Efficient T-CONT-agnostic Bandwidth and Wavelength Allocation for NG-PON2

Dynamic bandwidth and wavelength allocation are used to demonstrate high quality of service (QoS) in time wavelength-division multiplexed–passive optical networks (TWDM-PONs). Both bandwidth and wavelength assignment are performed on the basis of transmission containers (T-CONTs) and therefore by means of upstream service priority traffic flows. Our medium access control (MAC) protocol therefore ensures consistency in processing alike classes of service across all optical network units (ONUs) in agreement with their QoS figures. For evaluation of the MAC protocol performance, a simulator has been implemented in OPNET featuring a 40 km, 40 Gbps TWDM-PON with four stacked wavelengths at 10 Gbps each and 256 ONUs. Simulation results have confirmed the efficiency of allocating bandwidth to each wavelength and the significant increase of network traffic flow due to adaptive polling from 9.04 to 9.74 Gbps. The benefit of T-CONT-centric allocation has also been measured with respect to packet delay and queue occupancy, achieving low packet delay across all T-CONTs. Therefore, improved NG-PON2 performance and greater efficiency are obtained in this first demonstration of T-CONTs allocated to both wavelength and time.Peer reviewe

Evolutionary optical framework - NG-PON2: controlo e sincronização de ONUs via ICTP (Inter- Channel-Termination Protocol)

The study of new technologies with the potential to support high transfer rates is important to respond to the constant evolution of Internet information consumption. The Next-Generation Passive Optical Networks (NG-PON) tries to overcome this obstacle. The most recent one, NG-PON2, uses several channels in the same fiber to transmit and receive data, considerably increasing the bandwidth of a single fiber. This new form of communication has introduced a new problem, the exchange of information between these channels with a minimum of disturbances on the network. The Inter-Channel-Termination Protocol (ICTP) was presented to certify that this communication is done correctly in a multi-operator environment. Based on a pre-built environment with the cooperative use of Gigabit PON (GPON) and NG-PON2 technologies, a system with similar characteristics to those of a real scenario was developed. In this system, two ICTP use cases were implemented and, for each one, two events were tested. The results obtained showed the possibility of being used in a real scenario, without failures and with small delays.O estudo de novas tecnologias com potencial para suportar taxas de transferência elevadas é importante para dar resposta à constante evolução do consumo de informação da Internet. As Redes Óticas Passivas de Próxima Geração (NG-PON) vêm tentar ultrapassar este obstáculo. A mais recente, NGPON2, utiliza vários canais na mesma fibra para transmitir e receber dados, aumentando consideravelmente a largura de banda de uma única fibra. Esta nova forma de comunicação veio a introduzir um novo problema: a troca de informação entre estes canais com o mínimo de distúrbios na rede. O Protocolo Inter-Channel-Termination (ICTP) foi apresentado para certificar que esta comunicação é feita corretamente num ambiente de vários operadores. Baseado num ambiente pré-construído com o uso simultâneo das tecnologias Gigabit PON (GPON) e NG-PON2, foi desenvolvido um sistema com características semelhantes às de um cenário real. Neste sistema, foram implementados dois casos de uso do ICTP e, para cada um, testaram-se dois eventos. Os resultados obtidos mostraram a possibilidade de serem usados num cenário real, sem falhas e com atrasos reduzidos.Mestrado em Engenharia de Computadores e Telemátic

Spectrally efficient and low cost time and wavelength division multiplexed passive optical network systems

The next-generation passive optical network stage 2 (NG-PON2) intends to support stacking 10 Gb/s wavelengths and maintaining the compatibility with the deployed legacy passive optical network (PON) systems. Essentially, Time and Wavelength Division Multiplexed-PON (TWDM-PON) is the best solution for NGPON2 that aims to support a symmetric 40 Gb/s data rate transmission, a split ratio of 1:64 and a distance up to 60 km. Unfortunately, most of the existing low cost and practical TWDM-PON solutions are still incapable to support remote users and inefficient for spectral bandwidth in higher services. Typically, low cost transceivers are avoided as they suffer from significant frequency chirp that seriously impact its transmission performance at the bit rate above 10 Gb/s. Therefore, the objectives of this thesis are to improve the current TWDM-PON power budget in supporting more access services reaching the remote customers to enhance the bandwidth capacity at lower cost and to reduce the complexity implementation problem. This is achieved by overcoming the significant frequency chirp of the low cost transceivers used such as reflective semiconductor optical amplifier (RSOA) and directly modulated lasers (DMLs), which are suitable for high data rate transmission. The RSOA chirp is mitigated using a single bi-pass delay interferometer (DI) at the optical line terminal (OLT) while the DML chirp is managed by ensuring its resulting current is in phase with the bandwidth enhancement factor, , at both optical network unit (ONU) and OLT. Apart from that, DML equipped with dispersion compensation fiber (DCF) technique for power budget improvement is also proposed. Furthermore, low cost schemes for even higher data rate TWDM-PON up to 56 Gb/s is proposed utilizing highly spectral efficient 16-quadrature amplitude modulation (16-QAM). The results are obtained from physical layer simulation, OptisystemTrademark and MatlabTrademark, where relevant significant parts are verified through theoretical analysis. The simulation results demonstrate a sufficient dispersion compensation with a record of 56.6 dB power bughet for DML-based TWDM-PON transmission system. While results are not absolute due to variations that can occur in practical implementation, analysis demonstrates the feasibility of the proposed methods

