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[en] METROPOLITAN SERVICE ETHERNET OPERATOR / [pt] OPERADORA ETHERNET DE SERVIÇO METROPOLITANOLUIS ANTONIO FRANCA SILVA 16 December 2005 (has links)
[pt] Este trabalho apresenta as principais características de
um sistema telefônico
de voz baseado na tecnologia TDM e de um sistema de
comunicações ópticas
baseado em no protocolo Ethernet. Os dois sistemas são
comparados
economicamente. A solução Ethernet foi então escolhida e
avaliada para ser
instalada priorizando sua utilização na área central do
Rio de Janeiro em
aplicações corporativas. Aplicações residenciais também
foram avaliadas, com
menor ênfase. / [en] This work shows the legacy telephone system and optical
communication
system based on the Ethernet protocol major
characteristics, compares both in
technical and economically aspects. Then, the
implementation of an optical
network based on the Ethernet protocol in some areas of
Rio de Janeiro is
assessed.
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Techno-economic analysis of Open Optical LineSystemsPapageorgiou, Vasileios January 2018 (has links)
Technology innovations and capacity upgrades in optical networks have influenced the optical transmission. As a result, network operators are considering separating hardware and software components in order to achieve efficiency and promising savings during network operation and network lifecycle. This leads to resolving the vendor lock-in and opening up the optical networks architectures such that different kinds of disaggregation models can be supported in the DWDM transport layer.In this master thesis, a techno-economic analysis which compares the economical differences between an integrated and disaggregated optical network has been conducted. For the analysis, an actual test case scenario of a European interregional network has been utilized. The line system and transponders components, price lists and features are based on actual vendor components in today’s optical transport networks.According to the results, it has been concluded that all total cost investments required for an integrated or disaggregated approach of DWDM system are traffic dependent. Moreover, capital expenses of open architecture are influenced by business model policy in price reduction due to multiple vendors’ competition on transponders. Calculations demonstrated that a disaggregated approach can introduce considerable total cost savings about 21% less total investments that include 25% less costs for capital expenses and 3% higher cost for operational expenses on an average traffic volume of European network. Finally, by increasing 5-10 times the traffic volume of European network it has been noticed that disaggregated system reduced total cost by 39% and 43% respectively. / Tekniska innovationer och trafiktillväxt påverkar utvecklingen av optisk transmission. En konsekvens av detta är att nätoperatörer undersöker möjligheten att separera hårdvara och mjukvarukomponenter för öka effektiviteten och sänka kostnader för drift. Detta minskar inlåsning till enskilda leverantörer och öppnar upp dom optiska näten för att byggas med olika typer av disaggregering i DWDM transporten.I den här masteruppsatsen har en tekno-ekonomisk analys utförts avseende den ekonomiska skillnaden mellan integrerade och disaggregerade optiska nät. Ett verkligt nät scenario användes för analysen. Komponenter och kostnader för linjesystem och transpondrar är baserade på existerande system och prislistor i dagens nät. Enligt det erhållna resultatet har slutsatsen dragits att totala kostnaden för integrerade och öppna system är trafikberoende. Vidare så är investeringen för öppna system påverkad av pris reduktionen pga. konkurrens på transpondrar.Beräkningarna visar att disaggregerade system kan sänka kostnaderna med 21%, i dessa siffror ingår 25% lägre kostnad för investeringar och 3% högre driftkostnader.Slutligen, genom att öka trafikvolymen med 5 respektive 10 ggr från den ursprungliga trafik matrisen så kan de totala kostnaderna sänkas med 39% och 43%.
