Esta investigación está conducida a la resolución del problema de encontrar soluciones rentables para el despliegue de redes de fibra hasta el hogar (Fibre to the Home - FTTH). En una red de FTTH, el equipo transmisor-receptor de usuario así como el despliegue de la fibra en la llamada 'última milla' son las barreras principales. Una topología que consiste en hacer llegar una única fibra para dirigirse a cada usuario reduce la cantidad de fibra requerida. Por otro lado, los componentes ópticos pasivos alivian los requisitos de mantenimiento de la red de acceso. El efecto del backscattering de Rayleigh se ha identificado como la interferencia más crítica de este tipo de transmisión, el efecto sobre el funcionamiento del sistema y las investigaciones de posibles soluciones al mencionado problema son centro de estudio de esta tesis. Los experimentos realizados, revelan que, a pesar de la interferencia causada por del effecto Rayleigh no se puede eliminar totalmente, hay diferentes técnicas capaces de atenuar dicho efecto. El uso de los amplificadores ópticos semiconductores para implementar las funciones de transmisión-recepción agrega simplicidad al diseño de red en términos de transparencia de la longitud de onda y gracias a las capacidades de la amplificación de esta familia de dispositivos.Los resultados experimentales presentaron en este trabajo demuestran con éxito la modulación y la detección a 1Gbit/s y 2.5Gbit/s con los dispositivos basados en semiconductores, en enlaces de hasta 30km e incluso de hasta 50km de longitud. Nuevos prototipos son potencialmente capaces de transmitir a 10Gbit/s. Estructuras reflectoras basadas en amplificadores ópticos semiconductores reflectores son los candidatos mas adecuados.Éstos, realizan funciones de transmisión eficientemente y proporcionan la amplificación adecuada. Sin embargo, es necesario el diseño de nuevos diseños capaces de transmitir datos a una velocidad mayor. Una estrategia de comunicación bidireccional mediante una única fibra es la arquitectura más interesante los términos de reducción de costes por usuario (CAPEX). Por estos motivos, la ONU se convierte en un elemento clave en redes de acceso y un área muy interesante de investigación. Para una evolución exitosa de FTTH el diseño de la unidad de red debe ser simple, robusto, flexible y bajo coste para el cliente final. La traducción de los requisitos anteriormente mencionados en especificaciones técnicas establece las pautas siguientes para el diseño del FTTH ONU- Una única fibra por cada usuario para reducir tamaño de la red de acceso- Independencia de la longitud de onda para permitir una operación transparente en redes WDM- Que no haya fuente de luz activa en las dependencias de usuario para prevenir el mantenimiento en el lado del usuario- Con amplificación y así poder aumentar el número de usuarios y alcanzar mayores distanciasDe esta manera, el objetivo principal de esta tesis es la investigación de unidades ópticas de red reflectoras, especialmente las basadas en amplificadores ópticos de semiconductor, así como su funcionamiento en redes de FTTH, basadas en tecnología de acceso WDM-PON. Esto implica fundamentalmente- Identificar arquitecturas y dispositivos propuestos por medio de la investigación del trabajo publicado relacionado y destacar limitaciones y requisitos de los sistemas actuales- evaluar las diversos alternativas para la ONU y para proponer soluciones mejoradas, demostradas con simulaciones y experimentos - investigar limitaciones posibles de los sistemas transmisión bidireccionales y desarrollar soluciones para la mejora de la transmisión- desarrollar descripciones analíticas de las señales implicadas en la transmisión / This research was conducted to deal with the problem of finding cost-effective solutions for Fibre-to-the-Home (FTTH) network deployment. In the FTTH network, the transceiver at the user premises and the deployment of fibre at the last mile are the major barriers. A single-fibre topology to address each user reduces the amount of fibre required; passive optical components alleviate maintenance requirements in the access network.The Rayleigh backscattering effect is identified as the most critical crosstalk in such transmission, the effect on the system performance and the investigations of possible solutions are presented in this thesis. The studies reveal that despite the Rayleigh backscattering crosstalk can not be totally eliminated, several techniques can mitigate the effect.The use of the semiconductor optical amplifiers to feature transceiver tasks at the user premises adds simplicity to the network design in terms of wavelength transparency and amplification capabilities. We propose implementations with semiconductor amplifiers and test modulation and detection potentials inside the optical network. The experimental results successfully demonstrate modulation and detection at 1Gbit/s and 2.5Gbit/s with semiconductor-based devices, in links of 30km and even though of 50km length; bit rate of 10Gbit/s is feasible with novel prototypes as well. Reflective structures based on reflective semiconductor optical amplifiers are potential candidates, as they perform transmission functions efficiently and provide adequate amplification however, it is necessary the design of further structures capable of transmitting at a higher bit rates.

