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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Estudo de esquemas de amplificação para redes PON de longo alcance / Study amplification schemes for long reach PON networks

Paiva, Getúlio Eduardo Rodrigues de 12 April 2012 (has links)
O surgimento de novos serviços que requerem uma largura de banda cada vez maior, bem como o crescente número de usuários de tais serviços, têm introduzido desafios às empresas operadoras de telecomunicações em sua capacidade de atender a estas demandas sem perda apreciável da qualidade de serviço e mantendo, ainda assim, os custos num nível aceitável pelos usuários. Neste contexto, redes ópticas passivas (PONs) vêm atraindo grande interesse em anos recentes. Na sua variante de longo-alcance, as redes PON permitem uma consolidação do uso dos equipamentos e centrais de serviço requeridos, reduzindo custos operacionais e de instalação. Uma das formas de atingir este maior alcance dá-se por meio da inserção de amplificadores ópticos nas redes de acesso. Neste trabalho, portanto, estudaram-se alguns tipos de amplificadores ópticos e suas possíveis aplicações em redes de acesso, levando a topologias de longo alcance e alta capacidade. Foram realizadas avaliações experimentais de um extensor, baseado em amplificadores ópticos semicondutores (SOAs), na rede GPON do CPqD, sob a Meta 3 do Projeto GIGA, possibilitando a obtenção de uma topologia do tipo Fiber-to-the-Building (FTTB) com 80 km de extensão e 128 usuários atendidos por uma única central de serviço. Além dessas validações experimentais, foram simulados computacionalmente SOAs com características otimizadas bem como sistemas que utilizam fibras dopadas com érbio bombeadas remotamente, sendo que nestes últimos, atingiram-se distâncias superiores a 100 km. / The emergence of new services which require an increasing bandwidth, as well as the growing number of users of such services, have introduced challenges to the network operators in regard to their capacity of supporting these demands with no penalty on the required quality of service, while keeping the costs at an acceptable level for the users. In this context, passive optical networks (PONs) have attracted a great deal of interest in recent years. In the long-reach configuration, PON networks allow for a consolidation of equipament usage, reducing operational and installation costs. One way to achieve this longer reach is by the insertion of optical amplifiers in the access network. Therefore, in our work, we have investigated several optical amplifier configurations, as well as their application in access networks, leading to longreach and high capacity network topologies. Experimental evaluations of an extender, based on semiconductor optical amplifiers, were carried out in the CPqD GPON network, under Goal 3 of GIGA Project, allowing the achievement of a Fiber-to-the-Building (FTTB) topology with 80km of extension and 128 users served by a single central office. Besides these experimental validations, were simulated computationally SOAs with optimized characteristics as well as systems using remotely pumped erbium-doped fibers, whereas in the latter were reached distances exceeding 100 km.
32

Topologias WDM-PON utilizando auto-alimentação com dupla cavidade óptica para Fronthaul analógico de redes 5G / Double-cavity self-seeding WDM-PON topologies as 5G networks analog Fronthaul

