Fiber Optics Illustrated Dictionary - Part 8 doc

Fiber
Optics
Illustrated
Dictionary
interface builder about
two
years later, which took
aesthetics, utility,
and
logical linking
to
object-ori-
ented structures several steps beyond Power
Win-
dows,
and
facilitated graphical creation ofwindows,
menus, tables, buttons,
and
much
more,
providing a
fast
and
easy
way
to
create
an
interface
and

connect-
ing structures that were consistent with
the
NeXT
application framework.
An
hour with
the
interface
builder
could
easily
equal
two
days
ofcoding
by
hand
with a text
editor.
In
the
1990s,
other desktop
sys-
tems
began
to
come
out

with interface builders,
an
idea that
has
great practical value, especially
as
ob-
ject-oriented environments became more prevalent.
Some authoring systems
also
function
as
application
generators,
as
do
some programmable databases.
If
the
software front-end that allows authoring
and
da-
tabase configuration without programming
also
pro-
vides
an
option
to
save

code
that
can
be
accessed
and
manipulated, usually with atext editor,
and
to
link
to
operating system
or
program structures,
then
it
is
a
form
ofapplication
generator.
See
application
frame-
work.
application layer
In
layered hierarchy network
sys-
tems,

the
layer that provides services
to
the
applica-
tions programs
(as
in
the
Open
Systems Interconnec-
tion [OSI]model)
or
the
layer
that
runs
the
applica-
tions themselves, depending
upon
the
network layer
design.
In
OSI,
the
application layer ensures avail-
ability ofparties,
may

provide authentication,
checks
the available resources, negotiates data, privacy,
and
error-checking parameters,
and
application-level
pro-
tocols.
See
Open
Systems
Interconnection
for
achart
that describes layer relationships.
application program Avery broad, generic term
for
almost
any
user-level computer program. That's not
to
say
that system administrators don't
use
applica-
tions;
they
do.
They

just happen
to
be
more techni-
cal
applications
aimed
at
atechnical user
level.
Short,
specific applications that
do
a single task
or
a small
number of
tasks
are
sometimes called utilities,
such
as
a disk utility
for
formatting disks,
or
a conversion
utility
for
changing a

TIFF
file
to
a BMP
file,
or
a
copy utility
for
duplicating
disks.
Application pro-
grams commonly used
in
telecommunications in-
clude
Web
browsers,
FTP
clients, chat clients,
gam-
ing
clients (such
as
bridge, chess,
Go,
and
casino
ap-
plications), compression/decompression utilities,

and
file
translation utilities.
Application
Program
Interface
API.
1.
An
interapplication
or
intervendor interface
that
provides
a somewhat standardized means
of
allowing pro-
grams
to
talk
and
work together.
The
Apache server
and
the
Netscape server
API
are
common interfaces

used
to
implement network applications services.
In
acompetitive environment,
API
conformance within
consumer
products
is
rarely
perfect.
By
making
subtle
changes
to
aspecification
in
an
industry-leading
prod-
uct,
vendors
often slow
down
the
competition (e.g.,
faster
modems)

and
create a short business window
during
which
they
are
the
only company
to
support a
particular product
or
specification (i.e., a temporary
monopoly).
However, acertain
level
ofadherence
to
62
standards also
has
competitive advantages
in
that
it
is
easier
for
third party vendors
to

support a leading
product.
2.
In
the
XOpen/Architectural Framework
Technical
Reference
Model,
the
Application Program
Interface
is
one
of
five
basic elements
and
one
of
two
interface
types
(the other being
the
External Environ-
ment
Interface).
The
API

is
aspecification
for
the
data
link
between
the
Application Software
and
the
Ap-
plication Platform
upon
which
all
the
services
are
pro-
vided,
thus
facilitating portability
and
interoperability
among
systems.
The
API
includes

the
semantics,
syn-
tax,
protocols, data structures,
and
other definitions
necessary
to
ensure compatibility.
See
External
En-
vironment Interface.
Application Service Provider
ASP.
A vendor that
distributes software functionality over data networks
such
as
telephone networks, the Internet, or local!
wide
area
networks.
To
get
an
idea
of
what

this
means,
think of
the
different ways
in
which a person can
get
voicemail messages.
The
user can get a voicemail
modem
and
set
up
the
mailboxes
on
the
computer
and
manage
the
messages that
are
received after a call
comes
through
to
the

