Layered switch architectures for high-capacity optical transport networks

Cataloged from PDF version of article.We propose and analyze layered switch architectures that possess high design flexibility, greatly reduced switch size, and high expandability. The improvement in loss and crosstalk due to the reduced switch size is also discussed. Theoretical models have been developed to compute the network blocking probability using these architectures. Low blocking probability and high network utilization are achieved because of the capability of communication between layers in adjacent switches. The results show that the proposed layered switch architectures are very attractive for high-capacity optical transport networks

Cross-Layer Platform for Dynamic, Energy-Efficient Optical Networks

The design of the next-generation Internet infrastructure is driven by the need to sustain the massive growth in bandwidth demands. Novel, energy-efficient, optical networking technologies and architectures are required to effectively meet the stringent performance requirements with low cost and ultrahigh energy efficiencies. In this thesis, a cross-layer communications platform is proposed to enable greater intelligence and functionality on the physical layer. Providing the optical layer with advanced networking capabilities will facilitate the dynamic management and optimization of optical switching based on performance monitoring measurements and higher-layer attributes. The cross-layer platform aims to create a new framework for networks to incorporate packet-scale measurement subsystems and techniques for monitoring the health of the optical channel. This will allow for quality-of-service- and energy-aware routing schemes, as well as an enhanced awareness of the optical data signals. This thesis first presents the design and development of an optical packet switching fabric. Leveraging a networking test-bed environment to validate networking hypotheses, advanced switching functionalities are demonstrated, including the support for quality-of-service based routing and packet multicasting. The investigated cross-layering is based on emerging optical technologies, enabling packet protection techniques and packet-rate switching fabric reconfiguration. Coupled with fast performance monitoring, the platform will achieve significant performance gains within the endeavor of all-optical switching. Allowing for a more intelligent, programmable optical layer aims to support greater flexibility with respect to bandwidth allocation and potentially a significant reduction in the network's energy consumption. The ultimate deliverable of this work is a high-performance, cross-layer enabled optical network node. The experimental demonstration of an initial prototype creates a dynamic network element with distributed control plane management, featuring fast packet-rate optical switching capabilities and embedded physical-layer performance monitoring modules. The cross-layer box enables an intelligent traffic delivery system that can dynamically manipulate optical switching on a packet-granular scale. With the goal of achieving advanced multi-layer routing and control algorithms, the network node requires an intelligent co-optimization across all the layers. The proposed cross-layer design should drive optical technologies and architectures in an innovative way, in order to fulfill the void between the design of basic photonic devices and the networking protocols that use them. The performance of the entire network -- from the optical components, to the routing algorithms and user applications -- should be optimized in concert. This contribution to the area of cross-layer network design creates an adaptable optical pipe that is extremely flexible and intelligent aware of both the physical optical signals and higher-layer requirements. The impact of this work will be seen in the realization of dynamic, energy-efficient optical communication links in future networking infrastructures

Wavelength conversion in optical packet switching

A detailed traffic analysis of optical packet switch design is performed. Special consideration is given to the complexity of the optical buffering and the overall switch block structure is considered in general. Wavelength converters are shown to improve the traffic performance of the switch blocks for both random and bursty traffic. Furthermore, the traffic performance of switch blocks with add--drop sports has been assessed in a Shufflenetwork showing the advantage of having converters at the inlets. Finally, the aspect of synchronization is discussed through a proposal to operate the packet switch block asynchronously, i.e., without packet alignment at the input

Design, protocol and routing algorithms for survivable all-optical networks.

by Hui Chi Chun Ronald.Thesis submitted in: December 1998.Thesis (M.Phil.)--Chinese University of Hong Kong, 1999.Includes bibliographical references (leaves 62-66).Abstract also in Chinese.Chapter Chapter 1. --- Introduction --- p.1Chapter Chapter 2. --- AON Architecture --- p.7Chapter 2.1 --- WCC Dimension Reduction Node Architecture --- p.10Chapter 2.2 --- Restoration of a Survivable AON --- p.13Chapter Chapter 3. --- Network Dimensioning Problem --- p.15Chapter 3.1 --- Problem Setting --- p.16Chapter 3.2 --- Two Solution Approaches --- p.16Chapter 3.2.1 --- Minimum Variance Algorithm (MVA) --- p.17Chapter 3.2.2 --- Minimum Variance Subroutine (MVS) --- p.19Chapter 3.3 --- Shortest Path Algorithm (SPA) --- p.21Chapter 3.4 --- An Illustrative Example --- p.22Chapter 3.5 --- Performance Comparisons --- p.26Chapter Chapter 4. --- Network Management for AON Restoration --- p.31Chapter 4.1 --- Surveillance Network --- p.31Chapter 4.2 --- Signaling Network --- p.32Chapter 4.3 --- Network Management System --- p.32Chapter 4.4 --- CCS7 Adaptation for Supporting AON Restoration --- p.34Chapter Chapter 5. --- Complete Restoration Algorithm for AON --- p.40Chapter 5.1 --- Link-Based Restoration Algorithm --- p.43Chapter 5.2 --- Source-Based Restoration Algorithm --- p.44Chapter 5.3 --- Case Studies --- p.45Chapter 5.3.1 --- Case I and II --- p.45Chapter 5.3.2 --- Case III --- p.50Chapter 5.4 --- Completely Restorable Network planning --- p.52Chapter 5.5 --- A Summary on Problem Formulations --- p.55Chapter Chapter 6. --- Conclusion --- p.57Reference --- p.6

Performance of WDM transport networks

Wavelength division multiplexed point-to-point transport is becoming commonplace in wide area networks. With the expectation that the next step is end-to-end networking of wavelengths (in the optical domain without conversion to electronics), there is a need for new design techniques, a new understanding of the performance issues, and a new performance evaluation methodology in such networks. This paper describes approaches to that end, summarizes research results, and points to open problems

In situ method for power re-equalization of wavelength pulses inside of OCDMA codes

A simple in-situ method to equalize power among individual wavelengths pulses representing two-dimensional wavelength-hopping time-spreading OCDMA code originally generated by a fibre Bragg grating-based OCDMA encoder is presented. Experimental data obtained in a field-based multiuser OCDMA testbed shows that applying this method results in system performance enhancements which was demonstrated by observing improved bit error rate (BER) during the field trials