Communications Standard Dictionary

1208 Pages·1996·77.723 MB·English

by  Martin H. Weik D.Sc. (auth.)

Communications
Standard
Dictionary
Third Edition
Martin H. Weik, D.Se.
fonnerly on staff of:
U.S. Forces European Theater
Columbia University
University of Delaware
U.S. Anny Ballistic Research Laboratories
U.S. Anny Office of the Chief of Research and Development
Defense Communications Agency
National Communications System
fonner consultant to:
Naval Sea Systems Command
Space and Naval Warfare Systems Command
consulting affiliations:
Dynamic Systems, Incorporated, Alexandria, Virginia
Science Applications International Corporation, Sierra Vista, Arizona
fonner:
Chainnan, Glossary Subcommittee
Federal Telecommunication Standards Committee
National Communications System
Chainnan, Glossary Subcommittee
Computer Society Standards Committee
Institute of Electrical and Electronic Engineers
Chainnan, Technical Committee X3K5
Vocabulary for Infonnation Systems
American National Standards Institute
Chief U.S. Delegate to TC97/SCI
Vocabulary for Infonnation Systems
International Organization for Standardization
Communications
Standard
Dictionary
Third Edition
Martin H. Weik, D.Se.
CHAPMAN & HALL
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DOl: 10.1004/978-1-4613-0429-6
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To my wife, Helen,
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during the preparation oj this and prior editions.
And God said, Let there be light:
and there was light. And God saw the light,
that it was good: and God divided the light from the darkness.
Genesis 1:3-4
Now the whole earth had one language and few words.
And the Lord said, "Behold, they are one people,
and they have all one language;
and this is only the beginning of what they will do;
and nothing that they propose to do
will now be impossible for them."
Genesis 11: 1, 6
In the beginning was the Word,
and the Word was with God,
and the Word was God.
John 1:1
Contents
Preface xi
Introduction xv
Definitions 1
Appendixes 1103
A. Abbreviations and Acronyms 1103
B. Tables 1179
Table 1: Frequency Ranges and Designators 1179
Table 2: Higher Frequency Ranges and Extension Designators 1180
Table 3: The Metric System of Units 1180
Table 4: Prefixes Used with Metric Units 1181
Table 5: Radiometric Terms 1182
Table 6: T-Carrier Hierarchy for North America 1182
Table 7: T-Carrier Hierarchy for Japan 1183
Table 8: T-Carrier Hierarchy for Europe (CEPT) 1183
Table 9: Near, Intermediate, and Far Electromagnetic Fields 1184
Table 10: T-Carrier Characteristics 1184
C. Bibliography 1185
Preface
The Early Days
The modern age of communications began in the latter half of the nineteenth cen
tury with the advent of the telegraph and the telephone. Three-quarters of a century
later, about the middle of the twentieth century, electronic computers made their de
but. The computer age was introduced by gargantuan building-size computing ma
chines, such as (a) the ENIAC (Electronic Numerical Integrator and Calculator), a
decimal machine with 20 words of decade ring counter storage, 19,000 full-size
vacuum (radio) tubes, a 400-ms (millisecond) operation time, and programming
based on external wiring which had to be rewired each time the program was
changed, (b) the EDVAC (Electronic Discrete Variable Automatic Computer), a ser
ial binary machine with 1024 words of mercury tube storage, a 48-f.1s (microsecond)
operation time, and internally stored programming, and (c) the ORDVAC (Ord
nance Variable Automatic Computer), a parallel digital machine with an analog
adder that had an operation time of the order of several microseconds, depending on
the nature of the operands, 1024 words of cathode ray tube storage (Williams
tubes), and internally stored programming. The ENIAC and EDVAC were devel
oped by the University of Pennsylvania and the ORDVAC by the University of Illi
nois. All were installed, further developed, and operated at the U.S. Army's Ab
erdeen Proving Ground primarily for ballistic computations, numerical analyses,
and other scientific applications. Along with a pair of Bell relay computers, a Busch
Mechanical Differential Analyzer, and punch card facilities, these machines consti
tuted the largest single concentration of computer capability in the world. Their
combined capacity and computing power was a small fraction of the power of a sin
gle modern electronic computer.
No Interconnection and No Networking
Visitors from around the world, including Japan, came to witness the Aberdeen ma
chines in operation. The year was 1950. There were no commercially produced elec
tronic computers. Teams of government engineers and technicians spent years to
complete the development and connect input/output and peripheral devices to these
machines. Though all the machines were installed in the same Ballistic Research
Laboratories building, not a word was uttered about connecting these machines di
rectly to each other, not to mention connection to other machines via telephone lines.