Souza, Adelcio Marques de 10 September 2018 (has links)
As futuras redes de acesso sem-fio, como a quinta geração de telefonia celular (5G), estão introduzindo e consolidando diversas tecnologias, tais como a operação em ondas milimétricas, picocélulas e o emprego massivo de antenas para diversidade espacial e temporal. Todas essas mudanças trazem desafios para a capacidade dos enlaces presentes nessas redes, como o backhaul e fronthaul. Nas últimas gerações, o ifronthaul tem utilizado Rádio-sobre-Fibra Digital (D-RoF, Digital Radio-over Fiber). Entretanto, neste novo paradigma, o processo de digitalização pode vir a consumir uma largura de banda excessiva e a transmissão analógica dos sinais de RF sobre a fibra se torna uma solução mais atrativa. Ao mesmo tempo, WDM-PON (Wavelength-Division-Multiplexing Passive-Optical-Network) é uma proeminente alternativa para o futuro das PONs, especialmente considerando o seu emprego como fronthaul. Para reduzir a necessidade de diversos transmissores diferentes, várias técnicas de auto-alimentação para obtenção de fontes ópticas agnósticas em comprimento de onda têm sido propostas. O presente trabalho faz um estudo de topologias de auto-alimentação com dupla cavidade para operarem como fronthaul analógico nas futuras redes de acesso sem-fio. Simulações numéricas utilizando o software Optisystem demonstram a viabilidade destas topologias em diversos cenários previstos para estas redes de acesso, especialmente considerando a operação em ondas milimétricas. Transmissões bem sucedidas foram obtidas para sinais ASK, M-PSK e M-QAM em frequências de microondas (1,25, 2,5 e 5 GHz) e ondas milimétricas (38 e 60 GHz) com vazões de 155 Mbps a 10 Gbps utilizando modulação direta e modulação externa. / Future radio access networks, such as the fifth generation mobile network (5G), are introducing and consolidating disruptive technologies, such as millimeter wave operation, dense picocell coverage and massive use of antennas for spatial and temporal diversity. These new technologies present a challenge for the capacity of the links that are present on these networks, including backhaul and fronthaul. In the latest cellular network generations, the fronthaul was typically implemented by Digital Radio-over-Fiber (D-RoF) technique. However, in this future context, the digitalization process would require a prohibitive bandwidth and the analog transmission of RF signals over the fiber can be a more attractive solution when compared to D-RoF. At the same time, Wavelength-Division-Multiplexing PON (WDM-PON) is prominent alternative for the future of PONs, especially considering its use as fronthaul. In order to avoid employing numerous distinct transmitters, several self-seeding techniques have been proposed to achieve colorless optical sources. This dissertation presents a numerical study of double-cavity self-seeding topologies to serve as analog fronthaul for future radio access networks. Numerical simulations using the software Optisystem demonstrate the feasibility of these topologies in various scenarios envisioned for these access networks, especially considering operation in millimeter waves. Successful transmission was achieved for ASK, M-PSK and M-QAM signals at microwave (1.25, 2.5 and 5 GHz) and millimeter wave (38 and 60 GHz) frequencies with throughput of 155 Mbps to 10 Gbps using direct and external modulation.
33

Deploying Monitoring Trails for Fault Localization in All-optical Networks and Radio-over-Fiber Passive Optical Networks

Maamoun, Khaled M. 24 August 2012 (has links)
Fault localization is the process of realizing the true source of a failure from a set of collected failure notifications. Isolating failure recovery within the network optical domain is necessary to resolve alarm storm problems. The introduction of the monitoring trail (m-trail) has been proven to deliver better performance by employing monitoring resources in a form of optical trails - a monitoring framework that generalizes all the previously reported counterparts. In this dissertation, the m-trail design is explored and a focus is given to the analysis on using m-trails with established lightpaths to achieve fault localization. This process saves network resources by reducing the number of the m-trails required for fault localization and therefore the number of wavelengths used in the network. A novel approach based on Geographic Midpoint Technique, an adapted version of the Chinese Postman’s Problem (CPP) solution and an adapted version of the Traveling Salesman’s Problem (TSP) solution algorithms is introduced. The desirable features of network architectures and the enabling of innovative technologies for delivering future millimeter-waveband (mm-WB) Radio-over-Fiber (RoF) systems for wireless services integrated in a Dense Wavelength Division Multiplexing (DWDM) is proposed in this dissertation. For the conceptual illustration, a DWDM RoF system with channel spacing of 12.5 GHz is considered. The mm-WB Radio Frequency (RF) signal is obtained at each Optical Network Unit (ONU) by simultaneously using optical heterodyning photo detection between two optical carriers. The generated RF modulated signal has a frequency of 12.5 GHz. This RoF system is easy, cost-effective, resistant to laser phase noise and also reduces maintenance needs, in principle. A revision of related RoF network proposals and experiments is also included. A number of models for Passive Optical Networks (PON)/ RoF-PON that combine both innovative and existing ideas along with a number of solutions for m-trail design problem of these models are proposed. The comparison between these models uses the expected survivability function which proved that these models are liable to be implemented in the new and existing PON/ RoF-PON systems. This dissertation is followed by recommendation of possible directions for future research in this area.
34