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[en] CATV / GIGABIT ETHERNET / DWDM : NEW TECHNICAL AND ECONOMIC ALTERMATIVES TO THE LAST MILE / [pt] CATV/GIGABIT ETHERNET/DWDM: NOVAS ALTERNATIVAS TÉCNICAS E ECONÔMICAS PARA A ÚLTIMA MILHA13 August 2002 (has links)
[pt] CATV / Gigabit Ethernet / DWDM : Novas Alternativas
Técnicas e Econômicas para a Última Milha tem como objetivo
descrever a ativação de novas funcionalidades de uma rede
de distribuição de CATV associada à distribuição de dados
em faixa larga. A utilização da tecnologia DWDM no domínio
óptico, associada a novas topologias de distribuição em
cabo coaxial e ao padrão Gigabit Ethernet, permite a
obtenção de uma nova concepção em rede de telecomunicações,
onde os serviços tradicionais de distribuição analógica são
inteiramente preservados. As vantagens desta solução
residem na obtenção de uma rede de muito alta velocidade,
ideal para aplicações Internet de segunda geração e em um
dramático aumento do retorno econômico nas redes CATV já
instaladas. / [en] CATV / Gigabit Ethernet / DWDM : New Technical and Economic
Altermatives to the Last Mile is aiming at describing the
activation of a new family of functionalities applicable to
a CATV distribution network together with a delivery of
broadband data. Optical domain DWDM technology is used,
associated with new coaxial cable distribution topologies
and the Gigabit Ethernet standard, allowing for a new
telecommunications network concept, where the traditional
analogical distribution services are totally preserved. The
above proposed solution presents two advantages. The first
is such that a very high-speed data network becomes
available. This last, is an ideal outfit for second
generation Internet. The second advantage is that the
obtained data network provides for economic revenues by far
greater than those of the traditional CATV networks.
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Analysis of the Performance of Different DWDM FilterTechnologies for Mobile Fronthaul ApplicationsAhlbom, Fredrik January 2016 (has links)
In recent years, several studies and simulations have been made on changing the current Radio Access Network (RAN) architecture into a more centralized access network where the base band processing is done in a central oce (CO) instead of out by the antenna site. This new architecture is denoted as the mobile fronthaul and is planned to be in use for the coming 5G network. The studies that have been made so far suggest that the new architecture can reduce cost, power usage and latency which are important factors regarding environmental, economical and data transmission issues. Furthermore, the new architecture allows a smarter distribution of data for each sector covered by the antennas, reducing redundant data transmission and thus increases the data eciency. The disadvantage or challenge however is that some of the optical components will be transferred from the currently controlled environment in the CO to an uncontrolled outdoor environment at the antenna site, which may generate risks as these components may be sensitive to especially changes in temperature. In this master thesis, the optical performance of four di erent passive lter setups, using a thin lm lter (TFF), an arrayed waveguide grating (AWG) and an interleaver, has been studied and compared in order to nd the most suitable lter setup for the mobile fronthaul. These optical parameters include insertion loss, isolation, crosstalk, 3 dB passband, center wavelength drift and also bit error-rate (BER) which have all been measured over a temperature interval of -40-85oC. Moreover, the measurement results have been compared with results from simulations done with VPItransmissionmaker. From the measurement results, the TFF had a better optical performance and reliability compared to the AWG mainly due to a higher isolation and a lower BER penalty of 0.2 dB compared to 0.5-1.5 dB for the AWG. Considering data capacity and economical aspects for a more realistic mobile fronthaul scenario with 80 channels using dense wavelength division multiplexing (DWDM) however, the AWG connected to the interleaver is more benecial without risking negative a ects on trac performance. / Under senare år har flera studier och simulationer utförts med syfte att ändra arkitekturen på dagens radioaccess-nätverk till ett mer centraliserat nätverk där basbandsprocesseringen sker i en central nod istället för ute vid antennen och radiomasterna. Denna nya arkitektur kallas mobile fronthaul och planeras att realiseras till 5G-nätet. De studier som har gjorts hittills indikerar på att den nya arkitekturen kan minska ekonomiska kostnader, elanvändningen och latens vilka är viktiga faktorer som bland annat rör miljö-, ekonomi och kapacitetrelaterade områden. Dessutom kan data fördelas på ett smartare sätt över alla delområden som antennerna täcker vilket minskar redundant datatrafik och därmed ökar den effektiva mängden data som skickas ut. Problemet eller utmaningen är att vissa optiska komponenter behöver flyttas från en nuvarande kontrollerad miljö till en okontrollerad utemiljö vid radiomasterna vilket kan medföra risker då dessa komponenter främst kan vara väldigt temperaturkänsliga. Inom detta examensarbete har optisk prestanda studerats, analyserats och jämförts mellan fyra olika filterkonstellationer bestående av ett tunnfilmsfilter, ett AWG-filter och en interleaver med syfte att finna vilken konstellation som passar bäst för mobile fronthaularkitekturen. De optiska parametrarna består av insertionsförluster, isolation, överhörningsinterferens, 3 dB-passband, centervåglängdsdrift samt bitfelsgrad vilka alla har blivit undersökta över ett temperaturintervall på -40-85oC. Utöver detta så har mätresultaten jämförts med simulationer gjorda med VPItransmissionmaker. Utifrån mätresultaten kunde det konstateras att tunnfilmfiltret hade bättre optiska egenskaper och även högre trovärdighet jämfört med AWG-filtret främst på grund av en högre isolation och lägre bitfelsgradsstraff på 0.2 dB jämfört med 0.5-1.5 dB för AWG-filtret. Om en endast avväger datakapacitet och ekonomiska aspekter för ett mer realistiskt scenario för mobile fronthaul med 80 DWDM-kanaler så är AWG-filtret tillsammans med interleavern mer foördelaktig att välja utan att riskera några negativa påverkningar på trafikprestandan.