Sistemas de calibração automático para transceivers NG-PON2

The current society is increasingly dependent on communication services, requiring better and faster connections, predicting in a near future connections in the order of hundreds of Gbit/s. During the data transmissions, the increase of speed reflects an increase of the error ratio due to factors such as noise, reductions of signal or jitter, which for low speed these were not emphasized so much. This project involves the development of a BER test system for both continuous and Burst mode of the transmission, demonstrating the viability of communication over the next-generation technology, NG-PON2, which uses high transmission rates (10 Gbit/s). For this purpose, an FPGA architecture was implemented that allows for long distances in the optical network, high transmission rates. This choice reflects a more economical alternative in relation to commercial equipment and has several advantages, such as the flexibility to reprogram and prepare the architecture according to the needs of the user. To achieve the proposed requirements, the project was divided into three parts. In the first part an architecture was developed that allows to obtain the error rate during a continuous mode transmission. In order to obtain the real-time viability of the communication referred and to have control over the system, an interface was developed between the computer and the FPGA to change certain characteristics of the communication channel. This is the second part of the project. The last part of the project has an architecture similar to the previous one, that is, instead of the transmission to be done in continuous mode, it is performed in mode Burst, being this the requirement with more interest to the technology NG-PON2. Finally, proof of concept was performed through an optical network provided by the company PICadvanced that allowed the validation of the different parts of the project. These validations will allow the development of new modules that will later contribute to the main project that is under development in the company PICadvanced, which aims at the construction of an automatic calibration board for the XFP transceivers.A sociedade atual depende cada vez mais dos serviços de comunicação, exigindo melhores ligações e mais rápidas, prevendo-se num futuro próximo a necessidade de ligações na ordem das centenas de Gbit/s. O aumento dos ritmos de transmissão refletem um aumento no que se refere à taxa de erro (BER), uma vez que o impacto associado a fatores como ruı́do ou interferência entre sı́mbolos, é maior do que para baixos ritmos. Este trabalho foca-se no desenvolvimento de um sistema de teste BER, tanto para uma transmissão contı́nua como para transmissão em rajadas, que demonstre a viabilidade da comunicação sobre a tecnologia da próxima geração, Next Generation Passive Optical Network 2 (NG-PON2), que utiliza débitos de transmissão elevados (10 Gbit/s). Para este efeito foi implementado uma arquitetura em Field-programmable gate array (FPGA) que possibilita para longas distâncias na rede ótica, elevados ritmos de transmissão. Esta escolha reflete uma alterativa mais económica em relação aos equipamentos comerciais e apresenta vantagens tais como a flexibilidade de reprogramar e preparar a arquitetura de acordo com as necessidades do utilizador. Para cumprir os requisitos propostos o projeto dividiu-se em três partes. Numa primeira parte do projeto desenvolveu-se uma arquitetura que permite adquirir a taxa de erros durante uma transmissão contı́nua. Com o intuito de analisar a viabilidade em tempo real da comunicação em questão, bem com o utilizador ter controlo sobre o sistema, alterando certas caracterı́sticas do canal de comunicação, desenvolveu-se numa segunda parte do projeto uma interface entre o computador e a FPGA. Numa última parte do projeto desenvolveu-se uma arquitetura semelhante à anterior, na qual se permite igualmente adquirir a taxa de erros com transmissão em rajadas (Burst), sendo este um dos requisitos de maior interesse na tecnologia NG-PON2. Por fim, a prova de conceito foi realizada através de uma rede ótica disponibilizada pela empresa PICadvanced, que permitiu a validação das diversas partes do projeto. Estas validações vão permitir a conceção de novos módulos que posteriormente vão contribuir para o projeto fonte que está em desenvolvimento na empresa PICadvanced, que visa a implementação de uma placa de calibração automatizada para os transceptores 10 Gigabit Small Form Factor Pluggables (XFP).Mestrado em Engenharia Eletrónica e Telecomunicaçõe

