Fiber Optics Illustrated Dictionary - Part 21 doc

Fiber
Optics
Illustrated
Dictionary
code
rejects
In
packet
networking,
codes
that
are
not
used
or
not
recognized
are
processed
as
code
rejects.
co
dec encode/decode, coder/decoder. A
system
to
convert
analog
signals,
such
as

video
and
voice,
to
digital signals
for
transmission,
then
back
to
analog
at
the
destination.
Codec
mechanisms
were
originally
installed
on
trunk lines, but
as
the
cost
of
electron-
ics
dropped,
they
moved

closer
and
closer
to
the
home
and
office
until
now,
with
systems
such
as
DSL,
the
codec
is
installed
and
performed right
on
the
pre-
mises.
Contrast
with
modem.
coded mark inversion
CM!.

In
SONET
and
SDH
networks, a two-level non-return-to-zero coding
scheme.
Binary
values
are
coded
in
relation
to
a
bi-
nary
unit
time
interval
(T). A
one
(I)
is
coded
for
a
full
time
interval
at

one
of
two
amplitude
levels
(low
and
high)
such
that
the
level
alternates
for
successive
ones.
A
zero
(0)
is
coded
by
apositive
transition
from
one
to
the
other
consecutive amplitude

level
at
the
midpoint
of
the
time
interval
for
half a
binary
unit
time
interval
(T/2).
Code Red An
intrusive
program
called
a
worm
that
used
a
unicode
encoding
technique
to
infect
systems.

A
buffer
overflow
vulnerability
in
the
indexing
server
was
exploited
to
insert
the
worm
onto
a
new
system.
Once
a
system
had
been
infected,
the
worm
used
it
to
perform denial

of
service attacks
on
www.whitehouse.govand,
in
some
cases,
defaced
the
server's
home
page.
It
spread
by
randomly
generat-
ing
IP
addresses
for
new
systems
to
infect.
Windows
NT
and
Windows
2000

systems
using
the
Microsoft
Internet
Information
Server
(llS)
were
vulnerable.
In
response,
vendors
such
as
Cisco
Systems
took
steps
to
update
systems
to
prevent
this
type of security
breach and Microsoft issued a Security Bulletin
MS01-033
with
information

on
patches.
coding violation Cy'
In
ATM
networking, a
coding
violation
results
when
bit
interleaved
parity
errors
are
detected
on
an
incoming
signal.
Each
BIP
error
(typi-
cally
up
to
8,
16,
or

24)
increments
a
CV
counter.
In
SONET,
the
section,
line,
and
path
errors
are
located
in
their
associated
overhead
frames.
Thus,
in
a
BIP-8
system,
up
to
8x N
coding
violations

may
be
associ-
ated
with
a
frame.
One
or
more
coding
violations
in
a
second
on
a
layer
results
in
an
errored
second
(ES)
or
a severely errored second
(SES).
See
bit
inter-

leaved
parity.
See
RFC
1595.
cohere
To
come
together
firmly,
to
be
cohesive,
to
coalesce,
to
hold
together,join,
unite,
merge.
The
term
particularly
applies
to
the
action
of
small,
discrete

parts
or
granules.
coherent light
Light
in
which
the
wave
lengths
are
aligned
or
ill
phase
to
create a
very
straight,
narrow
beam,
in
contrast
to
light
from
lamps
and
flashlights
that

spreads
out
and
quickly
diminishes
in
intensity.
Coherent
Light
can
be
generated
by
lasers
and
by
some
light-emitting
diodes
(LEDs).
Both
lasers
and
LEDs
are
used
as
light
sources
for

fiber
optic
cables.
coherer A
device
that
causes
particles
to
join,
lump,
or
clump
together
when
exposed
to
a nearby
dis-
charge ofelectricity
or
to
a current running
to
the
particles
through
a
wire.
As

the
particles
are
stimu-
192
lated
to
arrange themselves
in
a
more
coherent
fash-
ion,
that
is,
to
align
themselves
so
that
resistance
is
lowered,
they
collectively provide a better conduct-
ing
surface.
Many
early coherers consisted ofa

glass
tube
corked
at
each
end
with
filings
sealed
inside.
The
coherer
was
connected
in
series
with
a battery-driven
electrical circuit.
Early
experif11ents
by
O.
Lodge
in
1894,
D.
Hughes
in
1878,

and
E.
Branly
in
1890
resulted
in
acohering
apparatus
that
could
behave
as
an
on/off
switch
by
serving
as
a nonconductor, unless stimulated
by
a
spark,
and
returning quickly
to
nonconducting
sta-
tus
once

the
spark
and
the
current
had
passed
through.
This
useful
device
was
adapted
by
Marconi
for
im-
provements
in
radio
devices.
See
Branly
detector.
Marconi & Castelli Coherers
This historic Marconi cohereI' is only a couple
of
inches long, a delicate glass tubing supported
by
an

ivOly base. It
is parr
of
the American Radio Museum
collection. Coherers were the forerunners to rectify-
ing crystal detectors in crystal radio sets.
This diagram
of
a Castelli cohen!r shows a tube (1)
within which are conductorplugs (2,2') separated
by
an iron
plug
(4) and two mercurypockets (3,3
').
This
cohereI' was used by Guglielmo Marconi in transat-
lantic experimell1s. [ScienlijicAmerican,
Oct.
4,
1902.}
coil
In
its
simplest
sense,
a
loop
or
number

of
con-
tinuous
turns
of
wire
or
other material.
The
coil
may
have
successive
windings
that
are
touching,
or
that
may
be
spaced
and
stretched
out
like
a
spring.
Coils
are

often
used
in
wireless communications
technolo-
gies
where
a
long
length
of
wire
must
fit
in
a
small
amount
of
space,
where
abroader
conductive
surface
area
is
needed,
or
where
the

proximi
ty
of
the
wire
loops
changes
its
overall
conductive properties.
In
antennas,
receptivity
to
electromagnetic
waves
is
based
in
part
on
matching
the
length
ofa
lorlg
wave;
consequently,
very
long

wires
are
needed
for
some
applications.
There
are
many
ways
to
wind
and
use
coils.
Tables
© 2003 by CRC Press LLC
are
published
in
electronics
guides
describing
the
length
and
diameter
of
cores,
and

the
gauge
and
num-
ber
of
windings
needed
for
the
wire.
Open
coils
with
few
turns
are
used
as
load
coils
in
voice
grade
tele-
phone
wire
installations.
Wound
coils, wrapped

around
~
metal
core,
can
be
used
to
create
an
arma-
ture.
Sending/receiving coils
can
be
created
with
many
windings
over
a
core
or
a
frame,
utilizing
the
thickness
of
the

wire,
the
shape
of
the
coil,
and
other
characteristics
to
control
which
frequencies
are
trans-
mitted
or
received.
Sometimes
dual
windings
are
used,
that
is,
a
smaller
coil
inside
a larger

one,
with
an
insulating
layer
in
between.
A
spark
coil
for
a
ba-
sic
wireless
transmitter
can
be
constructed
with
an
inner
primary
winding
coil
and
an
outer
secondary
winding

coil
encasing
a
soft
iron
core.
Commercial
induction
coils,
based
upon
the
same
structure
as
the
simple
spark
coil,
were
used
for
decades
to
generate
intennittent
high
voltage.
One
unsettling

historical
fact
is
that
X
-ray
coils
were
used
in
the
early
part
of
the
century
for
sending
wire-
less
communication
signals.
Load
coils
are
commonly
used
on
copper
telephone

wire
installations
to
improve
signals
at
voice
grade
levels,
but
they
cause
problems
when
data
is
sent
at
high
speed
through
the
wires,
as
in
digital
subscriber
line
(DSL)
services;

DSL
transmissions
are
highly
sensitive
to
noise
and
distance.
See
antenna,
arma-
ture,
basket
winding,
induction
coil,
load
coil,
wind-
ing,
winding
machine.
Armature
Coil
Windings
Two
simple types
of
armature coils

are
shown
here.
On
the left
is
a single
coil,
on
the
right,
a double
coil,
wound
in
parallel. Armature coils
can
be quite
large
and intricate and
are
the basis
of
electric
'dynamos,
'
now
more
often
calledgenerators.

cold docking
Hooking
components
into
a
base
or
desktop
unit
while
one
or,
preferably,
both
units
are
powered
off.
This
is
done
to
prevent
danger
of
elec-
trical
shock
or
damage

to
sensitive
electronic
com-
ponents.
See
docking.
cold
start
Starting
a
system
from
a
power
off
condi-
tion.
In
a
computerized
system,
it
also
means
there
is
no
software
online.

