Field demonstration of a tunable WDM-PON system with novel SFP+ modules and centralized wavelength control

We report on a demonstration of a novel tunable WDM-PON system over 25km of field deployed fiber. We show error-free operation at 1 GbE with sensitivity better than -30dBm and centralized control of the ONU wavelengths.This work has been supported by the EU ERA-NET+ projects PIANO+ IMPACT and PIANO+ TUCAN co-funded by the German BMBF, the UK Technology Strategy Board and the Austrian FFG. Also support from the UK EPSRC INTERNET project is acknowledged.This is the author accepted manuscript. The final version is available from OAS Publishing via http://dx.doi.org/10.1364/OFC.2015.M2A.

Analog radio over fiber solutions for multi-band 5g systems

This study presents radio over fiber (RoF) solutions for the fifth-generation (5G) of wireless networks. After the state of the art and a technical background review, four main contributions are reported. The first one is proposing and investigating a RoF technique based on a dual-drive Mach-Zehnder modulator (DD-MZM) for multi-band mobile fronthauls, in which two radiofrequency (RF) signals in the predicted 5G bands individually feed an arm of the optical modulator. Experimental results demonstrate the approach enhances the RF interference mitigation and can prevail over traditional methods. The second contribution comprises the integration of a 5G transceiver, previously developed by our group, in a passive optical network (PON) using RoF technology and wavelength division multiplexing (WDM) overlay. The proposed architecture innovates by employing DD-MZM and enables to simultaneously transport baseband and 5G candidate RF signals in the same PON infrastructure. The proof-of-concept includes the transmission of a generalized frequency division multiplexing (GFDM) signal generated by the 5G transceiver in the 700 MHz band, a 26 GHz digitally modulated signal as a millimeter-waves 5G band, and a baseband signal from an gigabit PON (GPON). Experimental results demonstrate the 5G transceiver digital performance when using RoF technology for distributing the GFDM signal, as well as Gbit/s throughput at 26 GHz. The third contribution is the implementation of a flexible-waveform and multi-application fiber-wireless (FiWi) system toward 5G. Such system includes the FiWi transmission of the GFDM and filtered orthogonal frequency division multiplexing (F-OFDM) signals at 788 MHz, toward long-range cells for remote or rural mobile access, as well as the recently launched 5G NR standard in microwave and mm-waves, aiming enhanced mobile broadband indoor and outdoor applications. Digital signal processing (DSP) is used for selecting the waveform and linearizing the RoF link. Experimental results demonstrate the suitability of the proposed solution to address 5G scenarios and requirements, besides the applicability of using existent fiber-to-the-home (FTTH) networks from Internet service providers for implementing 5G systems. Finally, the fourth contribution is the implementation of a multi-band 5G NR system with photonic-assisted RF amplification (PAA). The approach takes advantage of a novel PAA technique, based on RoF technology and four-wave mixing effect, that allows straightforward integration to the transport networks. Experimental results demonstrate iv uniform and stable 15 dB wideband gain for Long Term Evolution (LTE) and three 5G signals, distributed in the frequency range from 780 MHz to 26 GHz and coexisting in the mobile fronthaul. The obtained digital performance has efficiently met the Third-Generation Partnership Project (3GPP) requirements, demonstrating the applicability of the proposed approach for using fiber-optic links to distribute and jointly amplify LTE and 5G signals in the optical domain.Agência 1Este trabalho apresenta soluções de rádio sobre fibra (RoF) para aplicações em redes sem fio de quinta geração (5G), e inclui quatro contribuições principais. A primeira delas refere-se à proposta e investigação de uma técnica de RoF baseada no modulador eletroóptico de braço duplo, dual-drive Mach-Zehnder (DD-MZM), para a transmissão simultânea de sinais de radiofrequência (RF) em bandas previstas para redes 5G. Resultados experimentais demonstram que o uso do DD-MZM favorece a ausência de interferência entre os sinais de RF transmitidos. A segunda contribuição trata da integração de um transceptor de RF, desenvolvido para aplicações 5G e apto a prover a forma de onda conhecida como generalized frequency division multiplexing (GFDM), em uma rede óptica passiva (PON) ao utilizar RoF e multiplexação por divisão de comprimento de onda (WDM). A arquitetura proposta permite transportar, na mesma infraestrutura de rede, sinais em banda base e de radiofrequência nas faixas do espectro candidatas para 5G. A prova de conceito inclui a distribuição conjunta de três tipos de sinais: um sinal GFDM na banda de 700 MHz, proveniente do transceptor desenvolvido; um sinal digital na frequência de 26 GHz, assumindo a faixa de ondas milimétricas; sinais em banda base provenientes de uma PON dedicada ao serviço de Internet. Resultados experimentais demonstram o desempenho do transceptor de RF ao utilizar a referida arquitetura para distribuir sinais GFDM, além de taxas de transmissão de dados da ordem de Gbit/s na faixa de 26 GHz. A terceira contribuição corresponde à implementação de um sistema fibra/rádio potencial para redes 5G, operando inclusive com o padrão ―5G New Radio (5G NR)‖ nas faixas de micro-ondas e ondas milimétricas. Tal sistema é capaz de prover macro células na banda de 700 MHz para aplicações de longo alcance e/ou rurais, utilizando sinais GFDM ou filtered orthogonal frequency division multiplexing (F-OFDM), assim como femto células na banda de 26 GHz, destinada a altas taxas de transmissão de dados para comunicações de curto alcance. Resultados experimentais demonstram a aplicabilidade da solução proposta para redes 5G, além da viabilidade de utilizar redes ópticas pertencentes a provedores de Internet para favorecer sistemas de nova geração. Por fim, a quarta contribuição trata da implementação de um sistema 5G NR multibanda, assistido por amplificação de RF no domínio óptico. Esse sistema faz uso de um novo método de amplificação, baseado no efeito não linear da mistura de quatro ondas, que vi permite integração direta em redes de transporte envolvendo rádio sobre fibra. Resultados experimentais demonstram ganho de RF igual a 15 dB em uma ampla faixa de frequências (700 MHz até 26 GHz), atendendo simultaneamente tecnologias de quarta e quinta geração. O desempenho digital obtido atendeu aos requisitos estabelecidos pela 3GPP (Third-Generation Partnership Project), indicando a aplicabilidade da solução em questão para distribuir e conjuntamente amplificar sinais de RF em enlaces de fibra óptica

