Reconfigurable remote nodes for hybrid passive optical networks

Mestrado em Engenharia Electrónica e TelecomunicaçõesO presente documento tem por objectivo demonstrar, analisar e optimizar nós remotos passivos para redes ópticas passivas baseadas numa topologia de anel de dupla fibra com multiplexagem no comprimento de onda onde estão penduradas árvores mono fibra baseadas na multiplexagem no tempo. A rede ‘Scalable Advanced Ring-based passive Dense Access Network Architecture’ (SARDANA) baseada nesta topologia é apresentada e demonstrada. Na rede SARDANA a interligação entre o anel e as árvores é realizada pelo intermédio de um nó especial denominado de nó remoto. Esse nó remoto é um elemento fundamental para o funcionamento, resiliência e escalabilidade da rede. Neste documento são apresentadas e comparadas diferentes topologias para a implementação desse nó remoto. É também apresentada a reconfigurabilidade remota desses mesmos nós remotos através de módulos de conversão energética e controlo, implementada nos nós remotos. Um factor importante para a optimização dos nós remotos é a amplificação remota realizada por intermédio de fibras dopadas de érbio pelo que o seu estudo é também apresentado. Finalmente é demonstrado um protótipo de um nó remotamente reconfigurado e eficiente. ABSTRACT: The objective of this document is to demonstrate, analyze and optimize remote nodes for passive optical networks based on double fiber ring multiplexed in wavelength connected to single fiber trees multiplexed in time. The network ‘Scalable Advanced Ring-based passive Dense Access Network Architecture’ (SARDANA) based on this topology is presented and demonstrated. In the SARDANA network the interconnection between the ring and the trees is done by means of a special node, the remote node. This node is a fundamental element to the operation, resiliency and scalability of the network. This document presents and compares different topologies to the implementation of the remote node. Remotely reconfigurability of the remote nodes is also demonstrated by means of optical conversion and control modules. An important factor to the optimization of the remote nodes is the remote amplification done by means of erbium doped fibers being presented the analysis of the amplifier. Finally is demonstrated a prototype of a node remotely reconfigured and efficient

Schemes for building an efficient all-optical virtual private network.

by Tam Scott Kin Lun.Thesis submitted in: October 2005.Thesis (M.Phil.)--Chinese University of Hong Kong, 2006.Includes bibliographical references (leaves 58-64).Abstracts in English and Chinese.Chapter 1. --- Introduction --- p.1Chapter 1.1. --- Optical Networks --- p.1Chapter 1.1.1. --- IP over Optical Networks --- p.1Chapter 1.1.2. --- Challenges in Optical Networks --- p.4Chapter 1.2. --- Virtual Private Networks (VPN) --- p.5Chapter 1.2.1. --- CE Based VPN --- p.6Chapter 1.2.2. --- Network Based VPN --- p.7Chapter 1.2.2.1. --- MPLS Layer 2 VPN --- p.8Chapter 1.2.2.2. --- MPLS Layer 3 VPN --- p.9Chapter 1.2.3. --- Optical VPN --- p.9Chapter 1.2.4. --- Challenges in VPN Technologies --- p.11Chapter 1.3. --- Objective of this Thesis --- p.11Chapter 1.4. --- Outline of this Thesis --- p.12Chapter 2. --- Architecture of an All-Optical VPN --- p.13Chapter 2.1. --- Introduction --- p.13Chapter 2.2. --- Networking Vendor Activities --- p.13Chapter 2.3. --- Service Provider Activities --- p.15Chapter 2.4. --- Standard Bodies Activities --- p.16Chapter 2.5. --- Requirements for All-Optical VPN --- p.17Chapter 2.6. --- Reconfigurability of an All-Optical VPN --- p.19Chapter 2.7. --- Switching Methods in All-Optical VPN --- p.20Chapter 2.8. --- Survivability of an All-Optical VPN --- p.23Chapter 3. --- Maximizing the Utilization Of A Survivable Multi-Ring WDM Network --- p.25Chapter 3.1. --- Introduction --- p.25Chapter 3.2. --- Background --- p.25Chapter 3.3. --- Method --- p.26Chapter 3.3.1. --- Effect on packet based services --- p.28Chapter 3.3.2. --- Effect on optical circuit based services --- p.28Chapter 3.4. --- Simulation results --- p.29Chapter 3.5. --- Chapter Summary --- p.36Chapter 4. --- Design of an All-Optical VPN Processing Engine --- p.37Chapter 4.1. --- Introduction --- p.37Chapter 4.2. --- Concepts of Optical Processors --- p.38Chapter 4.3. --- Design Principles of the All-Optical VPN Processing Engine --- p.40Chapter 4.3.1. --- Systolic System --- p.41Chapter 4.3.2. --- Design Considerations of an Optical Processing Cell --- p.42Chapter 4.3.2.1. --- Mach-Zehnder Structures --- p.43Chapter 4.3.2.2. --- Vertical Cavity Semiconductor Optical Amplifier --- p.43Chapter 4.3.2.3. --- The Optical Processing Cell --- p.44Chapter 4.3.3. --- All-Optical VPN Processing Engine --- p.47Chapter 4.4. --- Design Evaluation --- p.49Chapter 4.5. --- Application Example --- p.50Chapter 4.6. --- Chapter Summary --- p.54Chapter 5. --- Conclusion --- p.55Chapter 5.1. --- Summary of the Thesis --- p.55Chapter 5.2. --- Future Works --- p.56Chapter 6. --- References --- p.5

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

Design of survivable WDM network based on pre-configured protection cycle

Wavelength Division Multiplexing (WDM) is an important technique which allows the trans- port of large quantities of data over optical networks. All optical WDM-based networks have been used to improve overall communication capacity and provide an excellent choice for the design of backbone networks. However, due to the high traffic load that each link can carry in a WDM network, survivability against failures becomes very important. Survivability in this context is the ability of the network to maintain continuity of service against failures, since a failure can lead to huge data losses. In recent years, many survivability mechanisms have been studied and their performance assessed through capacity efficiency, restoration time and restorability. Survivability mechanisms for ring and mesh topologies have received particular attention