SHAPING AMERICAN TELECOMMUNICATIONS A History of Technology, Policy, and Economics TELECOMMUNICATIONS A Series of Volumes Edited by Christopher H. Sterling
Selected titles include:
Borden/Harvey The Electronic Grapevine: Rumor, Reputation, and Reporting in the New On-Line Environment
Cherry/Wildman/Hammond Making Universal Service Policy: Enhancing the Process Through Multidisciplinary Evaluation
Gattiker The Internet as a Diverse Community: Cultural, Organizational, and Political Issues
Gillett/Vogelsang Competition, Regulation, and Convergence: Current Trends in Telecommunication Policy Research
Hudson From Rural Village to Global Village: Telecommunications for Development in the Information Age
Pelton/Oslund/Marshall Communications Satellites: Global Change Agents
Sterling/Bernt/Weiss Shaping American Telecommunications: A History of Technology, Policy, and Economics SHAPING AMERICAN TELECOMMUNICATIONS A History of Technology, Policy, and Economics
Christopher H. Sterling George Washington University Phyllis W. Bernt Ohio University Martin B. H. Weiss University of Pittsburgh
LAWRENCE ERLBAUM ASSOCIATES, PUBLISHERS 2006 Mahwah, New Jersey London This edition published in the Taylor & Francis e-Library, 2008. “To purchase your own copy of this or any of Taylor & Francis or Routledge’s collection of thousands of eBooks please go to www.eBookstore.tandf.co.uk.”
CopyrightÓ2006byLawrenceErlbaumAssociates,Inc. All rights reserved. No part of this book may be reproduced in any form, by photostat, microform, retrieval system, or any other means, without the prior written permission of the publisher.
Lawrence Erlbaum Associates, Inc., Publishers 10 Industrial Avenue Mahwah, New Jersey 07430 www.erlbaum.com
Library of Congress Cataloging-in-Publication Data
Sterling, Christopher H., 1943- Shaping American telecommunications : a history of technology, policy, and economics / Christopher H. Sterling, Phyllis Bernt, Martin Weiss. p. cm. — (Telecommunications) Includes bibliographical references and index. ISBN 0-8058-2236-4 (cloth : alk. paper) ISBN 0-8058-2237-2 (pbk. : alk. paper) 1. Telecommunication—United States. 2. Telecommunication policy—United States. I. Bernt, Phyllis. II. Weiss, Martin B. H. III. Title. IV. Telecommunications (Mahwah, N.J.).
HE7775S.S76 2006 384.0973—dc22 2005045616 CIP
ISBN 1-4106-1695-9 Master e-book ISBN For Ellen (as always, and for every reason), Jennifer and Robin (our best products from four decades), and Rachel (our first grandchild) —Chris Sterling
For Joe, who brings me joy and laughter; and for my colleagues at the former Lincoln Tel & Tel, who faced challenging times with grace and teamwork —Phyllis Bernt
To Karen for her constant love and support, to Evan and Maddy, in lieu of time I would have otherwise spent with them, and to Eric and Carena, just because —Martin Weiss This page intentionally left blank Contents
Preface xv
About the Authors xvii
1 Introducing Telecommunications 1 1.1 Technology—The Means 2 Basics 2 Telephone Systems 4 Local Loop 6 Digital Transmission Systems 7 High-Capacity Channels 8 Data Networks 10 1.2 Economics—Paying for It 12 Supply and Demand 12 Market Structure 13 Cost–Benefit Analysis 18 1.3 Policy—Building Boundaries 20 Communication Common Carriers 21 Public Utility Concept 22 Legal Bases of Regulation 23 Constitutional Bases of Regulation 26 Regulatory Theories 27 Regulatory Structure 30 Jurisdictional Issues 32
vii viii N CONTENTS
2 Telegraph to Telephone (to 1893) 36
2.1 Technology—Limits and Opportunities 37 Electrical Industry 37 Role of Patents 38 2.2 Telegraphy—Creating New Patterns (to 1860) 38 Morse 38 Extending the Telegraph 40 Railway Synergy 41 Western Union 42 2.3 Building a Telegraph Industry (1860–76) 43 Supportive Role of Government 44 Monopoly 45 Network Economics 47 Impact of Instant Communication 48 Submarine Telegraphy—Going International 49 2.4 Telephony—Adding Voices (1876–85) 50 Bell’s Device—“Nothing Much New” 50 Search for Support 51 Building a Telephone System 53 Patent Fight 55 2.5 Developing the Telephone Industry (1885–93) 56 Fractious Local Exchanges 56 Western Electric 57 Developing AT&T 58
3 Era of Competition (1893–1921) 64
3.1 Improving Technologies 65 Switching—Connecting Everyone 65 Automatic Switching 66 Long Distance Transmission 67 Wireless Telegraphy and Telephony 68 Patent Pool 70 3.2 Competition Appears 70 Rise of the “Independents” 71 Vail and AT&T Centralization 72 Bell’s Response to Competition 74 3.3 Twisting Path of Government Regulation 77 Interconnection 78 Mann–Elkins Act 78 1913 Antitrust Suit 79 Kingsbury Commitment 80 Wartime Government Control 81 Willis–Graham Act 82 CONTENTS N ix
