225 research outputs found
Regressive Prediction Approach to Vertical Handover in Fourth Generation Wireless Networks
The over increasing demand for deployment of wireless access networks has made wireless mobile devices to face so many challenges in choosing the best suitable network from a set of available access networks. Some of the weighty issues in 4G wireless networks are fastness and seamlessness in handover process. This paper therefore, proposes a handover technique based on movement prediction in wireless mobile (WiMAX and LTE-A) environment. The technique enables the system to predict signal quality between the UE and Radio Base Stations (RBS)/Access Points (APs) in two different networks. Prediction is achieved by employing the Markov Decision Process Model (MDPM) where the movement of the UE is dynamically estimated and averaged to keep track of the signal strength of mobile users. With the help of the prediction, layer-3 handover activities are able to occur prior to layer-2 handover, and therefore, total handover latency can be reduced. The performances of various handover approaches influenced by different metrics (mobility velocities) were evaluated. The results presented demonstrate good accuracy the proposed method was able to achieve in predicting the next signal level by reducing the total handover latency
Intégration et gestion de mobilité de bout en bout dans les réseaux mobiles de prochaine génération
Résumé - Pendant les dix derniÚres années, l'utilisation des systÚmes de communication sans fil est devenue de plus en plus populaire tant chez les entreprises que chez les particuliers. Cette nouvelle tendance du marché est due, en grande partie, à la performance grandissante des réseaux mobiles qui concurrencent davantage les réseaux filaires en termes de bande passante, de coût et de couverture. Toutefois, cette catégorie de solutions sans fil est conçue pour des services spécifiques et utilise des technologies trÚs variées. De plus, les usagers sont de plus en plus mobiles et requiÚrent des applications sensibles au délai (voix, multimédia, etc.).
Dans ce nouveau contexte de mobilité, la prochaine génération des réseaux sans fil (4G) s'annonce comme l'ultime solution visant à satisfaire les exigences des usagers tout en tirant profit de la complémentarité des services offerts par les systÚmes mobiles existants. Pour ce faire, la principale vocation de la future génération (4G) consiste en l'intégration et la convergence des technologies sans fil existantes et celles à venir. Cette intégration passe obligatoirement par l'utilisation du protocole IP (Internet Protocol) qui permet de cacher l'hétérogénéité des systÚmes intégrés puisqu'il demeure l'unique couche commune à toutes les plateformes mobiles.
Plusieurs solutions d'intégration ont été proposées dans la littérature. Celles-ci concernent des architectures d'intégration et des mécanismes de gestion de mobilité. Cependant, les approches proposées ne font pas l'unanimité et souffrent de plusieurs handicaps liés, en particulier, à l'interopérabilité et la garantie des relÚves sans coupures.----------ABSTRACT
During the last few years, the use of wireless systems is becoming more and more popular. This tendency can be explained by the fact that mobile technologies are gaining in performance in terms of bandwidth, coverage and cost compared to the traditional wired solutions. However, each mobile network is tailored for a specific type of services and users. Moreover, end users are expected to become more and more mobile and show an increasing interest to real-time applications. In these circumstances, the next generation of mobile networks (4G) appears to be the ultimate solution that will satisfy mobile user demands and take benefit of the existing wireless systems. Indeed, the future generation consists of integrating, in an intelligent manner, the existing/future wireless systems in a way that users can obtain their services via the best available network.
This integration passes through the use of the Internet Protocol (IP) that will hide the heterogeneity pertaining to the integrated networks. To deal with this very important task, several solutions are available in the literature. The proposed approaches cover some basic topics such as interworking architecture and mobility management. Nevertheless, these proposals suffer from drawbacks relevant to the guarantee of QoS through heterogeneous technologies
Design and Experimental Validation of a Software-Defined Radio Access Network Testbed with Slicing Support
Network slicing is a fundamental feature of 5G systems to partition a single
network into a number of segregated logical networks, each optimized for a
particular type of service, or dedicated to a particular customer or
application. The realization of network slicing is particularly challenging in
the Radio Access Network (RAN) part, where multiple slices can be multiplexed
over the same radio channel and Radio Resource Management (RRM) functions shall
be used to split the cell radio resources and achieve the expected behaviour
per slice. In this context, this paper describes the key design and
implementation aspects of a Software-Defined RAN (SD-RAN) experimental testbed
with slicing support. The testbed has been designed consistently with the
slicing capabilities and related management framework established by 3GPP in
Release 15. The testbed is used to demonstrate the provisioning of RAN slices
(e.g. preparation, commissioning and activation phases) and the operation of
the implemented RRM functionality for slice-aware admission control and
scheduling
Exploring the benefits of multipath TCP In wireless networks
The revolution of the information society has created a completely new situation in the
telecommunications markets. As the average user data demands in today's society grow bigger,
since users nowadays are demanding a faster, wider and more reliable communication service
from the operators so they can watch more videos, listen to more music or access the Internet
in general with a better quality, a lower latency and seamlessly to the network access they are
using, the network operators face the challenge to fit this demands into their existing networks.
