Dot-Dash to Dot.Com How Modern Telecommunications Evolved from the Telegraph to the Internet

Andrew Wheen

Dot-Dash to Dot.Com How Modern Telecommunications Evolved from the Telegraph to the Internet

Published in association with

£} Springer Praxis Publishing Chichester, UK

Dr. Andrew Wheen Baldock Herts UK

SPRINGER-PRAXIS BOOKS IN POPULAR SCIENCE SUBJECT ADVISORY EDITOR: Stephen Webb, B.Sc, Ph.D.

ISBN 978-1-4419-6759-6 e-ISBN 978-1-4419-6760-2 DOI 10.1007/978-1-4419-6760-2 Springer New York Dordrecht Heidelberg London

Library of Congress Control Number: 2010929000

© Springer Science+Business Media, LLC 2011 All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer Science+Business Media, LLC, 233 Spring Street, New York, NY 10013, USA) except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights.

Cover design: Jim Wilkie Project copy editor: Christine Cressy Typesetting: BookEns, Royston, Herts., UK

Printed on acid-free paper

Springer is part of Springer Science+Business Media (www.springer.com)

Contents

Acknowledgments ix List of figures xi List of pictures xiii List of tables xv About the author xvii

Introduction 1

1 The birth of an industry 3

2 The telegraph goes global 19

3 A gatecrasher spoils the party 31

4 Early telephone networks 49

5 Going digital 67

6 A bit of wet string 81

7 The last mile 103

8 Computers get chatty 113

9 The birth of the Internet 127

10 Life in cyberspace 139

11 The mobi le revolut ion 163

12 When failure is not an option 175

13 What comes next? 183

Appendices 203 A Duplex telegraph 203 B Baudot Code 205 C Microphone wars 208 D Digital signal processing 210 E DSL technologies 218 F Leveling up the playing field 220 G Fixed wireless access networks 222 H Internet Service Provider networks 225

vi Dot-Dash to Dot.Com

I The Internet address shortage 226 J Virtual private networks 228 K Internet voice services 232 L IP television 235 M GSM networks 239 N Wideband CDMA 242 O Network reliability 245 P Availability 248 Q Error detection and correction 250

Notes 253 Glossary 281 Bibliography 293 Index 295

For Carol, Laura and Alex

Acknowledgments

A large number of people have contributed to this book in one way or another, and I am grateful to them all. However, particular thanks are due to the following:

Eric Benedict, who first suggested that there might be a need for this book.

Clive Horwood and the Praxis staff, for guiding me through the intricacies of the publication process.

Stephen Webb, for reviewing the manuscript and for contributing many helpful suggestions.

Robert Dudley, Francis Wheen and Julia Jones, for the benefit of their extensive knowledge of the publishing industry.

David Brown, John Davies, Andy Doyle, Bob Partridge, David Posner and Joe Savage, for acting as referees.

John Jenkins, Sam Hallas, Professor Nigel Linge, Keith Schneider, Don Johnson and Motorola Heritage Services, for permission to use their photographs.

Wikimedia Commons, for making a wonderful range of old photographs available on the Internet.

Colleagues at Mott MacDonald and ex-colleagues at Mentor, for many thought-provoking conversations.

And, finally, to my family and friends, for their dependable support and encouragement during the years that it has taken me to write this book.

Figures

1 Basic telegraph 5 2 Pith ball telegraph 8 3 Cooke and Wheatstone telegraph 11 4 Telegraph relay 13 5 Earth return 21 6 Experiment with tuning forks 35 7 Experiment with tuned reed 36 8 Summing undulatory currents 37 9 Simplified experimental configuration 38 10 Telephone prototype design 39 11 Message routes between telegraph offices 51 12 Long-distance telephone call 53 13 Strowger selector 55 14 Two-motion selector 56 15 Shared uniselector 57 16 Trunk signaling 59 17 Telephone call routes between exchanges 62 18 Network architecture 63 19 Signal regeneration 64 20 Simple analog waveform 68 21 Voltage measurements 69 22 Voltage measurements with wider spacing 69 23 Waveform sampled at twice its highest frequency 70 24 Fitting an alternative waveform to the same samples 70 25 Analog-to-digital conversion process 73 26 Digital-to-analog conversion process 74 27 Output from digital-to-analog conversion 74 28 Using modems to transmit data over an analog network 79 29 Analog network with digital islands 79 30 Coaxial cable 84 31 Electromagnetic spectrum 94 32 Paths of light inside an optical fiber 99 33 Canceling induced currents in twisted pair cable 104 34 BT access network 105 35 Comparison of cable TV and traditional access network 106 36 Passive optical network 107 37 Route across packet switching network 114 38 Computers linked by coaxial cable 116 39 LAN segments linked by a switch 117 40 Voice and data network topologies 118

xii Dot-Dash to Dot.Com

41 42 43 44 45 46 47 48 49 50 51 52 53 54

A D-1 D-2 D-3 D-4 D-5 D-6 D-7 E-1 E-2 F C-1 G-2 1-1 1-2 1-3 1-4 1-5 K-1 K-2 L-1 L-2 L-3 L-4 M-1 M-2 N-1 N-2 0 P

ISO seven-layer model Computers communicating across a network Message in nested protocol wrappers Switches and routers Internet concept Domain name structure Peer-to-peer and client-server St Louis mobile telephone system Mobile network cells Local exchange connections into core network Dedicated Protection Recovery after link failure Traffic flowing across a mesh network Service restoration after link failure