4 Regulated Monopoly (1921–56) 86 4.1 Further Technological Advance 86 Transmission—Multiplex 86 Transmission—Microwave 87 Switching 89 Radio Broadcasting 90 Transistors 91 4.2 Economics 93 Concepts of “Natural Monopoly” 93 Rate-of-Return Regulation 95 Separations 99 4.3 Regulation—Setting a Pattern 104 Radio Act 104 Splawn Report 104 Communications Act 105 FCC Telephone Investigation 106 Walker Report 107 4.4 Antitrust: The 1949 Suit 108 1949 Complaint 109 Derailing the Suit 110 1956 Final Judgment 112 Aftermath 113
5 Competition Reappears (1956–74) 118 5.1 Technology—Adding Competitive Options 118 Solid-State Electronics 119 Computer Revolution 120 Communication Satellites 121 Coaxial Cable 123 5.2 Terminal Equipment Competition 124 Hush-a-Phone 124 Carterfone 125 Bell System PCAs 126 FCC Certification 126 5.3 Opening Up Transmission 127 Above 890 Decision 127 TELPAK 129 Seven-Way Cost Study 130 5.4 Creating Specialized Carriers 131 Formation of MCI 131 Approving MCI 133 Interconnection Negotiations 133 More Applicants 134 SCC Decision 134 Domsats 135 x N CONTENTS
5.5 AT&T Responds to Competition 136 Changing Image 137 NARUC Speech 137 Defeating Datran 138 FX Service Decision 139 Going Public 140
6 Breaking Up Bell (1974–84) 145 6.1 Filing Suits 147 MCI Brings Suit 147 Justice Files Its Case 149 AT&T Responds 150 6.2 A Defining Interlude—Execunet 151 A New Service 152 FCC Versus the Court 153 ENFIA 153 6.3 Trial and Settlement 154 Paper Chase 154 Attempts to Settle 155 Trial 156 Settlement 157 6.4 Breakup: Defining the MFJ 158 Agreement 158 Defining “Local” 159 Reorganization 160 Line of Business Restrictions 162 6.5 Baby Bells 164 Concept—Limited Regional Power 164 People 167 6.6 Changing Economics 168 Rising Costs 168 Bypass Fear 170
7 Operating Under the MFJ (1984–96) 178 7.1 “Free the RBOC Seven” 178 Petitions for Change 179 Triennial Review 182 Decision 184 7.2 Long Distance Marketplace 185 AT&T Trivestiture 186 Lucent 187 Bell Labs 188 Long Distance Competition 188 7.3 Changing Economic Policies 189 Equal Access 190 Access Charges and NECA 193 CONTENTS N xi
Switched and Special Access 194 Impact on Universal Service 197 Accommodating Competition 199 Implementing Price Caps 201 7.4 To Regulate or Not to Regulate 204 FCC Computer Inquiries 204 Computer Inquiry III and ONA 208 Jurisdiction—Congress, the Courts, or the FCC? 210 7.5 Exporting Deregulation 212 Privatization and Liberalization 212 Market Flexibility 214 Opening Markets 217 Global Investments, Mergers, and Joint Ventures 218 Trade Issues and the WTO 219
8 Innovating New Services (1980s/1990s) 228 8.1 Digital Age 228 Basics 228 Switches 229 8.2 Wireless Telephony 231 Emerging Role of Wireless 231 Cellular Systems 232 Changing Cellular Standards 233 8.3 Managing Spectrum 234 Implementing Lotteries 235 Auctioning Spectrum 236 Auction Troubles 237 Spectrum Task Force 238 Finding 3G Spectrum 239 8.4 Cable Convergence 240 Rise of Cable Television 241 Cable/Telephone Ownership 241 First Merger Moves 243 Broadband Gambles 244 8.5 Internet and Information 246 Early Information Services 246 ARPANET 248 Commercialization 249 DSL Versus Cable Modems 249 Voice Over IP 253
9 1996 Act and Aftermath (1996–2000) 258 9.1 Why Change Took So Long 259 Earlier Attempts 260 1986 Dole Bill 260 xii N CONTENTS
Industry Complexity 261 Political Factors 262 9.2 Legislating Competition and Convergence 263 (Re)Introducing Local Competition 264 The “War of All Against All” 266 Convergence? 267 9.3 Streamlining Government 268 Easing FCC Rules and Regulations 268 Redefining State and Local Roles 269 9.4 Redefining Universal Service 270 Creating a National Policy 271 . . . and Paying for It 273 From Universal Service to Universal Access? 278 9.5 The FCC Implements New Regulations 279 Interconnection 279 Pricing Guidelines 282 Triennial Review 284 Section 271 Proceedings 286 9.6 Merger Fever 288 RBOC Mergers 289 Bellcore 291 Rise of WorldCom 292 9.7 Appeals, Delay, Decisions, and Impact 294 Appeals 294 The Courts Rule 296 Winners and Losers 299 Prospects 301
10 Meltdown . . . and the Future (Since 2000) 313 10.1 Overcapacity 314 Fiber Links 314 Wireless Networks 316 Broadband Services 318 Poor Predictions 319 10.2 Economic Pressure 320 Investment: Frenzy to Freeze 320 Stock Price Declines 322 Layoffs 323 Fraud 325 Bankruptcy 327 10.3 Waves of Disaster 328 First: Dot.coms 329 Second: Manufacturers 330 Third: CLECs 331 Fourth: Interexchange Carriers 334 Fifth: Wireless Providers 335 Smaller Waves? 337 CONTENTS N xiii
