Recently, the Birkhoff-von Neumann (BvN) switch has become a typical model for providing QoS in input-queued switch. The major idea is to consider a set of predetermined permutation matrices as independent flows, and the scheduling problem in the input-queued switch can be simply handled by single-server scheduling algorithms, such as weighted fair queueing (WFQ). However, a number of problems are observed. Firstly, although WFQ is a fair algorithm, it has a poor delay performance that depends on the port counts. Secondly, the BvN switch does not perform well under certain traffic requirement, thus unable to provide tight performance guarantees. In this thesis, a set of admission control strategies and scheduling algorithms are therefore developed to improve the QoS performance. / The input-queued switch architecture is widely used in Internet routers, due to its ability to run at very high speeds. A central problem in designing an input-queued switch is choosing the scheduling algorithm, i.e. deciding which packets to transfer from input ports to output ports in a given timeslot. Recent research in packet switch scheduling algorithms has moved beyond throughput maximization to quality of service (QoS) control. / Choy Man Ting. / "September 2006." / Adviser: Tony T. Lee. / Source: Dissertation Abstracts International, Volume: 68-03, Section: B, page: 1815. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 89-94). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

by Philip Pak-tung To. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (p. 126). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web.

by Timothy Kai-Cheung Chung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references. / Chapter 1. --- INTRODUCTION --- p.1 / Chapter 2. --- ASYNCHRONOUS TRANSFER MODE SWITCHING --- p.4 / Chapter 2.1 --- Transfer Modes --- p.4 / Chapter 2.1.1 --- Circuit Switching --- p.4 / Chapter 2.1.2 --- ATM Switching --- p.6 / Chapter 2.1.3 --- Packet Switching --- p.8 / Chapter 2.2 --- Different Types of ATM Switching System --- p.8 / Chapter 2.2.1 --- Central Control Type --- p.9 / Chapter 2.2.2 --- Self-Routing Type --- p.9 / Chapter 2.3 --- Self-Routing Non-Buffering ATM Switching Node --- p.10 / Chapter 3. --- FUNCTIONAL DESCRIPTION OF MODULE ´بA´ة --- p.16 / Chapter 3.1 --- ATM Cell Format --- p.17 / Chapter 3.2 --- Concentrator --- p.17 / Chapter 3.3 --- Routing Cell --- p.19 / Chapter 4. --- PHYSICAL STRUCTURE OF MODULE ´بA´ة --- p.23 / Chapter 4.1 --- Clocking Scheme --- p.23 / Chapter 4.2 --- Concentrator --- p.25 / Chapter 4.2.1 --- 2-by-2 Sorter --- p.25 / Chapter 4.2.2 --- Input Framer --- p.30 / Chapter 4.2.3 --- Data Buffer --- p.38 / Chapter 4.3 --- Routing Cell --- p.38 / Chapter 4.3.1 --- Type I Router --- p.39 / Chapter 4.3.2 --- Type II Router --- p.42 / Chapter 4.4 --- Block By-Passed Function --- p.43 / Chapter 5. --- SIMULATION AND TEST --- p.48 / Chapter 5.1 --- Computer Simulation --- p.48 / Chapter 5.2 --- Actual Chip Testing --- p.53 / Chapter 5.3 --- Measurement Results --- p.55 / Chapter 5.3.1 --- Functionality --- p.55 / Chapter 5.3.2 --- Maximum Clock Frequency --- p.60 / Chapter 5.3.3 --- Power Dissipation --- p.61 / Chapter 6. --- CONCLUSION --- p.63 / Chapter A. --- BRIEF HISTORY OF ATM SWITCH ARCHITECTURE DEVELOPMENT --- p.65 / Chapter B. --- BIBLIOGRAPHY --- p.66 / Chapter C. --- A N-WELL CMOS PROCESS --- p.70 / Chapter D. --- CADENCE DESIGN FLOW --- p.73 / Chapter E. --- YERILOG SIMULATION PROGRAMS --- p.77 / Chapter F. --- SCHEMATIC DIAGRAMS --- p.100