The state of the art was not ready for the interconnection of computers. There were
no standards, no protocols, no computer interconnection, and no need or incentive
for such interconnection.
xi
First Preface
XlI
Computers and Communications
During the almost half century that followed these early computing stalwarts, a myr
iad of companies developed and marketed commercial electronic computers, always
increasing computer capabilities and decreasing size. Gradually, the electronic com
puter changed the face of communications systems. Computer-to-computer, data
base-to-database, and terminal-to-terminal communications capabilities were added
to the conventional person-to-person, multicast, and broadcast communications sys
tems. Up until the 1990s, the communications community considered computers as
just another end instrument on their communications lines. The computer community
considered communications lines simply as links between computers and work sta
tions. Multimedia interconnection became essential. Homes and offices with per
sonal computers required video and graphics. Broader bandwidths, higher data sig
naling rates, and more channels were required. The communications community
began to use computers to control their communications systems, and the communi
cations systems were used to interconnect computers. Finally, with remote job entry,
computer networking, and database interconnection, the boundary between the two
communities began to disappear.
The Superhighway
The computer and communications communities began supporting each other. Data
signaling rates and computer operational speeds were matched. Computers needed
the higher computer-to-computer transmission rates and broader bandwidths. Com
munications systems needed faster communications traffic control capabilities. Ini
tially there was no real amalgamation of communications, computer, data process
ing, and control systems. Only during the last decade of the twentieth century has
meaningful integration occurred, giving rise to the modem mix of communications
concepts, such as multimedia, cyberspace, the information superhighway, Internet,
servers, World Wide Web®, clients, B-ISDN, SONET, cellular telephones, personal
communications, open systems architecture, the OSI-RM, and E-mail, to name but a
few. All of these fast-moving and accelerated developments and applications
of communications systems occurred with equal rapidity in the military, civilian,
and commercial sectors. Integration of computer and communications systems be
came commonplace.
Real Time
Modem communications systems enable (a) real time acquisition and distribution of
information, (b) remote control of systems and devices, (c) telemetering of data from
any remote place to any other place, (d) search of remote databases, (e) conversa
tional operation of geographically widely separated personal computers, (f) remote
job entry and access into computers from and to nearly anywhere around the world,
and (g) worldwide rapid message and packet transmission. News reaches homes and
offices as it occurs. House-to-house street fighting in civil and national wars, the
devastating effects of earthquake, flood, and fire, and the investigations of legisla
tive, judicial, and law enforcement authorities may be witnessed in billions of homes
and offices around the world in the same moment in which they occur. Communica
tions has in fact tied the elements of the world together, though the elements may be
far from united in purpose.
xiii Preface
Security
The establishment of Internet, cyberspace, and the information superhighway has
given rise to a generation of predator hackers, crackers, and larcenists who invade
privacy, violate copyright laws, break security codes, steal trade and industrial se
crets, illegally manipulate financial accounts, illegally obtain information for private
profit, distribute pornographic literature, promote drug transactions, and entice un
suspecting citizens into illegal activities. Cyberspace is difficult to police, though
many traps have been set and many predators have been caught, arrested, and
charged. With little precedence for such cases, courts are ill prepared to handle them.
In many cases, legal procedures are not clear. Identification of exactly what is con
sidered criminal is difficult. Shortly after arrest and conviction, most crackers and
criminal hackers are given small fines, suspended sentences, and the freedom to con
tinue their clandestine illegal and illicit operations. Much needs to be done in the
area of secure communications systems to provide adequate protection against the
criminal hacker before the enormous benefits of the superhighway and the Internet
are further jeopardized. The situation is similar to that of the early days of the tele
phone when everyone was concerned about wiretapping. However, the current situa
tion goes beyond wiretapping. It includes illegal tapping of information resources.
Further enhancement of secure systems and firewalls is becoming more and more es
sential.
MARTIN H. WEIK, D.Sc.