3,763 research outputs found
Enhanced connectivity in wireless mobile programmable networks
MenciĂłn Interancional en el tĂtulo de doctorThe architecture of current operator infrastructures is being challenged by the non-stop growing demand of data hungry services appearing every day. While currently deployed operator networks have been able to cope with traffic demands so far, the architectures for the 5th generation of mobile networks (5G) are expected to support unprecedented traffic loads while decreasing costs associated with the network deployment and operations. Indeed, the forthcoming set of 5G standards will bring programmability and flexibility to levels never seen before. This has required introducing changes in the architecture of mobile networks, enabling different features such as the split of control and data planes, as required to support rapid programming of heterogeneous data planes. Network softwarisation is hence seen as a key enabler to cope with such network evolution, as it permits controlling all networking functions through (re)programming, thus providing higher flexibility to meet heterogeneous requirements while keeping deployment and operational costs low. A great diversity in terms of traffic patterns, multi-tenancy, heterogeneous and stringent traffic requirements is therefore expected in 5G networks. Software Defined Networking (SDN) and Network Function Virtualisation (NFV) have emerged as a basic tool-set for operators to manage their infrastructure with increased flexibility and reduced costs. As a result, new 5G services can now be envisioned and quickly programmed and provisioned in response to user and market necessities, imposing a paradigm shift in the services design. However, such flexibility requires the 5G transport network to undergo a profound transformation, evolving from a static connectivity substrate into a service-oriented infrastructure capable of accommodating the various 5G services, including Ultra-Reliable and Low Latency Communications (URLLC). Moreover, to achieve the desired flexibility and cost reduction, one promising approach is to leverage virtualisation technologies to dynamically host contents, services, and applications closer to the users so as to offload the core network and reduce the communication delay. This thesis tackles the above challengeswhicharedetailedinthefollowing. A common characteristic of the 5G servicesistheubiquityandthealmostpermanent connection that is required from the mobile network. This really imposes a challenge in thesignallingproceduresprovidedtogettrack of the users and to guarantee session continuity. The mobility management mechanisms will hence play a central role in the 5G networks because of the always-on connectivity demand. Distributed Mobility Management (DMM) helps going towards this direction, by flattening the network, hence improving its scalability,andenablinglocalaccesstotheInternet and other communication services, like mobile-edge clouds. Simultaneously, SDN opens up the possibility of running a multitude of intelligent and advanced applications for network optimisation purposes in a centralised network controller. The combination of DMM architectural principles with SDN management appears as a powerful tool for operators to cope with the management and data burden expected in 5G networks. To meet the future mobile user demand at a reduced cost, operators are also looking at solutions such as C-RAN and different functional splits to decrease the cost of deploying and maintaining cell sites. The increasing stress on mobile radio access performance in a context of declining revenues for operators is hence requiring the evolution of backhaul and fronthaul transport networks, which currently work decoupled. The heterogeneity of the nodes and transmisiĂłn technologies inter-connecting the fronthaul and backhaul segments makes the network quite complex, costly and inefficient to manage flexibly and dynamically. Indeed, the use of heterogeneous technologies forces operators to manage two physically separated networks, one for backhaul and one forfronthaul. In order to meet 5G requirements in a costeffective manner, a unified 5G transport network that unifies the data, control, and management planes is hence required. Such an integrated fronthaul/backhaul transport network, denoted as crosshaul, will hence carry both fronthaul and backhaul traffic operating over heterogeneous data plane technologies, which are software-controlled so as to adapt to the fluctuating capacity demand of the 5G air interfaces. Moreover, 5G transport networks will need to accommodate a wide spectrum of services on top of the same physical infrastructure. To that end, network slicing is seen as a suitable candidate for providing the necessary Quality of Service (QoS). Traffic differentiation is usually enforced at the border of the network in order to ensure a proper forwarding of the traffic according to its class through the backbone. With network slicing, the traffic may now traverse many slice edges where the traffic policy needs to be enforced, discriminated and ensured, according to the service and tenants needs. However, the very