Análisis de convergencia de FBMC y LTE en redes de acceso óptico

En este artículo se probó experimentalmente la transmisión conjunta de las señales de datos FBMC y LTE en una única longitud de onda sobre una red de acceso óptico de 25 Km. FBMC fue dejada en banda base mientras que la señal LTE fue centrada en frecuencia de 1.5 GHz. Después se caracterizó las señales de onda midiendo parámetros de desempeño como BER y EVM, posteriormente fue optimizada la potencia RF de la señal LTE. Ambas señales fueron detectadas correctamente con un único fotodiodo. Se obtuvo sensibilidades en el receptor de -25 dBm y -27 dBm con un BER 10-3 para las señales FBMC y LTE respectivamente. Los resultados muestran que es posible la convergencia de las señales antes mencionadas y además que la técnica de multiplexación de frecuencia RF puede ser empleada para la convergencia de datos cableados e inalámbricos.In this article, we experimentally transmitted jointly an FBMC data and LTE signal in a single wavelength within an optical access network of 25 Km. FBMC was left at baseband while LTE signal was centered at frequency of 1.5 GHz. Then the waveforms were characterized by measuring performance parameters such as BER and EVM, the RF power of the signal LTE was subsequently optimized. Both signals were correctly detected with a single photodiode. Receptor sensitivities of -25 dBm and -27 dBm were obtained with a BER of 10-3 for FBMC and LTE signal respectively. The results show that the convergence of the signals is possible, and the RF frequency multiplexing technique can be used for the convergence of wired and wireless data

Optical fiber transmission systems for in-door next generation broadband access network.

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University London.This thesis investigates the generation and radio-over-fibre (RoF) transport of unlicensed 60 GHz millimetre-wave (mm-wave) frequency band. The investigated benefits of transmission schemes applicable for the mm-wave generation include optical carrier suppression (OCS), optical frequency multiplication (OFM) and remote heterodyne detection (RHD). For the in-door cabling of the mm-wave transmission, a low-cost polymer optical fibre (POF) along with bend-insensitive single mode fibre (BI-SMF) has been investigated for short-range networks. Transporting mm-wave generated signals over POF and BI-SMF cables based on OCS scheme showed results with the highest spectral efficiency and least inter-symbol interference over a 2.5 Gbit/s data delivery. Based on this thesis analysis, OCS simulation of POF showed the most reliable power penalty performance and receiver sensitivity at 30-m whilst the BI-SMF fiber produced equal observations at 150-m and more. In observing the free space links of delivering the RoF signal, the attenuation on the received signal power for both POF and BI-SMF was insignificant but expected, as the simulation assumed complete and total collimation of the light beams onto the aperture of the photodetector. OCS scheme for mm-wave generation and transport was explored based on the cost effectiveness of using one external modulator compared to other generation schemes that utilised more than one external modulator. OFM scheme was simulated to transport LTE and Wi-Fi signals along with 60 GHz RF band through both SMF and MMF-POF/BI-SMF cables. OFM transport scheme produced the highest attenuation on LTE, Wi-Fi and mm-wave signals carrying 100 Mbit/s data as simulated POF lengths increased. The best performance POF length was observed at 10-m. The application of offset launch technique at the coupling of SMF and POF showed insignificant improvement on signal bandwidth. The free space OFM transmission also demonstrated negligible change to the received signal power. This reinforces the attributes of deploying OWC system in an in-door environment. In other investigation, the simulated successful delivery of mm-wave signal using RHD scheme modulated and transported 10 Gbit/s data signal over POF and BI-SMF cables. Additional observed unrecorded result also showed BI-SMF cable maintained a 2% reduction of received power for 450-m fiber cable from 150-m. The attributes to RHD includes its low operating power system application and delivery of localised 60 GHz signal for uplink RoF transmission. The conceptualised design of Gigabit data delivery for indoor customer applications either through POF or BI-SMF cable, transporting various wireless channels has been presented in this thesis for the design of a robust next generation Broadband access network to reinforce the fiber-inside-the-home (FiTH) deployment