From
a
cold
start,
many
systems
will
run
through
physical
and
logical
self-test
se-
quences
and
bootstrap sequences
to
load device
drivers
or
other
software
which
may
be
needed
to
rec-
ognize

and
bring
online
the
rest
of
the
system,
and
eventually
the
whole
operating
system.
Collaboration for
Interactive
Visual Distance
Learning
CIVDL.
Videoconferencing
technologies
applied
to
distance education
for
engineering
pro-
grams.
The
CIVDL

is
a
member
of
the
PUG
Alliance.
Colladon, Jean-Daniel (1802-1893) A
Swiss-born
physicist
and
engineer, Colladon
and
his
friend,
Charles-Fran~ois
Sturm,
traveled
to
Paris
in
1825
to
study
mathematics
and
physics
and
to
continue

col-
laborating
on
scientific
experiments.
Both
young
men
became
assistants
to
J.
Fourier.
On
their
second
at-
tempt,
they
jointly
won
the
prize
offered
by
the
Paris
Academy
for
research

on
the
compressibility
of
wa-
ter.
They
accurately
measured
the
speed
of
sound
in
water
and
provided
important
basic
research
as
well
as
a
chapter
in
the
history
of
sonar.

Colladon
was
in-
strumental
in
the
conversion
of
city
lighting
to
gas,
in
the
1840s
and
demonstrated
water
as
a
light
guide.
He
developed
a
type
of
photometer,
to
aid

him
in
mea-
suring
luminosity
for
his
projects.
Archival
collec-
tions
of correspondence
and
scientific
papers
are
housed
in
the
Geneva
public
and
universitY
libraries
and
the
Swiss
library
in
Bern.

See
Tyndall,
John.
collapsed backboneA
backbone
is
a
main
artery
or
trunk
in
a
network
system.
A
collapsed
backbone
is
one
in
which
the
physical
connections
are
incorpo-
rated
into
a centralized intelligent

hub
or
network
center,
providing
easier
access
and
administration.
collate
To
assemble
in
the
desired
order.
Many
print-
ing
programs,
word
processors,
desktop
publishing
programs,
and
photocopy
machines
now
have

set-
tings
that
allow
you
to
choose,
for
multiple
printouts
ofa
multipage
document,
whether
it
is
to
be
printed
sequentially
or
in
page
groups.
Collation
is
the
elec-
tronic
substitute

for
lining
up
three
card
tables
in
a
row
with
a
pile
of
each
page
ofa
twenty-page
docu-
ment
lying
side-by-side,
and
having
friends
and
co-
workers
walk
down
the

line
picking
up
one
of
each
page.
I'm
sure
most
readers
have
done
this
at
least
once
in
their
lifetimes.
Collating
settings
and
devices
are
great
time
savers.
collect callA
call,

usually
on
the
telephone,
in
which
the
receiver
pays
for
the
call
once
it
has
been
initi-
ated.
Most
collect
call
systems
require
the
prior
ap-
proval
of
the
person

receiving
the
call
before
the
call
is
pennitted
to
continue.
Person-to-person
calls
are
generally
more
expensive
than
station-to-station
calls.
It
is
more
difficult
now
to
connect
collect
calls,
as
many

people
have
answering machines
to
screen
calls,
and
may
not
hear
the
operator
requesting
au-
thorization.
collimate
lJ.
To
make
parallel,
to
cause
to
follow
par-
allel
trajectories.
See
coherent.
collimation

1.
The
process of
making
something
travel
parallel,
with
a
minimum
of
divergence
or
con-
vergence.
2.
The
process
of
making
light
waves
travel
parallel
without
diverging
or
converging.
This
pro-

cess
is
useful
in
testing
and
aligning
optical
instru-
ments
and
is
essential
for
technologies
that
require
a
coherent
beam
that
doesn't significantly
lose
power
over
distance
due
to
spreading
or

scattering.
collision
In
data
networks,
there
are
commonly
many
193
© 2003 by CRC Press LLC
Fiber
Optics
Illustrated
Dictionary
devices
trying
to
send
signals
at
the
same
time.
If
this
happens
at
exactly
the

same
time,
collisions
may
oc-
cur.
There
are
a
number
of
mechanisms
to
manage
collision-detection
and
traffic
flow,
includingjam
sig-
nals
for
preventing
simultaneous
transmissions.
Typi-
cally,
the
jam
signals

will
cause
devices
to
back
off
and
wait
for
a
random
period
of
time
before
trying
again.
The
introduction
of
the
random
time
factor
re-
duces
the
chance
of
the

same
devices
starting
the
transmission
again
at
exactly
the
same
time.
Care
must
also
be
taken
to
ensure
that
not
too
many
colli-
sions
occur.
If
there
are
many
collisions,

and
devices
are
constantly backing off
and
trying
again,
then
throughput
may
be
compromised.
Excessive
colli-
sions
may
mean
that
an
additional
router
or
bridge
needs
to
be
added
to
the
system

or
that
some
devices
need
to
be
disengaged.
collision detection
On
data
networks,
the
means
by
which
the
system
detects
that
more
than
one
device
is
attempting
to
transmit
data
at

the
same
time.
This
detection
may
be
done
in
a
number
of
ways,
with
ac-
knowledgments
being
one
means
of
signaling
a
sys-
tem
that
data
has
made
it
successfully

through.
If
it
hasn't,
and
no
acknowledgment
is
received
in
a
rea-
sonable
amount
of
time,
then
there
may
have
been
a
collision
and
the
system
reacts
accordingly.
One
type

of
mechanism
triggered
by
collision
detection
is
ajam
signal,
which
alerts
devices
to
back
off
until
the
jam
is
cleared.
See
collision,
jam,
jam
signal.
collocation
1.
Adjacent
placement.
2.

Physical
place-
ment
of
customer transport and/or multiplexing
equipment
within
the
carrier's
premises.
collodionA
viscous
solution
introduced
into
the
pro-
cessing
of
photographic
prints
in
the
1850s.
color burst.
See
burst.
color
carrier
referenceA

continuous
signal,
related
to
a
color
burst
signal,
used
for
modulation
and
de-
modulation.
color codeAn
identification
system
based
upon
col-
ors
or
specified
widths
or
patterns
of
color.
Many
in-

dustries
color
code
their
dials,
wires,
and
components
for
quick
recognition
and
selection.
Electronic
com-
ponents
such
as
resistors
are
often
labeled
as
to
their
values
with
bars
of
colors

in
particular
sequences.
Color Graphics Adapter
CGA.
A color
graphics
standard
introduced
by
International
Business
Ma-
chines
(ffiM)
in
1983
as
their
first
color
graphics
con-
troller
card.
Until
then,
ffiM
computers
with

native
controllers
displayed
only
in
monochrome.
CGA
sup-
ported
a
display
resolution
of320 x
200.
It
has
since
been
superseded,
first
by
EGA,
and
then
by
VGA,
and
now,
almost
entirely

by
SVGA.
color modelA
conceptual
description
of
how
colors
are
detected,
perceived
(usually
by
humans),
or
re-
produced.
Human
color
perception
is
an
exquisitely
sophisticated phenomenon,
as
is described
insightfully
and
anecdotally
in