basic nature that makes this efficient management and operation possible in a flexible way â the logical centralisation â poses important challenges due to the lack of proper monitoring tools, suited for SDN-based architectures. In order to take timely and right decisions while operating a network, centralised intelligence applications need to be fed with a continuous stream of up-to-date network statistics. However, this is not feasible with current SDN solutions due to scalability and accuracy issues. Therefore, an adaptive telemetry system is required so as to support the diversity of 5G services and their stringent traffic requirements. The path towards 5G wireless networks alsopresentsacleartrendofcarryingoutcomputations close to end users. Indeed, pushing contents, applications, and network functios closer to end users is necessary to cope with thehugedatavolumeandlowlatencyrequired in future 5G networks. Edge and fog frameworks have emerged recently to address this challenge. Whilst the edge framework was more infrastructure-focused and more mobile operator-oriented, the fog was more pervasive and included any node (stationary or mobile), including terminal devices. By further utilising pervasive computational resources in proximity to users, edge and fog can be merged to construct a computing platform, which can also be used as a common stage for multiple radio access technologies (RATs) to share their information, hence opening a new dimension of multi-RAT integration.La arquitectura de las infraestructuras actuales de los operadores estĂĄ siendo desafiada por la demanda creciente e incesante de servicios con un elevado consumo de datos que aparecen todos los dĂas. Mientras que las redes de operadores implementadas actualmente han sido capaces de lidiar con las demandas de trĂĄfico hasta ahora, se espera que las arquitecturas de la quinta generaciĂłn de redes mĂłviles (5G) soporten cargas de trĂĄfico sin precedentes a la vez que disminuyen los costes asociados a la implementaciĂłn y operaciones de la red. De hecho, el prĂłximo conjunto de estĂĄndares 5G traerĂĄ la programabilidad y flexibilidad a niveles nunca antes vistos. Esto ha requerido la introducciĂłn de cambios en la arquitectura de las redes mĂłviles, lo que permite diferentes funciones, como la divisiĂłn de los planos de control y de datos, segĂșn sea necesario para soportar una programaciĂłn rĂĄpida de planos de datos heterogĂ©neos. La softwarisaciĂłn de red se considera una herramienta clave para hacer frente a dicha evoluciĂłn de red, ya que proporciona la capacidad de controlar todas las funciones de red mediante (re)programaciĂłn, proporcionando asĂ una mayor flexibilidad para cumplir requisitos heterogĂ©neos mientras se mantienen bajos los costes operativos y de implementaciĂłn. Por lo tanto, se espera una gran diversidad en tĂ©rminos de patrones de trĂĄfico, multi-tenancy, requisitos de trĂĄfico heterogĂ©neos y estrictos en las redes 5G. Software Defined Networking (SDN) y Network Function Virtualisation (NFV) se han convertido en un conjunto de herramientas bĂĄsicas para que los operadores administren su infraestructura con mayor flexibilidad y menores costes. Como resultado, los nuevos servicios 5G ahora pueden planificarse, programarse y aprovisionarse rĂĄpidamente en respuesta a las necesidades de los usuarios y del mercado, imponiendo un cambio de paradigma en el diseño de los servicios. Sin embargo, dicha flexibilidad requiere que la red de transporte 5G experimente una transformaciĂłn profunda, que evoluciona de un sustrato de conectividad estĂĄtica a una infraestructura orientada a servicios capaz de acomodar los diversos servicios 5G, incluso Ultra-Reliable and Low Latency Communications (URLLC). AdemĂĄs, para lograr la flexibilidad y la reducciĂłn de costes deseadas, un enfoque prometedores aprovechar las tecnologĂas de virtualizaciĂłn para alojar dinĂĄmicamente los contenidos, servicios y aplicaciones mĂĄs cerca de los usuarios para descargar la red central y reducir la latencia. Esta tesis aborda los desafĂos anteriores que se detallan a continuaciĂłn. Una caracterĂstica comĂșn de los servicios 5G es la ubicuidad y la conexiĂłn casi permanente que se requiere para la red mĂłvil. Esto impone un desafĂo en los procedimientos de señalizaciĂłn proporcionados para hacer un seguimiento de los usuarios y garantizar la continuidad de la sesiĂłn. Por lo tanto, los mecanismos de gestiĂłn de la movilidad desempeñarĂĄn un papel central en las redes 5G debido a la demanda de conectividad siempre activa. Distributed Mobility Management (DMM) ayuda a ir en esta direcciĂłn, al aplanar la red, lo que mejora su escalabilidad y permite el acceso local a Internet y a otros servicios de comunicaciones, como recursos en ânubesâ situadas en el borde de la red mĂłvil. Al mismo tiempo, SDN abre la posibilidad de ejecutar una multitud de aplicaciones inteligentes y avanzadas para optimizar la red en un controlador de red centralizado. La combinaciĂłn de los principios arquitectĂłnicos DMM con SDN aparece como una poderosa herramienta para que los operadores puedan hacer frente a la carga de administraciĂłn y datos que se espera en las redes 5G. Para