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

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

Análise tecno-económica em redes de acesso óptico

Mestrado em Engenharia de Computadores e TelemáticaEsta dissertação tem como objectivo analisar os principais problemas que os fornecedores de serviços têm que considerar ao implementar e ao migrar as redes de acesso ópticas existentes e futuras. Iremos considerar a migração da rede GPON, como rede de acesso actual, para as Redes Óticas de Acesso de Próxima Geração (NG-OANs), como a WDM-PON e a OFDM-PON. O trabalho foca-se nos Custos de Capital (CapEx) por utilizador, e em três factores que condicionam este custo: densidade populacional, topologia da rede e custo dos componentes. Uma visão geral e avaliação das redes óticas passivas existentes e futuras é apresentada. Um modelo tecno-económico para o cálculo do custo das redes de acesso é proposto, tendo em conta o efeito da taxa de subscrição. O custo total de cada tecnologia de rede é calculado. O CapEx por utilizador para esquemas divisores simples e em cascata é também calculado, para diferentes taxas de subscrição. O custo dos componentes é considerado quando o preço é extrapolado em função do tempo e do volume.This dissertation aims to analyse the main issues to be faced by the service providers in implementation and migration of existing and future optical access networks. We are going to consider the migration of the networks from GPON, as the current access network technology, to Next Generation Optical Access Networks (NG-OANs), such as WDM-PON and OFDM-PON. The work focuses on the Capital Expenditures (CapEx) per user and three factors that drive this cost: population density, network topology and components cost. An overview and assessment of existing and future passive optical networks is provided. A techno-economic model for calculating of deployment cost of access networks is presented, accounting for the effect of take rate. The total cost of each network technology is calculated. The CapEx per user for both single and cascaded splitter schemes for different take rates is also calculated. Furthermore the components cost is considered, when the price is extrapolated considering time and volume

Thirty Years of Machine Learning: The Road to Pareto-Optimal Wireless Networks

Future wireless networks have a substantial potential in terms of supporting a broad range of complex compelling applications both in military and civilian fields, where the users are able to enjoy high-rate, low-latency, low-cost and reliable information services. Achieving this ambitious goal requires new radio techniques for adaptive learning and intelligent decision making because of the complex heterogeneous nature of the network structures and wireless services. Machine learning (ML) algorithms have great success in supporting big data analytics, efficient parameter estimation and interactive decision making. Hence, in this article, we review the thirty-year history of ML by elaborating on supervised learning, unsupervised learning, reinforcement learning and deep learning. Furthermore, we investigate their employment in the compelling applications of wireless networks, including heterogeneous networks (HetNets), cognitive radios (CR), Internet of things (IoT), machine to machine networks (M2M), and so on. This article aims for assisting the readers in clarifying the motivation and methodology of the various ML algorithms, so as to invoke them for hitherto unexplored services as well as scenarios of future wireless networks.Comment: 46 pages, 22 fig

Optical Orthogonal Frequency Division Multiplexed communication systems: analysis, design and optimization

En este trabajo se realiza una intensiva labor teórica de descripción de sistemas de comunicaciones ópticas que utilizan la técnica de multiplexación por división de frecuencias ortogonales (OFDM en inglés), más concretamente en sistemas con modulación directa de la intensidad de un láser y detección directa. Se parte pues de un modelo analítico que estudia con detalle todos aquellos fenómenos que afectan a la señal de información detectada en el receptor. Tales fenómenos son: la nolinealidad del láser, las modulaciones de intensidad y de fase ópticas, la propagación a través de la fibra óptica teniendo en cuenta la dispersión cromática de primer orden, y la detección de intensidad óptica final mediante un detector de ley cuadrática. El modelo analítico es validado mediante comparaciones con resultados obtenidos a través de simulaciones con software comercial. Dada la característica singularidad de las señales OFDM debidas a su naturaleza multi-portadora, la amplitud de la señal generada es aleatoria, y el modelo analítico es complementado con un estudio que contempla el recorte o "clipping" en el transmisor. Además, se tiene en cuenta los efectos de filtrado de la señal a lo largo de sistema de comunicaciones. Con el trabajo analítico realizado se está en disposición de realizar una descripción bastante completa de los principales fenómenos y realizar estudios para evaluar el funcionamiento final ante diferentes valores de los parámetros del sistema. Es bien sabido que los sistemas de comunicaciones ópticas con modulación y detección directa se ven perjudicados por la distorsión no lineal, que para señales multi-portadora como OFDM se traduce en la mezcla de los símbolos de información que transportan las diferentes subportadoras. Para mitigar la distorsión no lineal y así mejorar el funcionamiento del sistema, se propone el uso de una técnica de pre-distorsión que se basa en el modelo analítico previamente propuesto. Esta técnica mejora la eficiencia de modulación, haciendo posible incrementar el término de la señal de información sin que se vea incrementada la distorsión no lineal en el receptor. La técnica aquí propuesta se compara también con otra ya publicada con el objetivo de evaluar su funcionamiento. Otra técnica para la mejora de sistemas con modulación y detección directas es la realizada mediante filtrado óptico. Aunque se conoce de forma más o menos intuitiva su funcionamiento para formatos de modulación ópticos tradicionales, es preciso disponer de una formulación matemática para señales ópticas OFDM para entender de forma exacta su principio de operación, las mejoras obtenidas, así como su potencial. En esta estapa se realiza esta formulación matemática ampliando el análisis teórico previamente propuesto, y se aplica para evaluar el funcionamiento obtenido con diversas estructuras de filtrado óptico. Finalmente, puesto que un potencial escenario de funcionamiento para señales ópticas OFDM son las redes de acceso donde operan más de un usuario, se propone y se estudia la técnica "interleaving division multiple access" (IDMA) en combinación con OFDM.Sánchez Costa, C. (2014). Optical Orthogonal Frequency Division Multiplexed communication systems: analysis, design and optimization [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/39375TESI