This has forced the operators to think in terms of how optimal they are on providing their
services if they want to fulfil the customer requirements in this new environment.
At the same time we need to keep in mind that simultaneously to this new user's habits
smartphones revolution has created, it has also made it possible to have accessible communication
devices which have the necessary hardware and horsepower to keep different network
interfaces up, and so it has become a common thing to reach the Internet via different kind of
networks along the day. Even more it has enabled a rich communications environment where
different connection possibilities are available to the user at the same time.
In this context, the idea of multipath communication emerges. The idea of taking advantage
of a dense wireless communication offer through the use of multipath (sending and receiving
information through different network interfaces simultaneously) looks promising to overcome a
situation where user's communications services demand grows and at the same time the mobile
network load becomes stronger. The newfangled protocol Multipath TCP (MPTCP) is a technology
which is enabling in practice this king of multipath communication, and it is the focus
of this project to dig into possible benefits the protocol may bring to the table by defining a
set of use cases, test-bed implementations and experiments with MPTCP which we present and
analyse in this document.La revoluciĂłn de la sociedad de la informaciĂłn ha creado una situaciĂłn que es completamente
nueva en los mercados de telecomunicaciones. A medida que el usuario medio aumenta su
demanda de datos, ya que hoy en dĂa los hĂĄbitos de estos pasan por conexiones mĂĄs rĂĄpidas y
fiables que les permitan reproducir contenido (video, mĂșsica, pĂĄginas web) con mejor calidad,
menor latencia y transparentemente a la red que estén utilizando, los operadores de red afrontan
nuevos retos a la hora de encajar estas expectativas del usuario dentro de las posibilidades que
ofrece la red. Esto estĂĄ forzando a los operadores a buscar una manera mĂĄs Ăłptima de gestionar
el trĂĄfico de sus clientes para asĂ poder satisfacer la demanda de unos servicios de mayor calidad
que estos realizan.
Al mismo tiempo hay que tener en mente que, de la misma manera que el impacto que esta
esta revoluciĂłn de los smartphones ha tenido en los hĂĄbitos de consumo del usuario ha creado
nuevos y complejos problemas, también ha hecho posible que existan dispositivos económicamente
accesibles para el pĂșblico con el hardware y la capacidad de procesamiento necesarias para incorporar
mĂșltiples adaptadores de red, y esto a su vez ha llevado a al escenario actual en el
que comĂșnmente coexisten en el mismo lugar diferentes posibilidades para conectarse a internet
(tĂpicamente Wi-Fi y conexiĂłn mĂłvil, pero tambiĂ©n podrĂamos nombrar tecnologĂas como el
Bluetooth o la clĂĄsica conexiĂłn de Ethernet en ordenadores portĂĄtiles)
Es en este contexto en el que surge la idea de la comunicaciĂłn multi-trayecto. La idea
de aprovechar un entorno con una densa pero heterogénea oferta de conexión a través del
uso del multi-trayecto (enviar y recibir informaciĂłn a travĂ©s de mĂșltiples interfaces de red simultĂĄneamente) aparece como una posibilidad prometedora para los operadores para mejorar
la experiencia del usuario al mismo tiempo que se gestiona el trĂĄfico en la red de una manera
mĂĄs eficiente.
El protocolo experimental Multipath TCP es una extensiĂłn del TCP clĂĄsico que hace posible
este uso simultĂĄneo de mĂșltiples interfaces para la comunicaciĂłn, y es objetivo de este proyecto
diseñar, implementar y testear el protocolo en diferentes casos de uso en los que el multi-trayecto
ofrece, a priori, algunas ventajas. En las siguientes pĂĄginas explicaremos que casos de uso hemos
elegido para probar el protocolo y por qué, cómo hemos diseñado e implementado los bancos
de pruebas y que resultados hemos obtenido en nuestro experimentos sobre el rendimiento del
protocolo, realizando al mismo tiempo un anĂĄlisis crĂtico de los resultados de los resultados.IngenierĂa de TelecomunicaciĂł
Design and experimental validation of a software-defined radio access network testbed with slicing support
Network slicing is a fundamental feature of 5G systems to partition a single network into a number of segregated logical networks, each optimized for a particular type of service or dedicated to a particular customer or application. The realization of network slicing is particularly challenging in the Radio Access Network (RAN) part, where multiple slices can be multiplexed over the same radio channel and Radio Resource Management (RRM) functions shall be used to split the cell radio resources and achieve the expected behaviour per slice. In this context, this paper describes the key design and implementation aspects of a Software-Defined RAN (SD-RAN) experimental testbed with slicing support. The testbed has been designed consistently with the slicing capabilities and related management framework established by 3GPP in Release 15. The testbed is used to demonstrate the provisioning of RAN slices (e.g., preparation, commissioning, and activation phases) and the operation of the implemented RRM functionality for slice-aware admission control and scheduling.Peer ReviewedPostprint (published version
A cross-layer mobility management framework for next-generation wireless roaming
Word processed copy.Includes bibliographical references (leaves 62-64).This thesis proposes a mobility management framework that aims to provide a framework for advanced mobility algorithms that allows the challenges of next-generation roaming to be met. The framework features tools that gather context and content information, guarantee low-level QoS, provide security, and offer link and handoff management. The framework aims to be scalable and reliable for all-IP heterogeneous wireless networks whilst conforming to 4G service requirements
Performance Comparison of Dual Connectivity and Hard Handover for LTE-5G Tight Integration in mmWave Cellular Networks
MmWave communications are expected to play a major role in the Fifth
generation of mobile networks. They offer a potential multi-gigabit throughput
and an ultra-low radio latency, but at the same time suffer from high isotropic
pathloss, and a coverage area much smaller than the one of LTE macrocells. In
order to address these issues, highly directional beamforming and a very
high-density deployment of mmWave base stations were proposed. This Thesis aims
to improve the reliability and performance of the 5G network by studying its
tight and seamless integration with the current LTE cellular network. In
particular, the LTE base stations can provide a coverage layer for 5G mobile
terminals, because they operate on microWave frequencies, which are less
sensitive to blockage and have a lower pathloss. This document is a copy of the
Master's Thesis carried out by Mr. Michele Polese under the supervision of Dr.