Study of converged 60 GHz radio over fiber with WDM-PON access networks / Optical heterodyne detection of 60 GHz UWB signals

Shao, Tong 25 June 2012 (has links)
Récemment, la convergence des techniques radio à 60 GHz sur fibre optique (radio over fiber - RoF) et des réseaux d’accès optiques passifs à multiplexage en longueurs d’ondes (wavelength division multiplexing-WDM) a suscité un très grand intérêt dans la communauté scientifique. L’objectif de cette thèse est d’étudier les solutions pour faire converger les systèmes RoF à 60 GHZ et les réseaux passifs optiques (passive optical network – PON) utilisant le WDM, appelés dans la suite PON-WDM. Les résultats principaux de cette thèse axée sur la technologie des systèmes RoF et l’intégration des systèmes RoF avec les réseaux d’accès PON-WDM sont les suivants : Un système RoF utilisant un démultiplexeur WDM, compatible avec les réseaux d’accès PON-WDM, est proposé dans cette thèse. Nous avons mené une étude théorique complète du bruit de phase. Elle inclut la contribution des bruits de phase des générateurs de signaux électriques et celle de la conversion de bruit de phase optique en bruit d’intensité. Cette dernière conversion est due à la détection de deux signaux cohérents, retardés l’un par rapport à l’autre si les longueurs optiques entre les deux canaux optiques se recombinant sont différentes. La densité spectrale de puissance du signal millimétrique généré optiquement est analysée théoriquement et démontrée expérimentalement. Son étude donne une méthode pour compenser un éventuel délai optique │τd│. L’amplitude du vecteur d’erreur (error vector magnitude –EVM) est théoriquement calculée et expérimentalement démontrée, en fonction du rapport │τd│/τcOP où τcOP est la durée de cohérence de la source optique utilisée. Cela donne une règle de conception pour insérer le démultiplexeur optique dans le système d’hétérodynage optique.  Nous avons validé expérimentalement la technique d’hétérodynage optique qui utilise un démultiplexeur pour générer un signal millimétrique respectant le standard ECMA 387. Nous avons proposé un système combinant une partie RoF et un réseau PON-WDM, permettant la génération simultanée d’un signal millimétrique respectant le standard ECMA 387 et la transmission d’un signal en bande de base à plusieurs gigabits par seconde. Nous avons réalisé expérimentalement avec succès la transmission simultanée d’un signal à 60 GHZ, modulé avec une modulation BPSK par un signal à 1588 Mbit/s et celle d’un signal en bande de base à 10 Gbit/s.  Nous avons proposé une nouvelle technique de modulation multi-bandes : la modulation de phase parallèle utilisant un unique modulateur de Mach-Zehnder. Cette technique présente des avantages significatifs comparée à n’importe quelle autre technique de modulation multi-bandes. Il n’y a aucun impact de la modulation en bande de base sur la génération millimétrique. L’impact de la modulation RF sur la transmission en bande de base (impact dû à la non-linéarité de la modulation de phase) est limité. Le taux d’erreurs binaires du signal en bande de base intégrant l’effet du signal RF a été théoriquement calculé et expérimentalement validé. Cela donne des règles de conception pour la technique de modulation de phase parallèle avec un unique modulateur de Mach-Zehnder. Nous avons proposé une architecture et réalisé un démonstrateur d’un système bas-coût bidirectionnel pour la transmission RoF. Ce système utilise le mélange optoélectronique et la technique d’hétérodynage optique. Nous avons prouvé que :  Des signaux à 60 GHz modulés à 397 Mbit/s et 794 Mbit/s avec une modulation BPSK sont convertis vers la bande basse de fréquence en utilisant la technique de mélange optoélectronique : les contraintes du standard ECMA 387 sont respectées.  Pour la liaison descendante utilisant la technique d’hétérodynage optique, aucune pénalité sur l’EVM n’est causée par le choix du régime non linéaire de la photodiode. / Recently, convergence of 60 GHz radio over fiber (RoF) technique with wavelength division multiplexing (WDM) passive optical networks (PON) has raised great interests because it provides the possibility for simultaneous broadband 60 GHz signal generation and multi-gigabit per second wireline transmission. The objective of the thesis is to study the solutions for converged 60 GHz RoF and WDM-PON technique. In this thesis, we have made the following achievements for RoF technology and the integration of RoF technology with WDM-PON access networks: A RoF system using WDM DEMUX which is supposed to be compliant with WDM-PON access networks is proposed in this thesis. Phase noise including optical phase to intensity noise conversion contribution due to the delayed coherent detection induced by the different optical lengths between the two optical channels and the phase noise contribution due to the electrical generators has been theoretically studied. PSD of the optical mmW is theoretically analyzed and experimentally demonstrated, which gives a solution to compensate different optical delay │τd│ EVM as function of │τd│/τcOP is theoretically derived and experimentally proved, which gives a design rule for optical heterodyning using WDM DEMUX The optical heterodyning technique using WDM DEMUX for mmW generation respecting ECMA 387 standard is validated by the experiment. We proposed a simple combination of RoF with WDM-PON supporting mmW generation respecting ECMA 387 standard and multi-gigabit per second baseband transmission. Simultaneous transmission of 1588 Mbps BPSK 60 GHz signal and 10 Gbps baseband signal is experimentally proved. A novel WDM-RoF-PON access networks with multi-band modulation technique is proposed in order to lower the cost of infrastructure. We propose a novel parallel phase modulation technique with a single MZM. This technique can offer several significant advantages compared to any other multi-band modulation technique. No impact from baseband modulation to mmW generation. Limited impact from RF modulation to baseband transmission due to the non-linearity of the phase modulation. BER of baseband signal with RF impact is theoretically studied and experimentally demonstrated, which gives a design rule for parallel phase modulation technique with a single MZM A low-cost bidirectional RoF transmission using optoelectronic mixing and optical heterodyning technique is proposed and experimentally demonstrated. It has been proved that: 397 Mbps and 794 Mbps BPSK 60 GHz uplink signal is down-converted to IF band respecting the ECMA 387 standard by using the optoelectronic mixing technique. No EVM penalty is paid to the non-linearity biased PD for downlink transmission by optical heterodyning technique. 6 dB power penalty need to be paid for the non-linear biased PD, which can be compensated by using high gain LNA after the PD.
35