WDM/TDM PON bidirectional networks single-fiber/wavelength RSOA-based ONUs layer 1/2 optimization

This Thesis proposes the design and the optimization of a hybrid WDM/TDM PON at the L1 (PHY) and L2 (MAC) layers, in terms of minimum deployment cost and enhanced performance for Greenfield NGPON. The particular case of RSOA-based ONUs and ODN using a single-fibre/single-wavelength is deeply analysed. In this WDM/TDM PON relevant parameters are optimized. Special attention has been given at the main noise impairment in this type of networks: the Rayleigh Backscattering effect, which cannot be prevented. To understand its behaviour and mitigate its effects, a novel mathematical model for the Rayleigh Backscattering in burst mode transmission is presented for the first time, and it has been used to optimize the WDM/TDM RSOA based PON. Also, a cost-effective, simple design SCM WDM/TDM PON with rSOA-based ONU, was optimized and implemented. This prototype was successfully tested showing high performance, robustness, versatility and reliability. So, the system is able to give coverage up to 1280 users at 2.5 Gb/s / 1.25 Gb/s downstream/upstream, over 20 Km, and being compatible with the GPON ITU-T recommendation. This precedent has enabled the SARDANA network to extend the design, architecture and capabilities of a WDM/TDM PON for a long reach metro-access network (100 km). A proposal for an agile Transmission Convergence sub-layer is presented as another relevant contribution of this work. It is based on the optimization of the standards GPON and XG-PON (for compatibility), but applied to a long reach metro-access TDM/WDM PON rSOA-based network with higher client count. Finally, a proposal of physical implementation for the SARDANA layer 2 and possible configurations for SARDANA internetworking, with the metro network and core transport network, are presented

A remodulation scheme for wavelength-division multiplexing passive optical network using time-interleaved differential phase shift keying modulation format.