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ASSESSMENT OF PHOTONIC SWITCHES AS FUTURE REPLACEMENT FOR ELECTRONIC CROSS-CONNECT SWITCHESYoussef, Ahmed H. 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper presents the future of optical networking via photonic switches as a potential replacement for the existing electronic cross-connects. Although optical amplifiers are now mainstream and wave division multiplexing (WDM) systems are a commercial reality, the industry’s long-term vision is one of the all-optical network. This will require optical switching equipment such as all-optical or “photonic” cross-connect switches that will provide packet switching at an optical layer. Currently, as voice calls or data traffic are routed throughout Range and commercial networks, the information can travel through many fiber-optic segments which are linked together using electronic cross-connects. However, this electronic portion of the network is the bottleneck that is preventing the ideal network from achieving optimal speeds. Information is converted from light into an electronic signal, routed to the next circuit pathway, then converted back into light as it travels to the next network destination. In an all-optical network, the electronics are removed from the equation, eliminating the need to convert the signals and thereby significantly improving network performance and throughput. Removing the electronics improves network reliability and restoration speeds in the event of an outage, provides greater flexibility in network provisioning, and provides a smooth transition when migrating to future optical transmission technologies. Despite the fact that photonic switching remains uncommercialized, it now seems apparent that the core switches in both the public networks and DoD Range networks of the early 21st century will probably carry ATM cells over a photonic switching fabric.
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Design and Characterization of Silicon-on-Insulator Passive Polarization Converter with Finite-Element AnalysisDeng, Henghua January 2005 (has links)
As optical fiber systems evolve to higher data rates, the importance of polarization control and manipulation steadily increases. Polarization manipulating devices, such as polarization splitters and converters, can be realized by introducing material anisotropy or geometric asymmetry. Compared to active devices, passive polarization converters are more simply fabricated and controlled; therefore they have attracted increasing attention during the past two decades. However, materials employed in previous polarization rotating waveguides are mainly limited to low index-contrast III-V semiconductors such as InP and GaAs. Such III-V devices possess large radiation loss, large curvature loss, and low coupling efficiency to single-mode fibers; in addition, due to the weak optical confinement, the device spacing has to be large, which prevents high-density and large-scale integration in optoelectronic integrated circuits (OEIC) and planar lightwave circuits (PLC). <br /><br /> In this dissertation, the silicon-on-insulator (SOI) technology is introduced to the design and fabrication of passive polarization rotators (PR). Efficient and accurate full-vectorial finite-element eigenmode solvers as well as propagation schemes for characterizing novel SOI PRs are developed because commercial software packages based on finite-difference techniques are inefficient in dealing with arbitrary waveguide geometries. <br /><br /> A set of general design procedures are accordingly developed to design a series of slanted-angle polarization converters, regardless of the material system (SOI or III-V), outer-slab layer configuration (symmetric or asymmetric), and longitudinal loading (single- or multi-section). In particular, our normalized design charts and simple empirical formula for SOI polarization converters are applicable to a wide range of silicon-guiding-film thickness, e. g. , from 1 to 30 μm, enabling fast and accurate polarization rotator design on most commercial SOI wafers. With these procedures, in principle 100% polarization conversion efficiency can be achieved by optimizing waveguide geometric parameters. <br /><br /> A novel configuration with asymmetric external waveguiding layers is proposed, which is advantageous for fabrication procedure, manufacturing tolerance, single-mode region, and conversion efficiency. By etching along the crystallographic plane, the angled-facet can be perfectly fabricated. Completely removing external waveguiding layer beside the sloped sidewall not only simplifies production procedures but also enhances fabrication tolerances. <br /><br /> To accurately and efficiently characterize asymmetric slanted-angle SOI polarization converters, adaptive mesh generation procedures are incorporated into our finite-element method (FEM) analysis. In addition, anisotropic perfectly-matched-layer (PML) boundary condition (BC) is employed in the beam propagation method (BPM) in order to effectively suppress reflections from the edges of the computation window. For the BPM algorithm, the power conservation is strictly monitored, the non-unitarity is thoroughly analyzed, and the inherent numerical dissipation is reduced by adopting the quasi-Crank-Nicholson scheme and adaptive complex reference index. <br /><br /> Advantages of SOI polarization rotators over III-V counterparts are studied through comprehensive research on power exchange, single-mode condition, fabrication tolerance, wavelength stability, bending characteristics, loss and coupling properties. The performance of SOI PRs is stable for wavelengths in the ITU-T <em>C</em>-band and <em>L</em>-band, making such devices quite suitable for DWDM applications. Due to the flexible cross-section of SOI polarization converters, the coupling loss to laser diodes and single mode fibers (SMF) can be designed to be very small and can be further reduced by a tapered waveguide with cross-sections always satisfying the single-mode criteria. Slanted-angle SOI polarization rotators display asymmetric bending characteristics and permit extremely small curvatures with negligible radiation loss when the angled-facet is located at the outer bend radius. Moreover, SOI polarization rotators can be manufactured with low-price processing techniques that are fully compatible with CMOS integrated circuits (IC) technology, and thus can be integrated on both photonic and electronic chips. <br /><br /> Experimental verifications have shown good agreement with theoretical analysis and have confirmed the promising characteristics of our novel asymmetric SOI polarization converters. Similar asymmetric-outer-slab geometry has recently been employed by peer researchers to fabricate high performance III-V polarization rotators. We therefore believe that results in this dissertation will contribute much to related research fields.
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Design and Characterization of Silicon-on-Insulator Passive Polarization Converter with Finite-Element AnalysisDeng, Henghua January 2005 (has links)
As optical fiber systems evolve to higher data rates, the importance of polarization control and manipulation steadily increases. Polarization manipulating devices, such as polarization splitters and converters, can be realized by introducing material anisotropy or geometric asymmetry. Compared to active devices, passive polarization converters are more simply fabricated and controlled; therefore they have attracted increasing attention during the past two decades. However, materials employed in previous polarization rotating waveguides are mainly limited to low index-contrast III-V semiconductors such as InP and GaAs. Such III-V devices possess large radiation loss, large curvature loss, and low coupling efficiency to single-mode fibers; in addition, due to the weak optical confinement, the device spacing has to be large, which prevents high-density and large-scale integration in optoelectronic integrated circuits (OEIC) and planar lightwave circuits (PLC). <br /><br /> In this dissertation, the silicon-on-insulator (SOI) technology is introduced to the design and fabrication of passive polarization rotators (PR). Efficient and accurate full-vectorial finite-element eigenmode solvers as well as propagation schemes for characterizing novel SOI PRs are developed because commercial software packages based on finite-difference techniques are inefficient in dealing with arbitrary waveguide geometries. <br /><br /> A set of general design procedures are accordingly developed to design a series of slanted-angle polarization converters, regardless of the material system (SOI or III-V), outer-slab layer configuration (symmetric or asymmetric), and longitudinal loading (single- or multi-section). In particular, our normalized design charts and simple empirical formula for SOI polarization converters are applicable to a wide range of silicon-guiding-film thickness, e. g. , from 1 to 30 μm, enabling fast and accurate polarization rotator design on most commercial SOI wafers. With these procedures, in principle 100% polarization conversion efficiency can be achieved by optimizing waveguide geometric parameters. <br /><br /> A novel configuration with asymmetric external waveguiding layers is proposed, which is advantageous for fabrication procedure, manufacturing tolerance, single-mode region, and conversion efficiency. By etching along the crystallographic plane, the angled-facet can be perfectly fabricated. Completely removing external waveguiding layer beside the sloped sidewall not only simplifies production procedures but also enhances fabrication tolerances. <br /><br /> To accurately and efficiently characterize asymmetric slanted-angle SOI polarization converters, adaptive mesh generation procedures are incorporated into our finite-element method (FEM) analysis. In addition, anisotropic perfectly-matched-layer (PML) boundary condition (BC) is employed in the beam propagation method (BPM) in order to effectively suppress reflections from the edges of the computation window. For the BPM algorithm, the power conservation is strictly monitored, the non-unitarity is thoroughly analyzed, and the inherent numerical dissipation is reduced by adopting the quasi-Crank-Nicholson scheme and adaptive complex reference index. <br /><br /> Advantages of SOI polarization rotators over III-V counterparts are studied through comprehensive research on power exchange, single-mode condition, fabrication tolerance, wavelength stability, bending characteristics, loss and coupling properties. The performance of SOI PRs is stable for wavelengths in the ITU-T <em>C</em>-band and <em>L</em>-band, making such devices quite suitable for DWDM applications. Due to the flexible cross-section of SOI polarization converters, the coupling loss to laser diodes and single mode fibers (SMF) can be designed to be very small and can be further reduced by a tapered waveguide with cross-sections always satisfying the single-mode criteria. Slanted-angle SOI polarization rotators display asymmetric bending characteristics and permit extremely small curvatures with negligible radiation loss when the angled-facet is located at the outer bend radius. Moreover, SOI polarization rotators can be manufactured with low-price processing techniques that are fully compatible with CMOS integrated circuits (IC) technology, and thus can be integrated on both photonic and electronic chips. <br /><br /> Experimental verifications have shown good agreement with theoretical analysis and have confirmed the promising characteristics of our novel asymmetric SOI polarization converters. Similar asymmetric-outer-slab geometry has recently been employed by peer researchers to fabricate high performance III-V polarization rotators. We therefore believe that results in this dissertation will contribute much to related research fields.
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Low-cost micromechanically tunable optical devices strained resonator engineering, technological implementation and characterization /Tarraf, Amer. Unknown Date (has links)
University, Diss., 2005--Kassel.
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Micro-electromechanical structural design and optimization of vertical cavity photonic devices with wide continuous tuningAtaro, Edwin Omondi. Unknown Date (has links)
University, Diss., 2005--Kassel.
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Evaluación de Disponibilidad de una Red Metro Enmallada DWDM con ROADMPinedo Ried, Andrés January 2010 (has links)
El objetivo de la memoria es obtener la disponibilidad de servicio para
una red enmallada DWDM (dense wave division multiplexer). Se
entiende por disponibilidad la cifra por ciento que representa la fracción
del tiempo que la red está disponible para entregar servicios de
comunicaciones.
Toda nueva tecnología presenta riesgos de tener una disponibilidad
baja, debido a que en el proceso de puesta en marcha e inicio de
operaciones la red puede fallar por el desconocimiento del
comportamiento de equipos o bien de perturbaciones externas no
consideradas en la planificación. Este es un escenario posible en el
desempeño de la red DWDM con ROADM (reconfigurable optical add
drop multiplexer): las componentes pueden fallar y este es el problema
analizado en esta memoria sobre la base de distintas modelaciones.
Se formula un modelo clásico basado en la normativa ETSI adaptado,
esto es, se consideran interfaces STM-16/64 de altas velocidades (2,5 y
10 Gb/s) en el modelo de la ETSI. Con esto, es posible estimar una
disponibilidad verdadera y útil para la red, pero invariante (es decir, que
no tiene oscilaciones) en el tiempo.
Los fundamentos analíticos de la normativa ETSI se rescatan para
formular un segundo modelo que debido a su dificultad (NP-complejo) es
sólo posible resolverlo con heurísticas. El modelo permite representar a
la disponibilidad a través de la tasa de fallas como una cantidad variante
en el tiempo. El diseño, que ocupa tabla lógicas para varias fallas
simultáneas, permite analizar la tasa de fallas a través de tres zonas de
tiempo, y permite llegar a valores medios de la disponibilidad de la red.
La modelación usada es la Cadena de Markov apoyada en la hipótesis
que caracteriza a la distribución de Weibull.
Finalmente, la representación es contrastada con la anterior mejorando
las proyecciones para una determinación más exacta de la
disponibilidad. Se hacen cálculos para: redes grandes (más de 10
nodos); redes nacionales; y la red NTFS de Estados Unidos. De esta
manera, se concluye que la red enmallada es más confiable que la red
anillada primitiva y que usando la teoría de Markov es posible modelar
este problema de manera simple y consistente.
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