Oliver Sacks'
An
Anthropologist
on
Mars.
Many,
many
color
models
ex-
ist'
none
of
which
is
complete
or
generalizable
to
every
situation.
See
CMYK.,
color
space,
Maxwell's
triangle,
Munsell's
color
model,

RGB.
color monitorA
monitor
that
uses
color
transistors
194
or
LEDs
or
is
coated
on
the
inside
front
of
the
tube
with
phosphors
which
when
excited
glow
in
particu-
lar
colors

(usually
red,
green,
and
blue),
which
com-
bined
can
appear
as
any
of
millions
of
colors.
Red,
green,
and
blue
are
considered
primary
colors
in
light,
because
their
combination
in

different
intensities
pro-
duces
virtually
any
color.
(Pigment
systems
define
red,
yellow,
and
blue
as
the
primary
colors.)
Thus,
most
color
systems
in
cathode-ray
tubes
employ
three
electron
guns
and

are
commonly
known
as
RGB
systems.
color space A
model
or
scheme
for
objectifying
the
representation
of
color.
Many
color
spaces
exist,
most
of
them
devised
to
work
with
specific
technologies.
Color

spaces
for
printing
pigments
assign
numeric
values
to
particular
hues
which
are
further
coded
so
that
the
printer
can
mix
the
correct
inks
for
use
on
the
press.
color sub
carrier

A
monochrome
broadcast
signal
that
is
modulated
with
sideband
information
in
or-
der
to
convey
color.
color television
standards
Different parts of
the
world
have
standardized
on
different
formats
and
even
different
subformats,

many
of
which
are
not
intercompatible.
The
common
ones
for
color
televi-
sion
are
NTSC,
PAL,
and
SECAM.
colorimeterAn
optical
instrument
for
measuring
and
comparing
colors
from
different
sources,
often

used
to
match
or
calibrate colors according
to
a color
model
or
sample.
colorimetryA
quantitative
method
of
specifying
col-
ors
through
attributes
such
as
wavelength
(color),
excitation
purity
(saturation),
and
luminance
(intensity).
Colossus

Mark
I A
code-breaking
machine
devel-
oped
by
Alan
Turing
and
others,
put
into
service
in
1944
in
Bletchley
Park,
England,
to
help
decrypt
messages
from
other
nations,
particularly
Germany,
transmitted

during
World
War
II.
It
was
delivered
under
the
leadership
of
Tom
Flowers,
representing
the
Telephone
Research
Establishment;
Max
Newman
and
Harry
Hinsley
played
prominent
roles.
The
ex-
istence
of

this
machine
was
not
publicly
known
until
almost
three
decades
later.
See
Manchester
Mark
I;
Turing,
Alan.
COLP connected
line
identification presentation
(e.g.,
as
in
ISDN
Q.81
and
Q.731
number
identifica-
tion

services).
COLR
connected
line
identification
restriction
(e.g.,
as
in
ISDN
Q.81
and
Q.731
number
identification
services).
Columbia Broadcasting System
CBS.
This
major
U.S.
network
was
granted
its
fITst
commercial
broad-
cast
license

in
1941
and
not
long
after
began
to
de-
velop
a
color
television
system.
COM
1.
See
Component
Object
Model.
2.
See
con-
tinuation
of
message.
Com21, Inc.A
publicly
trading
American-based

glo-
bal
ISO
900
I-registered
supplier
for
the
broadband
access
market,
founded
in
1992.
The
company
pro-
vides
ATM,
nOCSIS,
and
EuroSIS
products
to
cable
service
providers
and
operators
for

delivering
high-
speed
Internet
and
telephony
applications.
Com21
has
a
research
facility
based
in
Ireland.
© 2003 by CRC Press LLC
combination antennaAn
antenna
designed
to
cover
a
range
of
frequencies,
usually
UHF,
VHF,
and
FM,

in
a
single
unit.
Combination
antennas
have
a
vari-
ety
of
elements
including
reflectors,
Yagi-Uda
arrays,
and
log-periodic
components
to
accommodate
a
va-
riety
of
signals
with
good
gain.
Since

several
signals
are
being
received,
the
down-lead
will
usually
require
a splitter
to
feed
the
individual
signals
into
the
ap-
propriate
components,
or
in
a
combination
compo-
nent,
into
the
appropriate

input
receptacles.
See
an-
tenna,
UHF
antenna,
VHF
antenna.
COMETT
Community
Action
Programme
in
Edu-
cation
and
Training
for
Technology.
An initiative of
the
European
Union.
Comisi6n de Regulaci6n de Telecomunicaciones
CRT.
The
telecommunications
regulatory
commis-

sion
of
the
Republic
of
Columbia.
/>Comisi6n FederaldeTelecomunicaciones
Cofetel.
An
administrative
agency
of
the
Secretary
of
Com-
munications
and
Transportation
of
Mexico.

Comisi6n Nacional de Comunicaciones
The
na-
tional
communications commission of
Argentina.
/>Comisi6n
Nacional

de
Telecomunicaciones
CONATEL.
The
national
telecommunications
com-
mission
of
Honduras.
/>Comite Consultatif International Telegraphique
et Telephonique
CCITT.
This
important
standards
body
is
now
known
as
the
lTU.
See
ANSI,
CCITT,
International
Telecommunication
Union.
command buffer A

portion
of
memory
that
stores
recently
executed
commands
or
frequently
executed
commands,
so
that
the
command
can
quickly
be
fetched
and
re-executed
if
needed.
A
buffer
is
a
type
of

simple
memory
cache
used
to
speed
up
the
over-
all
performance
ofa
system.
See
cache.
command lineinterface, command lineinterpreter
CLI.
The
software
interpreter
that
accepts
text
com-
mands
input
by
the
user,
attempts

to
fulfill
the
request
by
interpreting
them
into
machine
language,
then
re-
sponds
with
an
answer,
information,
or
error
message.
Most
operating
systems
come
standard
with
a
com-
mand
line

interpreter;
the
Macintosh
is
a
notable
ex-
ception.
On
many
computers,
such
as
Amiga
and
Unix
systems,
new
commands
can
be
readily
added
to
a
bin
directory
and
henceforth
executed

in
the
same
manner
as
the
default
command
set.
See
command
line.
command pathA
location
designator
for
directories
on
a
system
that
hold
system
commands
or
com-
mands
that
are
to

be
activated
from
anywhere
on
the
system
without
having
to
type
the
full
path
from
the
current
directory.
Most
systems
have
a
configuration
file
that
allows
common
path
names
to

be
established
at
start-up
time,
and
these
generally
stay
active
while
the
system
is
powered
up.
If
path
names
are
changed,
it
will
be
necessary
to
reread
the
path
file

to
estab-
lish
the
new
paths
and,
on
some
systems,
you
may
have
to
reboot
the
machine
(very
inconvenient).
Commercial CableCompanyA
historic
communi-
cations
cable
company
founded
in
1883
by
John

