Showing papers by "Mike J. O'Mahony published in 2006"

Future Optical Networks

Abstract: This paper presents views on the future of optical networking. A historical look at the emergence of optical networking is first taken, followed by a discussion on the drivers pushing for a new and pervasive network, which is based on photonics and can satisfy the needs of a broadening base of residential, business, and scientific users. Regional plans and targets for optical networking are reviewed to understand which current approaches are judged important. Today, two thrusts are driving separate optical network infrastructure models, namely 1) the need by nations to provide a ubiquitous network infrastructure to support all the future services and telecommunication needs of residential and business users and 2) increasing demands by the scientific community for networks to support their requirements with respect to large-scale data transport and processing. This paper discusses these network models together with the key enabling technologies currently being considered for future implementation, including optical circuit, burst and packet switching, and optical code-division multiplexing. Critical subsystem functionalities are also reviewed. The discussion considers how these separate models might eventually merge to form a global optical network infrastructure

A view on enabling-consumer oriented grids through optical burst switching

Abstract: As grid computing continues to gain popularity in the research community, it also attracts more attention from the enterprise and consumer levels. Applications in these domains generate large amounts of jobs, with individual jobs having only modest resource requirements. In this article, a novel architecture to realize a highly scalable and flexible platform for consumer-oriented grids is proposed. The architecture is based on an optical burst switched network, complemented with an advanced control and signaling plane. The architecture, functionality, and interfaces of all the relevant entities are presented and issues, current initiatives, and future directions for the control and management of these grid networks are discussed.

Waveband converters based on four-wave mixing in SOAs

Abstract: Four wave mixing (FWM) is distinguished from other wavelength conversion techniques by its ability to simultaneously convert a number of input wavelength channels. In this case, optical signal-to-noise ratio (OSNR) is insufficient to describe the performance of the device as many effects are involved. A multiwavelength FWM model is used here to simulate a waveband converter (WBC). The numerical model predicts the waveform of the FWM product. Based on that output, the Q factor of the signal and the power penalty induced to the signal can be calculated to evaluate the performance of such a device. Meanwhile, an analytical model is used for the calculation of the signal power levels and the standard deviation of the fluctuation; hence, it describes the constituent effects-namely, the extinction ratio (ER) degradation, the OSNR degradation, the gain modulation (GM) related crosstalk, and interference. The model's validity is tested against the numerical results. To the best of the authors' knowledge, this is the first time that a numerical model and an analytical model are used to systematically investigate a WBC and to identify the specific effects and derive the design rules. These rules are tested in the experiment. Finally, a tunable WBC (TWBC) based on the dual-pump configuration is described and implemented experimentally

Dynamic behavior of wavelength converters based on FWM in SOAs

Abstract: As wavelength converters based on four-wave mixing (FWM) in semiconductor optical amplifiers (SOAs) attract more attention, dynamic effects and wavelength dependent performance become key aspects to be investigated. Such issues are particularly important, as complex configurations are likely to be used to overcome challenges like tunability and polarization dependence. In this paper a numerical model is used to predict the dynamic performance of three FWM configurations and an analytical model is used to derive design rules. First, the wavelength dependent behavior of a wavelength converter is investigated and the requirement for a widely tunable converter is identified. Secondly, a configuration for extinction ratio (ER) improvement is studied and novel design rules are obtained analytically, tested experimentally and explained by the numerical model; experimental results with ER improvement at 10 Gb/s were achieved for the first time. The third configuration studied is a dual-pump arrangement enabling wide tunability. Fixed input/tunable output and tunable input/fixed output configurations are discussed in terms of optical signal-to-noise ratio and tunability. Design rules are extracted and verified for all three configurations that are likely to be deployed: simple wavelength converters, regenerating converters and tunable wavelength converters.

QoS-aware ingress optical grid user network interface: high-speed ingress OBS node design and implementation

Abstract: This paper presents a novel transport technique implemented by an optical grid user network interface. Wire speed electronic processing that classifies grid-IP traffic and maps it to optical burst is demonstrated.

Single-layer multigranular optical cross-connect architecture with conversion capability and enhanced flexibility

Abstract: Feature Issue on Waveband Switching, Routing, and GroomingThe rapid advances in WDM technology are expected to bring about tremendous growth in the size of optical cross connects (OXCs). In this context, multigranular OXCs (MG-OXCs) have been suggested as a means of reducing the amount of equipment required. Here we expand the concept of MG-OXCs to include optical packet granularity and review the key building blocks for the advent of MG-OXCs. A single-layer MG-OXC is suggested that offers enhanced flexibility with respect to other single-layer concepts, conversion capability, and good physical performance. Concatenation performance is analytically investigated.

Demonstration of a complete and fully functional end-to-end asynchronous optical packet switched network

Abstract: A fully functional optical packet switched network able to transport variable length and asynchronous optical packets is demonstrated. This includes packet switching, label recognition and rewriting, fast laser tuning, wavelength conversion, optical packet transceiver functionality.

Demonstration of an Application-aware Hybrid Optical Burst/Circuit Switched Ingress Edge Router for Future Optical Networks

Abstract: This paper demonstrates an application-aware optical burst/circuit switched ingress router able to map IP traffic into optical bursts or optical circuits. The solution utilises a fast widely tuneable laser and a high speed hardware platform.

Applications of Ultra-Short Pulse Sources in OTDM Networks

Abstract: Novel all-optical and high-speed time-multiplexed space (TMS) switch architectures can be realised with the use of ultra-short pulse sources and ultra-fast all-optical wavelength converters. Example architectures, which only require low speed electronics, are outlined. Experimental results from an associated time-slot interchange architecture demonstrate error-free performance at 40 Gbit/s. The proposed architectures can be used in a WDM/OTDM optical cross-connect node, able to switch circuits in space, wavelength, and time.

FWM wavelength conversion with pump suppression

Abstract: A novel scheme that significantly improves the performance of FWM wavelength conversion is proposed and demonstrated. The scheme offers substantial pump suppression and OSNR improvement and intended for ultra-fast wavelength routing and packet switching applications.

An All-Optical Time-Slot Interchange Architecture

Abstract: A novel, bit-rate scaleable and transparent Time-Slot Interchange architecture is proposed and experimental results demonstrate error-free performance at 40Gbit/s. The proposed architecture can be used in an OTDM-based optical cross-connect node.