Enhanced WDM-OFDM-PON System Based on Higher Data Transmitted with Modulation Technique

ABSTRACT:- Studies among the field communication system existing technique and proposes and by experimentation demonstrate a multiuser wavelengthdivision-multiplexing passive optical network (WDM-PON) system combining with orthogonal frequency division multiple (OFDM) technique. A tunable multiwavelength optical comb is intended to provide flat optical lines for helping the configuration of the multiple source-free optical network units WDM-OFDM-PON system supported normal single-mode fiber (SSMF). In WDM based on fiber, optical network communications using wavelength with multiplex or demultiplex may be a technology that multiplexes a variety of optical carrier signals onto one fiber by victimization completely different wavelengths of optical device lightweight. this system allows bidirectional communications over one strand of fiber, also as multiplication of capability and calculate BER (Bit Error Rate) and OSNR (optical signal noise ratio) finally; a comparison of by experimentation achieved receiver sensitivities and transmission distances victimization these receivers is given. The very best spectral potency and longest transmission distance at the very best bit rate. WDM based applications like transmission data, medical imaging data, and digital audio data and video conferencing data are information measure-intensive with the Advance in optical technology providing verdant bandwidth, it's natural to increase the multicast construct to optical networks so as to realize increased performance. Our projected scheme (PGA) based on information load transmitted capability improve supported higher information transmitted over these channels and high data up to develop in Matlab tool and using optical Interleaved the OFDM model and analysis the performance of the WDM-PON system

Symmetric 80 Gbps Next Generation Passive Optical Network Stage Two NG-PON2

In this research, a design of a symmetric 80 Gbps Passive Optical Network that meets the requirements of Next Generation Passive Optical Network Stage Two (NG-PON2) is proposed. According to The Full-Service Access Network (FSAN), The Time and Wave Length Division Multiplexing (TWDM) is chosen as the best solution to implement NG-PON2. TWDM network of NG-PON2 can be implemented in many wavelength plans to replace or co-exist with previous PON technologies. The proposed design was simulated taking into consideration the practical parameters of existing systems, the results shows that the system is reliable for implementation for 80 Gbps bitrate utilizing 8 pairs of wavelengths transmitted over 40 Km and distributed and received by 128 users with acceptable data rate

Directly Phase Modulated Transmitters and Coherent Recivers for Future Passive Optical Networks (PON)

