20 research outputs found

    Joint distribution of polarization-multiplexed UWB and WiMAX radio in PON

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    In this paper, the feasibility of the joint distribution of ultra-wideband (UWB) and WIMAX wireless using polarization multiplexing as a coexistence technique is proposed and experimentally demonstrated within the framework of passive optical networks (PON). Four single- and orthogonal-polarization multiplexing schemes are studied targeting to reduce the mutual interference when UWB and WiMAX are distributed jointly through standard single-mode fiber (SSMF) without transmission impairments compensation techniques and amplification. Experimental results indicate successful transmission up to 25 km, in SSMF exceeding the range in typical PON deployments. The radio link penalty introduced by optical transmission is also investigated in this paper

    Étude des interférences liées à la coexistence de l'UWB et du WiMAX dans un environnement minier souterrain

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    Les communications à large bande, notées en bref comme Ultra Wide Band (UWB), est une technologie sans fil qui a révolutionné les applications à courte portée (> 8km). Cette technologie offre des services d'accès large bande fixe et mobile [2]. Les technologies sans fil sont de plus en plus intégrées avec d'autres réseaux de communications [3]. La coexistence de ces deux technologies donne forcement naissance à des interférences que chacune exerce sur l'autre car les deux technologies opèrent dans la même bande de fréquences plus précisément 3.5 GHz pour le WiMAX et de 3.1 à 10.6 GHz pour le WiMédia et les deux utilisent la modulation OFDM. Autrement dit, le déploiement du WiMAX dans la bande 3,5 GHz est sensible aux interférences dues aux dispositifs UWB opérants dans le 1er groupe de bandes (3.168GHz à 4.752GHz) selon les spécifications WiMédia et inversement [4- 10]. Dans le cadre de notre travail, ces deux systèmes ont été étudiés ainsi que les interférences liées à leur coexistence. Aussi, une solution pour combattre ces interférences est proposée afin d’améliorer les communications souterraines. Pour ce faire, une simulation de ces interférences est réalisée sur MA TLAB et à partir de là, un filtre adaptatif est créé pour corriger l’effet de ces interférences sur le canal. Afin d'étudier l'efficacité de ce filtre, une compagne de mesure d'interférences a été réalisée, dans un premier temps, au laboratoire, puis à la mine laboratoire de CANMET pour démonter les performances de ce filtre adaptatif. Cette évaluation a été faite en termes de capacité et de taux d'erreur des paquets (PER) pour la simulation et les mesures expérimentales

    A Quantitative Assessment of the Compatibility of Ultra Wideband with Broadband Wireless Access and Radar Services

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    In July 2008, following a request made by the Radio Spectrum Policy Unit in DG INFSO (Unit B4), a pilot phase of twelve months was agreed with Member States representatives in the Radio Spectrum Committee. During this time the Institute for the Protection and Security of the Citizen of the EC Joint Research Centre (IPSC-JRC) has been mandated to provide testing facilities to support the development of Community spectrum legal measures under the Radio Spectrum Decision (676/2002/EC). In the frame of this pilot phase, IPSC-JRC has successfully completed the implementation and extensive testing of both a state-of-the-art laboratory test-bed and a simulation tool, which have been specifically designed for two different coexistence studies. Firstly, the coexistence between broadband wireless access (BWA) and ultra wideband (UWB) services in the 3.5 GHz frequency band; and secondly, the coexistence between radiolocation (i.e. radar) and UWB services in the 3.1-3.4 GHz frequency band. The selection of these two coexistence scenarios is not casual and has been made based on the fact that they have been considered highly relevant in the CEPT-ECC studies on UWB mandated by the European Commission.JRC.G.6-Security technology assessmen

    Architectures and Novel Functionalities for Optical Access OFDM Networks "Arquitecturas y Nuevas Funcionalidades para Redes OFDM de Acceso Óptico"