Projeto e dimensionamento de redes ópticas passivas (PONs) / Project and dimensioning of passive optical networks (PONs)

Paulo Takeuti 01 August 2005 (has links)
Redes ópticas passivas são redes de acesso que utilizam fibras ópticas interligadas na topologia estrela e na configuração ponto-multiponto, sendo constituídas apenas por componentes ópticos passivos entre o terminal de linha óptica (optical line terminal - OLT) e a unidade de rede óptica (optical network unit - ONU). Como estratégia de evolução tecnológica, podem ser utilizadas para aproveitar a base instalada de cabos de cobre e cabos coaxiais na rede de acesso, servindo como cabo alimentador para uso das tecnologias digital subscriber line (DSL), cable modem e local multipoint distribution system (LMDS), e, no futuro, para disponibilizar a fibra óptica até às instalações do usuário. O principal mérito da arquitetura das redes ópticas passivas está na redução dos custos de implantação e de manutenção, pela ampliação da largura de banda disponível sem a necessidade de aumento no número de componentes ópticos ativos na rede, como lasers e amplificadores ópticos. Neste contexto, este trabalho define as redes ópticas passivas, apresenta o histórico de seu desenvolvimento, seu princípio de funcionamento e suas aplicações como forma de acesso a serviços de banda larga, identifica fornecedores visando à implementação de um teste de campo e discute as perspectivas para o futuro dessa tecnologia / Passive optical networks (PONs) are access networks which use interconnected optical fibers configured in a point to multipoint star topology having only passive optical components between the optical line terminal (OLT) and the optical network unit (ONU). As a strategy for technological evolution they can be used to take advantage of copper and coax base cables installed in the access network, serving as a feeder cable for the use of DSL, cable modem and LMDS technologies, in order to allow optical fibers to reach customers' facilities. The main merit of the passive optical networks architecture consists on the cost reduction involved on its implantation and maintenance, offering bandwidth enlargement without increasing the number of active optical components, such as lasers and optical amplifiers, in the network. In this context, this text defines PONs, presents its development history, operation principle and their applications as a way to provide broadband access services, identifies suppliers for field test implementation and discusses the perspectives for the future
36