W.
Mackay
and
James
Gordon
Bennett,
Jr.
The
company
laid
some
of
the
earliest
cables
between
Ireland
and
the
west
coast
of
North
America,
and
later
to
conti-
nental
Europe

as
well.
The
company
was
hotly
com-
petitive
with
Western
Union
but
needed
land
systems
to
be
completely
independent
of
Western
Union.
As
a
consequence,
Mackay
purchased
a
controlling
share

of
Postal
Telegraph
Company.
Commercial
Internet
Exchange
CIE.
An
alliance
of
CERFnet,
UUNET,
and
PSI
in
1991.
Since
that
time,
other services
have
fonned
agreements
with
CIX
to
allow
unrestricted
flow

of
traffic
across
net-
works
in
the
CIX
backbone.
For
a
fee,
service
provid-
ers
may
access
and
send
traffic
across
the
network.
Commercial Internet ExchangeAssociation
CIX.
A
nonprofit
trade
association
established

to
promote
and
support
the
use
of
the
Internet
for
commercial
activities.
Its
members
consist
of
public
data
inter-
network service providers supporting
public
data
communications.
CIX
provides
a
forum
for
the
ex-

change
of
ideas
and
information
and
encourages
tech-
nical
research
and
development.
Membership
is
open
to
organizations
offering
TCP/IP
or
Open
Systems
Interconnect
(OSI)
public
data
intemetworking
ser-
vices
to

the
general
public.
/>Commercial Space LaunchAct
of
1984 A
U.S.
act
of
Congress
that
provided
support
for
private
satel-
lite
communications
systems
launching
and
opera-
tion.
The
regulation
at
present
is
light,
mostly

related
to
Federal
Communications
Commission
(FCC)
fre-
quency
assignments
and
the
positions ofsatellite
or-
bits,
but
this
situation
may
change
in
the
decades
ahead
as
more
and
more
satellites
vie
for

space
in
Earth
orbit.
See
Telecommunications
Act
of
1996.
committed
burst
size
Be.
See
burst
size,
committed.
committed information rate
CIR.
A
service
rate
and
traffic
flow
commitment
level
established
for
service

in
a
Frame
Relay
network.
That
is,
the
CIR
is
a
level
that
is
agreed
upon
for
data
transmission
rates.
The
user
may
use
higher
transmission
rates,
but
the
ex-

cess
data
will
be
marked
as
discard
eligible
(DE)
in
the
case
of
network
congestion.
Since
rates
may
vary,
it
is
a
computed
average
over a
specific
period of
time.
See
cell

rate.
committed rate measurement interval
Tc.
In
net-
working,
the
nonperiodic
time
interval
used
to
mea-
sure
incoming
data,
during
which
the
user
can
send
only
committed
burst
size
committed
amount
of
data

and
excess
burst size
excess
amount
of
data.
Gener-
ally,
the
duration
of
this
measurement
interval
is
pro-
portional
to
traffic
burstiness.
See
committed
infor-
mation
rate,
committed
burst
size.
Committee

Tl
An
ANSI-accredited organization
established
in
1984
that
develops
and
publishes
U.S.
network
reliability
standards
and
technical
informa-
tion
ofinterest
to
network
equipment
developers,
in-
stallation
and
maintenance
personnel,
and
system

ad-
ministrators.
The
organization contributed
to
the
lTU-T
I-series
recommendations
for
B-ISDN
among
others.
Documents
related
to
safety,
power,
ISDN,
SONET,
195
© 2003 by CRC Press LLC
Fiber
Optics
Illustrated
Dictionary
SS7,
and
wireless communications are available
through Committee

TI
's sponsor,
the
Alliance
for
Telecommunications Industry Solutions
(ATIS)
in
Washington,
D.C.
Committee
T1
works
in
coopera-
tion
with
organizations
such
as
the
Network Reliabil-
ity
Council.
See
Alliance
for
Telecommunications
Industry Solutions. />Committee
Tl

Technical Reports
The
Committee
T1
provides a series
of
telecommunications techni-
cal
documents
available
for
a
fee,
and
some
that
can
be
freely
downloaded
off
the
Internet
in
Adobe
Post-
Script
or
Adobe
Portable Document Fonnat

(which
can
be
read
with
one
of
the
many
freely distributed
Adobe
PDF
readers). Abstracts
for
Approved ANSI
TI
Standards
are
also
available.
Since
many of
these
are
ofdirect interest
to
people developing, installing,
and
maintaining
communications

networks,
a
few
are
listed
in
the
Committee
T1
Technical Report Ex-
amples
chart.
Commodore
64
computer
C64.
A low-cost 8-bit
computer
introduced
by
Commodore Business
Ma-
chines
in
the
early
1980s,
aimed
at
the

home
and
school
markets.
Listed
at
under
$600
U.S.,
the
C64
included
a
6510
CPU
with
64KRAM, a
built-in
sound
generator,
the
Digital
Research
CP/M
operating
system,
and
game
controllers
and

cartridge
slot.
It
featured
320
x
200
pixel
color
graphics,
was
competitive
with
the
Apple
IIe
(48K)
and
the
Atari
800
(16K),
and
con-
tinued
to
be
popular
for
a couple of years after

the
Amiga
was
introduced
by
Commodore
in
1985.
The
CI28
was
an
expanded
version
of
the
C64.
CommodoreAmiga
See
Amiga
computer.
Commodore Business Machines
CBM.
Fonnerly
an
office equipment
company
selling calculators
and,
later, the Commodore PET (Personal Electronic

Transactor)
computer,
CBM
is
now
best
remembered
for
its
introduction of
the
Amiga computer.
In
the
mid-1980s,
when
Radio
Shack
had
lost
its
enonnous
market
share
to
IBM
computers,
Commodore
acquired
acomputer

named
the
Lorraine
and
launched
it
in
the
Fall
of
1985
as
the
Amiga
(despite protestations
from
its
developers
that
the
operating system
(OS)
wasn't
finished
and
that
the
hardware should
have
slots

and
more
memory).
Due
to
problems
in
management
and
marketing,
CBM
or Commodore-Amiga,
as
it
came
to
be
known,
folded,with
the
Amiga
assets
bought
out
by
aGennan company
and
later
sold
to

Gateway,
Inc.
Licensing
use
was
subsequently
sold
to
Amino
De-
velopment Corporation, now Amiga Corporation
(though
Gateway retained ownership
of
the
patents).
Commodore folded
in
1994,
but
the
Amiga didn't.
Developers' conferences
were
reinstituted
in
1997
and
the
Amiga2001

show
was
held
in
St.
Louis
in
March
200
I.
See
Amiga computer; Apple Comput-
ing;
Miner,
Jay.
Commodore PET Personal Electronic Transactor.
One
of
the
earliest commercially successful micro-
computers,
the
PET
was
introduced early
in
1977
by
Commodore Business Machines.
It

was
competitive
with
the
Tandy
Radio Shack
TRS-80,
which
initially
was
also
black
and
white
with
4 kilobytes
of
RAM,
but
both
computer
systems
were
eventually
overshad-
owed
by
Apple
and
IBM

computers.
Common Applications Environment
CAE.
Aset
of
standards intended
to
provide a
framework
for
inte-
grated
systems, developed
by
the
X/Open
Company.
See
Single
UNIX
Specification.
Common Architecture for Next Generation Inter-
net Protocol
CATNIP.
When
IPv6,
the
successor
to
IPv4

for
the
Internet,
was
in
the
design
stages,
a
num-
ber
ofproposed fonnats
were
submitted.
CATNIP
is
one
of
three fonnats
that
were
incorporated
into
the
IPv6
specification
by
the
Internet Engineering
Task

Force
(IETF).
See
IPv6.
common battery
In
early
telephone
central
offices,
a
24-
or
48-volt battery called a talking battery
was
used
for
supplying
the
power
for
a
phone
conversa-
tion.
Later,
starting
around
1893,
these

were
replaced
by
48-volt common batteries
at
the
central office
which supplied
the
talking battery
to
each subscriber
through
the
wireline, rather
than
each subscriber
individually providing battery
power.
This practice
Committee
Tl
Technical
Report
Examples
Number Date
Title
TR-7
June
1986

3-DSO
Transport
of
ISDN
Basic
Access
on
a
DS
I Facility
TR-13
Dec.
1991
A
Methodology
for
Specifying
Telecommunications
Management
Network
Interface
TR-15
March
1992
Private
ISDN
Networking
TR-21
Sept.
1993