10.4 Policy Confusion 338 “Promise” of the 1996 Act 339 Tauzin–Dingell Debate 339 FCC Deregulatory Mantra 340 Auction Debacle 342 Antitrust as Policy 343 10.5 Looking to the Future 345 Clearing the Glut 345 Consolidating Further 346 Reforming Management 348 Continuing Research 349 Reviving Policymaking 350 Summing Up 351
Appendices
A. Regulatory Concepts in Telecommunications Economics, Finance, and Accounting 360 A.1 Regulatory Regimes 360 A.2 Cost Issues 367 A.3 Pricing Issues 372
B. Glossary 376
C. Chronology 384
D. Historical Statistics 394
References 398
Author Index 411
Subject Index 415 This page intentionally left blank Preface
This book—like so many others—has been a long time coming. Phyllis Bernt and Martin Weiss (who earlier authored a book about in- ternational telecommunication) began an effort a decade ago to author a comprehensive introductory history of American telecommunications. But then both got pulled into administrative and other duties on their re- spective campuses. A bit later, Christopher Sterling had launched a sepa- rate effort to co-author a book about the dramatic changes wrought on AT&T. Both projects were under contract to Lawrence Erlbaum Associ- ates for LEA’s Telecommunication Series. About five years ago, the two projects were merged as Sterling joined with Bernt and Weiss to revive and revamp their project. But academic administration (each of us has held an associate deanship at some point in this process) kept intruding, the field—and thus our story—kept changing, and the book’s manu- script eluded completion. Over the past two years, Bernt and Sterling, each finally freed of such “administrivia,” focused on getting the book completed. Our intent throughout this long writing process (during which the in- dustry has taken an almost 180-degree turn from dramatic growth to drastic decline and, more recently, elements of consolidation) has been to provide a historical analysis of the technical, economic, and policy basics of American telecommunications over about 160 years. We seek to pro- vide historical context for what is happening today. This is a history filled with fascinating people, often complex companies, and changing government policies. As with any industrial sector story that has a com- plex background and is loaded with jargon, those seeking to learn more
xv xvi N PREFACE may find the process difficult going. It is an effort worth pursuing, how- ever, because telecommunications is central to our daily lives in ways many of us never realize. We hope that this book makes that effort a bit less onerous.
ACKNOWLEDGMENTS
We express our sincere thanks to Jill F. Kasle of George Washington Uni- versity. Jill and Chris Sterling embarked back in 1995 on a book about AT&T’s story amidst all the dramatic changes we trace on the following pages. As will sometimes happen with team projects, however, we con- cluded that we had different concepts of what such a book should be and contain. She very kindly let Sterling take their shared though incomplete work product to become a part of the book you now hold. Linda Bathgate, our editor at Lawrence Erlbaum, has once again de- fined patience as she first shepherded two books, and then one, through to the publication stage. She demonstrates just the right balance of push and patience (and a sense of humor, which always helps) and we are all grateful to her for staying the course. Trevor Roycroft, then at Ohio University, was the first “outsider” sub- jected to reading the whole manuscript, and we are grateful for his many suggestions, nearly all of which are reflected in changes made here. On a more personal level, Chris Sterling thanks Ellen (in our 40th an- niversary year!) for her continuing support and interest in this latest project. While the material may not fascinate her as it does her husband, she has provided invaluable back-up to help get it written. Phyllis Bernt thanks the students in her introductory regulation courses for their feed- back and encouragement when asked to use various drafts of the manu- script as required reading material.
C. H. S. P. W. B. M. B. W. July 2005 About the Authors
Christopher H. Sterling has taught media and telecommunications courses at George Washington University for nearly a quarter century. He’s authored or edited 20 books, including a four-volume anthology of excerpted documents from the break-up of AT&T. With research inter- ests focusing on media and telecommunications history and policy, Ster- ling also edits Communication Booknotes Quarterly and the “Telecommuni- cation Series,” both published by LEA, and serves on the editorial boards of seven journals. He was a senior staffer at the Federal Communications Commission in the early 1980s, and holds a PhD from the University of Wisconsin–Madison.