user's premises,
or
she
or
he
can
get
a phone with built-in voicemail capabilities.
On
the
other
hand,
an
ASP,
such
as
the
local
telephone
carrier
or
a third-party applications phone services
provider,
can
set
up
a phone line
so
that if
it

is
busy
or
isn't answered within acertain number ofrings,
it
will
be
redirected
to
a voicemail service associated
with the carrier's equipment. That carrier
is
thus
a
voicemail
ASP.
With
the
tremendous growth
in
digital telephony
and
data services,
it
is
likely that markets
for
ASPs
will
grow,

especially
for
services that
are
not
easy
for
us-
ers
to
set
up
and manage themselves.
See
ASP
Indus-
try
Consortium, Enhanced Service Provider.
Application Software Interface
ASI.
A means
of
working within a common application interface
for
provision ofISDN-related digital telephony services.
See
North American
ISDN
Users Forum.
Application Specific

Fiber
Platform
ASFP.
As
implemented
by
Southampton Photonics
(SPI),
aplat-
form
comprising core technologies ofspecialty fiber
design
and
manufacturing, fiber Bragggrating design
and
fabrication,
and
amplifier
and
laser technology.
ASFP
facilitates
the
volume manufacture
of
high-
performance in-fiber components
and
subsystems.
application-specific integrated circuit ASIC. A

computer
chip
or
small, specialized circuit designed
to
enable
or
enhance a specific
type
of application.
As
examples,
ASIC
video cards
have
been
designed
to
drive specialized monitors,
ASIC
modem
cards
provide functionality
to
specialized
or
enhanced
mo-
dems,
ASIC

daughterboards
sometimes
provide hard-
ware
support
to
rendering
and
ray-tracing
applications.
applications access point
AAP.
In
general,
an
access
point
is
a device
or
system that allows users
to
ac-
cess a particular
type
ofservice.
An
applications
ac-
cess

point
is
one
that
permits access
to
applications
software.
The
access
point
is
usually instituted
for
the
management ofresource sharing and/or
for
security
reasons. Applications that
may
be
shared through
an
© 2003 by CRC Press LLC
access
point
typically
include
databases
that

are
ac-
cessed
or
managed
by
multiple
users
or
collaborative
work
applications
in
which
changes
and
updates
are
relayed
to
the
various
participants.
applications processorA
computerized
system
that
can
be
integrated

with
a
phone
system
to
add
func-
tionality.
Functions
may
include voicemail,
Auto-
mated
Attendant, Call Detail, networking (packet
switching),
and
others.
See
peripheral
device.
Applications Technology Satellite
program
ATS.
A
series
(ATS-l,
ATS-
2,
etc.)
ofsatellite

launchings
carried
out
by
the
U.S.
National Aeronautics
and
Space
Administration
(NASA)
to
test
payloads
and
study
space.
Five
of
these
craft
in
three
configura-
tions
were
manufactured
by
Hughes
between

1966
and
1969.
See
Applications
Technology
Satellite
Pro-
gram
chart.
Applied Computer Telephony
ACT.
A
commercial
product
from
Hewlett-Packard
Company
for
integrat-
ing
voice
and
data
analysis
technologies
on
HP
sys-
tems.

The
system
is
used
in
conjunction
with
private
branch
phone
exchanges
to
record,
handle,
and
evalu-
ate
call-related
transactions.
See
Hewlett-Packard.
APPN
See
Advanced
Peer-to-Peer
Networking.
approved circuit
See
protected
distribution

system.
approximate discrete
Radon
transform
ADRT.
A
mathematical
technique
used
in
situations
where
sub-
stantial
redundancy
is
expected
or
encountered.
See
discrete
cosine
transform,
Fourier
transform.
APR
American
Public
Radio.
See

Public
Radio
In-
ternational.
APS
1.
See
Advanced
Photo
System.
2.
See
Auto-
matic
Protection
Switching.
APTS
Association
of
Public
Television
Stations.
AQL acceptable quality level. An industry-estab-
lished
confidence
level.
Aqua A
new,
aesthetically
appealing,

customizable
user
interface
introduced
by
Apple
Computer
with
Mac
OS
X
for
PowerPC-
and
Intel-based
platforms.
SeeMacOSX.
Ar
symb.
argon.
See
argon.
ARA
See
AppleTalk
Remote
Access.
ARABSAT A
communications
satellite