System
and
Service
Objectives
for
Low-Power
Wireless
Access
to
Personal
Communications
TR-36
May
1994
A
Comparison
of
SONET
and
SDH
TR-45
Dec.
1995
Speech
Packetization
TR-47
June
1996
Digital
Subscriber

Signaling
System
Number
I
(DSS
I)
-
Codepoints
for
Integrated
Services
Digital
(ISDN)
Supplementary
Services
TR-53
June
1997
Transmission
Performance
Guidelines
for
ATM
Technology
Intended
for
Integration
into
Networks
Supporting

Voiceband
Services
196
© 2003 by CRC Press LLC
made
it
possible
for
smaller
home
phones
to
be
de-
signed.
See
battery.
common
bell
A
bell
that
rings
when
any
of
the
des-
ignated
lines

on
a
phone
system
ring.
It
is
often
in-
stalled
on
main
consoles,
to
allow
an
operator
to
in-
tercept
calls,
or
on
night
systems,
so
a
single
person
can

answer
calls
on
several
lines
that
would
normally
be
answered
individually.
common
carrier
A
public
communications
service
carrier,
usually
regulated
and
licensed
by
a
government
agency.
A
common
carrier
may

not
withhold
service
or
discriminate
against
any
public
purchaser of
the
services.
Common
Carrier
Bureau
CCB.
A
large
department
of
the
U.S.
Federal
Communications
Commission
(FCC)
that
recommends
and
implements
regulatory

policies
for
interstate
telecommunications
through
en-
forcement,
pricing,
accounting,
and
program
planning
of
network
services
and
wire
line
services.
Common
Channel
Interoffice
Signaling
CCIS.
An
out-of-band telecommunications signaling
system
that
encodes
information

and
sends
the
signaling
data
over
channels
separate
from
the
voice
signals,
using
digital
time-division
multiplexing
(TDM).
This
sys-
tem
is
more
efficient
-
full
voice-grade
paths
are
not
needed

for
sending
signaling
information
-
and
more
secure
than
older
signaling
systems
which
used
2600
and
3700
Hz
tones
as
supervisory
signals.
Some
of
the
key
points
in
CCIS
networks

include
Signal
Transfer
Points
(STPs),
tandem
switches
act-
ing
as
routers,
Signal
Control
Points
(SCPs),
data
application
servers,
and
Service Switching
Points
(SSPs)
capable
of
switching
tens
of
thousands
of
in-

dividuallines.
CCIS
was
introduced
by
AT&T
in
1976.
The
system
was
significant
in
that
it
introduced
a
new
out-of-band
network,
separate
from
the
network
carrying
the
voice
conversations,
for
the

telephone
signaling
transmis-
sions.
This
type
of
system
was
inherently
more
se-
cure
than
an
in-band
signaling
system
using
tones
that
could
potentially
be
introduced
into
the
circuits
by
a

user.
The
CCIT
adopted
CCIS
as
an
international
standard
called
Common
Channel
Signaling
System
7
(CCS7
or
more
commonly
now
SS7).
See
Signal-
ing
System
7.
Common
Channel
Signaling
CCS.

CCS
is
a
system
that
developed
as
local
telephone
carriers
gradually
linked
up
with
regional
systems,
necessitating
some
common
signaling
standards
for
compatibility.
Tele-
phony required
the
transmission
of
two
general

categories of
data,
the
informational content
of
a
phone
conversation
and
the
supervisory/control
sig-
nals
associated
with
establishing, maintaining
and
disconnecting
the
calls.
As
touch-tone
technology
developed
and
gradually
superseded
pulse
dialing,
and

digital
systems
gradu-
ally
emerged,
the
sophistication ofthe types ofsig-
naling that could
be
carried
over
phone
lines
in-
creased.
New
services
were
devised
that
took
advan-
tage
of
digital
signaling
(e.g.,
Caller
ID).
Originally

both
the
signaling
and
the
conversations
were
carried
on
the
same
channel.
However,
the
blue-
box
antics
of
telephone
phreakers
in
the
1970s
re-
vealed
significant
security
weaknesses
in
this

method,
and
out-band
signaling
took
precedence,
with
con-
tent
and
supervisory
data
carried
on
separate
chan-
nels.
(In-band signaling still exists
on
many
local
branch
systems
but
metropolitan
and
national
net-
~:~;~~:~7:
~I~~~~ri~~b~:::i~~~t::~

•
mentations,
the
signaling
and
call
content
had
to
be
interleaved rather
than
overlapped,
a
situation
that
limited
the
types
of
information
that
could
be
trans-
mitted
about
a
call
while

it
was
in
progress
(think
of
the
difference between a single-tasking operating
system
and
a
multitasking
operating
system
on
a
com-
puter
to
get
the
general
idea).
CCS
permitted
some
of
these
limitations
to

be
overcome,
and
it
began
to
be
more
widely
implemented
in
the
early
1990s.
Thus,
in
ATM
networks,
CCS
is
a
packet-based
sig-
naling
architecture
in
which
circuits
share
signaling

channels
in
which
the
administrative
and
content
sig-
nals
may
be
transmitted
at
the
same
time
(i.e.,
you
can
read
data
about
a
call
on
an
appropriate
device
while
the

call
is
in
progress).
CCS
channels
may
be
cross
connected.
CCS
uses
parameters
that
set
up
the
network
configu-
ration,
such
as
the
switch
type,
debug
level,
data
in-
version

mode,
correspondence between
maps
and
network
interfaces
and
signaling
instances,
layer
ac-
tivation
and
timers,
and
data
link
flags.
In
Transparent
Common
Channel
Signaling
(T-CCS),
private
branch
exchanges
can
be
interconnected

with
digital
interfaces
that
use
non-CCS
protocols
(e.g.,
a
proprietary
protocol)
without
the
CCS
signal
having
to
be
interpreted
to
process
calls
on
the
system.
The
proprietary signaling
is
preserved
and

transported
transparently through
the
data network through a
point-to-point
connection.
In
other
words,
instead
of
routing
the
transmissions,
a
preconfigured
route
is
used
in
conjunction
with
CCS
frame
forwarding
to
support
transparency.
CCS
has

been
defined
for
use
with
Signaling
System
7
(SS
7)
telephony.
CCS
facilitates
the
establishment
and
take-down
of
calls,
signal
monitoring,
internet-
work
transmissions,
and
special-case
call
handling
(e.g.,
calling

card
connections).
See
Signal
Transfer
Point,
Signaling
System
6,
Signaling
System
7.
Common
Channel
Signaling
Task
Force
One
ofa
number
of
task
forces
of
the
Presidential National
Security
Telecommunications
Advisory
Committee

(NSTAC)
that
looked
into
matters
such
as
security
of
the
public
telephone
network,
in
the
early
1990s,
and
issued
a
Final
Report
in
Jan.
1994.
In
May
2000,
NSTAC
issued

a
report
on
information
technology
(IT)
telecommunications
convergence
issues
for
na-
tional
security
and
emergency
preparedness
(NS/EP).
Common
Desktop Environment
CDE.
An
inte-
grated
graphical
user
interface
for
open
systems
fea-

turing
a
standard
interface
for
management
of
data
and
applications.
CDE
is
an
IETF
platform
Human
Computer
Interface
(HCI)
standard.
See
X
Window
System.
197
© 2003 by CRC Press LLC
Fiber
Optics
Illustrated
Dictionary

Common
Gateway
Interface
CGI.
A
means
of
com-
municating instructions
to
a
Web
server through
scripts
or
code,
in
order
to
enhance
the
utility of
Web
pages.
HTML,
a
markup
language
used
on

the
Web,
was
designed
for
formatting,
not
processing,
data
in-
teractions.
To
extend
the
utility of
HTML,
the
CGI
can
be
used
in
conjunction
with
input
to
Web
pages
to
process

forms,
messages,
chat
room
interactions,
database
records,
searches
and
more.
Perl
is
one
of
the
most
flexible,
powerful,
and
prevalent
languages
for
implementing
CGls
on
the
Web,
especially
for
text

processing,
database
searches,
and
fonns
parsing.
Sun's
Java
tends
to
be
used
in
situations
where
graphical
menus,
games,
or
images
are
desired.
See
ActiveX,
Java,
Perl.
Common
Intermediate Format
CIF.
A

subsection
of
the
lTU-
T
H.261
standard
that
specifies
various
broadcast
format
parameters
for
ISDN
videoconfer-
encing.
See
ISDN.
See
Common
Intermediate
For-
mat
Types
chart.
Common
Location
Language Identifier
CLLI.