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    En los últimos años ha habido un gran aumento en el despliegue de redes de acceso ópticas de fibra hasta el hogar (FTTH, del inglés fibre-to-the home). FTTH es una solución flexible, una tecnología de acceso de futuro que permite proporcionar tasas de datos del orden de Gbit/s por ususario. Diversos estudios indican que FTTH se convertirá en la diferencia clave entre los operadores más importantes. Además, FTTH es la única tecnolotgía capaz de crear nuevas fuentes de ingresos de aplicaciones de alta velocidad, como por ejemple entretenimiento de alta definición (vído y juegos de alta definición...) Dede el punto de vista del operador, una de las vientajas importantes que proporciona FTTH es que permite una mayor eficiencia operativa en coparción con otras tecnologías de acceso, principalmente por la reducción de costes de mantenimiento y de operación. Además, FTTH reduce los requisitos de los equipos de las centrales. Esta tesis doctoral tiene como ojetivo extender estas ventajas más allá del concepto FTTH mediante la integración de la red óptica de distribución desplegada dentro del hogar así como el enlace radio final de corto o medio alcance inalámbrico. Esto proporciona una arquitctura de red FFTH integrada de extremo a extremo. De este modo, los beneficios de la reducción de costes operativos y mayor eficiencia se extienden hasta el usuario final de la red. En esta tesis doctoral, se propone una arqutectura de acceso integrada óptica-radio basada en la multiplexación por división ortogonal de fecuencia (OFDM, del inglés orthogonal frequency división multiplexing) para proporcionar diferentes servicios al usuario como Internet, teléfono/voz, televisión de lata definición, conexión inalámbrica y seguridad en el hogar. Las señales OFDM se utilizan en muchos estándares inalámbricos como las señales de banda ultraancha (UWB, del inglés ultra-wide band), WiMAX, LTE, WLAN, DVB-T o DAB. Estos formatos aprovechan las características intrínsecas de la modulación OFDM como su mayor inmunidad ante desvanecimiento multi-camino. Esta tesis incluye la propuesta y la demostración experimental de la transmisión simultánea y bi-direccional de señales OFDM multi-estándar en radio-sobre-fibra proporcionando servicios triple-play basados en OFDM como UWB para televisión de alta definición, WiMAX para datos de Internet, y LTE para el servicio telefónico.Morant Perez, M. (2012). Architectures and Novel Functionalities for Optical Access OFDM Networks "Arquitecturas y Nuevas Funcionalidades para Redes OFDM de Acceso Óptico" [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/15076Palanci

    Estratégias de design de camada intermédia e cooperativa para redes sem fios energeticamente eficientes

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    Doutoramento conjunto MAP-i em InformáticaThe promise of a truly mobile experience is to have the freedom to roam around anywhere and not be bound to a single location. However, the energy required to keep mobile devices connected to the network over extended periods of time quickly dissipates. In fact, energy is a critical resource in the design of wireless networks since wireless devices are usually powered by batteries. Furthermore, multi-standard mobile devices are allowing users to enjoy higher data rates with ubiquitous connectivity. However, the bene ts gained from multiple interfaces come at a cost in terms of energy consumption having profound e ect on the mobile battery lifetime and standby time. This concern is rea rmed by the fact that battery lifetime is one of the top reasons why consumers are deterred from using advanced multimedia services on their mobile on a frequent basis. In order to secure market penetration for next generation services energy e ciency needs to be placed at the forefront of system design. However, despite recent e orts, energy compliant features in legacy technologies are still in its infancy, and new disruptive architectures coupled with interdisciplinary design approaches are required in order to not only promote the energy gain within a single protocol layer, but to enhance the energy gain from a holistic perspective. A promising approach is cooperative smart systems, that in addition to exploiting context information, are entities that are able to form a coalition and cooperate in order to achieve a common goal. Migrating from this baseline, this thesis investigates how these technology paradigm can be applied towards reducing the energy consumption in mobile networks. In addition, we introduce an additional energy saving dimension by adopting an interlayer design so that protocol layers are designed to work in synergy with the host system, rather than independently, for harnessing energy. In this work, we exploit context information, cooperation and inter-layer design for developing new energy e cient and technology agnostic building blocks for mobile networks. These technology enablers include energy e cient node discovery and short-range cooperation for energy saving in mobile handsets, complemented by energy-aware smart scheduling for promoting energy saving on the network side. Analytical and simulations results were obtained, and veri ed in the lab on a real hardware testbed. Results have shown that up to 50% energy saving could be obtained.A promessa de uma experiência realmente móvel é de ter a liberdade de deambular por qualquer sítio e não estar preso a um único local. No entanto, a energia requerida para manter dispositivos móveis conectados à rede, num período extenso de tempo, o mesmo rapidamente se dissipa. Na realidade, a energia é um recurso crítico no design de redes sem fios, uma vez que esses dispositivos são alimentados por baterias. Para além disso, dispositivos móveis multi-standard permitem que os utilizadores desfrutem de elevadas taxas de dados com conectividade omnipresente. No entanto, as vantagens adquiridas pelas múltiplas interfaces, imputa uma despesa, sendo essa um consumo maior de energia, numa era onde os dispositivos móveis têm de ser energicamente complacentes. Esta preocupação é reafirmada pelo facto de que a vida da bateria é uma das principais razões que impede os utilizadores de usufruir e utilizar de serviços de multimédia mais avançados nos seus dispositivos, numa base frequente. De forma a assegurar a entrada no mercado para serviços da próxima geração, eficiência energética tem de ser colocada na vanguarda do design de sistemas. No entanto, apesar de esforços recentes, funcionalidades que cumpram os requisitos energéticos em tecnologias "legacy" ainda estão nos seus primórdios e novas abordagens disruptivas são requeridas, juntamente com abordagem de design interdisciplinar, de forma a aproveitar a poupança energética das diversas camadas protocolares. Uma bordagem promissora são os sistemas de cooperação inteligente, que exploram não são contexto da informação, mas também as entidades que são igualmente capazes de formar uma coligação e cooperam de forma a atingir um objectivo comum. Migrar a partir destas referências, esta tese investiga como é que este paradigma tecnológico pode ser aplicado para reduzir a potência e consumo de energia em redes móveis. Para além disso, introduzimos uma dimensão de poupança energética adicional, para adopção de design de camadas intermédias, de forma a que as camadas de protocolos sejam concebidas para trabalhar em sinergia com o sistema anfitrião, ao invés de independentemente, para aproveitamento de energia. Neste trabalho, nós exploramos o contexto da informação, cooperação e design de camadas intermédias para desenvolver blocos de construção energicamente eficientes e tecnologias agnósticas para redes móveis. Estes habilitadores (enablers) tecnológicos incluem um nó de descoberta de energia eficiente e cooperação de curto alcance para poupança energética em aparelhos móveis, complementado com agendamento inteligente, energicamente consciente, de forma a promover a poupança de energia do lado da rede. Analiticamente e simultaneamente, foram obtidos resultados e verificados em laboratório, num modelo de hardware protótipo. Resultados demonstram que pode ser obtido uma poupança energética acima dos 50%