Phyllis W. Bernt is a professor of communication systems management at Ohio University. Her research interests include the viability of univer- sal service in a competitive telecommunications marketplace, trends in international telecommunications, and the social effects of information technologies, including issues of privacy and gender. For most of the 1980s she worked for Lincoln (Nebraska) Telephone, now part of Alltel, where she was responsible for rate development, cost analysis, and tariff preparation. She has been an institute associate at the National Regula- tory Research Institute, and is currently the lead Principal Investigator for an NSF grant investigating gender and racial representation of informa- tion technology in middle school students’ media environment. She holds a PhD from the University of Nebraska–Lincoln.
Martin B. H. Weiss serves as Associate Dean for Academic Affairs and Research at the School of Information Science and chairs the Information
xvii xviii N ABOUT THE AUTHORS
Science and Telecommunications department at the University of Pitts- burgh. His research interests include the analysis of situations where competing firms must cooperate, cost modeling of new technologies in telecommunications systems, and the evolution of telecommunications industry. For a decade beginning in 1978, he worked at Bell Labs, then Mitre, and finally with Deloitte, Haskins, and Sells. With Phyllis Bernt, he co-authored International Telecommunications (Howard Sams, 1993). He holds a PhD from Carnegie Mellon University. Chapter 1
Introducing Telecommunications
More than other sectors of a nation’s economy, telecommunications op- erates through a unique melding of technology, economics, and policy. At the most basic level, telephone, wireless or radio communication, and Internet connectivity all rely on technology. All forms of telecommunica- tion involve a message, a sender, and a receiver that utilize telecommuni- cations transmission. There are many variations in this transmission process—telephone networks and data networks may move, or switch, a message differently; and messages may be sent over narrow copper wires or over larger capacity fiber optic cables or through the air. Each mode operates under fundamental principles, and a basic knowledge of these is needed to understand how a telephone call takes place, or a byte of data moves through a network, or an Internet connection is made. An understanding of telecommunications also requires knowledge of economic and policy factors. U.S. telecommunications has developed from a long history of monopoly and regulation. While until recently telecommunication systems in virtually every other country in the world were government owned, in the United States telecommunications has operated as a commercial enterprise almost from its mid-19th- century inception. Government involvement in deployment and develop- ment of telecommunications took place here more through regulation than ownership. For decades the U.S. telephone system was largely con- trolled by the Bell System and a host of small local telephone companies dependent on Bell. The potential for substantial economic gain can, of course, lead to abuses when an essential service (like local telephony) is provided by a
1 2 N CHAPTER 1 monopolist free from competitive pressures when making pricing and production decisions. Regulation at both the federal and state levels emerged early in the 20th century as the best way to control these possi- ble abuses of monopoly power. In regulating telecommunications, the Federal Communications Commission (FCC), the 50 state public utility commissions (PUCs), and the D.C. commission do more than just control the price of service. Through regulatory decisions they have also struc- tured the industry, determined how services would be provided and by whom, and set service quality standards. Understanding the sometimes convoluted development of telecommunication thus requires some knowledge of these regulators’ modes of operation, sources of authority, and motivating principles. This chapter introduces the fundamentals of telecommunications technology, economics, and policy, including basic principles that will be helpful in understanding the history, issues, and concepts discussed in the chapters that follow.
1.1 TECHNOLOGY—THE MEANS
As the historical core of telecommunications for more than 130 years, te- lephony is the process of transmitting sound—usually the human voice— through electrical signals. For this transmission to occur, sound waves must be converted to electrical signals at the originating point of a call and then the electrical signals must be reconverted to sound waves at the terminating point of the call. A microphone, or transducer, converts the human voice to electrical signals and then a speaker converts the electrical signals back to sound waves. In a modern telephone, the microphone and speaker are combined into one telephone handset, so that the telephone set can both generate and receive calls. A transmission medium,suchasa copper wire, a fiber optic cable, or the air waves, carries the electrical sig- nals between telephone handsets.
Basics
Human speech occupies a variable range of frequencies that depend on the speaker and the moment (as when people raise and lower the pitch of their voices to convey meaning). Generally human speech—and hear- ing—can range from a low of about 300 Hz (Hertz) to a high of about 10,000 Hz (or 10 kHz). Experiments have found that language can be understood and speakers readily identified using a narrower frequency range of 300 to 3400 Hz. The International Telecommunication Union (ITU) recommends that telephone systems be designed to carry at least INTRODUCING TELECOMMUNICATIONS N 3 this range, referred to as a signal’s bandwidth (for this and other terms, see Appendix B). While telephone systems have long been designed to transmit human speech, increasingly systems are used for other purposes as well, such as connecting computers (via modems) and transmitting documents (via fax). The traditional telephone network was largely analog; in other words, the electrical signals transmitted were analogous to, or replicated, the sound waves formed by human speech. Data emanating from com- puters, on the other hand, consisted, not of electrical waves, but rather of bits and bytes of data, or combinations of zeros and ones. Modems (mod- ulator/demodulators) were needed to convert the digital data stream of bits and bytes into an analog speech-like signal (unintelligible to most people) that the largely analog telephone network could carry. The transmission medium traditionally consisted of copper wires which were connected to the transducer via a circuit called a hybrid. The function of the hybrid was (and is) to separate signals being sent from those being received so that the received signal can be directed to the speaker, as illustrated in Fig. 1.1.
