Please use this identifier to cite or link to this item: http://hdl.handle.net/10397/3109
Title: Design and analysis of high performance multicast time-multiplexed switches
Authors: Chan, Man-chi
Subjects: Telecommunication -- Traffic.
Telecommunication -- Switching systems.
Hong Kong Polytechnic University -- Dissertations
Issue Date: 1998
Publisher: The Hong Kong Polytechnic University
Abstract: This thesis focuses on the time slot assignment (TSA) problems associated with multicast time multiplexed switches (TMS). It begins with a brief review of the problems and existing solutions. Based on the review, existing methods in solving these problems are systematically classified and organized according to their pros and cons. Having recognized the demand for more promising approach to tackle the TSA problems, especially, for the multicast mixed traffic, the project aims to study how a multicast TMS can he designed to overcome these problems. By understanding the nature of the problems and the shortcomings of the existing methods, an effective switching technique, namely, zone switching, is proposed as a hint for designing a high-performance multicast TMS. The idea of zone switching is to provide more rooms for call scheduling via a proper switch design. The switch using this technique in principle can eliminate most of call blocking inherently without the need of sophisticated control algorithm, which would limit the growth of switch in terms of size and speed. To implement this switching concept, two efficient switch architectures are developed for multicast TMS. The first design has a demux-mux architecture, which is a building block for cross-connect nodes in various broadband communication systems. By exploiting trunk grouping at both input and output ports, the demux-mux switch can remove most slot contentions and achieves better performance. The second one is a simple multistage switch. It is designed to implement a novel scheduling scheme, window scheduling, which is the simplest and an efficient way to implement zone switching. Since the multistage switch consists only of several switching planes and a set of delay elements, it is very suitable for using in an all-optical network (AON). Although zone switching has very outstanding performance, it does not work well when one or more involved lines are heavily loaded. Another efficient design technique, internal bandwidth expansion, is thus proposed. As illustrated from its name, this technique reduces the level of slot contention by increasing the internal bandwidth, which in turn provides more alternatives to connect a call request. Based on this concept, a time-space-time (TST) switch with intermediate line dilation is developed. This switch has internal bandwidth doubled and can eliminate almost all the slot contentions. However, the tradeoff may be the requirement of buffer stages at both input and output time slot interchangers (TSI). This greatly reduces the feasibility of implementing it in lightwave systems. Indeed, multicast TMS designed based on either one of these techniques can achieve substantial performance improvement. For cost-efficient design, it is suggested to use internal bandwidth expansion, if its implementation is feasible. Otherwise, zone switching is a good alternative to provide the same extent of improvement. Throughout this thesis, the switch performance is measured as the average call blocking probability and is evaluated via purely analytical means. The analytical results are each comparable to those predicted via computer simulations, which shows that the analytical models are valid for use.
Description: x, 113 leaves : ill. ; 30 cm.
PolyU Library Call No.: [THS] LG51 .H577M ENC 1998 Chan
Rights: All rights reserved.
Type: Thesis
URI: http://hdl.handle.net/10397/3109
Appears in Collections:EIE Theses
PolyU Electronic Theses

Files in This Item:
File Description SizeFormat 
b14211865_link.htmFor PolyU Users 162 BHTMLView/Open
b14211865_ir.pdfFor All Users (Non-printable)3.24 MBAdobe PDFView/Open


All items in the PolyU Institutional Repository are protected by copyright, with all rights reserved, unless otherwise indicated. No item in the PolyU IR may be reproduced for commercial or resale purposes.