Blocking performance of tree establishment in time-space switched optical networks

Multicasting in the optical layer has gained significant importance in the recent years due to several factors. Most of the research work in this area concentrate either on minimizing the number of wavelengths required to meet a given static demand or on multicast route selection algorithms to achieve efficient utilization of fiber bandwidth. Very few significant research has been found, to the best of authors\u27 knowledge, in developing an analytical model for evaluating the blocking performance of tree establishment in optical networks, which motivates this research. In this paper, an analytical model for evaluating the blocking performance of multicast tree establishment in time-space switched optical networks is developed. The performance of different switch architectures are then studied using the analytical model. it is observed that if the multicast tree has very low degree of branching, the blocking probability of establishing the tree is the same as that of establishing a path with same number of links

Design of Routers for Optical Burst Switched Networks

Optical Burst Switching (OBS) is an experimental network technology that enables the construction of very high capacity routers using optical data paths and electronic control. In this dissertation, we study the design of network components that are needed to build an OBS network. Specifically, we study the design of the switches that form the optical data path through the network. An OBS network that switches data across wavelength channels requires wave-length converting switches to construct an OBS router. We study one particular design of wavelength converting switches that uses tunable lasers and wavelength grating routers. This design is interesting because wavelength grating routers are passive devices and are much less complex and hence less expensive than optical crossbars. We show how the routing problem for these switches can be formulated as a combinatorial puzzle or game, in which the design of the game board determines key performance characteristics of the switch. In this disertation, we use this formu-lation to facilitate the design of switches and associated routing strategies with good performance. We then introduce time sliced optical burst switching (TSOBS), a variant of OBS that switches data in the time domain rather that the wavelength domain. This eliminates the need for wavelength converters, the largest single cost component of systems that switch in the wavelength domain. We study the performance of TSOBS networks and discuss various design issues. One of the main components that is needed to build a TSOBS router is an optical time slot interchanger (OTSI). We explore various design options for OTSIs. Finally, we discuss the issues involved in the design of network interfaces that transmit the data from hosts that use legacy protocols into a TSOBS network. Ag-gregation and load balancing are the main issues that determine the performance of a TSOBS network and we develop and evaluate methods for both

Modeling all-optical space/time switching fabrics with frame integrity

All-optical networks have attracted significant attention because they promise to provide significant advantages in throughput, bandwidth, scalability, reliability, security, and energy efficiency. These six features appealed to optical transport-network operators in the past and, currently, to cloud-computing and data-center providers. But, the absence of optical processors and optical Random Access Memory (RAM) has forced the optical network designers to use optical-to-electrical conversion on the input side of every node so the node can process packet headers and store data during the switching operation. And, at every node’s output side, all data must be converted from its electronic form back to the optical domain before being transmitted over fiber to the next node. This practice reduces all six of those advantages the network would have if it were all-optical. So, to achieve a network that is all-optical end-to-end, many all-optical switching fabrics have been proposed. Many of these proposed switching fabrics lack a control algorithm to operate them. Two control algorithms are proposed in this dissertation for two previously-proposed switching fabrics. The first control algorithm operates a timeslot interchanger and the second operates a space/time switching fabric - where both these photonic systems are characterized by active Feed-Forward Fiber Delay Line (FF-FDL) and the frame-integrity constraint. In each case, the proposed algorithm provides non-blocking control of its corresponding switching fabric. In addition, this dissertation derives the output signal power from each switching fabric in terms of crosstalk and insertion loss

Architectural Considerations for Photonic Switching Networks

Photonic technologies are reviewed that could become important components of future telecommunication systems. Photonic devices and systems are divided into two classes according to the function they perform. The first class, relational, refers to devices, that map the input channels to the output channels under external control. The second class, logic, perform some type or combination of Boolean logic functions. Some of the strengths and weaknesses of operating in the photonic domain are presented. Relational devices and their applications are discussed. Optical logic devices and their potential applications are reviewed

Performance analysis on multi-dimensional optical routing networks.