FIG. 1.1. Basic telecommunications link.
By the early 20th century, the most widely used transmission medium was a twisted pair of copper wires. Earlier transmission most commonly utilized a single strand of iron wire, which had also been the standard for telegraph systems. Such “open wire” systems were relatively cheap but were more prone to interference, especially from the electric power sys- tems that were proliferating in the late 19th and early 20th centuries. To- day, fiber optic cable is beginning to replace twisted pair copper. All transmission media can be evaluated according to their attenuation and their susceptibility to noise. Attenuation is the reduction of signal strength, and this increases with both distance covered and the frequency used. A weaker signal is, of course, more difficult to hear. The bandwidth of a transmission medium really is the range of frequencies that a trans- mission medium can carry with acceptable attenuation for a specified distance. The history of transmission media can be seen as a quest for in- creases in acceptable bandwidth. Twisted pair copper was able to trans- 4 N CHAPTER 1 mit a wider range of frequencies over longer distances than iron wire; to- day, fiber optic cable is able to transmit much higher bandwidth than twisted pair copper. As is discussed in later chapters, local telephone com- panies (providers of traditional telephone network service based on twisted pair copper) are under increasing pressure to replace copper with more fiber optic cable, also called broadband facilities. The questions of how the local telephone companies will pay for these broadband facilities, and how they will recover the cost of the twisted pair copper already in use, are major issues of concern to telecommunications policymakers (as discussed in chaps. 8–10, of this volume). Noise refers to unwanted signal energy (sometimes called interference) from any source. In other words, the intended signal is the electrical en- ergy that has been converted from the sound waves; noise is any other electrical energy that manages to invade the transmission path of the in- tended signal. Although intended signals suffer attenuation, noise nor- mally does not because it can enter the transmission medium at any point, not just at the beginning point of the signal. Thus the effect of at- tenuation is not just that the signal (the desired information) becomes weaker, but also that the signal becomes more difficult to distinguish from noise. Engineers capture this notion in the signal-to-noise ratio,in which the signal power is divided by the noise power. If this ratio is small, then the signal will be more difficult to discern than when the ratio is large. It is the combination of the bandwidth of a transmission medium and the signal-to-noise ratio that governs the capacity of a channel to carry information.
Telephone Systems
Telephone systems involve key components that must fit and work to- gether to enable telephone service. To place a telephone call, a subscriber must have equipment, usually a telephone, through which he or she is able to connect with the telephone network in order to send a message to a desired telephone number. The subscriber establishes a connection to the network by going “off hook,” or lifting the telephone receiver. By do- ing so, the subscriber establishes a connection with a switch. The sub- scriber then “tells” the switch the number he or she wishes to reach by di- aling that number. The switch recognizes the number and routes the call—or rather establishes a channel through other switches and trans- mission media—between the calling subscriber and the called number. For policy reasons that will be discussed further (see sections 6.4, 7.1, and 7.2), telephone network service is provided by two different types of companies: local telephone companies or local exchange carriers (LECs) and long distance companies or interexchange carriers (IXCs). LECs pro- INTRODUCING TELECOMMUNICATIONS N 5 vide local service and own the facilities closest to the subscriber; IXCs pro- vide long distance service and use the LECs’ facilities, along with their own facilities, in order to provide long distance calls. This relationship is illustrated in Fig. 1.2.
FIG. 1.2. Industry structure.
A LEC’s network is structured as shown in Fig. 1.3, with the LEC own- ing the local connection to the subscriber (the loop); as well as Central Of- fice (CO), or local, switches; tandem switches through which LECs accu- mulate traffic from several central office switches; and transmission systems connecting switches. IXC networks do not include the local con- nection to the subscriber or local switches. Instead IXC networks consist of large capacity long distance switches and transmission systems that haul telephone calls from city to city and state to state. (As is discussed in section 9.2, this neat distinction is changing because of Congress’s pas- sage of the Telecommunication Act of 1996. As a result of that act, such LECs as Verizon are now offering long distance service once restricted to IXCs, and some IXCs, such as AT&T, are offering local service once re- served for LECs.)
FIG. 1.3. Local exchange network.