En los últimos años, el tráfico de dato transmitido en las redes ópticas de acceso ha crecido exponencialmente debido a nuevos servicios como pueden ser la computación en la nube, el video online, la realidad virtual y aumentada, el internet de las cosas (IoT) y la convergencia entre las redes ópticas y redes inalámbricas en el paradigma del 5G. Estos nuevos servicios endurecen los requerimientos de las redes ópticas de acceso, como pueden ser unas tasas de datos más altas, un mayor alcance y un mayor número de usuarios. Para abordar estos requerimientos, esta tesis ha investigado, desarrollado y analizado nuevas tecnologías para transmisores y receptores orientadas a los dos tipos de redes ópticas de acceso que la comunidad científica ha identificado como posibles candidatas. Estos dos tipos de redes ópticas son las redes uDWDM y las redes TWDM como las redes NG-PON2 y sus evoluciones.Las redes uDWDM están basadas en la transmisión de tasas de datos relativamente bajas, por debajo de 2.5 Gbps, que son dedicadas en su totalidad a los usuarios finales. Estas tasas de datos relativamente bajas son multiplexadas en longitud de onda usando intervalos frecuenciales estrechos, del orden de 12.5 GHz o 6.25 GHz. En esta tesis, los transmisores modulados directamente en fase se han propuesto como posibles candidatos para estas redes uDWDM. En concreto, se han propuesto un DFB modulado directamente en fase con una tasa de datos de 1 Gbps; un RSOA bombeado por un VCSEL y modulado directamente en fase con una tasa de datos de 1 Gbps; y un VCSEL modulado directamente en fase con una tasa de datos de 1.25 Gbps y 2.5 Gbps. Estas señales moduladas directamente en fase son recibidas con un receptor heterodino con un único fotodiodo (PD) para mantener el coste tan bajo como sea posible. La combinación de estos transmisores modulados directamente en fase con el receptor heterodino con un único PD ha sido probada como unos candidatos muy prometedores para las redes ópticas de acceso basadas en redes uDWDM. Estas combinaciones proveen sensibilidades que varían entre -39.5 dBm y -52 dBm, que se traducen en balances de potencia que van desde 38.5 dB a 51 dB y por lo tanto en ratios de división o número de usuarios de entre 128 y 1024 después de una transmisión de 50 km a través de fibra monomodo estándar (SSMF).Además, los links de 1 Gbps formados por la modulación directa de DFBs o de RSOAs bombeados por VCSELs y el receptor heterodino con un único PD son usados como enlace de subida en canales bidireccionales. Estos enlaces de subida son combinados con enlaces de bajada basados en Nyquist-DPSK generada con un MZM y recibidos con un receptor heterodino de un único PD. Como parte de análisis de los canales bidireccionales, se ha analizado el estudio de la viabilidad del uso de LOs de bajo coste, como DFBs o VCSELs, en los receptores heterodinos con un único PD. Estos canales bidireccionales son también unos candidatos prometedores para las futuras redes uDWDM, ya que en esta tesis se ha probado que pueden proveer enlaces full-duplex de 1 Gbps usando intervalos frecuenciales tan pequeños como 6.25 GHz o 5 GHz. Estos canales bidireccionales tienen balances de potencia que van desde 37 dB a 42 dB y tienen posibles ratios de división de 128 o 256 después de una transmisión de 50 km a través de SSMF.Esta tesis también ha investigado y desarrollado receptores quasicoherentes para redes NG-PON2 y sus evoluciones. Este tipo de redes están basadas en altas tasas de datos, como 10 Gbps para redes NG-PON2 y 25 Gbps para las futuras evoluciones de NG-PON2, en entornos multi longitud de onda donde los usuarios son multiplexados en tiempo y longitud de onda (TWDM). El receptor quasicoherente usa la amplificación coherente gracias a la recepción heterodina y por tanto la sensibilidad del receptor es mejorada en comparación con los esquemas de detección directa. El receptor quasicoherente es independiente a la polarización, lo cual es una característica importante para los receptores coherentes. Además, el receptor quasicoherente permite seleccionar el canal de trabajo sin la necesidad de filtros ópticos y es un receptor independiente de la longitud de onda debido a que el canal de trabajo se puede elegir ajustando la longitud de onda del LO. El receptor quasicoherente de 10 Gbps muestra una sensibilidad -35.2 dBm y por tanto permite un balance de potencias de 35.64 dB y un ratio de división de 128 después de una transmisión de 40 km a través de SSMF.La combinación del receptor quasicoherente con un ecualizador FFE/DFE permite combatir la dispersión cromática de la banda C y conseguir un link de 25 Gbps con un alcance de 20 km a través de SSMF. El receptor quasicoherente a 25 Gbps con ecualización FFE/DFE muestra una mejor sensibilidad de -30.5 dBm con el llamado ecualizador de altas prestaciones, lo que lleva a un balance de potencias de25 dB. Si se utilizada el llamado ecualizador de baja complejidad, la sensibilidad cae a -27 dBm y el balance de potencias cae a 23 dBm. En ambos casos, el receptor quasicoherente a 25 Gbps con ecualización FFE/DFE permite un ratio de división de 32 después de una transmisión de 20 km a través de SSMF.En conclusión, esta tesis ha presentado transmisores (DFB, RSOA y VCSEL) modulados directamente en fase combinados con un receptor heterodino con un único PD como potenciales candidatos para las redes uDWDM. Esta tesis también ha presentados los receptores quasicoherentes como unos candidatos muy prometedores para las redes NG-PON2 y sus futuras evoluciones.<br /

