Design and cost performance of WDM pons for multi-wavelength users

Die rasante Verbreitung des Internet führt zu einem steigenden Bedarf an höheren Bitraten in Telekommunikationsnetzwerken. Dieser kann derzeit nur mit optischen Netzwerken erfüllt werden, insbesondere mit der Wellen¬längen¬multiplex-Technik (WDM). Viele Forschungsergebnisse weisen darauf hin, dass WDM Passive Optische Netzwerke (PON) die nächste Generation der optischen Zugangsnetze darstellen. Die Wellenlängenmultiplex-Technik beruht darauf, dass mehrere optische Kanäle mit niedrigen Bitraten über eine Faser übertragen werden und so ein WDM Signal mit hoher Bitrate erzeugen. Ziel dieser Arbeit ist die Identifizierung von neuen Architekturen, welche jedem Benutzer und jedem Dienst mindestens eine Wellenlänge zur Verfügung stellen. Neue Methoden und Modelle zur Berechnung von ein- und mehrstufigen WDM PONs werden eingeführt. Um alle technologisch realisierbaren ein- und mehrstufigen WDM PONs zu berechnen und zu analysieren wurde ein Design Tool entwickelt. Für einen flächendeckenden kommerziellen Einsatz reicht es nicht aus, funktionierende Technologien anzubieten, vielmehr müssen ökonomische Über¬legungen miteinbezogen werden. Diese Arbeit ermöglicht einen Vergleich unterschiedlicher Architekturen hinsichtlich ihrer Wirtschaftlichkeit und zielt darauf ab, jene Architekturen zu identifizieren, welche kostenoptimal sind. Neue kosten¬optimale Netzwerk-Architekturen führen zu einer schnelleren Marktpenetration und dazu, Fiber-to-the-Home (FTTH) Realität werden zu lassen.Due to the incomparable popularity of the Internet, the already enormous and still rocketing bandwidth demand may only be satisfied by optical networks, particularly by using the Wavelength Division Multiplexing (WDM) technology. In many research labs, WDM Passive Optical Networks (PON) access networks are considered as the next generation optical access. To obtain WDM signals with high bit rates, multiple channels operating at a lower transmission speed can be supported on a single optical fiber. The subject of this thesis will be engineering new cutting edge architectures offering each user and service at least one wavelength. New techniques and models are introduced to design single and multistage WDM PONs. A design tool was implemented to analyze all technologically feasible single and multistage WDM PON architectures. During real deployments, the technology has worked but the economic factors have proven to be too costly. Thus, it is important to examine these economic aspects. The objective is to identify those architectures that minimize costs. Access to these newly identified network architectures will prompt market introduction as well as market penetration helping Fiber-to-the-Home (FTTH) to become reality

REAM intensity modulator-enabled 10Gb/s colorless upstream transmission of real-time optical OFDM signals in a single-fiber-based bidirectional PON architecture

Reflective electro-absorption modulation-intensity modulators (REAM-IMs) are utilized, for the first time, to experimentally demonstrate colorless ONUs in single-fiber-based, bidirectional, intensity-modulation and direct-detection (IMDD), optical OFDM PONs (OOFDM-PONs) incorporating 25km SSMFs and OLT-side-seeded CW optical signals. The colorlessness of the REAM-IMs is characterized, based on which optimum REAM-IM operating conditions are identified. In the aforementioned PON architecture, 10Gb/s colorless upstream transmissions of end-to-end realtime OOFDM signals are successfully achieved for various wavelengths within the entire C-band. Over such a wavelength window, corresponding minimum received optical powers at the FEC limit vary in a range as small as <0.5dB. In addition, experimental measurements also indicate that Rayleigh backscattering imposes a 2.8dB optical power penalty on the 10Gb/s over 25km upstream OOFDM signal transmission. Furthermore, making use of on-line adaptive bit and power loading, a linear trade-off between aggregated signal line rate and optical power budget is observed, which shows that, for the present PON system, a 10% reduction in signal line rate can improve the optical power budget by 2.6dB. © 2012 Optical Society of America

Subsystems for future access networks

Current evolution and tendencies of Telecom Networks in general and more specifically optical Metro and Access Networks and their convergence are reported. Based on this evolution, a set of research lines are foreseen regarding subsystems and devices as: high speed optical sources, modulators and receivers, for the next generation of Passive Optical Networks. The ICT project EURO-FOS is achieving European level cooperative research among academia and industry, enabling future telecommunication networks