The research presented in this thesis aims to demonstrate that fuzzy logic is a useful tool for developing mechanisms for controlling traffc flow in ATM based multimedia networks to maintain quality of service (QoS) requirements and maximize resource utilization. The study first proposes a hierarchical, multilevel control structure for ATM networks to exploit the reported strengths of fuzzy logic at various control levels. Then, an extensive development and evaluation is presented for a subset of the proposed control architecture at the congestion control level. An ATM based multimedia network must have quite sophisticated traffc control capabilities to effectively handle the requirements of a dynamically varying mixture of voice, video and data services while meeting the required levels of performance. Feedback control techniques have an essential role for the effective and efficient management of the resources of ATM networks. However, development of conventional feedback control techniques relies on the availability of analytical system models. The characteristics of ATM networks and the complexity of service requirements cause the analytical modeling to be very difficult, if not impossible. The lack of realistic dynamic explicit models leads to substantial problems in developing control solutions for B-ISDN networks. This limits the ability of conventional techniques to directly address the control objectives for ATM networks. In the literature, several connection admission and congestion control methods for B-ISDN networks have been reported, and these have achieved mixed success. Usually they either assume heavily simplified models, or they are too complicated to implement, mainly derived using probabilistic (steady-state) models. Fuzzy logic controllers, on the other hand, have been applied successfully to the task of controlling systems for which analytical models are not easily obtainable. Fuzzy logic control is a knowledge-based control strategy that can be utilized when an explicit model of a system is not available or, the model itself, if available, is highly complex and nonlinear. In this case, the problem of control system design is based on qualitative and/or empirically acquired knowledge regarding the operation of the system. Representation of qualitative or empirically acquired knowledge in a fuzzy logic controller is achieved by linguistic expressions in the form of fuzzy relational equations. By using fuzzy relational equations, classifications related to system parameters can be derived without explicit description. The thesis presents a new predictive congestion control scheme, Fuzzy Explicit Rate Marking (FERM), which aims to avoid congestion, and by doing so minimize the cell losses, attain high server utilization, and maintain the fair use of links. The performance of the FERM scheme is extremely competitive with that of control schemes developed using traditional methods over a considerable period of time. The results of the study demonstrate that fuzzy logic control is a highly effective design tool for this type of problems, relative to the traditional methods. When controlled systems are highly nonlinear and complex, it keeps the human insight alive and accessible at the lower levels of the control hierarchy, and so higher levels can be built on this understanding. Additionally, the FERM scheme has been extended to adaptively tune (A-FERM) so that continuous automatic tuning of the parameters can be achieved, and thus be more adaptive to system changes leading to better utilization of network bandwidth. This achieves a level of robustness that is not exhibited by other congestion control schemes reported in the literature. In this work, the focus is on ATM networks rather than IP based networks. For historical reasons, and due to fundamental philosophical differences in the (earlier) approach to congestion control, the research for control of TCP/IP and ATM based networks proceeded separately. However, some convergence between them has recently become evident. In the TCP/IP literature proposals have appeared on active queue management in routers, and Explicit Congestion Notication (ECN) for IP. It is reasonably expected that, the algorithms developed in this study will be applicable to IP based multimedia networks as well.

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 143-150). Available also in a digital version from Dissertation Abstracts.

Copies of author's previously published articles inserted / Bibliography: leaves 179-186 / 186 leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Electrical and Electronic Engineering, 1993

Thesis (Ph.D.) - Swinburne University of Technology, School of Biophysical Sciences and Electrical Engineering, 2000. / Submitted for the degree of Doctor of Philosophy, School of Biophysical Science & Electrical Engineering, 2000. Typescript. Includes bibliographical references (p. 133-145).

Thesis (Ph. D.)--University of Adelaide, Dept. of Electrical and Electronic Engineering, 1993. / Copies of author's previously published articles inserted. Includes bibliographical references (leaves 179-186).

Thesis (Ph. D.)--University of Canterbury, 2007. / Typescript (photocopy). Includes bibliographical references (p. 111-121). Also available via the World Wide Web.

Thesis (M. Eng.)--Carleton University, 2001. / Includes bibliographical references (p. 129-132). Also available in electronic format on the Internet.