“Connected society” where everything and everyone are connected at any time and on any location brings new challenges for the network operators. This leads to the need of upgrading the transport networks as the segment of Internet infrastructure connecting the fixed users and mobile base stations to the core/aggregation in order to provide high sustainable bandwidth, as well as supporting a massive number of connected devices. To do this, operators need to change the way that access networks are currently deployed. The future access network technologies will need to support very high capacity and very long distances, which are the inherited characteristics of optical transmission. Hence, optical fiber technology is recognized as the only future proof technology for broadband access. Capacity upgrade in the access networks can lead to a huge capacity demand in the backbone network. One promising solution to address this problem, is to keep the local traffic close to the end users as much as possible, and prevent unnecessary propagation of this type of traffic through the backbone. In this way, operators would be able to expand their access network without the significant capacity upgrade in the higher aggregation layers. Motivated by this need, a comprehensive evaluation of optical access networks is carried out in this thesis regarding ability of accommodating local traffic and amount of possible saving in the backbone by implementing locality awareness schemes. Meanwhile, next generation optical access (NGOA) networks have to provide high capacity at low cost while fulfilling the increasing reliability requirements of future services and customers. Therefore, finding cost-efficient and reliable alternative for future broadband access is one of the most important contributions of this thesis. We analyzed the tradeoff between the cost needed to deploy backup resources and the reliability performance improvement obtained by the proposed protection mechanism. Among different NGOA architectures, hybrid time and wavelength division multiplexing passive optical network (TWDM PON) is considered as a proper candidate providing high capacity and large coverage. Therefore, this approach is further analyzed and several tailored protection schemes with high flexibility are proposed to statisfy different requirements from the residential and business users in the same PON.  The work carried out in the thesis has proved that TWDM PON can also offer high reliability performance while keeping the network expenditures at an acceptable level. Considering some other advantages such as low power consumption and high flexibility in resource allocation of this architecture, it has high potential to be the best candidate for NGOA networks.  Moreover, new deployments of radio access networks supporting the increasing capacity demand of mobile users lead to the upgrade of the backhaul segment as a part of broadband access infrastructure. Hence, this thesis also contributes with a comprehensive techno-economic evaluation methodology for mobile backhaul. Several technologies are investigated in order to find the most cost-efficient solution for backhauling the high capacity mobile networks.  Finally, a PON-based mobile backhaul with high capacity and low latency has been proposed for handling coordinated multipoint transmission systems in order to achieve high quality of experience for mobile users. / <p>QC 20150320</p>

Optical fibre communication is very much preferred for the communication of signals over bandwidth of a gigabits per second over distances more than hundreds of kilometres. For a long period of time optical fibre communication has been about how to provide higher bandwidths with reduced cost per bit transmitted. However, this trend has changed from optical transmission to optical networking. By exploiting the wavelength division multiplexing (WDM) technology, optical networks have expanded from backbone networks to metropolitan and access networks to deliver high bandwidth services to the users in a seamless fashion with reduced cost. The ultimate evolution of the optical access network involves fibre-to-the-home (FTTH) technologies, which can potentially offer every kind of information and communication related services. Out of all FTTH technologies, the passive optical network (PON) can potentially offer the most cost-effective solution as the optical network is shared between a number of end users. PONs have significant advantage over competing access technologies as the fibre infrastructure can be effectively future-proofed for upgrades. A number of demonstrations have been carried out for the cost effective deployment of the PONs. However, as these networks evolve, advanced functionalities have to be added over the existing end to end transmissions between the service providers and end users.