Li, Pulan.Thesis (M.Phil.)--Chinese University of Hong Kong, 2011.Includes bibliographical references (p. 60-66).Abstracts in English and Chinese.Chapter Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Overview of wavelength division multiplexed passive optical network (WDM-PON) and colorless optical network unit (ONU) --- p.1Chapter 1.2 --- Implementation of colorless ONU --- p.4Chapter 1.3 --- Rayleigh backscattering in WDM-PON --- p.6Chapter 1.4 --- Motivation of this thesis --- p.9Chapter 1.5 --- Outline of this thesis --- p.11Chapter Chapter 2 --- Previous works of remodulation for WDM-PON --- p.12Chapter 2.1 --- Introduction --- p.12Chapter 2.2 --- Devices utilized by colorless ONU in remodulation schemes --- p.13Chapter 2.2.1 --- Injection-locked Fabry-Perot laser diode at ONU --- p.13Chapter 2.2.2 --- Reflective semiconductor optical amplifier --- p.15Chapter 2.2.3 --- Reflective electro-absorption modulator and semiconductor optical amplifier (REAM-SOA) --- p.17Chapter 2.3 --- Modulation methods in remodulation schemes --- p.18Chapter 2.4 --- Summary --- p.23Chapter Chapter 3 --- A remodulation scheme based on time-interleaved DPSK modulation format --- p.25Chapter 3.1 --- Introduction --- p.25Chapter 3.2 --- Operation principle: time-interleaving technology for phase-modulated signal --- p.27Chapter 3.3 --- System architecture --- p.28Chapter 3.4 --- Experimental results and discussion --- p.31Chapter 3.5 --- Effect of timing misalignment on proposed remodulation scheme --- p.33Chapter 3.6 --- Summary --- p.35Chapter Chapter 4 --- Enhanced Tolerance to Rayleigh Backscattering in Remodulation Scheme Using Time-Interleaved DPSK Format --- p.37Chapter 4.1 --- Introduction --- p.37Chapter 4.2 --- Studies on Rayleigh backscattering suppression in optical domain --- p.39Chapter 4.2.1 --- RB suppression in carrier-distributed schemes --- p.39Chapter 4.2.2 --- RB suppression in remodulation schemes --- p.40Chapter 4.2 --- Experimental setup and results --- p.42Chapter 4.3 --- Discussion on RB suppression effect of the proposed scheme --- p.46Chapter 4.3.1 --- Theoretical study and simulation results --- p.46Chapter 4.3.2 --- Experimental demonstration of spectral relationship between signals and RB crosstalk --- p.49Chapter 4.4 --- Summary --- p.53Chapter Chapter 5 --- Conclusion and Future Works --- p.55Chapter 5.1 --- Conclusion of this thesis --- p.55Chapter 5.2 --- Future works --- p.57List of Publications --- p.59Bibliography --- p.6

Digital signal processing waveform aggregation and its experimental demonstration for next generation mobile fronthaul