Topologias WDM-PON utilizando auto-alimentação com dupla cavidade óptica para Fronthaul analógico de redes 5G / Double-cavity self-seeding WDM-PON topologies as 5G networks analog Fronthaul

Adelcio Marques de Souza 10 September 2018 (has links)
As futuras redes de acesso sem-fio, como a quinta geração de telefonia celular (5G), estão introduzindo e consolidando diversas tecnologias, tais como a operação em ondas milimétricas, picocélulas e o emprego massivo de antenas para diversidade espacial e temporal. Todas essas mudanças trazem desafios para a capacidade dos enlaces presentes nessas redes, como o backhaul e fronthaul. Nas últimas gerações, o ifronthaul tem utilizado Rádio-sobre-Fibra Digital (D-RoF, Digital Radio-over Fiber). Entretanto, neste novo paradigma, o processo de digitalização pode vir a consumir uma largura de banda excessiva e a transmissão analógica dos sinais de RF sobre a fibra se torna uma solução mais atrativa. Ao mesmo tempo, WDM-PON (Wavelength-Division-Multiplexing Passive-Optical-Network) é uma proeminente alternativa para o futuro das PONs, especialmente considerando o seu emprego como fronthaul. Para reduzir a necessidade de diversos transmissores diferentes, várias técnicas de auto-alimentação para obtenção de fontes ópticas agnósticas em comprimento de onda têm sido propostas. O presente trabalho faz um estudo de topologias de auto-alimentação com dupla cavidade para operarem como fronthaul analógico nas futuras redes de acesso sem-fio. Simulações numéricas utilizando o software Optisystem demonstram a viabilidade destas topologias em diversos cenários previstos para estas redes de acesso, especialmente considerando a operação em ondas milimétricas. Transmissões bem sucedidas foram obtidas para sinais ASK, M-PSK e M-QAM em frequências de microondas (1,25, 2,5 e 5 GHz) e ondas milimétricas (38 e 60 GHz) com vazões de 155 Mbps a 10 Gbps utilizando modulação direta e modulação externa. / Future radio access networks, such as the fifth generation mobile network (5G), are introducing and consolidating disruptive technologies, such as millimeter wave operation, dense picocell coverage and massive use of antennas for spatial and temporal diversity. These new technologies present a challenge for the capacity of the links that are present on these networks, including backhaul and fronthaul. In the latest cellular network generations, the fronthaul was typically implemented by Digital Radio-over-Fiber (D-RoF) technique. However, in this future context, the digitalization process would require a prohibitive bandwidth and the analog transmission of RF signals over the fiber can be a more attractive solution when compared to D-RoF. At the same time, Wavelength-Division-Multiplexing PON (WDM-PON) is prominent alternative for the future of PONs, especially considering its use as fronthaul. In order to avoid employing numerous distinct transmitters, several self-seeding techniques have been proposed to achieve colorless optical sources. This dissertation presents a numerical study of double-cavity self-seeding topologies to serve as analog fronthaul for future radio access networks. Numerical simulations using the software Optisystem demonstrate the feasibility of these topologies in various scenarios envisioned for these access networks, especially considering operation in millimeter waves. Successful transmission was achieved for ASK, M-PSK and M-QAM signals at microwave (1.25, 2.5 and 5 GHz) and millimeter wave (38 and 60 GHz) frequencies with throughput of 155 Mbps to 10 Gbps using direct and external modulation.
37

Estudo de esquemas de amplificação para redes PON de longo alcance / Study amplification schemes for long reach PON networks