The aim of this work is an overview of the proposal for FTTx Optical Access Networks. In the introductory chapter written about the optical fiber and the transmission. Furthermore, as already discussed various options with regard to the implementation instead of the end of optical fiber - FTTN, FTTC, FTTP, FTTB, FTTH and standards, which are used to build fiber optic networks. The next chapter is an overview of the network elements that are in different layers reference model ISO / OSI used. The final theoretical chapter is devoted to progressive technologies for the construction of optical access networks, which has recently been used. Concepts are explained as HDPE pipe, microtubing or self-supporting cables. The practical part design model, passive optical networks in the area Slavičín, located in the Zlín region. FTTB architecture was chosen, where for each connection object is used in the existing copper lines. The proposed route will use a standard technology GEPON Wavelength division WDM, so to connect the individual buildings will be used only one thread. Realization of optical networking technology will be excavation. The optical cables and optical fiber bundles are protected by HDPE pipes stored in the bed of sand. For the optical signal split into multiple lines will be used by an optical splitter 1 / 16, located in an outdoor cabinet optic pathway. The distribution of signals for the settlement will take care Alloptic central station, which is optimized for the transmission of Triple Play services. On the basis of the proposal is to created a financial analysis that shows the return on the project. An important part of the network is also monitoring the network. The last part of this work therefore deals with the possibilities of monitoring networks in order to continuously monitor the network, in order to prevent any disturbances or quickly respond to network problems.

Diploma thesis is dealing with access networks, especially with the passive optical network. The theoretical part is a list of different types of passive optical access networks, including theirs basic description, which then goes on to feature connectivity options for optical units, customers, including topology of distribution network. Analysis of different types of networks and the possibility of physical and logical design is the basis for successful design and prepa-ration of future optical access networks. Practical part is devoting to data analysis of measurement existing metropolitan network to be used for construction of optical access network in Brno, Ţlutý kopec – Preslova location. Data evaluation showed possibility of connecting with already installed network hence is created proposal of optical access network mentioned before. Selected location is analysed in detail and illustrated on situational scheme of location and customers, whose will be passive split-ters to central office. Consequently is developed project of optical access network based on data analysed date from measurements. Project is study and description of planned solution of optical access network in order to bring Triple Play services to customers. Within the interpretation of the feasibility of the project and verification physical layer pa-rameters of network was made a simulation in OptiSystem. The possibility of successful op-eration of the optical access network with the attributes entered in its design is approved in accordance with the evaluation results. The proposed network is passive in character of GPON standard, and the text describes in detail physical layer, proposed transmission speed, wave and attenuation plan of optical net-work. The work implies a specific line of HDPE ducts and microducts in them, including drawing the maps and identification in-depth. The work contains a description of the elements that are installed on the route – the number, type and eventually its length. Diploma thesis is introducing the technology and construction sequence of access network leading to its opera-tional state.

A utilização, em sistemas de comunicações ópticas, de formatos de modulação digitais é vista, atualmente, como uma forma promissora de aumentar a eficiência espectral, frente aos diversos efeitos de degradação do sinal em fibra óptica, sem alterar a infraestrutura já implantada. É neste contexto que surge a técnica OFDM (orthogonal frequency division multiplexing) que estabelece sobreposição espectral das subportadoras e, desta forma, permite a transmissão dos dados em forma multiplexada com grande eficiência espectral. No presente trabalho, foi proposta a simulação da técnica OFDM com modulação QAM (quadrature amplitude modulation) no software Optisystem, versões 9.0 e 10.0. O objetivo principal da pesquisa é estudar algumas configurações de sistemas OFDM óptico, com detecção direta e coerente, visando avaliar seu desempenho sistêmico frente a efeitos de propagação. Usando as figuras de mérito BER e diagrama de constelação para estabelecer a meta de ótimo desempenho, analisamos a técnica OFDM com detecção coerente em configurações aplicáveis, principalmente, para redes ópticas de acesso com alcance estendido. Para validação dos resultados, são apresentados também estudos que relacionam as degradações do sinal em fibra óptica e a técnica OFDM. Estes resultados foram comparados com os existentes na literatura, apresentando boa concordância. / The development of digital modulation formats in optical communications systems is considered to be a promising way to increase the spectral efficiency and to combat the effects of signal degradation in optical fiber without changing the infrastructure already deployed. In this context, the technique called OFDM (orthogonal frequency division multiplexing) establishes a particular spectral overlap of the subcarriers, which allows data transmission to be multiplexed with high spectral efficiency. The main objective of the research is to study some configurations of optical OFDM systems with direct detection and coherent in order to evaluate their performance against propagation effects. Using the figures of merit BER and constellation diagram to establish the goal of optimal performance, we analyze the OFDM technique with coherent detection in configurations more applicable for optical access networks with extended reach. To validate the results we also present some studies that relate the degradation of the signal in an optical fiber and the OFDM technique. These results were compared with those described in literature, showing good agreement.