The components of a telephone network consist of customer premise equipment (CPE), such as telephones, modems, and fax machines; the lo- cal loop; switches (CO and tandem); and transmission systems. Since the late 1970s, subscribers have been able to purchase the CPE of their choice 6 N CHAPTER 1
(as long as it meets specific FCC technical standards); earlier CPE could only be leased from the local telephone company. The contracts that long governed the interconnection of the LEC and IXC networks were termed the “separations and settlements” procedures discussed later (see section 4.2), since replaced by “access charge” arrange- ments (see section 7.3). IXCs pay LECs access charges for the use of the LEC network. As a result of Congress’s desire to see the development of com- petition in all parts of the telephone system, competitive local exchange carriers (CLECs) developed in parallel to the LECs. IXCs negotiate arrange- ments with the CLECs to use their facilities, just as they have used the LECs’ facilities. For reasons explored later, however, few CLECS have sur- vived into the 21st century.
Local Loop
The local loop refers to the set of technologies used to connect end user lo- cations with the LEC’s CO. From the late 19th century well into the 20th, this was done via a direct connection between these users over twisted pair wire. This type of wire is inexpensive and easy to manage, though its transmission characteristics are far from ideal. The local loop has been one of the costliest components of a network, in large part because a sep- arate connection is required for virtually every customer. Shared tele- phone infrastructure used by multiple consumers did not appear until development of the CO switch. In the last 40 years, local loop technology has undergone significant changes. The consequence of these changes has been to move the point at which the infrastructure is shared gradually closer to the customer, so that the local loop could become less costly. Today’s local loop consists of a combination of loop carrier systems and remote switching partitions/ concentrators. Loop carrier systems are designed to connect clusters of customers with the CO over transmission facilities shared by many end users. That is, in- dividual customers no longer have dedicated connections to the CO. Un- der most circumstances, this is transparent to customers because most people use their telephone for only a small percentage of the time. Unlike loop carrier systems, host-remote switches consist of a portion of the CO switch that has been placed among a cluster of customers. Host-remote switches handle some of the switching functions, which can further re- duce the capacity needed to connect the remote to the main CO switch. In effect, the switch is partially distributed throughout the service area us- ing such an architecture. Local loop facilities will appear in this book as a point of controversy. While local telephone companies have sought ways to reduce loop costs INTRODUCING TELECOMMUNICATIONS N 7 through carrier systems and host-remote switching configurations, ex- isting loop investment remains a major portion of LEC costs. The issue of how this cost should be recovered, whether through local rates or through long distance charges, has been a major point of contention since the 1930s and continues to be controversial today.
Digital Transmission Systems
Transmission systems are facilities intended to connect switches with other switches. Since the 1920s, they have often been high capacity sys- tems. As twisted pair cables offer relatively poor performance over longer distances, engineers developed such other media as coaxial cable, wave- guides, microwave, satellite, and, most recently, optical fiber, all of which are superior to twisted pair in capacity and noise performance. To overcome the attenuation effects associated with distance, engi- neers developed electronic (vacuum tube-based) amplifiers early in the 20th century. These systems boosted the power of the incoming signal (as well as the incoming noise, unfortunately), which meant that the sig- nal-to-noise ratio deteriorated over distance despite the amplifiers, limit- ing the information-carrying capacity of telephone channels. The only solution to this problem was to discover ways of regenerating only the desired signal and not the noise—the solution being the development of digital transmission beginning in the 1950s. Unlike traditional analog transmission techniques, in which every in- cremental signal level had meaning, digital systems depended only on two signal levels. Analog amplifiers had no choice but to amplify noise because there was no way to distinguish signal from noise. Digital sys- tems, however, would detect only high or low voltage levels, so any ad- ditive noise was not meaningful and could be discarded. Thus digital re- peaters could be engineered to regenerate signals that were nearly indistinguishable from the original signal, thus avoiding the deteriora- tion of the desired signal-to-noise ratio over distance. With digital trans- mission systems, however, the end-to-end signal can still deteriorate if the signal-to-noise ratio at the input of any repeater is too low for it to correctly distinguish a high or a low voltage; this inability would result in bit errors, which, though correctable, introduce noise on an end-to- end basis. Since voice or music signals originate at a microphone in analog for- mat, it is necessary to convert them to a digital format if the full advan- tage of digital transmission systems is to be gained. The location of this conversion has evolved over time, starting at the transmission system terminal, then moving to the local loop side of the CO switch. There has been a slow attempt to finally shift this process to the telephone itself, 8 N CHAPTER 1 though this has not happened yet on a widespread basis. A codec device converts an analog signal into the digital pulse code modulation (PCM) format. To accomplish this, the codec samples the analog telephone sig- nal 8000 times per second, and then converts each sample into digitized samples of zeros and ones which are converted back to analog format at the other end without loss of fidelity.
High-Capacity Channels
Since the bandwidth of a voice signal remains constant, higher capacity media like optic cable would be of little value without some additional equipment to take advantage of this higher capacity by finding ways to transmit multiple voice channels across a single medium. In other words, instead of handling one voice channel, these media would handle hun- dreds of voice channels at once. The collection of technologies that achieve this are referred to as multiplexers, and are of two types: frequency divi- sion multiplexing (FDM) and time division multiplexing (TDM). FDM is the technique used initially and consisted of subdividing the high bandwidth media into many subchannels, each of which matched the bandwidth of a telephone channel. This is completely analogous to the broadcast spectrum, in which AM and FM bands are separated into many different channels, each of which is occupied by a single broad- caster per location. Figure 1.4 illustrates the operation of FDM.