Getúlio Eduardo Rodrigues de Paiva 12 April 2012 (has links)
O surgimento de novos serviços que requerem uma largura de banda cada vez maior, bem como o crescente número de usuários de tais serviços, têm introduzido desafios às empresas operadoras de telecomunicações em sua capacidade de atender a estas demandas sem perda apreciável da qualidade de serviço e mantendo, ainda assim, os custos num nível aceitável pelos usuários. Neste contexto, redes ópticas passivas (PONs) vêm atraindo grande interesse em anos recentes. Na sua variante de longo-alcance, as redes PON permitem uma consolidação do uso dos equipamentos e centrais de serviço requeridos, reduzindo custos operacionais e de instalação. Uma das formas de atingir este maior alcance dá-se por meio da inserção de amplificadores ópticos nas redes de acesso. Neste trabalho, portanto, estudaram-se alguns tipos de amplificadores ópticos e suas possíveis aplicações em redes de acesso, levando a topologias de longo alcance e alta capacidade. Foram realizadas avaliações experimentais de um extensor, baseado em amplificadores ópticos semicondutores (SOAs), na rede GPON do CPqD, sob a Meta 3 do Projeto GIGA, possibilitando a obtenção de uma topologia do tipo Fiber-to-the-Building (FTTB) com 80 km de extensão e 128 usuários atendidos por uma única central de serviço. Além dessas validações experimentais, foram simulados computacionalmente SOAs com características otimizadas bem como sistemas que utilizam fibras dopadas com érbio bombeadas remotamente, sendo que nestes últimos, atingiram-se distâncias superiores a 100 km. / The emergence of new services which require an increasing bandwidth, as well as the growing number of users of such services, have introduced challenges to the network operators in regard to their capacity of supporting these demands with no penalty on the required quality of service, while keeping the costs at an acceptable level for the users. In this context, passive optical networks (PONs) have attracted a great deal of interest in recent years. In the long-reach configuration, PON networks allow for a consolidation of equipament usage, reducing operational and installation costs. One way to achieve this longer reach is by the insertion of optical amplifiers in the access network. Therefore, in our work, we have investigated several optical amplifier configurations, as well as their application in access networks, leading to longreach and high capacity network topologies. Experimental evaluations of an extender, based on semiconductor optical amplifiers, were carried out in the CPqD GPON network, under Goal 3 of GIGA Project, allowing the achievement of a Fiber-to-the-Building (FTTB) topology with 80km of extension and 128 users served by a single central office. Besides these experimental validations, were simulated computationally SOAs with optimized characteristics as well as systems using remotely pumped erbium-doped fibers, whereas in the latter were reached distances exceeding 100 km.
38

Modelagem de diodos laser de Fabry-Pérot travados por injeção de sinal óptico externo para uso em redes WDM-PON. / Modelling of diodes lasers Locked Fabry-Pérot óptical signal injection for use in external networks WDM-PON.

Ulysses Rondina Duarte 14 April 2011 (has links)
A disponibilização de fontes ópticas multi-comprimento de onda de baixo custo certamente é um dos aspectos fundamentais para viabilizar a implantação de redes WDMPON (Wavelength Division Multiplexing-Passive Optical Network). Na literatura, são encontradas propostas de algumas tecnologias para a construção de tais dispositivos como a utilização de fontes ópticas sintonizáveis, uso de um vetor de lasers DFB (Distributed Feedback Laser) ou, até mesmo, o fatiamento espectral de uma fonte de banda larga. Contudo, essas propostas apresentam custo elevado, ou limitações de operação, tornando-se inapropriadas para a aplicação de interesse. Uma alternativa que vem sendo amplamente utilizada é o travamento óptico de diodos laser de Fabry-Pérot (FP-LD - Fabry-Pérot laser diode), realizado por meio da injeção de sinal óptico externo provindo do fatiamento espectral de uma fonte de banda larga. O travamento óptico possibilita o controle espectral do FP-LD, e o seu baixo custo torna essa fonte óptica atrativa na implantação de redes WDM. O entendimento do mecanismo de travamento torna-se, então, crucial na descrição da dinâmica de tais fontes ópticas. Desta forma, nesta dissertação, foi desenvolvido o estudo dos modelos matemáticos que descrevem a dinâmica de lasers travados, assim como foi investigado o desempenho de redes WDM-PON empregando estas fontes ópticas. / The availability of low cost multi-wavelength optical sources is certainly one of the fundamental aspects to allow the deployment of WDM-PON networks. Several technologies for the implementation of such optical sources are discussed in the literature, including tunable lasers, DFB arrays and spectral slicing of a broadband light source. However, those propositions suffer from high cost or operational limitations. One alternative is the optical injection locking of a Fabry Pérot laser diode (FPLD), in which the external optical injection signal is obtained from the spectral slicing of a broadband light source. This option has been widely investigated because the optical injection locking process allows for the FP-LD optical spectral control and wavelength selection. In addition, the low cost of such device makes this optical source an attractive solution for WDM-PON widespread deployment. In this context, the understanding of the locking mechanism becomes important in the optimization of such optical sources. Thus, in this dissertation, we conducted a study of mathematical models that describe the dynamics of locked lasers as well as investigated the performance of WDM-PON based on those optical sources.
39