satisfacer la demanda futura de usuarios mĂłviles a un coste reducido, los operadores tambiĂ©n estĂĄn buscando soluciones tales como C-RAN y diferentes divisiones funcionales para disminuir el coste de implementaciĂłn y mantenimiento de emplazamientos celulares. El creciente estrĂ©s en el rendimiento del acceso a la radio mĂłvil en un contexto de menores ingresos para los operadores requiere, por lo tanto, la evoluciĂłn de las redes de transporte de backhaul y fronthaul, que actualmente funcionan disociadas. La heterogeneidad de los nodos y las tecnologĂas de transmisiĂłn que interconectan los segmentos de fronthaul y backhaul hacen que la red sea bastante compleja, costosa e ineficiente para gestionar de manera flexible y dinĂĄmica. De hecho, el uso de tecnologĂas heterogĂ©neas obliga a los operadores a gestionar dos redes separadas fĂsicamente, una para la red de backhaul y otra para el fronthaul. Para cumplir con los requisitos de 5G de manera rentable, se requiere una red de transporte Ășnica 5G que unifique los planos de control, datos y de gestiĂłn. Dicha red de transporte fronthaul/backhaul integrada, denominada âcrosshaulâ, transportarĂĄ trĂĄfico de fronthaul y backhaul operando sobre tecnologĂas heterogĂ©neas de plano de datos, que estĂĄn controladas por software para adaptarse a la demanda de capacidad fluctuante de las interfaces radio 5G. AdemĂĄs, las redes de transporte 5G necesitarĂĄn acomodar un amplio espectro de servicios sobre la misma infraestructura fĂsica y el network slicing se considera un candidato adecuado para proporcionar la calidad de servicio necesario. La diferenciaciĂłn del trĂĄfico generalmente se aplica en el borde de la red para garantizar un reenvĂo adecuado del trĂĄfico segĂșn su clase a travĂ©s de la red troncal. Con el networkslicing, el trĂĄfico ahora puede atravesar muchos fronteras entre ânetwork slicesâ donde la polĂtica de trĂĄfico debe aplicarse, discriminarse y garantizarse, de acuerdo con las necesidades del servicio y de los usuarios. Sin embargo, el principio bĂĄsico que hace posible esta gestiĂłn y operaciĂłn eficientes de forma flexible â la centralizaciĂłn lĂłgica â plantea importantes desafĂos debido a la falta de herramientas de supervisiĂłn necesarias para las arquitecturas basadas en SDN. Para tomar decisiones oportunas y correctas mientras se opera una red, las aplicaciones de inteligencia centralizada necesitan alimentarse con un flujo continuo de estadĂsticas de red actualizadas. Sin embargo, esto no es factible con las soluciones SDN actuales debido a problemas de escalabilidad y falta de precisiĂłn. Por lo tanto, se requiere un sistema de telemetrĂa adaptable para respaldar la diversidad de los servicios 5G y sus estrictos requisitos de trĂĄfico. El camino hacia las redes inalĂĄmbricas 5G tambiĂ©n presenta una tendencia clara de realizar acciones cerca de los usuarios finales. De hecho, acercar los contenidos, las aplicaciones y las funciones de red a los usuarios finales es necesario para hacer frente al enorme volumen de datos y la baja latencia requerida en las futuras redes 5G. Los paradigmas de âedgeâ y âfogâ han surgido recientemente para abordar este desafĂo. Mientras que el edge estĂĄ mĂĄs centrado en la infraestructura y mĂĄs orientado al operador mĂłvil, el fog es mĂĄs ubicuo e incluye cualquier nodo (fijo o mĂłvil), incluidos los dispositivos finales. Al utilizar recursos de computaciĂłn de propĂłsito general en las proximidades de los usuarios, el edge y el fog pueden combinarse para construir una plataforma de computaciĂłn, que tambiĂ©n se puede utilizar para compartir informaciĂłn entre mĂșltiples tecnologĂas de acceso radio (RAT) y, por lo tanto, abre una nueva dimensiĂłn de la integraciĂłn multi-RAT.Programa Oficial de Doctorado en IngenierĂa TelemĂĄticaPresidente: Carla Fabiana Chiasserini.- Secretario: Vincenzo Mancuso.- Vocal: Diego Rafael LĂłpez GarcĂ
Quality of Service Controlled Multimedia Transport Protocol
PhDThis research looks at the design of an open transport protocol that supports a range of
services including multimedia over low data-rate networks. Low data-rate multimedia
applications require a system that provides quality of service (QoS) assurance and flexibility.
One promising field is the area of content-based coding. Content-based systems use an array
of protocols to select the optimum set of coding algorithms. A content-based transport
protocol integrates a content-based application to a transmission network.
General transport protocols form a bottleneck in low data-rate multimedia
communicationbsy limiting throughpuot r by not maintainingt iming requirementsT. his work
presents an original model of a transport protocol that eliminates the bottleneck by
introducing a flexible yet efficient algorithm that uses an open approach to flexibility and
holistic architectureto promoteQ oS.T he flexibility andt ransparenccyo mesi n the form of a
fixed syntaxt hat providesa seto f transportp rotocols emanticsT. he mediaQ oSi s maintained
by defining a generic descriptor. Overall, the structure of the protocol is based on a single
adaptablea lgorithm that supportsa pplication independencen, etwork independencea nd
quality of service.