    System design and validation of multi-band OFDM wireless communications with multiple antennas

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    A General Framework for Analyzing, Characterizing, and Implementing Spectrally Modulated, Spectrally Encoded Signals

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    Fourth generation (4G) communications will support many capabilities while providing universal, high speed access. One potential enabler for these capabilities is software defined radio (SDR). When controlled by cognitive radio (CR) principles, the required waveform diversity is achieved via a synergistic union called CR-based SDR. Research is rapidly progressing in SDR hardware and software venues, but current CR-based SDR research lacks the theoretical foundation and analytic framework to permit efficient implementation. This limitation is addressed here by introducing a general framework for analyzing, characterizing, and implementing spectrally modulated, spectrally encoded (SMSE) signals within CR-based SDR architectures. Given orthogonal frequency division multiplexing (OFDM) is a 4G candidate signal, OFDM-based signals are collectively classified as SMSE since modulation and encoding are spectrally applied. The proposed framework provides analytic commonality and unification of SMSE signals. Applicability is first shown for candidate 4G signals, and resultant analytic expressions agree with published results. Implementability is then demonstrated in multiple coexistence scenarios via modeling and simulation to reinforce practical utility

    The dynamics and strategic analysis of wireless communications technology in the healthcare industry

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    Thesis (S.M.)--Massachusetts Institute of Technology, Sloan School of Management, 2006.Includes bibliographical references (leaves 98-99).The healthcare industry like other industry is on the cross roads as a result of rising demand for healthcare delivery and service, the industry is facing declining revenues and increasing cost. As a result, one of the industry's strategic arsenal to avert the continual declines in revenue and increases operating cost is to effectively use modern technology in form of wireless computing and communications technology to change the paradigm shift to improve outcomes of clinical services, enhance physician and nurse productivity and work flow efficiency, reduce supply chain cost, improve revenue collection and practice profitability. This report presents the dynamic and strategic analysis of wireless communications technology in the healthcare industry, by first evaluating the wireless technologies, industry standards and regulations, applicable standards for the healthcare information systems and innovative healthcare technologies.(cont.) Based on an in-depth technical analysis of the wireless technology, I analyzed the market and industry by applying frameworks including Porter's 5 forces and The Delta model and system dynamics models presented to illustrate contributing factors affecting new technology adoption in the healthcare industry and a holistic view of a healthcare IT system architecture. Lastly, I analyzed emerging wireless technologies including WiMAX, UltraWide -Band and RFID, and reviewed market opportunities in the healthcare industry through 2011.by John K. Eyemaro.S.M
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