A
unique
identifier
system,
developed
by
Bellcore,
for
certain
regions
and
equipment.
Thus,
various
ex-
changes,
buildings,
and
facilities
could
be
coded.
A
CLlI
consists
offoUT
characters
for
the
location,

fol-
lowed
by
two
characters
for
the
region,
and
five
char-
acters
for
the
item.
Common Management Information Protocol
CMIP.
A
standardized
connection-oriented
network
management
protocol
based
upon
the
Open
Systems
Interconnection
(OSI)

model.
CMIP
supports
infor-
mation
exchange
(as
opposed
to
network
functional-
ity)
between
network
management
applications
and
management
agents
through
managed
objects.
CMIP
is
part
of
the
X.700
Recommendation
of

the
lTU-T
(also
ISO/IEC
7498/4).
CMIP
was
designed
by
in-
dustry
and
government
participants
to
be
the
heir
to
the
simpler
Simple
Network
Management
Protocol
(SNMP).
CMIP
supports
security
features,

including
access
controls,
activity
logging,
and
authorization.
It
works
in
conjunction
with
the
Common
Manage-
ment
Information
Service
(CMIS),
which
defines
services
for
accessing information
about
network
objects
or
devices.
A

number
of
vendors
have
implemented
CMIP.
For
example,
Solstice
CMIP
has
been
developed
to
pro-
vide
CMIP
services
on
Sun
Microsystems'
Solaris
64-bit
platform.
In
the
early
1990s,
AT&T
and

NCR
released
StarPRO
CMIP
compatible
with
Base
WorX
UNIX-based
systems.
See
Common
Management
Information
Services.
Common Management Information Services
CMIS.
A
standardized
network
services
mechanism
to
enable
peer
processes
to
exchange
information
and

instructions
through
a
defined
message
command
set.
CMIS
works
in
conjunction
with
Common
Manage-
ment
Information
Protocol
(CMIP).
The
CMIS
Y.2
definitions
and
protocol
were
described
in
ITU-T
X.710/711
Recommendations

in
1991.
CMIS
was
standardized
in
the
mid-1990s
as
ISO/IEC
9595/2.
In
1997,
S.
Mazumdar
of
Bell
Labs
proposed
a
set
of
extensions that defined interfaces for providing
CMIS-based
services
using
the
Object
Management
Group

(OMG)
object
services
such
that
CMIS-based
objects
could
be
made
compatible
with
other
man-
aged
objects
in
a
native
Common
Object
Request
Broker
Architecture
(CORBA)
environment.
Common
Management Information
Services
and

Protocol over TCPIIP
CMOT.
CMOT
is
an
Inter-
net
Protocol
information
service
mechanism
in
the
context
of
ISO-standardized
Common
Management
Information
Services/Common
Management
Infor-
mation Protocol (CMIS/CMIP)
as
it
applies
to
a
TCP/IP
environment.

CMOT
was
submitted
as
an
RFC
by
Warrier
and
Besaw
in
April
1989
and
updated
October
1990
as
a
move
toward
international
stan-
dards
suitable
for
implementation
over
the
evolving

Internet.
CMOT
provided
a
means
for
implementing
the
Draft
International
Standard
version
of
CMIS/CMIP
over
Internet
transport
protocols
in
order
to
carry
manage-
ment
information.
See
Common
Management
Infor-
mation

Protocol.
See
RFC
1189
(which
obsoletes
RFC
1095).
Common Intermediate Format (CIF) Types
Format
Lines
x Pixels
Defined within Standard Notes
General
H.320
An
umbrella
encompassing
the
following
ClF, FCIF,
and
QCIF
standards,
sometimes
collectively
called
p*64.
CIF
352 x 288

color
H.261
Suitable
for
large
format
videoconferencing.
Requires
two
B
channels
to
support
both
audio
and
video.
H.221, H.230, H.242
Communications,
control,
and
indication.
H.711, G.722, G.728
Audio
signals.
FCIF
352 x 288

QCIF
176 x 144

H.276
Requires
less
bandwidth
than
CIF
but
also
provides
less
resolution.
198
© 2003 by CRC Press LLC
Common Part Convergence Sublayer
CPCS.
In
ATM
networking,
a
portion
of
the
convergence
sub-
layer
of
an
ATM
adaptation
layer

(AAL)
that
remains
common
to
different
types
of
traffic.
common
part indicator
CPI.
In
ATM
networking,
a
I-byte
field
used
to
interpret
the
remaining
fields
in
the
header
and
trailer.
Common

ObjectRequestBrokerArchitecture
See
CORBA.
Common
Open
Policy
Service Protocol
COPS.
A
simple,
extensible
client/server
protocol
model
for
supporting policy control over quality
of
service
(QoS)
network
signaling
protocols.
COPS
is
a
query
and
response
protocol
that

enables
policy
informa-
tion
to
be
exchanged
between
a
policy
server
and
its
clients
(e.g.,
RSVP
router).
See
RFC
2748.
Communications
Act
of
1934
A
U.S.
federal
regu-
lations
act

to
organize
and
promote
competitive
com-
munications
technologies
and
services.
This
act
es-
tablished
and
described
the
responsibilities
and
ju-
risdiction
of
the
Federal
Communications
Commis-
sion
(FCC)
which
was

descended
from
the
Federal
Radio
Commission
(FRC)
formed
from
the
Radio
Act
of
1927.
The
Communications
Act
of
1934
was
amended
by
the
Omnibus
Budget
Reconciliation
Act
(OBRA)
to
preempt

state
jurisdiction
in
such
a
way
that
indi-
vidual
states
were
no
longer
regulating
rates
and
en-
try
by
companies
offering
wireless
services.
It
fur-
ther
organized
wireless
into
two

categories:
commer-
cial
mobile
radio
services
(CMRS),
including
cellu-
lar
radio
services
and
personal
communications
ser-
vices (PCS), and private mobile radio services
(PMRS),
including public safety
and
government
services.
CommunicationsAct of
1996
See
Telecommunica-
tions
Act
of
1996.

Communications Applications Specification
CAS.
A
communications
protocol
developed
in
the
late
1980s
by
Intel
and
Digital
Communications
Associ-
ates,
Inc.
(DCA)
for
use
with
computer
peripherals
to
enable
software
to
communicate
with

fax/modem
interfaces.
This
protocol,
along
with
Class
1,
2,
and
3
fax
standards,
helped
standardize
computer
fac-
simile
communications,
enabling
software
from
dif-
ferent
vendors
to
exchange
data.
Communications Authority of Thailand
CAT.