The transportp rotocol was evaluatedth rougha set of assessmentos:f f-line; off-line
for a specific application; and on-line for a specific application. Application contexts used
MPEG-4 test material where the on-line assessmenuts eda modified MPEG-4 pl; yer. The
performanceo f the QoSc ontrolledt ransportp rotocoli s often bettert hano thers chemews hen
appropriateQ oS controlledm anagemenatl gorithmsa re selectedT. his is shownf irst for an
off-line assessmenwt here the performancei s compared between the QoS controlled
multiplexer,a n emulatedM PEG-4F lexMux multiplexers chemea, ndt he targetr equirements.
The performanceis also shownt o be better in a real environmentw hen the QoS controlled
multiplexeri s comparedw ith the real MPEG-4F lexMux scheme
Application of advanced on-board processing concepts to future satellite communications systems: Bibliography
Abstracts are presented of a literature survey of reports concerning the application of signal processing concepts. Approximately 300 references are included
Deliverable D2.1 - Ecosystem analysis and 6G-SANDBOX facility design
This document provides a comprehensive overview of the core aspects of the 6G-SANDBOX project. It outlines the project's vision, objectives, and the Key Performance Indicators (KPIs) and Key Value Indicators (KVIs) targeted for achievement. The functional and non-functional requirements of the 6G-SANDBOX Facility are extensively presented, based on a proposed reference blueprint. A detailed description of the updated reference architecture of the facility is provided, considering the requirements outlined. The document explores the experimentation framework, including the lifecycle of experiments and the methodology for validating KPIs and KVIs. It presents the key technologies and use case enablers towards 6G that will be offered within the trial networks. Each of the platforms constituting the 6G-SANDBOX Facility is described, along with the necessary enhancements to align them with the project's vision in terms of hardware, software updates, and functional improvements
Wireless triple play system
Dissertação para obtenção do Grau de Mestre em
Engenharia Electrotécnica e ComputadoresTriple play is a service that combines three types of services: voice, data and multimedia
over a single communication channel for a price that is less than the total price of the individual services. However there is no standard for provisioning the Triple play services, rather they are provisioned individually, since the requirements are quite different for each service. The digital revolution helped to create and deliver a high quality media solutions. One of the most demanding services is the Video on Demand (VoD). This implicates a dedicated streaming channel for each user in order to provide normal media player commands (as pause, fast forward).
Most of the multimedia companies that develops personalized products does not always fulfil the users needs and are far from being cheap solutions. The goal of the project was to create a reliable and scalable triple play solution that works via Wireless Local Area Network (WLAN), fully capable of dealing with the existing state of the art multimedia technologies only resorting to open-source tools.
This project was design to be a transparent web environment using only web technologies
to maximize the potential of the services. HyperText Markup Language (HTML),Cascading Style Sheets (CSS) and JavaScript were the used technologies for the development
of the applications. Both a administration and user interfaces were developed to
fully manage all video contents and properly view it in a rich and appealing application,
providing the proof of concept.
The developed prototype was tested in a WLAN with up to four clients and the Quality
of Service (QoS) and Quality of Experience (QoE) was measured for several combinations
of active services. In the end it is possible to acknowledge that the developed prototype was capable of dealing with all the problems of WLAN technologies and successfully delivery all the proposed services with high QoE
Automatic Understanding of ATC Speech: Study of Prospectives and Field Experiments for Several Controller Positions
Although there has been a lot of interest in recognizing and understanding air traffic control (ATC) speech, none of the published works have obtained detailed field data results. We have developed a system able to identify the language spoken and recognize and understand sentences in both Spanish and English. We also present field results for several in-tower controller positions. To the best of our knowledge, this is the first time that field ATC speech (not simulated) is captured, processed, and analyzed. The use of stochastic grammars allows variations in the standard phraseology that appear in field data. The robust understanding algorithm developed has 95% concept accuracy from ATC text input. It also allows changes in the presentation order of the concepts and the correction of errors created by the speech recognition engine improving it by 17% and 25%, respectively, absolute in the percentage of fully correctly understood sentences for English and Spanish in relation to the percentages of fully correctly recognized sentences. The analysis of errors due to the spontaneity of the speech and its comparison to read speech is also carried out. A 96% word accuracy for read speech is reduced to 86% word accuracy for field ATC data for Spanish for the "clearances" task confirming that field data is needed to estimate the performance of a system. A literature review and a critical discussion on the possibilities of speech recognition and understanding technology applied to ATC speech are also given
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