FIG. 1.4. Frequency division multiplexing.
In order to flexibly provide resources to the network as needed, and be- cause different media had different capabilities, multiplex hierarchies were developed. These allowed managers to use a building block approach to provisioning capacity and allowed for manufacturing efficiencies. The basic level of multiplexing in the FDM hierarchy was a group of just 12 telephone channels. The next level was a supergroup (five groups, or 60 INTRODUCING TELECOMMUNICATIONS N 9 telephone channels), or a mastergroup (10 supergroups, or 600 telephone channels), which could be multiplexed onto a transmission system. Higher capacity systems were also available, up to a jumbogroup, which consisted of 10,800 telephone channels over a single transmission system. Carrier systems based on this multiplex hierarchy were the mainstay of the telephone network until the 1960s, when they were gradually supplanted by digital transmission systems that used the time division multiplex hierarchy. Just as FDM was well suited to analog transmis- sion, so too is TDM suited to digital transmission. Unlike FDM, in which the bandwidth of the transmission system is subdivided into subbands, TDM allocates the entire bandwidth to a single channel for a short period in regular intervals. This is illustrated in Fig. 1.5.
FIG. 1.5. Time division multiplexing.
With TDM, each time the bandwidth of the transmission system is de- voted to a particular telephone channel, the entire digitized sample (i.e., 8 bits) must be transmitted. Since the telephone channel is sampled 8000 times per second, the transmission system must devote a slot to each voice channel every 125 microseconds (µsec) (=1/8000). As more chan- nels are carried, the amount of time in which the 8 bits must be transmit- ted decreases, so that the bit rate of the transmission system must in- crease. It can be demonstrated relatively easily that an increase in bit rate is directly proportional to an increase in the bandwidth required by the system. Thus, using a different technique, TDM systems perform essen- tially the same functions with the similar trade-offs as do FDM systems. As with FDM systems, TDM employs a multiplex hierarchy. The orig- inal digital transmission system was the T1 carrier system and repre- sented the first level of multiplexing in the TDM hierarchy. The T1 sys- tem consists of 24 telephone PCM telephone channels (and is sometimes called a digroup because it is equivalent to two FDM groups). The next 10 N CHAPTER 1 level of TDM that is in common use is the T3 carrier system, which con- sists of 28 T1 channels or 672 telephone channels. As was the case with FDM, the TDM hierarchy defined by the ITU is not consistent with this one. In the 1980s, an international standard-setting effort sought devel- opment of a very high speed multiplex hierarchy called SONET (for Syn- chronous Optical NETwork) or SDH (Synchronous Digital Hierarchy). SONET is now the standard for most heavy-duty (carrier grade) net- works, although T1 and T3 services are still used as well. Development of multiplexing changed the relationship between the telephone companies and their users, especially larger customers. As the telephone industry developed an ability to handle 24 calls over one digital T1 line, large customers demanded T1 service at a discount, rather than paying for 24 single voice channels. In effect, the large customers wanted to profit from the cost savings that multiplexing provided, rather than letting the telephone companies reap all of the benefits. To retain their customers, telephone carriers (still heavily regulated at the time) asked state utility commissions and the FCC for the authority to provide T1, T3, and higher capacity services at discounted rates.