Zhang Yu.Thesis (M.Phil.)--Chinese University of Hong Kong, 2002.Includes bibliographical references (leaves 67-72).Abstracts in English and Chinese.Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Overview of Optical Networking --- p.1Chapter 1.2 --- Mechanism in Optical Routing Networks --- p.3Chapter 1.3 --- Related Work on Optical Routing Networks --- p.4Chapter 1.4 --- The Motivation of This Thesis --- p.7Chapter 1.5 --- Thesis Structure --- p.8Chapter 2 --- Technologies for Multi-dimensional Optical Routing Networks --- p.10Chapter 2.1 --- Background --- p.10Chapter 2.2 --- Multi-fiber WDM Networks --- p.11Chapter 2.2.1 --- Phased-Array-Based WDM Device --- p.11Chapter 2.2.2 --- Wavelength-tunable lasers --- p.11Chapter 2.2.3 --- Tunable optical Filter --- p.12Chapter 2.2.4 --- Wavelength Converter --- p.13Chapter 2.3 --- OCDM/WDM --- p.16Chapter 2.3.1 --- Optical En/Decoder --- p.17Chapter 2.3.2 --- Optical Switch --- p.18Chapter 2.3.3 --- Optical Code Conversion --- p.18Chapter 2.4 --- OTDM/WDM --- p.21Chapter 2.4.1 --- Fast Optical Switch --- p.22Chapter 2.4.2 --- Optical Time Slot Interchanger (OTSI) --- p.22Chapter 2.5 --- Conclusion --- p.23Chapter 3 --- Performance of Code/Wavelength Routing Networks --- p.24Chapter 3.1 --- Background --- p.24Chapter 3.2 --- Reconfiguration Capability --- p.25Chapter 3.3 --- Analytic Models --- p.27Chapter 3.3.1 --- Trunk Switched Model --- p.27Chapter 3.3.2 --- Assumptions --- p.28Chapter 3.3.3 --- Blocking of the Paths with Various Configurations --- p.29Chapter 3.4 --- Numerical Results --- p.34Chapter 3.5 --- Conclusion --- p.35Chapter 4 --- Decomposition Schemes --- p.40Chapter 4.1 --- Introduction --- p.40Chapter 4.2 --- Inclusive Converted Networks --- p.41Chapter 4.3 --- Decompositions --- p.43Chapter 4.3.1 --- Spatial Decomposition (S.D.) --- p.43Chapter 4.3.2 --- Dimensional Decomposition (D.D.) --- p.44Chapter 4.3.3 --- Iterative Decompositions --- p.45Chapter 4.4 --- Conclusion --- p.46Chapter 5 --- Performance of Multi-Dimensional Optical Routing Networks --- p.48Chapter 5.1 --- Homogeneous Trunk Switched Networks --- p.48Chapter 5.2 --- Analytical Model --- p.49Chapter 5.3 --- Utilization Gain --- p.53Chapter 5.4 --- Conversion Gain --- p.54Chapter 5.5 --- Comparison on the Utilization Gain by Multiplexing and by Conversion --- p.56Chapter 5.6 --- Conclusion --- p.57Chapter 6 --- Conclusion --- p.65Chapter 6.1 --- Summary of the Thesis --- p.65Chapter 6.2 --- Future Work --- p.6

Design and Analysis of Optical Interconnection Networks for Parallel Computation.

In this doctoral research, we propose several novel protocols and topologies for the interconnection of massively parallel processors. These new technologies achieve considerable improvements in system performance and structure simplicity. Currently, synchronous protocols are used in optical TDM buses. The major disadvantage of a synchronous protocol is the waste of packet slots. To offset this inherent drawback of synchronous TDM, a pipelined asynchronous TDM optical bus is proposed. The simulation results show that the performance of the proposed bus is significantly better than that of known pipelined synchronous TDM optical buses. Practically, the computation power of the plain TDM protocol is limited. Various extensions must be added to the system. In this research, a new pipelined optical TDM bus for implementing a linear array parallel computer architecture is proposed. The switches on the receiving segment of the bus can be dynamically controlled, which make the system highly reconfigurable. To build large and scalable systems, we need new network architectures that are suitable for optical interconnections. A new kind of reconfigurable bus called segmented bus is introduced to achieve reduced structure simplicity and increased concurrency. We show that parallel architectures based on segmented buses are versatile by showing that it can simulate parallel communication patterns supported by a wide variety of networks with small slowdown factors. New kinds of interconnection networks, the hypernetworks, have been proposed recently. Compared with point-to-point networks, they allow for increased resource-sharing and communication bandwidth utilization, and they are especially suitable for optical interconnects. One way to derive a hypernetwork is by finding the dual of a point-to-point network. Hypercube Q\sb{n}, where n is the dimension, is a very popular point-to-point network. It is interesting to construct hypernetworks from the dual Q\sbsp{n}{*} of hypercube of Q\sb{n}. In this research, the properties of Q\sbsp{n}{*} are investigated and a set of fundamental data communication algorithms for Q\sbsp{n}{*} are presented. The results indicate that the Q\sbsp{n}{*} hypernetwork is a useful and promising interconnection structure for high-performance parallel and distributed computing systems

Effective fiber bandwidth utilization in TDM WDM optical networks

Ph.DDOCTOR OF PHILOSOPH