A utilização, em sistemas de comunicações ópticas, de formatos de modulação digitais é vista, atualmente, como uma forma promissora de aumentar a eficiência espectral, frente aos diversos efeitos de degradação do sinal em fibra óptica, sem alterar a infraestrutura já implantada. É neste contexto que surge a técnica OFDM (orthogonal frequency division multiplexing) que estabelece sobreposição espectral das subportadoras e, desta forma, permite a transmissão dos dados em forma multiplexada com grande eficiência espectral. No presente trabalho, foi proposta a simulação da técnica OFDM com modulação QAM (quadrature amplitude modulation) no software Optisystem, versões 9.0 e 10.0. O objetivo principal da pesquisa é estudar algumas configurações de sistemas OFDM óptico, com detecção direta e coerente, visando avaliar seu desempenho sistêmico frente a efeitos de propagação. Usando as figuras de mérito BER e diagrama de constelação para estabelecer a meta de ótimo desempenho, analisamos a técnica OFDM com detecção coerente em configurações aplicáveis, principalmente, para redes ópticas de acesso com alcance estendido. Para validação dos resultados, são apresentados também estudos que relacionam as degradações do sinal em fibra óptica e a técnica OFDM. Estes resultados foram comparados com os existentes na literatura, apresentando boa concordância. / The development of digital modulation formats in optical communications systems is considered to be a promising way to increase the spectral efficiency and to combat the effects of signal degradation in optical fiber without changing the infrastructure already deployed. In this context, the technique called OFDM (orthogonal frequency division multiplexing) establishes a particular spectral overlap of the subcarriers, which allows data transmission to be multiplexed with high spectral efficiency. The main objective of the research is to study some configurations of optical OFDM systems with direct detection and coherent in order to evaluate their performance against propagation effects. Using the figures of merit BER and constellation diagram to establish the goal of optimal performance, we analyze the OFDM technique with coherent detection in configurations more applicable for optical access networks with extended reach. To validate the results we also present some studies that relate the degradation of the signal in an optical fiber and the OFDM technique. These results were compared with those described in literature, showing good agreement.

This master´s thesis explores a comparison of the transmission parameters in time division networks and wavelength division networks. The paper is divided into the three sections. The first part deals with preparation of individual standards time division networks and specific wavelength division networks, along with passive components used passive optical networks. The second part briefly describes the possibility of transmission of television signals in optical networks and the last part is devoted to simulating networks GPON and WDM-PON and comparison simulated values.

The purpose of this master’s thesis is to explain the issues of the FTTx network design. The main idea of this work is to describe to readers the methods of the designing the optical access networks. Especially we will speak about the building technologies and different topologies used in a practice. The different technologies of optical access networks’ building and various parameters, which are necessary to take into account in the designing of these networks, will be introduced. In the theoretical part, methods of measurement, which are like the needed part of each optical access networks’ building, will be described. Two purposes of the FTTB networks with all proprieties will be made and offered. One purpose will be solved by Point to Point topology and the second purpose will be solved by Point to Multipoint topology. Following the confrontation one of these purposes will be chosen and realized. By ITU recommendation, measurements will be performed on the built optical trace. The final protocols will be elaborated from these measurements. The built trace with all final reports will be prepared for assignment to the subscriber.

The objective of diploma thesis is describe problems connected with designed of FTTX networks and bring the reader problems of data transmission in optical acces networks the type of PON. In the introduction are mentinoned individual technologies that already operate, and there are describe advantages disadvantages of the use topology point-to-point and point-to-multipoint. In the following chapters are dealt with problems with data broadcasting in the direction from final participant. In the other part of diploma thesis are described elements, that were used for the proposed transmission route. The own PON acces network was presented on the basis information obtained by comparing the various networks and the elements involved in them. The network presented in conclusion diploma thesis is involved in topology point to multipoint. This transmission route is simulated in the program that allows the involvement of network by the user’s need with real values. The acces network is simulated for different transmission speed and different distances. The assesment of created optical route results from the measured values, theirs source is program OptiSystem, these values are summarized in the final chapter.