Analysis, design and performance evaluation of a video and computer teleconference system for distance learning Item Type text; Thesis-Reproduction (electronic) Authors Stubblebine, Stuart Gerald, 1961- Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 01/10/2021 00:51:32 Link to Item http://hdl.handle.net/10150/276930 INFORMATION TO USERS The most advanced technology has been used to photo­ graph and reproduce this manuscript from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer prints. 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The University of Arizona, 1988 UMI SOON.ZeebRd Ann Aibor, MI 48106 ANALYSIS, DESIGN AND PERFORMANCE EVALUATION OF A VIDEO AND COMPUTER TELECONFERENCE SYSTEM FOR DISTANCE LEARNING by Stuart Gerald Stubblebine A Thesis Submitted to Faculty of the DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING In Partial Fulfillment of the Requirements For the Degree of MASTER OF SCIENCE WITH A MAJOR IN ELECTRICAL ENGINEERING In the Graduate College THE UNIVERSITY OF ARIZONA 1 9 8 S STATEMENT BY AUTHOR This thesis has been submitted in partial fulfillment of requirements for an advanced degree at The University of Arizona and is deposited in the University Library to be made available to borrowers under the rules of the Library. Brief quotations from this thesis are allowable without special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his or her judgment the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author. SIGNED: APPROVAL BY THESIS DIRECTOR This thesis has been approved on the date shown below: / Ralph Martinez Date Associate Professor ^ of Electrical Engineering ACKNOWLEDGEMENTS The thoughtful criticisms, suggestions and guidance from my professors have added greatly to this thesis. In particular I wish to thank my thesis advisor Dr. Ralph Martinez for his guidance. I am also indebted to Dr. William Sanders for his direction in the performance evaluation. Dr. Larry Schooley for his noteworthy suggestions, and Don lozia and John Gross for their invaluable technical assistance. iii TABLE OF CONTENTS Page LIST OF ILLUSTRATIONS viii LIST OF TABLES x ABSTRACT xi CHAPTER 1 INTRODUCTION 1 1.1 The Evolution of Teleconferencing .... 1 1.2 Teleconferencing and Educational Television at University of Arizona ... 4 1.2.1 Campus Facilities 6 1.2.1.1 Video Architecture 8 1.2.1.2 Audio Architecture 9 1.2.2 Transmission Paths 9 1.2.2.1 Tucson Broadcast 9 1.2.2.2 Fort Huachuca, Arizona Link. 11 1.2.2.3 National Technological University 12 1.2.3 Remote Conference Centers 13 1.3 Motivation For Change 14 1.4 Thesis Objective 15 2 REQUIREMENTS ANALYSIS 16 2.1 Lecture Reception 16 2.1.1 Display 17 2.1.2 Interaction During Lecture .... 18 2.1.3 Course Material Reception 20 2.2 Lecture Delivery 21 2.2.1 Presentation 21 2.2.2 Course Material Distribution. ... 22 iv V TABLE OF CONTENTS —continued 2.3 Course Support 22 2.3.1 Electronic Mail 23 2.3.2 Remote Use of Computing Resources . 24 2.3.3 Grading 26 3 ANALYSIS OF DESIGN APPROACHES 27 3.1 Video Broadcast with Audio Conference . 28 3.2 Video and Data Broadcast with Audio Conference 31 3.3 Data and Audio Conference 35 3.4 Video, Data and Audio Conference Using ISDN Technology 40 4 VIDEO AND DATA BROADCAST SYSTEM FUNCTIONAL DESIGN 46 4.1 Overview 46 4.1.1 Design Choice 46 4.1.2 System Organization 47 4.2 Control Site 49 4.2.1 Conference Components 49 4.2.1.1 Audio 51 4.2.1.2 Video 53 4.2.1.3 Data 53 4.2.2 Transmission Components 55 4.2.2.1 Satellite 55 4.2.2.2 Microwave Radio 56 4.2.2.3 Television Broadcast (ITFS). 