-layer proposto é
estendido com eventos e comandos genéricos e independentes da tecnologia
para optimizar os procedimentos de mobilidade em ambientes WiMAX. Foram
realizados testes para avaliar o desempenho dos procedimentos de QoS e
mobilidade da arquitectura WiMAX definida, demonstrando que esta é
perfeitamente capaz de entregar serviços de tempo real sem introduzir custos
excessivos na rede.
No seguimento das extensões de QoS e mobilidade apresentadas para a
tecnologia WiMAX, o âmbito desta Tese foi alargado para ambientes de
acesso sem-fios heterogéneos. Neste sentido, é proposta uma arquitectura de
mobilidade transparente com suporte de QoS para redes de acesso multitecnologia.
A arquitectura apresentada integra uma versão estendida do IEEE
802.21 com suporte de QoS, bem como um gestor de mobilidade avançado
integrado com os protocolos de gestão de mobilidade do nível IP. Finalmente,
para completar o trabalho desenvolvido no âmbito desta Tese, é proposta uma
extensão aos procedimentos de decisão de mobilidade em ambientes
heterogéneos para incorporar a informação de contexto da rede e do terminal.
Para validar e avaliar as optimizações propostas, foram desenvolvidos testes
de desempenho num demonstrador inter-tecnologia, composta pelas redes de
acesso WiMAX, Wi-Fi e UMTS/HSPA.Ubiquitous Internet access is one of the main challenges for the
telecommunications industry in the next decade. The number of users
accessing the Internet is growing exponentially and the network access
paradigm of “always connected, anytime, anywhere” is a central requirement
for the so-called Next Generation Mobile Networks (NGMN). WiMAX, together
with LTE, was recently recognized by ITU as one of the compliant access
technologies for 4G. Nevertheless, WiMAX is not yet fully prepared for next
generation environments, mainly due to the lack of QoS and mobility crosslayer
procedures to support real-time multimedia services delivery.
Furthermore, besides the 4G compliant WiMAX and LTE radio access
technologies, UMTS/HSPA and Wi-Fi will also have a significant impact in the
mobile communications during the next years. Therefore, it is fundamental to
ensure the coexistence of multiple radio access technologies in what QoS and
mobility procedures are concerned, thereby allowing the delivery of real-time
services in mobile networks.
In order to provide the WiMAX mobile users with the demanded multimedia
services, it is proposed in this Thesis a WiMAX cross-layer manager integrated
in an end-to-end all-IP QoS enabled architecture. The presented framework
enables the QoS control and bidirectional communication between WiMAX and
the upper layer network entities. Furthermore, the proposed cross-layer
framework is extended with media independent events and commands to
optimize the mobility procedures in WiMAX environments. Tests were made to
evaluate the QoS and mobility performance of the defined architecture,
demonstrating that it is perfectly capable of handling and supporting real time
services without introducing an excessive cost in the network.
Following the QoS and mobility extensions provided for WiMAX, the scope of
this Thesis is broaden and a seamless mobility architecture with QoS support in
heterogeneous wireless access environments is proposed. The presented
architecture integrates an extended version of the IEEE 802.21 framework with
QoS support, as well as an advanced mobility manager integrated with the IP
level mobility management protocols. Finally, to complete the work within the
framework of this Thesis, it is proposed an extension to the handover decisionmaking
processes in heterogeneous access environments through the
integration of context information from both the network entities and the enduser.
Performance tests were developed in a real testbed to validate the
proposed optimizations in an inter-technology handover scenario involving
WiMAX, Wi-Fi and UMTS/HSPA
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