Deploying Monitoring Trails for Fault Localization in All-optical Networks and Radio-over-Fiber Passive Optical Networks

Maamoun, Khaled M. January 2012 (has links)
Fault localization is the process of realizing the true source of a failure from a set of collected failure notifications. Isolating failure recovery within the network optical domain is necessary to resolve alarm storm problems. The introduction of the monitoring trail (m-trail) has been proven to deliver better performance by employing monitoring resources in a form of optical trails - a monitoring framework that generalizes all the previously reported counterparts. In this dissertation, the m-trail design is explored and a focus is given to the analysis on using m-trails with established lightpaths to achieve fault localization. This process saves network resources by reducing the number of the m-trails required for fault localization and therefore the number of wavelengths used in the network. A novel approach based on Geographic Midpoint Technique, an adapted version of the Chinese Postman’s Problem (CPP) solution and an adapted version of the Traveling Salesman’s Problem (TSP) solution algorithms is introduced. The desirable features of network architectures and the enabling of innovative technologies for delivering future millimeter-waveband (mm-WB) Radio-over-Fiber (RoF) systems for wireless services integrated in a Dense Wavelength Division Multiplexing (DWDM) is proposed in this dissertation. For the conceptual illustration, a DWDM RoF system with channel spacing of 12.5 GHz is considered. The mm-WB Radio Frequency (RF) signal is obtained at each Optical Network Unit (ONU) by simultaneously using optical heterodyning photo detection between two optical carriers. The generated RF modulated signal has a frequency of 12.5 GHz. This RoF system is easy, cost-effective, resistant to laser phase noise and also reduces maintenance needs, in principle. A revision of related RoF network proposals and experiments is also included. A number of models for Passive Optical Networks (PON)/ RoF-PON that combine both innovative and existing ideas along with a number of solutions for m-trail design problem of these models are proposed. The comparison between these models uses the expected survivability function which proved that these models are liable to be implemented in the new and existing PON/ RoF-PON systems. This dissertation is followed by recommendation of possible directions for future research in this area.
40

Nasazení FTTH v lokálních sítích / FTTH deployment in local networks

Horníček, Lukáš January 2013 (has links)
The master’s thesis is focused on the theoretical and practical issues of optical access networks. The first chapter of the thesis deals with the concept of the access networks known as FTTx. The second and third chapters focus on the principles and standardization of the active optical network AON P2P and the passive optical network TDM PON. The fourth chapter of the thesis focuses on the network WDM PON, wavelength multiplexes, solution concept and the LG-Ericsson EA 1100 platform. The fifth chapter of the thesis deals with the infrastructure of the optical paths for optical access networks. The sixth chapter of the thesis presents custom design of the headend for reception, processing and distribution of television broadcasting. Two custom access network solutions (AON P2P and WDM PON) for the town Bystřice nad Pernštejnem are presented in the seventh chapter. Case studies include the design of the optical paths infrastructure, central office infrastructure, end-user infrastructure, CAPEX/OPEX economic analysis and basic simulation in OptSim.

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