60 4.2.3 Conference Control Processes ... 63 4.2.3.1 Main Process 64 4.2.3.2 Presentation Software ... 67 4.2.3.3 Telecommunications Package . 68 4.3 Remote Site 70 4.3.1 Work Station Components 71 4.3.2 Work Station Processes 74 vi TABLE OF CONTENTS —continued 4.3.3 Reception Components 77 4.3.3.1 Satellite 77 4.3.3.2 Microwave Radio 78 4.3.3.2 Television Reception (ITFS). 79 4.4 Lecture Generation Support Facility ... 79 4.4.1 Lecture and Class Note Generation . 80 4.4.2 Class Note Distribution 80 4.4.2.1 Bulletin Board System Operation 82 4.4.2.2 Bulletin Board Choice ... 83 5 PERFORMANCE EVALUATION 84 5.1 Simulation Goals 84 5.2 Performance Variables 85 5.3 Model Development 85 5.4 Input Parameters 91 5.4.1 Observed Data 92 5.4.1.1 File Sizes 92 5.4.1.2 Display Times . 93 5.4.2 Probability Distributions 96 5.4.3 Hypotheses Testing 97 5.5 Simulation Tests and Results 104 5.5.1 Transmission Protocol .... 106 5.5.2 Bit Error Rate 107 5.5.3 Transmission Rate 107 5.5.4 File Size 107 5.5.5 Display Time 110 6 SUMMARY AND CONCLUSION 112 6.1 Summary 112 6.1 Cost Analysis 114 6.2 Future Work 114 APPENDIX A: SIMSCRIPT II.5 SOURCE PROGRAM FOR SIMULATION 116 vii TABLE OF CONTENTS —continued APPENDIX B: EQUIPMENT LIST AND APPROXIMATE COSTS ... 125 LIST OF REFERENCES 129 LIST OF ILLUSTRATIONS Figure Page 1.1 University of Arizona Microcampus 7 Components 1.2 Transmission to Remote Sites 10 3.1 Video Broadcast with Audio Conference Approach 30 3.2 Video and Data Broadcast with Audio Conference 33 3.3 Data and Audio Conference 38 3.4 ISDN Information Flow for Video, Data and Audio Conferencing 43 4.1 System Components and Information Flow ... 48 4.2 Control Site Conference Components 50 4.3 Signal Channel Spectrum 57 4.4 Control Site Satellite Transmission Components 58 4.5 Control Site Microwave Transmission Components 61 4.6 Overview of Control Site Software 65 4.7 Control Site Telecommunications Package Flow Chart 69 4.8 Long Haul Remote Site Components 72 4.9 Local Remote Site Components 73 4.10 Overview of Reception Processes 76 4.11 Lecture Generation Support Facility 81 5.1 System Diagram 87 viii ix LIST OF ILLUSTRATIONS —continued Figure Page 5.2 SIMSCRIPT Processes 90 5.3 Histogram of Observed File Sizes 94 5.4 Histogram of Observed Display Times 95 5.5 Density/Histogram Over Plot for File Sizes 103 5.6 Density/Histogram Over Plot for Display Times 103 5.7 BER Threshold for Incorrectly Displayed Files 108 5.8 BER Threshold for Files Requiring Retransmissions 109 5.9 System Performance Due to a Shift in File Sizes Ill LIST OF TABLES Table Paae 5.1 Observed Sample File Size Statistics .... 94 5.2 Observed Sample Display Time Statistics . 95 5.3 Model Parameters for File Size 98 5.4 Model Parameters for Display Time 99 5.5 Hypotheses Test Comparison for File Size . 101 5.6 Hypotheses Test Comparison for Display Time . 102 X ABSTRACT Video teleconferencing is a successful tool in the education and business industry because of its ability to reach a large audience at numerous remote locations. New computer and communications technology allows for advances in teleconferencing capabilities. In this thesis, an analysis of educational teleconferencing requirements is performed to develop viable educational teleconferencing design approaches. These design approaches must consider various transmission means and typical methods of instruction. One design approach is selected and a functional design is performed. The design is evaluated using performance models and the Simscript II.5 simulation language.