Glossary
AC
alternating current
ADPCM
adaptive delta pulse code modulation
ANSI
American National Standards Institute
AT&T
American Telephone and Telegraph Company
BCD
binary-coded decimal
BER
bit error rate
BITS
building integrated timing supply
BOC
Bell Operating Company
BSRF
Basic Synchronization Reference Frequency
CATV
cable television
CCITT
International Consultative Committee on Telegraphy and Telephony
CCS
common channel signaling
CCZ
Coastal Confluence Zone
CDE
clock distribution equipment
CENTREX
central exchange
CI
carrier interconnection
CMTS
Cellular Mobile Telephone Services
CNS
Commercial Network Survivability
CONUS
coterminous United States
CPE
customer-premises equipment
CSI
Commercial Satellite Interconnectivity
DACS
digital automatic cross-connect system
DDS
Digital Data System
DFS
disciplined frequency standard
DNHR
dynamic nonhierarchical routing
DoD
U.S. Department of Defense
DoT
U.S. Department of Transportation
DSP
digital signal processing
DTD
digital time division
DTMF
dual-tone multifrequency signaling
ECSA
Exchange Carrier Standards Association
EO
Executive Order
FAA
Federal Aviation Administration
FCC
Federal Communications Commission
FDDI
fiber digital distribution interface
5ESS
No. 5 Electronic Switching System
4ESS
No. 4 Electronic Switching System
GOES
Geosynchronous Orbiting Environmental Satellite
GPS
Global Positioning System
HDTV
high-definition television
IDTV
improved definition television
IEC
interexchange carrier
INTELSAT
International Telecommunications Satellite Organization
ISDN
integrated services digital network
LAN
local area network
LATA
local access transport area
LEC
local exchange carrier
LED
light-emitting diode
LMSS
land mobile satellite systems
LORAN-C
Long-Range Navigation System-C
MAN
metropolitan area network
MCI
MCI Communications Corporation
MF
multifrequency signaling
ms
milliseconds
µs
microseconds
MTBF
mean time between failure
MTSO
mobile telephone switching office
MTT
mobile transportable telecommunications
MTTR
maximum time to repair
NASA
National Aeronautics and Space Administration
NBS
National Bureau of Standards
NCC
National Coordination Center
NCS
National Communications System
NETS
Nationwide Emergency Telecommunications Service
NIST
National Institute of Standards and Technology
NLP/NSEP
National-Level Program/National Security Emergency Preparedness
NRC
National Research Council
ns
nanoseconds
NSDD
National Security Decision Directive
NSEP
national security emergency preparedness
NSTAC
National Security Telecommunications Advisory Committee
NTSC
National Television Standards Committee
ONA
Open Network Architecture
OSI
open system interconnection
PBX
private branch exchange
PPS
Precise Positioning Service
PRS
primary reference standard
ps
picoseconds
PSN
public switched networks
PUC
public utility commission
RBOC
Regional Bell Operating Company
RMS
root mean square
SF
single-frequency signaling
SLC-96
Subscriber Loop Carrier-96
SNA
System Network Architecture
SONET
Synchronous Optical Network
SSB
single sideband
STP
signal transfer point
TAI
International Atomic Time (Temps Atomique International)
TCP/IP
Transmission Control Protocol/Internet Protocol
TDMA
time division multiple access
TSP
Telecommunications Service Priority
ULSI
ultra large scale integration
UT
Universal Time
UTC
Coordinated Universal Time (Universal Time, Coordinated)
VAN
value-added network
VLSI
very large scale integration
VSAT
very small aperture terminal
WAN
wide area network