L'abstract è presente nell'allegato / the abstract is in the attachmen

Dynamically reconfigurable long-reach PONs for high capacity access

Fibre-to-the-Premises (FTTP) is currently seen as the ultimate in high-speed transmission technologies for delivering ubiquitous bandwidth to customers. However, as the deployment of network infrastructure requires a substantial investment, the main obstacle to fibre deployment is that of financial viability. With this in mind, a logical strategy to offset network costs is to optimise the infrastructure in order to capture a greater amount of customers over larger areas with increased sharing of network resources. This approach prompted the design of a long-reach passive optical network (LR-PON) in which the physical reach and split of a conventional PON is significantly increased through the use of intermediate optical amplification. In particular, the LR-PON architecture effectively integrates the metro and access networks enabling the majority of local exchange sites to be bypassed resulting in a substantial reduction in field equipment requirements and power consumption. Furthermore, the extension in physical reach and split can be coupled with an increased information capacity through the use of time- and wavelength division multiplexing (TWDM) which serve to exploit the large bandwidth capabilities offered by single-mode fibre. In this project, reconfigurable TWDM LR-PON architectures which dynamically exploit the wavelength domain are proposed, assembled and characterised in order to establish an economically viable ‘open access’ environment that is capable of concurrently supporting multiple operators offering converged services (residential, business and mobile) to support diverse customer requirements and locations. The main investigations in this work address the key physical layer challenges within such wavelength-agile networks. In particular, a range of experimental analysis has been carried out in order to realise the critical component technologies which include low-cost, 10G-capable, wavelength-tuneable transmitters for mass-market residential deployment and the development of gain-stabilised optical amplifier nodes to support the targeted physical reach (≥ 100km) and split (≥ 512). Finally, the feasibility of the proposed dynamically reconfigurable LR-PON configurations as a flexible and cost-effective solution for future access networks is verified through full-scale network demonstrations using an experimental laboratory test-bed

Optical frequency comb source for next generation access networks

The exponential growth of converged telecommunication services and the increasing demands for video rich multimedia applications have triggered the vast development of optical access technology to resolve the capacity bottleneck at metropolitan-access aggregations. To further enhance overall performance, next generation optical access networks will require highly efficient wavelength division multiplexing (WDM) technology beyond the capability of current standard time division multiplexed (TDM) systems. The successful implementation of future-proof WDM access networks depends on advancements in high performance transmission schemes as well as economical and practical electronic/photonic devices. This thesis focuses on an investigation of the use of optical frequency comb sources, and spectrally efficient modulation formats, in high capacity WDM based optical access networks. A novel injected gain switched comb generation technique which deliver simplicity, reliability, and cost effectiveness has been proposed and verified through experimental work. In addition, a detailed characterization of the optical comb source has been undertaken with special attention on the phase noise property of the comb lines. The potential of the injected gain switched comb source is then demonstrated in a digital coherent receiver based long reach WDM access scenario, which intends to facilitate 10 - 40 Gbit/s data delivery per channel . Furthermore, an optical scalar transmission scheme enabling the direct detection of higher order modulation format signals has been proposed and experimentally investigated

Wavelength reconfigurability for next generation optical access networks

Next generation optical access networks should not only increase the capacity but also be able to redistribute the capacity on the fly in order to manage larger variations in traffic patterns. Wavelength reconfigurability is the instrument to enable such capability of network-wide bandwidth redistribution since it allows dynamic sharing of both wavelengths and timeslots in WDM-TDM optical access networks. However, reconfigurability typically requires tunable lasers and tunable filters at the user side, resulting in cost-prohibitive optical network units (ONU). In this dissertation, I propose a novel concept named cyclic-linked flexibility to address the cost-prohibitive problem. By using the cyclic-linked flexibility, the ONU needs to switch only within a subset of two pre-planned wavelengths, however, the cyclic-linked structure of wavelengths allows free bandwidth to be shifted to any wavelength by a rearrangement process. Rearrangement algorithm are developed to demonstrate that the cyclic-linked flexibility performs close to the fully flexible network in terms of blocking probability, packet delay, and packet loss. Furthermore, the evaluation shows that the rearrangement process has a minimum impact to in-service ONUs. To realize the cyclic-linked flexibility, a family of four physical architectures is proposed. PRO-Access architecture is suitable for new deployments and disruptive upgrades in which the network reach is not longer than 20 km. WCL-Access architecture is suitable for metro-access merger with the reach up to 100 km. PSB-Access architecture is suitable to implement directly on power-splitter-based PON deployments, which allows coexistence with current technologies. The cyclically-linked protection architecture can be used with current and future PON standards when network protection is required