Next Generation Access in a Rural Community Context: An Innovation Analysis

This thesis explores how to resolve the digital divide in Wales. This is important because access to advanced broadband is considered an essential requirement, particularly post-COVID19. UK Government is advocating next generation access (NGA) to capitalise on Industry 4.0. However, the financial costs and complexities of connecting the final few rural areas is a persisting problem area. Hence, this thesis explores new innovative approaches to provide NGA (product) to a final few (market). Studies revealed superfast broadband in remote rural communities has four-fold human, social, environmental and financial capital benefits. Analysis resulted in a new conceptual framework which combines neo-endogenous theories alongside a four-fold capital model to characterise the complex ecosystem. Previous literature focused on either supply or demand, but few studies had investigated both together at the local level. Human & social capital were identified as critical success factors in community-led initiatives, thus providing a theoretical underpinning for this thesis. This study employed a novel mutual business approach utilising the Hybrid Value System (HVS) as an ecosystem connecting the core assets of several stakeholders. Furthermore, the World Bank Social Capital Assessment Tool was modified to investigate social capital fertility to enhance investment. Henceforth, a qualitative multi-method and in-depth intrinsic case study was used to explore the ecosystem. The contribution to knowledge is how to engage multi-stakeholder and multi-capital analysis to resolve the problem area. The results identified human capital productivity, social capital collective action, and shared financial capital are required at the local level to reach the final few. The mutual business paradigm challenges all stakeholders to value non-financial capital alongside financial capital for problem area resolution. This thesis concludes that HVS methodology coupled with complex ecosystem-network visualisation techniques, provide academics, management and government policy makers with practical tools to value four-fold capital resources and bridge the digital divide

Renewable Economies in the Arctic

"This book offers multidisciplinary perspectives on renewable economies in the Arctic and how these are being supported scientifically, economically, socially, and politically by Arctic states. The economic development of the Arctic region is witnessing new, innovative trends which hold promise for the sustainable development of the region. This book discusses the emerging forms of renewable economies to understand where intellectual and technological innovations are being made. It draws on the expertise of scholars from across the Arctic and provides the reader with a foundation of knowledge to identify the unique challenges of the region and explore opportunities to unlock the immense potential of renewable resources to boost the region’s economy. This book offers a holistic Arctic perspective against the backdrop of prevailing social, economic, and climatic challenges. With critical insights on the economic state of play and the role of renewable resources in the development of the Arctic region, this book will be a vital point of reference for Arctic scholars, communities, and policy makers.

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The Value of Earthworms by Eric Johnson (page 1) Golf Course Bridge Construction by Robert A. Huntley (2) Importance of Trees and Care by Donald Pipczinski (3) Management Practices Help Control Turf Diseases by Larry Bunn (3) Class Will of \u2769 (5) Famous Sayings of \u2769 (6) The Reluctant Human by John Denison (A-1) Communicating by Frank Gallagher (A-4) Vandalism on the Golf Course by Edward B. Patroski (A-7) The GCSAA Organization - What it Means to You (A-13) Role of Potash in Turf Production by Lindsay D. Brown (A-17) Dew is Note Dew by Tom Mascaro (A-28) Insects in Turf and Their Control by John C. Schread (A-36) Turf Treatment and the Balance of Nature by Haim B. Gunner (A-39) The After-Effects of Irrigation by John C. Harper, II (A-40) Athletic Field Specifications by John C. Harper, II (A-45) Pennsylvania Turfgrass Survey by John C. Harper, II (A-52) Seeding Vs. Sodding by Norman Gray (A-54) Synthetic Turf by R. Spencer Thompson (A-58) Why Do We Have Dealers .. Does He Justify His Existence? (A-61) The Importance of Suppliers of Turf materials by John N. Magovern (A-64) Golf Course Maintenance at St. Andrews by John C. Campbell (A-68) Ground Covers for Golf Courses by Jack Eggens (A-75) Gardening - 600 BC to Country Club Road by Warren Bidwell (A-79) Blues Vs. Bents for Fairway Turf by James L. Holmes (A-87

Renewable Economies in the Arctic

"This book offers multidisciplinary perspectives on renewable economies in the Arctic and how these are being supported scientifically, economically, socially, and politically by Arctic states. The economic development of the Arctic region is witnessing new, innovative trends which hold promise for the sustainable development of the region. This book discusses the emerging forms of renewable economies to understand where intellectual and technological innovations are being made. It draws on the expertise of scholars from across the Arctic and provides the reader with a foundation of knowledge to identify the unique challenges of the region and explore opportunities to unlock the immense potential of renewable resources to boost the region’s economy. This book offers a holistic Arctic perspective against the backdrop of prevailing social, economic, and climatic challenges. With critical insights on the economic state of play and the role of renewable resources in the development of the Arctic region, this book will be a vital point of reference for Arctic scholars, communities, and policy makers.