Optimal design of 32 channels spectrum slicing WDM for optical fiber access network system

In this article, the spectrum sliced dense wavelength division multiplexed passive optical network (SS-DWDM–PON) has been investigated as a power efficient and cost effective solution for optical access networks. In this work an AWG demultiplexer is used to operate as slicing system. The high speed SS-DWDM system has been realized and investigated for 32 channels with data rate up to 3 Gb/s using broadband ASE source (LED). The 3 Gb/s signals both non-return-to-zero (NRZ) and return-to-zero (RZ) were demonstrated in 40 km optical fiber link with BER < 10−12. The results obtained here demonstrate that SS-DWDM is well suited for Fiber-to-the-Home (FTTH) network

Multistage WDM access architecture employing cascaded AWGs

Here we propose passive/active arrayed waveguide gratings (AWGs) with enhanced performance for system applications mainly in novel access architectures employing cascaded AWG technology. Two technologies were considered to achieve space wavelength switching in these networks. Firstly, a passive AWG with semiconductor optical amplifiers array, and secondly, an active AWG. Active AWG is an AWG with an array of phase modulators on its arrayed-waveguides section, where a programmable linear phase-profile or a phase hologram is applied across the arrayed-waveguide section. This results in a wavelength shift at the output section of the AWG. These architectures can address up to 6912 customers employing only 24 wavelengths, coarsely separated by 1.6 nm. Simulation results obtained here demonstrate that cascaded AWGs access architectures have a great potential in future local area

Self-Seeded RSOA-Fiber Cavity Lasers vs. ASE Spectrum-Sliced or Externally Seeded Transmitters—A Comparative Study

Reflective semiconductor optical amplifier fiber cavity lasers (RSOA-FCLs) are appealing, colorless, self-seeded, self-tuning and cost-efficient upstream transmitters. They are of interest for wavelength division multiplexed passive optical networks (WDM-PONs) based links. In this paper, we compare RSOA-FCLs with alternative colorless sources, namely the amplified spontaneous emission (ASE) spectrum-sliced and the externally seeded RSOAs. We compare the differences in output power, signal-to-noise ratio (SNR), relative intensity noise (RIN), frequency response and transmission characteristics of these three sources. It is shown that an RSOA-FCL offers a higher output power over an ASE spectrum-sliced source with SNR, RIN and frequency response characteristics halfway between an ASE spectrum-sliced and a more expensive externally seeded RSOA. The results show that the RSOA-FCL is a cost-efficient WDM-PON upstream source, borrowing simplicity and cost-efficiency from ASE spectrum slicing with characteristics that are, in many instances, good enough to perform short-haul transmission. To substantiate our statement and to quantitatively compare the potential of the three schemes, we perform data transmission experiments at 5 and 10 Gbit/s

Switching Equipment Location/Allocation in hybrid PONs

Our research goal is to investigate the FTTX (Fiber-to-the Home/Premises/Curb) passive optical network (PON) for the deployment of BISAN (Broadband Internet Subscriber Access Network) to exploit the opportunities of optical fiber enabled technologies as well as of passive switching equipment. Indeed, the deployment of FTTX PON is the most OPEX-friendly scenario, because it allows for completely passive access networks through minimizing the number of active components in the network. Previously, most FTTX PON architectures are designed based on the principle of either time division multiplexing (TDM) technology or wavelength division multiplexing (WDM) technology. We focus on designing the best possible architectures of FTTX PON, specifically hybrid PONs, which embraces both TDM and WDM technology. A hybrid PON architecture is very efficient as it is not limited to any specific PON technology, rather it is flexible enough to deploy TDM/WDM technology depending on the type (i.e unicast/multicast) and amount of traffic demand of the end-users. The advantages of a hybrid PON are of two folds: (i) it can offer increased data rate to each user by employing WDM technology, (ii) it can provide flexible bandwidth utilization by employing TDM technology. In this thesis, we concentrate on determining the optimized covering of a geographical area by a set of cost-effective hybrid PONs. We also focus on the greenfield deployment of a single hybrid PON. It should be worthy to mention that while investigating the deployment of hybrid PONs, the research community around the world considers the specifications of either the physical layer or the optical layer. But an efficient planning for PON deployment should take into account the constraints of the physical and optical layers in order that both layers can work together harmoniously. We concentrate our research on the network dimensioning and the selection as well as the placement of the switching equipment in hybrid PONs with the intention of considering the constraints of both physical and optical layers. We determine the layout of an optimized PON architecture while provisioning wavelengths in a hybrid PON. We also propose to select the switching equipment depending on the type (unicast/multicast) of traffic demand. Finally, we determine the best set of hybrid PONs along with their cascading architecture, type and location of their switching equipment while satisfying the network design constraints such as the number of output ports of the switching equipment and maximum allowed signal power loss experienced at each end user’s premises. In this thesis, we propose two novel schemes for the greenfield deployment of a single hybrid PON. The first scheme consists of two phases in which a heuristic algorithm and a novel column generation (CG) based integer linear programming (ILP) optimization model are proposed in the 1st and 2nd phase respectively. In the second scheme, a novel integrated CG based ILP cross layer optimization model is proposed for the designing of a single hybrid PON. We also propose two novel schemes to deal with the greenfield deployment of multiple hybrid PONs in a given geographical area. These two schemes determine the best set of cost-effective hybrid PONs in order to serve all the end users in a given neighborhood. The first scheme executes in four phases in which two heuristic algorithms, a CG based ILP model and an ILP optimization model are proposed in the 1st, 2nd, 3rd and 4th phase respectively. In the second scheme, an ILP model as well as a CG based ILP model, another ILP model as well as another CG based ILP model, a CG based ILP model and an ILP optimization model are proposed during four consecutive phases. Our proposed scheme can optimize the design of a set of hybrid PONs covering a given geographic area as well as the selection of the best cascading architecture 1/2/mixedstage) for each selected PON. It minimizes the overall network deployment cost based on the location of the OLT and the ONUs while granting all traffic demands. The scheme emphasizes on the optimum placement of equipment in a hybrid PON infrastructure due to the critical dependency between the network performances and a proper deployment of its equipment, which, in turn depends on the locations of the users. It is a quite powerful scheme as it can handle data instances with up to several thousands ONUs. On the basis of the computational results, the proposed scheme leads to an efficient automated tool for network design, planning, and performance evaluation which can be beneficial for the network designers

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

Protection architectures for multi-wavelength optical networks.

by Lee Chi Man.Thesis (M.Phil.)--Chinese University of Hong Kong, 2004.Includes bibliographical references (leaves 63-65).Abstracts in English and Chinese.Chapter CHAPTER 1 --- INTRODUCTION --- p.5Chapter 1.1 --- Background --- p.5Chapter 1.1.1 --- Backbone network - Long haul mesh network problem --- p.5Chapter 1.1.2 --- Access network ´ؤ Last mile problems --- p.8Chapter 1.1.3 --- Network integration --- p.9Chapter 1.2 --- SUMMARY OF INSIGHTS --- p.10Chapter 1.3 --- Contribution of this thesis --- p.11Chapter 1.4 --- Structure of the thesis --- p.11Chapter CHAPTER 2 --- PREVIOUS PROTECTION ARCHITECTURES --- p.12Chapter 2.1 --- Introduction --- p.12Chapter 2.2 --- Traditional physical protection architectures in metro area --- p.13Chapter 2.2.1 --- Self healing ring --- p.17Chapter 2.2.2 --- Some terminology in ring protection --- p.13Chapter 2.2.3 --- Unidirectional path-switched rings (UPSR) [17] --- p.13Chapter 2.2.4 --- Bidirectional line-switched rings (BLSR) [17] --- p.14Chapter 2.2.5 --- Ring interconnection and dual homing [17] --- p.16Chapter 2.3 --- Traditional physical protection architectures in access networks --- p.17Chapter 2.3.1 --- Basic architecture in passive optical networks --- p.17Chapter 2.3.2 --- Fault management issue in access networks --- p.18Chapter 2.3.3 --- Some protection architectures --- p.18Chapter 2.4 --- Recent protection architectures on a ccess networks --- p.21Chapter 2.4.1 --- Star-Ring-Bus architecture --- p.21Chapter 2.5 --- Concluding remarks --- p.22Chapter CHAPTER 3 --- GROUP PROTECTION ARCHITECTURE (GPA) FOR TRAFFIC RESTORATION IN MULTI- WAVELENGTH PASSIVE OPTICAL NETWORKS --- p.23Chapter 3.1 --- Background --- p.23Chapter 3.2 --- Organization of Chapter 3 --- p.24Chapter 3.3 --- Overview of Group Protection Architecture --- p.24Chapter 3.3.1 --- Network architecture --- p.24Chapter 3.3.2 --- Wavelength assignment --- p.25Chapter 3.3.3 --- Normal operation of the scheme --- p.25Chapter 3.3.4 --- Protection mechanism --- p.26Chapter 3.4 --- Enhanced GPA architecture --- p.27Chapter 3.4.1 --- Network architecture --- p.27Chapter 3.4.2 --- Wavelength assignment --- p.28Chapter 3.4.3 --- Realization of network elements --- p.28Chapter 3.4.3.1 --- Optical line terminal (OLT) --- p.28Chapter 3.4.3.2 --- Remote node (RN) --- p.29Chapter 3.4.3.3 --- Realization of optical network unit (ONU) --- p.30Chapter 3.4.4 --- Protection switching and restoration --- p.31Chapter 3.4.5 --- Experimental demonstration --- p.31Chapter 3.5 --- Conclusion --- p.33Chapter CHAPTER 4 --- A NOVEL CONE PROTECTION ARCHITECTURE (CPA) SCHEME FOR WDM PASSIVE OPTICAL ACCESS NETWORKS --- p.35Chapter 4.1 --- Introduction --- p.35Chapter 4.2 --- Single-side Cone Protection Architecture (SS-CPA) --- p.36Chapter 4.2.1 --- Network topology of SS-CPA --- p.36Chapter 4.2.2 --- Wavelength assignment of SS-CPA --- p.36Chapter 4.2.3 --- Realization of remote node --- p.37Chapter 4.2.4 --- Realization of optical network unit --- p.39Chapter 4.2.5 --- Two types of failures --- p.40Chapter 4.2.6 --- Protection mechanism against failure --- p.40Chapter 4.2.6.1 --- Multi-failures of type I failure --- p.40Chapter 4.2.6.2 --- Type II failure --- p.40Chapter 4.2.7 --- Experimental demonstration --- p.41Chapter 4.2.8 --- Power budget --- p.42Chapter 4.2.9 --- Protection capability analysis --- p.42Chapter 4.2.10 --- Non-fully-connected case and its extensibility for addition --- p.42Chapter 4.2.11 --- Scalability --- p.43Chapter 4.2.12 --- Summary --- p.43Chapter 4.3 --- Comparison between GPA and SS-CPA scheme --- p.43Chapter 4.1 --- Resources comparison --- p.43Chapter 4.2 --- Protection capability comparison --- p.44Chapter 4.4 --- Concluding remarks --- p.45Chapter CHAPTER 5 --- MUL 77- WA VELENGTH MUL TICAST NETWORK IN PASSIVE OPTICAL NETWORK --- p.46Chapter 5.1 --- Introduction --- p.46Chapter 5.2 --- Organization of this chapter --- p.47Chapter 5.3 --- Simple Group Multicast Network (SGMN) scheme --- p.47Chapter 5.3.1 --- Network design principle --- p.47Chapter 5.3.2 --- Wavelength assignment of SGMN --- p.48Chapter 5.3.3 --- Realization of remote node --- p.49Chapter 5.3.3 --- Realization of optical network unit --- p.50Chapter 5.3.4 --- Power budget --- p.51Chapter 5.4 --- A mulTI- wa velength a ccess network with reconfigurable multicast …… --- p.51Chapter 5.4.1 --- Motivation --- p.51Chapter 5.4.2 --- Background --- p.51Chapter 5.4.3 --- Network design principle --- p.52Chapter 5.4.4 --- Wavelength assignment --- p.52Chapter 5.4.5 --- Remote Node design --- p.53Chapter 5.4.6 --- Optical network unit design --- p.54Chapter 5.4.7 --- Multicast connection pattern --- p.55Chapter 5.4.8 --- Multicast group selection in OLT --- p.57Chapter 5.4.9 --- Scalability --- p.57Chapter 5.4.10 --- Experimental configuration --- p.58Chapter 5.4.11 --- Concluding remarks --- p.59Chapter CHAPTER 6 --- CONCLUSIONS --- p.60LIST OF PUBLICATIONS: --- p.62REFERENCES: --- p.6