A
state
initiative
under
the
Ministry
of
Transport
and
Communications,
established
in
February
1977.
CAT
is
responsible
for
a
national
communications
network
linking
to
the
global
community.
/>Communications
Decency
Act of

1996
A
provision
of
the
Telecommunications
Reform
Act
that
aroused
extreme
controversy
and
opposition
by
the
Internet
community
as
it
made
it
a
federal
crime
to
send
cer-
tain
lewd,

indecent,
or
other
objectionable
commu-
nications
across
networks.
The
Internet
community
rallied
against
it
and,
in
a
June
1997
milestone
deci-
sion
in
the
case
of
Reno
versus
ACLU,
the

act
was
declared
an
unconstitutional
violation
of
individual
rights
to
freedom
of
speech.
See
Telecommunications
Act
of
1996.
Communications Management
Association
CMA.
Formerly
the
Telecommunication
Managers
Associa-
tion,
the
CMA
is

a
charitable
business
communica-
tions
trade
association
based
in
the
U.K.
The
CMA
supports
the
role
of
managers
in
communications
fields
by
providing
and
promoting
educational
activi-
ties
and
excellence

in
the
use
of
communications
technologies.
/>Communications
Policy
Project
CPP.
A
nonparti-
san
initiative of
the
Benton
Foundation
to
strengthen
public
interest
and
participation
in
the
shaping
of
the
National Information Infrastructure (NIl).
The

Benton
Foundation
seeks
to
promote
the
use
of
com-
munications
for
the
greater
social
good
and
encour-
ages
democratic
participation
in
policy
debates
and
regulatory
activities,
especially
those
relating
to

open
access
to
communications
technologies
and
the
pro-
motion
of diversity
in
services
beyond
the
obvious
commercial
applications.
Since
the
mid-1990s,
a
portion
of
the
Foundation's
efforts
has
gone
into
educating

the
public
about
new
digital
environments
and
broadcasting
media
and
the
importance
of
the
equitable
allocation of
radio
spec-
tra
for
positive
social
programming.
Among
other
things,
the
CPP
advocates
support

for
low-power
television
(LPTV)
stations,
as
these
pro-
vide
diversity
and
a
large
proportion of
social
and
educational
content.
Many
LPTV
stations
broadcast
local
news
and
proramming
for
hobby,
church,
ath-

letic,
and
community
groups.
LPTV
stations
often
broadcast
to
remote
or
small
communities
that
are
not
of
commercial
interest
to
large
corporations
because
they
don't
have
sufficient
subscribers
to
generate

a
profit.
There
is
a
persistent
danger
that
LPTV
services
can
be
crowded
out
by
commercial interests
with
strong
lobbies
and
economic
bases
if
they
are
not
ac-
tively
protected
and

promoted
by
the
public,
the
gov-
ernment,
and
communications
agencies
such
as
the
Federal
Communications
Commission.
See
Benton
Foundation,
Community
Broadcasters
Association,
National
Public
Radio,
Public
Radio
International.
Communications Research Centre
CRC.

A
major
communications
research
agency
of
Industry
Canada
located
at
a
secure
site
near
Ottawa,
Ontario
adjacent
to
the Defence Research Establishment Ottawa
(DREWO)
and
the
Canadian
Space
Agency.
The
CRC
engages
in
collaborative,

innovative
research
in
information
technologies,
communications,
and
broadcasting
in
support of Canadian knowledge-
based
economies.
It
further
provides
an
independent
voice
for
public policy
development.
Communications Security Establishment
CSE.
A
Canadian
federal
agency
for
providing
information

technology
(IT)
security
solutions
to
the
Canadian
government.

Communicator
ill
An
ffiM-licensed/Intel-based
PC
videoconferencing
product
with
audio,
video,
white-
board,
and
file
transfer
capabilities
from
EyeTel
Com-
munications, Inc. Communicator III works over
Switched

56,
ISDN,
TI,
Ethernet,
and
Token-Ring
networks.
It
uses
ITU-T
H
Series
Recommendation
standards
and
encoding.
199
© 2003 by CRC Press LLC
Fiber
Optics
Illustrated
Dictionary
Communique! A
Sun
SPARC-based
videoconfer-
encing
program
from
InSoft that

works
over
ISDN,
FOOl,
SMDS,
Ethernet,
ATM,
and
Frame
Relay
net-
works.
It
supports
audio,
visual,
whiteboarding,
file
transfers,
and
a
number
of
applications.
CellB,
JPEG,
and
Indeo standards and encoding are supported.
Community
Broadcasters

Association
CBA.
AU
.S.
national
professional
organization
devoted
to
support-
ing
and
enhancing
diversity
and
vitality
in
the
com-
munity
broadcasting
field,
with
a special interest
in
Class
A
and
low-power
television

technologies
which
are
widely
used
in
niche
market
and
local
commu-
nity
broadcasting.
The
CBA
sponsors
online
news,
workshops,
and
provides
input
into
government
poli-
cies.
See
Communications
Policy Project,
Commu-

nity
Broadcaster's Protection
Act,
low-power
televi-
sion,
World
Association
of
Community
Radio
Broad-
casters.
Community Broadcaster's Protection
Act
A
por-
tion
of
the
Omnibus
Appropriations Bill signed
into
law
by
President
Clinton
in
1999
as

a direct result of
lobbying
by
the
Community
Broadcasters Associa-
tion.
The
Act
established a
new
class
of television
broadcasting
in
the
U.S.,
making
it
possible
for
low-
power
television
(LPTV)
broadcasters
to
apply
for
permanent

status.
The
CBA
subsequently
sponsored
seminars
to
help
educate
broadcast
companies
and
individuals
on
the
implications
and
implementation
of
the
terms
of
the
Act
and
aided
them
in
understand-
ing

Class
A
Compliance
issues.
In
January
2000,
the
Federal
Communications
Com-
mission
(FCC)
adopted
the
Class
A Notice of
Pro-
posed
Rule
Making
(NPRM).
Three
months
follow-
ing,
it released a report
and
order establishing
the

Class
A
Television
Service,
followed
by
a list of
sta-
tions
considered
to
be
eligible
for
this
Service.
See
Communications
Policy
Project,
Community
Broad-
casters
Association.
Community Broadcasting
Association
ofAustra-
lia
CBAA.
The

national
representative
body
for
com-
munity broadcasters
in
Australia.
The
CBAA
pro-
vides
representation,
education,
and
support
for
li-
censed
stations
and
licensee
hopefuls
including
in-
formation
about
issues,
ethics,
intellectual

property,
fundraising,
and
Broadcasting
Services
Act
require-
ments.
The
CBAA
hosts
the
national
community
ra-
dio
satellite
service.
See
Community
Broadcasting
Foundation.
/>Community Broadcasting Foundation Ltd.
CBF.
An
independent
nonprofit
funding
body
for

commu-
nity
broadcasting
in
Australia, established
in
1984.
The
CBF
is
supported
by
the
Australian Dept.
of
Communications,
Information
Technology
and
the
Arts
(DCITA),
and
the
Aboriginal
and
Torres
Strait
Islander
Commission

(ATSIC).
It
solicits
funds
and
distributes
grants
for
ethnic
community
broadcasting,
print
handicapped
broadcasting,
general
community
broadcasting,
and
policy
development
projects.
See
Community
Broadcasting
Association of
Australia.
community dial
office
COO.
A

type
ofcentral
tele-
phone
switching
office
that
is
most
often
found
in
small
rural
communities.
It
is
an
unattended
switch-
200
ing
center that
is
serviced
only
as
needed
and
main-

tained
on
an
occasional
basis
by
a traveling mainte-
nance
technician.
community radio A radio broadcast system that
serves
the
cultural,
ethnic,
local
news,
special inter-
est,
or
social
needs
ofa
community.
Community
ra-
dio
stations
are
important because
they

are
often
the
only
venues
for
minority populations
or
isolated
in-
dividuals
to
access programming matching their
needs
and
interests.
Many
small
groups
are
not
served
by
large,
for-profit
broadcast
corporations.
Since
most
community

radio stations
are
low-profit
or
no-profit"
ventures,
they
do
not
have
the
same
lobbying
power
with
Congress
or
the
Federal
Communications
Com-
mission
as
large,
powerful broadcasting
conglomer-
ates.
It
is
therefore

up
to
listeners,
foundations,
edu-
cators,
and
related organizations
to
support
the
vital
role
played
by
community
radio
in
safeguarding
free-
dom
ofinformation
and
diversity.
The
growth
of
the
Internet
and