Transceivers para TWDM-PON

Mestrado em Engenharia Eletrónica e TelecomunicaçõesIn recent years, Internet has been assuming a fundamental role in everyday life. Traffic demands are increasing in such a way that the available technologies will presumably no longer satisfy the raised requirements. For the last years, operators have expressed a clear interest in the implementation and development of Passive Optical Network (PON) to provide several services and applications to a high flow rate per client. Comparing to other access technologies, PON is very attractive mainly due to reduction of maintenance and to the operational cost efficiency. As a consequence, PON systems were standardized and developed in the whole world, but the everincreasing bandwidth demand makes this type of network need to evolve. Therefore, the current standardized technologies Gigacapable PON and XG-PON need to be upgraded to Next-Generation PON2. In order to protect the initial investment and to reduce the operational costs, operators should keep the current optical distribution network, providing the technologies coexistence in the same fiber. The principle of NG-PON2 is to improve previous technologies, in terms of capacity, ODN compatibility, bandwidth and cost-efficiency. In April 2012, Full Service Access Network (FSAN) selected the time and wavelength multiplexing PON (TWDM-PON) technology as the solution of choice for NG-PON2. Almost one year later, ITU-T G.989.1 came out, providing some wavelength plans proposals. The ability to operate on existing fiber ODN, coexisting with legacy PON is the most important requirement. The current dissertation is based on the study of TWDM-PON upstream transmission. Both GPON and XG-PON work in burst mode for upstream direction, therefore in the current study also that type of data transmission is considered for upstream TWDM-PON. Once using this transmission mode, some parameters have to be taken into consideration, as the packets size and their separation length in order to understand which frame fits the best, considering the system performance. In the actual study, it was supposed to visualize transients in each packet, however it was experimentally proved that once the lifetime of the carriers is less than the burst time, it was not possible to identify any of them. It was also verified that increasing the guard time will decrease the performance of the system.A Internet tem vindo a assumir um papel fundamental no quotidiano de cada utilizador. A largura de banda exigida é cada vez mais alta, desta forma, as tecnologias actualmente disponíveis acabarão por deixar de satisfazer os requisitos emergentes. Nos últimos anos, as operadoras têm manifestado um interesse evidente no desenvolvimento de Redes Ópticas Passivas (PON), com o intuito de fornecer vários serviços e aplicações a uma taxa de fluxo elevada por cliente. Comparando com outras tecnologias de acesso, as redes PON são muito actrativas devido à sua baixa manutenção e aos custos/eficiência de operação. Como consequência, os sistemas PON foram padronizados e desenvolvidos em todo o mundo. No entanto, este tipo de tecnologia necessita de progredir ao longo do tempo, mantendo a satisfação dos requisitos de tráfego que lhe serão impostos. Assim, as tecnologias actualmente implementadas: GPON e XG-PON, necessitam de sofrer um upgrade para NG-PON2 (Next- Generation PON 2). De modo a proteger o investimento inicial, reduzindo os custos de operação, as operadoras devem manter e reutilizer a ODN já implementada, possibilitando a coexistência das tecnologias na mesma fibra. NG-PON2 é uma melhoria da capacidade, da compatibilidade na ODN, largura de banda e custo-eficiência das tecnologias anteriores. Em Abril de 2012, a FSAN selecionou a tecnologia TWDM-PON (Time and Wavelength Division Multiplexing PON) como solução do projecto NG-PON2. Um ano após a sua seleção, a norma ITU-T G.989.1 foi publicada, propondo alguns planos de comprimentos de onda. A coexistência de TWDM-PON com as PON anteriores na mesma ODN é o requisite mais importante. A presente dissertação baseia-se no estudo de transmissão upstream de TWDM-PON. Ambos GPON e XG-PON operam em modo burst para a direção upstream. Uma vez utilizao este modo de transmissão, é necessário considerer determinados parâmetros como o tempo de separação interburst – guard time, tal como o comprimento de cada pacote, com o intuito de compreender o impacto da variação destes mesmos campos no desempenho do sistema. No presente estudo, era susposto visualizar transientes em cada pacote de transmissão, no entanto foi comprovado experimentalmente, que uma vez que o tempo de vida dos portadores do EDFA selecionado é menor que o intervalo de cada burst, não se identificaram transientes. Verificou-se também que, o aumento da separação interburst degrada o desempenho do sistema

Transmission Convergence Layer of NG-PON2 in VPIphotonics Tool

Passive optical networks are the most promising solution for access networks. The first standard provided only 155 Mbit/s but current networks work according to ITU-T G.984.3 with 2.5 Gbit/s in downstream. However, NG-PON2 offers up to 40 Gbit/s in downstream by 4 different wavelengths. This article deals with an implementation of transmission convergence layer in VPIphotonics. This tool is dedicated only for simulations of physical layer. The main aim is to present a simulation of physical layer for NG-PON2 in comparison with our implementation of transmission convergence layer and encapsulated frames according to ITU-T G.989.3. Our results confirm expanding the entire system reach with the real encapsulation method of 3 sublayers model and error correction mechanism. The 3 sublayers model can be easily extended to all passive optical networks simulations in VPIphotonics simulation tool