Duplex telegraph Comparison of analog and digital signal processing Prediction in ADPCM Evenly spaced quantization levels Unevenly spaced quantization levels 2-wire to 4-wire conversion Echo suppressor Echo cancellation ADSL frequencies Broadband service delivery using ADSL Indirect access Point-to-point and point-to-multipoint networks Mesh radio network Office network in Bristol Linked office networks in Bristol and Bath Link to home network Virtual Private Network Transmitting a packet from Bath to Bristol Telephone call across the Internet PSTN gateway Video on Demand Video cache Multicasting for broadcast TV Changing channel in a multicast network GSM network GSM network with GPRS Decoding a CDMA signal Correlation Bathtub curve Service availability

120 121 122 124 135 145 155 166 166 178 179 179 180 180

203 210 211 212 213 215 216 217 218 219 220 222 223 228 229 229 230 231 232 233 235 236 237 237 239 240 242 243 245 248

Pictures

Samuel Morse - http://c0mm0ns.wikimedia.0rg/wiki/File:Samuel_M0rse.jpg 7 Wikimedia Commons, public domain

The Cooke and Wheatstone telegraph - http://commons.wikimedia.org/ 10 wiki/File:Cooke_and'_Wheatstone_electric_telegraph.jpg Wikimedia Commons, GNU Free Documentation License

Telegraph sounder and key - Jenkins, John: Where Discovery Sparks 14 Imagination, American Museum of Radio and Electricity, 2009

Telegraph register - Jenkins, John: Where Discovery Sparks Imagination, 14

American Museum of Radio and Electricity, 2009

Baudot distributor - Sam Hallas 23

Baudot keyboard - Sam Hallas 24

Reproduction of Morse's original design - Jenkins, John: Where Discovery 25 Sparks Imagination, American Museum of Radio and Electricity, 2009 Reproduction of gallows telephone - 40 http://commons.wikimedia.Org/wiki/File:Bell_System_1877.jpg Wikimedia Commons, GNU Free Documentation License

Extract from Bell's laboratory notebook for March 10, 1876 - 41 http://commons.wikimedia.0rg/wiki/File:AGBell_Notebook.jpg Wikimedia Commons, public domain

Alexander Graham Bell - 42 http://c0mm0ns.wikimedia.0rg/wiki/File:Alexander_Graham_Bell.jpeg Wikimedia Commons, public domain

Antonio Meucci - 46 http://commons.wikimedia.0rg/wiki/File:Antonio_Meucci.jpg Wikimedia Commons, public domain

Telephone exchange, 1892 - 54 http://commons.wikimedia.Org/wiki/File:Telephone_Exchange_1892.jpg Wikimedia Commons, Creative Commons Attribution ShareAlike 3.0 license

Uniselector - Professor Nigel Linge, University of Salford 55

Rotary dial - Andrew Wheen 58

xiv Dot-Dash to Dot.Com

Cap'n Crunch whistle - http://www.gasolinealleyantiques.com 60 Keith Schneider, Gasoline Alley Antiques

Speech spectrogram - http://cnx.Org/content/m0089/2.5/ 72 Johnson, Don: "Analyzing the Spectrum of Speech", Connexions, August 4, 2004

James Clerk Maxwell - 85 http://commons.wikimedia.Org/wiki/File:James_clerk_maxwell.jpg Wikimedia Commons, public domain

Recreation of Hertz's classic experiment - 86 Jenkins, John: Where Discovery Sparks Imagination, American Museum of Radio and Electricity, 2009

Heinrich Hertz - 87 http://c0mm0ns.wikimedia.0rg/wiki/File:Heinrich_Hertz.jpg Wikimedia Commons, public domain

Guglielmo Marconi - 93 http://commons.wikimedia.0rg/wiki/File:Guglielmo_Marconi.jpg Wikimedia Commons, public domain

Microwave tower - Andrew Wheen 95

lonica aerial - Andrew Wheen 108

Cerf and Kahn receiving the Presidential Medal of Freedom - 137 http://en.wikipedia.0rg/wiki/File:CerfKahnMedalOfFreedom.jpg

Wikimedia Commons, public domain

RSS Logo 1 - Mozilla Foundation 153

RSS Logo 2 - Mozilla Foundation 153

Motorola DynaTAC 8000X - 163 Motorola, Inc., Heritage Services & Archives, Schaumburg, IL Mobile base station - Andrew Wheen 169

front cover

Samuel Morse - Library of Congress, public domain

Alexander Graham Bell -http://commons.wikimedia.Org/wiki/File:1876_Bell_Speaking_into_Telephone.jpg Wikimedia Commons, public domain

Boy with Phone - www.shutterstock.com

Tables

1 2 3 4 5 6 7

B-1 B-2 0 Q-1 Q-2

Morse Code DTMF signaling tones Representing sample measurement with a single digit Representing sample measurement with two digits Advantages of fiber optics Emoticons Network problems

Baudot Code Numerical representation of album cover Network problems Parity check examples A very simple method of calculating a checksum

5 58 72 73

101 140 176

205 206 245 250 250

About the author

Andrew Wheen has worked in the telecommunications field since 1982. He has held senior engineering and product management roles with major suppliers of telecommunications equipment and was one of the original architects of the Energis network in the United Kingdom (now part of Cable & Wireless). More recently, he has worked as a management consultant in the telecommunications and broadcasting industries. Dr Wheen is a Fellow of the Institution of Engineering & Technology and is a Chartered Engineer. He is married with two children and lives near London.