the
capability ofserv-
ing
streaming
audio
to
millions
of
listeners
has
broad-
ened
the
reach
of
community
radio
broadcasting
and
the
concept
of
community.
While
still
not
a profit
venture
in
most

cases,
community
radio
stations
can
now
broadcast
to
a wider spectrum of
communities,
based
not
just
on
geographical
regions
through
low-
powered
transmitters,
but
to
the
entire
world,
through
Web
sites
that
can

be
accessed
long
distance
without
additional
fees
by
all
interested listeners
with
Inter-
net
access.
See
Community
Broadcasters
Assocation,
National Public Radio, People's Communication
Charter,
World
Association of Community Radio
Broadcasters.
Community Radio Charter for Europe A set of
priniciples
and
goals
adopted
by
AMARC

at
the
Pan-
European
Conference of
Community
Radio
Broad-
casters
in
September
1994.
The
Charter recognizes
community
radio broadcasting
as
avital
medium
for
fostering freedom of expression
and
information,
cultural
freedom
and
diversity,
and
local culture
and

traditions.
It
defines
ideals
and
objectives
to
help
ra-
dio
stations achieve
these
goals.
See
World
Associa-
tion
of
Community
Radio
Stations.
.
compact
disc
A
small,
flat,
circular,
optical, digital
random-access

storage
and
retrieval
medium.
CDs
are
written
and
read with laser
devices.
CDs
are
used
for
audio
recordings, audio/visual
sound
and
graphics,
and
computer data
and
multimedia applications.
The
CO
format
has
been
standardized
to

120
mm
(4.75")
diameter.
It
consists
ofa
thin
layer of
metal-
lic
film,
etched
with
microscopic
indentations called
pits spiraling literally
for
miles
around
the
recording
surface.
This
structure
is
coated
with
a
smooth

plas-
tic
surface.
The
data
is
stored
in
a
format
that
was
developed
by
Sony
and
Philips
and
agreed
upon
by
electronics
vendors
in
1981.
CD
players
first
began
to

be
marketed
in
Japan
and
Europe,
and
to
a limited extent
in
Canada,
in
1982.
They
did
not
begin
to
be
distributed widely
in
the
United
States
until
1983.
By
1986,
consumer
play-

ers
were
inexpensive
enough
to
promote
an
explo-
sion
ofinterest
in
audio
CDs.
See
SPARS
code.
© 2003 by CRC Press LLC
stereo
audio
compact
disc
interactive
CD-I.
A
more
recent
ver-
sion of
CD
fonnats with read-only players based

around
Motorola
68000
technology.
It
was
developed
by
Sony
and
Philips
and
released
in
1988.
CD-I
al-
lows
interactive
multimedia
use
of compact
discs.
The
CDs
can
be
recorded
with
infonnation

in
vari-
ous
fonns,
including
computer
data
files,
video
im-
ages
and
still
frames
at
more
than
one
resolution,
and
audio
in
three
fonnats.
Compact
Disc
Player -
SCSI
Connection
The

back andfront
of
a
NEe
external compact disc
drive
(CD)
showing
the
various selectors, connectors,
and
components.
Internal
CD
drives usually
don
t
re-
quire disc
caddies.
compact
disc
types and
uses
The
two
most
common
types
of

CDs
are
music
CDs
and
multimedia
com-
puter
application
CDs.
Music
CDs
are
supplanting
music
on
cassette
tapes
and
vinyl
records
due
to
the
greater
clarity
of
the
sound
(no

scratches
or
hiss)
and
greater
stability
of
the
medium
(magnetic
data,
and
the
thin
tapes
themselves
are
somewhat fragile).
CD-ROM
discs
hold
about
680
MBytes
of
data,
al-
though
actual
infonnational

content
may
be
greater
if
the
data
has
been
compressed.
Typically,
CDs
are
written
once
and
read
many
times,
although
the
data
on
PhotoCD
discs
may
be
extended
in
several sessions, with the

new
data being writ-
ten
to
an
unused
section
of
the
disc.
A multisession
CD
player
is
needed
to
read
discs
that
have
been
re-
corded
in
more
than
one
session.
See
bar

code,
com-
pact
disc;
digital
video
disc,
laserdisc,
PhotoCD.
compact
disc
video
CD-Video.
Avariation
on
com-
pact
disc
technology,
announced
in
1987,
which
de-
livered
audio
and
video
on
one

disc.
The
inner
por-
tion
of
the
disc
is
the
recorded
music
and
the
outer
portion
contains
up
to
about
five
minutes
of
analog
video
and
sound,
similar
to
a

small
laserdisc.
CD
players
that
support
the
video
portion
spin
the
disc
faster
than
when
playing
the
standard
audio
track
on
the
inner
portion of
the
disc.
compander A transmission
device
that
compresses

and
expands a
signal,
usually
to
save
transmission
time.
Modems
that
use
compression
techniques
on-
the-fly
are
companding
devices
and
are
typically
in-
stalled
at
each
end
ofa transmission
line.
companding A combination
and

telescoped
word
derived
from
compressing
and
expanding.
Compand-
ing
is
a
process
of
compressing
and
expanding
a
sig-
nal
and
is
used
for
a variety of
purposes,
including
noise
reduction,
security,
and

increased
transmission
speed.
Compaq ComputerCorporationA
successful
com-
puter
company
established
in
1982.
Compaq
shipped
its
first
product a
few
months
later,
in
January
1983,
achieving
phenomenal
first-year
sales.
Compaq
made
the
Fortune

500
list
in
1986.
It
bought
out
Digital
Equipment
Corporation
(DEC),
one
of
the
long-time,
well-known
companies
in
the
computer
industry,
in
1998,
and
subsequently
being
bought
out
by
Hewlett-

Packard.
Competitive
Access
Provider
CAP.
A
competitive
local
carrier
that
is
pennitted
to
compete
with
Local
Exchange
Carriers
(LECs)
and
Inter
Exchange
Car-
riers
(IXCs)
to
provide
voice
or
data

services.
See
Competitive
Local
Exchange
Carrier.
Competitive Local Exchange Carrier
CLEC.
A
competitive
carrier
that
is
permitted
to
compete
with
established
local
voice
and
data
service
providers,
as
a
result
of
the
deregulation

in
the
Telecommunica-
tions
Act
of
1996.
CLECs
may
build
their
own
wire-
lines or lease existing lines for resale of services.
CLECs
include
CAPs,
IXCs,
CATV
service
provid-
ers,
and
others.
See
Incumbent
Local
Exchange
Car-
rier.

Competitive Telecommunications Association
CAT.
A
Canadian-based
association
representing
new
entrants
in
the
telecommunications
service
business,
including
interexchange
carriers
(IECs),
competitive
access
providers
(CAPs),
and
resellers.
complete document recognition
CDR.
A process
that
goes
beyond
object

character
recognition
(OCR),
in
that it recognizes not only text
and
individual
blocks
or
elements
on
a
page,
but
the
general
layout
and
types
of
data.
CDR
software
is
quite
sophisticated
and
can
fairly
reliably distinguish

the
difference
be-
tween
text
and
images,
headlines
and
regular
text,
and
columns
and
sidebars.
completed call
In
the
telephone
industry,
completed
call
has
a fairly
specific
meaning,
describing
a
call
that

has
reached
and
been
answered
by
the
callee,
but
it
does
not
include
the
time
that
the
callee
actually
spends
on
the
conversation.
In
other
words,
the
mean-
ing
ofcompleted call

concerns
the
establishment
of
the
connection
with
the
person
being
called
and
not
the
actual
length
of
the
communication.
complex instruction set computing
CISC.
A
micro-
processor architecture
that
accommodates
complex
machine language instructions
in
which a single

operation
may
be
comprised
of
many
small
instructions
201
© 2003 by CRC Press LLC