Marco Mezzavilla and Prof. Michele Zorzi. It will propose an LTE-5G tight
integration architecture, based on mobile terminals' dual connectivity to LTE
and 5G radio access networks, and will evaluate which are the new network
procedures that will be needed to support it. Moreover, this new architecture
will be implemented in the ns-3 simulator, and a thorough simulation campaign
will be conducted in order to evaluate its performance, with respect to the
baseline of handover between LTE and 5G.Comment: Master's Thesis carried out by Mr. Michele Polese under the
supervision of Dr. Marco Mezzavilla and Prof. Michele Zorz
IEEE 802.21 in heterogeneous handover environments
Mestrado em Engenharia de Computadores e TelemĂĄticaO desenvolvimento das capacidades tecnolĂłgicas dos terminais mĂłveis, e das
infra-estruturas que os suportam, potenciam novos cenĂĄrios onde estes dispositivos
munidos com interfaces de diferentes tecnologias vagueiam entre
diferentes ambientes de conectividade. Ă assim necessĂĄrio providenciar meios
que facilitem a gestĂŁo de mobilidade, permitindo ao terminal ligar-se da melhor
forma (i.e., optando pela melhor tecnologia) em qualquer altura.
A norma IEEE 802.21 estĂĄ 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 cenårios 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 anålise extensiva da norma IEEE 802.21, introduzindo
um conjunto de simulaçÔes 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
Mobility management across converged IP-based heterogeneous access networks
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 8/2/2010.In order to satisfy customer demand for a high performance âglobalâ mobility service, network operators (ISPs, carriers, mobile operators, etc.) are facing the need to evolve to a converged âall-IPâ centric heterogeneous access infrastructure. However, the integration of such heterogeneous access networks (e.g. 802.11, 802.16e, UMTS etc) brings major mobility issues. This thesis tackles issues plaguing existing mobility management solutions in converged IP-based heterogeneous networks. In order to do so, the thesis firstly proposes a cross-layer mechanism using the upcoming IEEE802.21 MIH services to make intelligent and optimized handovers. In this respect, FMIPv6 is integrated with the IEEE802.21 mechanism to provide seamless mobility during the overall handover process. The proposed solution is then applied in a simulated vehicular environment to optimize the NEMO handover process. It is shown through analysis and simulations of the signalling process that the overall expected handover (both L2 and L3) latency in FMIPv6 can be reduced by the proposed mechanism by 69%. Secondly, it is expected that the operator of a Next Generation Network will provide mobility as a service that will generate significant revenues. As a result, dynamic service bootstrapping and authorization mechanisms must be in place to efficiently deploy a mobility service (without static provisioning), which will allow only legitimate users to access the service. A GNU Linux based test-bed has been implemented to demonstrate this. The experiments presented show the handover performance of the secured FMIPv6 over the implemented test-bed compared to plain FMIPv6 and MIPv6 by providing quantitative measurements and results on the quality of experience perceived by the users of IPv6 multimedia applications. The results show the inclusion of the additional signalling of the proposed architecture for the purpose of authorization and bootstrapping (i.e. key distribution using HOKEY) has no adverse effect on the overall handover process. Also, using a formal security analysis tool, it is shown that the proposed mechanism is safe/secure from the induced security threats. Lastly, a novel IEEE802.21 assisted EAP based re-authentication scheme over a service authorization and bootstrapping framework is presented. AAA based authentication mechanisms like EAP incur signalling overheads due to large RTTs. As a result, overall handover latency also increases. Therefore, a fast re-authentication scheme is presented which utilizes IEEE802.21 MIH services to minimize the EAP authentication process delays and as a result reduce the overall handover latency. Analysis of the signalling process based on analytical results shows that the overall handover latency for mobility protocols will be approximately reduced by 70% by the proposed scheme
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