Data Networks
Telephone networks operate using a technique called circuit switching. This process dedicates bandwidth exclusively to a specific call. In other words, a transmission path is created through the network for the call and that path is maintained until the call is ended. Circuit switching made a lot of sense historically and is generally well suited to voice com- munications which involves a continuous stream of communication. As digital computers emerged in the 1950s and 1960s, users soon sought to interconnect them. The ubiquitous (though analog) telephone network was the obvious medium for such interconnection. To allow the network to carry such digital signals, engineers had to develop modems that would convert the data stream from computers to tones that could be transmitted over the telephone network. As users gained experience with data transmission, it soon became clear that using circuit switching for data networks was not efficient because computers tend to send bursts of data followed by pauses. A sporadic rather than a dedicated transmission path would be more efficient. A better technique for data is to collect the transmitted data from many computers, carry them over a common network, and then distrib- ute them to their respective destinations. To accomplish this, it was nec- essary to encapsulate the data in packets, which would provide instruc- tions on where to send the enclosed data and how to treat it. This technique, called packet switching, makes more efficient use of the net- INTRODUCING TELECOMMUNICATIONS N 11 work because it is highly likely that each computer will send its burst of data at different times than other computers. Since devices made in different nations need to interconnect, data com- munications was an area ripe for standardization. Initially, standardiza- tion was provided within a given manufacturer’s set of products. As the need for more and faster data communications capabilities grew and de- mand for public data networks emerged, manufacturer standards were no longer sufficient. To address these emerging needs, the Swiss-based Inter- national Standards Organization (ISO) and International Telecommunica- tion Union (ITU) began to develop standards for data communications. While they coordinated their efforts, each had different objectives. The ITU sought standards for public data networks, while ISO was developing ar- chitectures and protocols for general computer interconnection. The eventual product of the ITU’s work was recommendation X.25, which specified the interconnection between a public data network and a user. By contrast, ISO produced its Open Systems Interconnection Refer- ence Model (OSI-RM) and eventually many of the protocols within the reference model. The OSI-RM is a standard way to organize the required functionality of data communications systems. It is organized around seven layers, each of which can be implemented by one or more distinct network protocols. Another similar, though unrelated, set of protocols were also developed under the auspices of the ARPANET project of the U.S. Department of Defense. These TCP/IP and associated protocols be- came the de facto worldwide standards, despite the work of ISO and ITU. These are routinely used to interconnect computers worldwide and are the underlying protocol for the Internet. While traditional telephone networks form the industry’s underlying infrastructure, the dynamic growth of today’s data networks (and espe- cially the Internet) strongly suggests that data networks will replace tra- ditional voice links. Until recently, voice and data networks were sepa- rate, with voice traffic traversing circuit switched networks and data being carried across packet networks. As technology developed, it became increasingly possible to “packetize,” combine, and transmit all video, au- dio, data, and voice signals across one network. For large businesses, this presented the opportunity to save money by combining voice and data services. Telephone company owners of the traditional voice network have also recognized, as they continue to install digital transmission me- dia and digital switches, that there are efficiencies inherent in moving from a network based on circuit switching to a packetized network. Even more significant perhaps, newer telephone company competitors recognize huge business opportunities inherent in offering Voice over Internet Protocol (VoIP). By packetizing voice and sending it over the Internet, competitors including cable television and Internet Service Pro- 12 N CHAPTER 1 viders (ISPs) can offer customers an alternative to the public circuit switched telephone network, often at substantial savings. Because the Internet is not regulated, these VoIP providers do not face the regulatory costs and restrictions borne by the telephone companies. As the quality of VoIP improves, and as CPE capable of handling VoIP is developed, VoIP is fast emerging as a viable competitor to the traditional voice network— and, as we shall see, raises new policy concerns.
1.2 ECONOMICS—PAYING FOR IT
In most sectors of the U.S. economy, firms are free to set the prices they will charge and how much they will produce. Their only guidance in mak- ing these decisions are the realities of the marketplace. In a few sectors, however, regulatory bodies, rather than market conditions, constrain what firms can charge and produce—and telecommunications is one such sector (others include power and transport). Because telecommunications was largely a monopoly for most of the 20th century, policymakers deter- mined that consumers should be protected from potential monopoly abuses through economic regulation. Instead of the workings of a compet- itive market, regulators have controlled the price and provision of telecom- munications services at the federal and state levels.
Supply and Demand
The marketplace is the usual determinant for what and how much is pro- duced and for the price that is paid for the results of production. The rela- tionship between supply, demand, and price can be quite clearly stated:
The price in a free market . . . is determined by the interaction of supply and demand. Suppliers (firms) attempt to maximize profits and compete with one another to obtain sales. Demanders (consumers) attempt to allocate their limited incomes over the available goods and services so as to satisfy their preferences. As these two groups interact under the given market con- ditions, an equilibrium price is established. It acts as a balancing mecha- nism to ration or allocate scarce economic resources.1
The function of price as a balancing mechanism between supply and demand can be represented graphically by the movements of the supply and demand curves (see Fig. 1.6). Because buyers are more likely to pur- chase more units of a product as price declines, the demand curve is downward sloping. On the other hand, suppliers are more likely to sup- ply more products the higher the price; this suggests that the supply curve is upward sloping. The price of a product is the point at which the supply and demand curves intersect, as shown in Fig. 1.6. Price, then, is a INTRODUCING TELECOMMUNICATIONS N 13
FIG. 1.6. Supply and demand. measure of the value placed on the product or service by both buyer and seller. Whether the price that results from the intersection of supply and de- mand allocates economic resources in the most efficient manner is largely dependent on market conditions under which buyers and sellers make de- cisions. If they face few constraints, then market forces are operating ef- ficiently and no intervention is necessary to protect the interests of either party. If, on the other hand, either is constrained in their choices, regula- tors may find it necessary to intervene in order to protect consumers or to control the effects of market imperfections. The level of constraint fac- ing buyers and sellers is affected by market structure.
Market Structure
Economists examine the interrelationships of price, supply, and demand through the use of several theoretical market structures. At one extreme is perfect competition; at the other is total monopoly. In between are oli- gopoly and monopolist competition. Each structure has a different effect on the interplay between supply and demand. The underlying assump- tions of the theoretical market structure of perfect competition are that: