Optical Burst Switching in WDM Ring Networks

Optical Burst Switching (OBS) is being envisaged as the next generation switching tech-nology to transmit Internet traffic directly over WDM networks with a fine granularity between Optical Circuit Switching (OCS) and Optical Packet Switching (OPS). It has higher bandwidth-efficiency than OCS. OBS is usually characterized by burstification, burst header packet (BHP) generation and data burst (DB) transmission. The burst header packet is transmitted first by the source to the destination followed by the data burst. Each intermediate node processes the header electronically so that the data burst corre-sponding to that BHP is transparently switched without requiring any O/E/O conversion. This unique feature of OBS requires a strict coordination between DB and BHP and thereby making it a challenging task. OBS has been implemented in WDM ring networks for FT-TR (Fixed tuned Transmitter and Tunable Receiver) systems and TT-FR (Tunable Transmitter and Fixed tuned Receiver) systems. In FT-TR systems, the number of chan-nel and destination collisions is higher whereas there is no source collision due to the fixed tuned nature of the transmitter. In TT-FR systems the number of channel collisions is large as multiple nodes communicate using the same channel but there is no destination collision. In this work I have implemented OBS in WDM ring networks for TT-TR (Tunable Transmitter and Tunable Receiver) systems. It has been shown that the pro-posed protocol is free from source and channel collisions, as well as reduces destination collision to a greater extent. The tunable transmitter and tunable receiver node architec-ture has been described. We compared the performance of TT-TR system with that of TT-FR system with respect to number of packets lost, average queuing delay and average propagation delay. It is found that the proposed protocol is more effective in avoiding collisions than the TT-FR

A tunable-channel multi-access wavelength division multiplexed network and surveillance schemes for optical cross-connects.

by Eddie Ting Pong Kong.Thesis (M.Phil.)--Chinese University of Hong Kong, 1999.Includes bibliographical references (leaves 61-68).Abstracts in English and Chinese.Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Optical Network Architecture --- p.1Chapter 1.2 --- High-Speed All-Optical Tunable-Channel Multi-Access Networks --- p.3Chapter 1.3 --- Fault Surveillance of Optical Cross-Connects in Wavelength Routing Network --- p.3Chapter 1.4 --- Outline of the Thesis --- p.5Chapter 2 --- Optical Multi-Access Networks --- p.6Chapter 2.1 --- All-Optical Networks --- p.6Chapter 2.2 --- Optical Multi-Access Schemes --- p.8Chapter 2.2.1 --- Wavelength-Division Multi-Access (WDMA) --- p.9Chapter 2.2.2 --- Time-Division Multi-Access (TDMA) --- p.12Chapter 2.2.3 --- Subcarrier Multi-Access (SCMA) --- p.14Chapter 2.3 --- Design Considerations --- p.14Chapter 3 --- All-Optical Tunable-Channel Multi-Access Networks --- p.18Chapter 3.1 --- Tunable-Channel Multi-Access Networks --- p.19Chapter 3.2 --- Protocols for TCMA Networks --- p.20Chapter 3.3 --- Photonic Implementation of a Wavelength Division TCMA Network with Time- Slot Access --- p.23Chapter 3.3.1 --- Proposed Network Architecture --- p.25Chapter 3.3.2 --- Experimental Results --- p.30Chapter 3.3.3 --- Discussion --- p.34Chapter 3.3.4 --- Summary --- p.35Chapter 4 --- Fault Surveillance for Optical Cross-Connects in Wavelength Routing Networks --- p.36Chapter 4.1 --- Wavelength Routing Networks --- p.37Chapter 4.2 --- Options in Fault Surveillance --- p.39Chapter 4.3 --- Optical Path Surveillance of Optical Cross-Connects in Wavelength Routing Networks --- p.41Chapter 4.3.1 --- Scanning Amplified Spontaneous Emission Identification Surveillance Scheme --- p.43Chapter 4.3.2 --- Pilot-Tone Based Surveillance and Removal Scheme --- p.49Chapter 4.4 --- Summary --- p.55Chapter 5 --- Conclusion --- p.57Chapter 5.1 --- Summary of the Thesis --- p.57Chapter 5.2 --- Future Work --- p.60Bibliography --- p.61Publication List --- p.5

Software Defined Applications in Cellular and Optical Networks

abstract: Small wireless cells have the potential to overcome bottlenecks in wireless access through the sharing of spectrum resources. A novel access backhaul network architecture based on a Smart Gateway (Sm-GW) between the small cell base stations, e.g., LTE eNBs, and the conventional backhaul gateways, e.g., LTE Servicing/Packet Gateways (S/P-GWs) has been introduced to address the bottleneck. The Sm-GW flexibly schedules uplink transmissions for the eNBs. Based on software defined networking (SDN) a management mechanism that allows multiple operator to flexibly inter-operate via multiple Sm-GWs with a multitude of small cells has been proposed. This dissertation also comprehensively survey the studies that examine the SDN paradigm in optical networks. Along with the PHY functional split improvements, the performance of Distributed Converged Cable Access Platform (DCCAP) in the cable architectures especially for the Remote-PHY and Remote-MACPHY nodes has been evaluated. In the PHY functional split, in addition to the re-use of infrastructure with a common FFT module for multiple technologies, a novel cross functional split interaction to cache the repetitive QAM symbols across time at the remote node to reduce the transmission rate requirement of the fronthaul link has been proposed.Dissertation/ThesisDoctoral Dissertation Electrical Engineering 201

Channel-tunable mode-locked laser transmitter for OTDM networks and modeling of mode-locked semiconductor laser.

by Hung Wai.Thesis (M.Phil.)--Chinese University of Hong Kong, 2000.Includes bibliographical references (leaves 69-[73]).Abstracts in English and Chinese.Chapter 1 --- Introduction --- p.1Chapter 1.1 --- All Optical Multi-Access Network --- p.1Chapter 1.2 --- Multi-access Techniques --- p.2Chapter 1.2.1 --- Wavelength-Division Multi-access (WDMA) --- p.2Chapter 1.2.2 --- Subcarrier Multi-Access (SCMA) --- p.3Chapter 1.2.3 --- Time-Division Multi-Access(TDMA) --- p.3Chapter 1.3 --- Numerical Modelling of Semiconductor Mode-locked laser --- p.4Chapter 1.4 --- Objective of this Thesis --- p.5Chapter 2 --- Optical TDMA networks --- p.7Chapter 2.1 --- Introduction --- p.7Chapter 2.2 --- OTDM --- p.8Chapter 2.3 --- Network Architecture --- p.9Chapter 2.3.1 --- Broadcast Networks --- p.9Chapter 2.3.2 --- Switch-based networks --- p.10Chapter 2.4 --- Key technologies for optical TDMA Network --- p.13Chapter 2.4.1 --- High Repetition Rate Short Pulse sources --- p.13Chapter 2.4.2 --- Multiplexer and de-multiplexers --- p.15Chapter 2.4.3 --- Optical Clock Recovery --- p.17Chapter 2.4.4 --- All optical logic gates --- p.18Chapter 2.5 --- Summary --- p.19Chapter 3 --- A Channel-Tunable Mode-locked Laser Transmitter for OTDM Networks --- p.20Chapter 3.1 --- Introduction --- p.20Chapter 3.2 --- Principle of Operation --- p.21Chapter 3.3 --- Experimental Demonstration --- p.23Chapter 3.4 --- The Channel Tuning Transient --- p.25Chapter 3.5 --- Experimental Investigation of channel-tuning transient --- p.28Chapter 3.6 --- Summary --- p.37Chapter 4 --- Modeling of Mode-Locked Semiconductor Laser --- p.38Chapter 4.1 --- Introduction --- p.38Chapter 4.2 --- Principle of Mode-Locking --- p.39Chapter 4.3 --- Simulation Model --- p.41Chapter 4.3.1 --- Travelling Wave Rate Equation Analysis --- p.41Chapter 4.3.2 --- Large Signal Time Domain Mode-locked Laser Model --- p.42Chapter 4.3.3 --- Modeling of Spontaneous Noise --- p.44Chapter 4.3.4 --- Modeling of Self-phase Modulation --- p.44Chapter 4.3.5 --- Frequency Dependent Gain Profile --- p.45Chapter 4.3.6 --- Computation Procedure --- p.45Chapter 4.4 --- Device Parameters --- p.47Chapter 4.5 --- Simulation Results on Passive Mode-locking --- p.48Chapter 4.5.1 --- Pulse Repetition Rate under Passive Mode-locking --- p.48Chapter 4.5.2 --- The effect of Differential Gain and Differential Absorption on Mode-locking Regimes --- p.50Chapter 4.5.3 --- The Effects of Linewidth Enhancement Factor and Ab- sorber Carrier Lifetime on Mode-locking Pulse Width --- p.53Chapter 4.6 --- Simulation Results on Hybrid and Subharmonic Mode-locking --- p.54Chapter 4.6.1 --- Modeling the Effect of Modulation on Absorber Section --- p.54Chapter 4.6.2 --- Modulation Phase Change Dynamics --- p.55Chapter 4.6.3 --- Subharmonc Mode-Locking Induced Amplitude Modulation --- p.62Chapter 4.7 --- Summary --- p.64Chapter 5 --- Conclusion --- p.66Chapter 5.1 --- Summary of the Thesis --- p.66Chapter 5.2 --- Future Work --- p.67Bibliography --- p.6

NASA Tech Briefs, March 2001

Topics include: Data Acuisition; Test and Measurement; Electronic components and Systems; Software; Materials

The Fifteenth Marcel Grossmann Meeting

The three volumes of the proceedings of MG15 give a broad view of all aspects of gravitational physics and astrophysics, from mathematical issues to recent observations and experiments. The scientific program of the meeting included 40 morning plenary talks over 6 days, 5 evening popular talks and nearly 100 parallel sessions on 71 topics spread over 4 afternoons. These proceedings are a representative sample of the very many oral and poster presentations made at the meeting.Part A contains plenary and review articles and the contributions from some parallel sessions, while Parts B and C consist of those from the remaining parallel sessions. The contents range from the mathematical foundations of classical and quantum gravitational theories including recent developments in string theory, to precision tests of general relativity including progress towards the detection of gravitational waves, and from supernova cosmology to relativistic astrophysics, including topics such as gamma ray bursts, black hole physics both in our galaxy and in active galactic nuclei in other galaxies, and neutron star, pulsar and white dwarf astrophysics. Parallel sessions touch on dark matter, neutrinos, X-ray sources, astrophysical black holes, neutron stars, white dwarfs, binary systems, radiative transfer, accretion disks, quasars, gamma ray bursts, supernovas, alternative gravitational theories, perturbations of collapsed objects, analog models, black hole thermodynamics, numerical relativity, gravitational lensing, large scale structure, observational cosmology, early universe models and cosmic microwave background anisotropies, inhomogeneous cosmology, inflation, global structure, singularities, chaos, Einstein-Maxwell systems, wormholes, exact solutions of Einstein's equations, gravitational waves, gravitational wave detectors and data analysis, precision gravitational measurements, quantum gravity and loop quantum gravity, quantum cosmology, strings and branes, self-gravitating systems, gamma ray astronomy, cosmic rays and the history of general relativity

The Fifteenth Marcel Grossmann Meeting

The three volumes of the proceedings of MG15 give a broad view of all aspects of gravitational physics and astrophysics, from mathematical issues to recent observations and experiments. The scientific program of the meeting included 40 morning plenary talks over 6 days, 5 evening popular talks and nearly 100 parallel sessions on 71 topics spread over 4 afternoons. These proceedings are a representative sample of the very many oral and poster presentations made at the meeting.Part A contains plenary and review articles and the contributions from some parallel sessions, while Parts B and C consist of those from the remaining parallel sessions. The contents range from the mathematical foundations of classical and quantum gravitational theories including recent developments in string theory, to precision tests of general relativity including progress towards the detection of gravitational waves, and from supernova cosmology to relativistic astrophysics, including topics such as gamma ray bursts, black hole physics both in our galaxy and in active galactic nuclei in other galaxies, and neutron star, pulsar and white dwarf astrophysics. Parallel sessions touch on dark matter, neutrinos, X-ray sources, astrophysical black holes, neutron stars, white dwarfs, binary systems, radiative transfer, accretion disks, quasars, gamma ray bursts, supernovas, alternative gravitational theories, perturbations of collapsed objects, analog models, black hole thermodynamics, numerical relativity, gravitational lensing, large scale structure, observational cosmology, early universe models and cosmic microwave background anisotropies, inhomogeneous cosmology, inflation, global structure, singularities, chaos, Einstein-Maxwell systems, wormholes, exact solutions of Einstein's equations, gravitational waves, gravitational wave detectors and data analysis, precision gravitational measurements, quantum gravity and loop quantum gravity, quantum cosmology, strings and branes, self-gravitating systems, gamma ray astronomy, cosmic rays and the history of general relativity