placed
into
orbit
in
the
mid-1980s.
The
ARAB
SAT
System
was
~:~~:~~~sl
~~~:r~
~:~~~;:;~~a~~f~:f
:n~o::
'.
cial
interaction
for
the
League
of
Arab
States.
This
effort
was
extended
in
1976

with
the
founding
of
the
Arab Satellite Communication Organization
(ARAB
SAT).
In
the
early 1980s, the French Aerospatiale
was
commissioned
to
manufacture three satellites.
ARABSAT
lA
and
IB
were
launched
in
the
mid-
1980s.
ARABSAT
1C
was
launched
in

February
1992
and
ARABSAT
lA
and
IB
were
turned
off
in
1992
and
1993.
ARABSAT
lC
is
expected
to
be
opera-
tional
until
2002.
ARABSAT
has control stations
at
Dirab, Saudi
Arabia,
and

Tunis,
Tunisia.
Telephony
and
television
services
are
provided, according
to
International
Standards,
to
the
Saudi
Arabia
and
northern
Africa
geographic
region.
Aragon,Dominique
In
1820,
Aragon
described
how
an
artificial
magnet
could

be
created
by
winding
a
coil
around
a
piece
of
iron
or
steel that
was
carrying
an
electrical
current.
Soon
after,
electromagnets
were
developed.
ARAM audio
RAM.
A low-cost, low-grade inte-
grated
memory
chip
suitable

for
digital
answering
machines
and
other
inexpensive
consumer
products.
aramid, aramid yarnA
strong
fibrous
material
com-
monly
used
to
reinforce
fiber
optic
cables,
especially
those
that
may
be
subject
to
rough
treatment

such
as
abrasion
by
rodents
or
small
pellet
shots.
Aramid
yam
is
favored
for
its
low
weight,
flexibil-
ity,
water resistance, low conductivity,
and
high
strength properties.
Aramid
may
be
used
in
several
parts

ofa
cable
assembly.
Most
often
it
is
a
reinforcing
strength
member,
but
it
may
also
provide
the
mate-
rial
for
the
central
element
in
a
fiber
bundle,
and
the
ripcord

used
to
open
cable
for
attaching
connectors.
Dupont
distributes a
type
of
aramid
yarn
under
the
Applications
Technology Satellite
Program
Satellite
Launched Notes
ATS-I
1966
Spin-stabilized
synchronous
altitude.
Electronically
despun
antenna.
Stationed
over

the
Pacific
Ocean.
Successfully
photographed
Earth
and
provided
a
presidential
communications
link
for
recovery
of
Apollo
II.
ATS-2
1967
Gravity
gradient
stabilized.
Insufficient
thrust
resulted
in
an
elliptical
orbit
and

it
lost
orbit
after
only
880
days.
ATS-3
1967
Synchronous
orbit.
Mechanical
despun
antenna,
color
camera
that
photographed
tornados
in
1968
and
an
eclipse
of
the
Sun
in
1970.
ATS-4

1968
Gravity
gradient
stabilization
in
synchronous
altitude.
Failed
to
reach
intended
orbit
and
lost
orbit
in
1968,
two
months
after
deployment.
ATS-5
1969
Synchronous
orbit.
Gravity
gradient
booms
for
stabilization

didn't
deploy
correctly,
but
some
of
the
experiments
were
successful.
It
was
retired
in
1984.
63
© 2003 by CRC Press LLC
Fiber
Optics
Illustrated
Dictionary
well-known
tradename
Kevlar.
See
Kevlar,
swelling
tape.
Aramid
Yarn

in
Fiber
Optic
Cable
In
a typicalfiber optic cable
assembly,
the
aramid
yarn layer
(1) provides
strength
and strain relief It
is
often inserted
between
the
outer
strength
member and
an
inner supporting
structure,
such
as
a water-resis-
tant
tube.
A ripcord (2)
may

be
provided
to
make it
easier
to
peel back
the
layer
in
preparation for
add-
ing a
connector.
ARB
1.
Administrative
Review
Board.
Established
in
1996
by
the
U.S.
Secretary
of
Labor within
the
Department

of
Labor.
2.
Air
Resources
Board.
3.
See
all
routes
broadcast.
arcA
very
bright
electrical
discharge
across
a
gap
in
a
circuit.
In
fiber
filament
fusion
splicers,
carefully
controlled,
electrode-generated

arcs
are
used
to
clean
and
heat
the
ends
to
be
spliced
so
they
will
fuse
into
a
continuous
light-guiding
path.
See
arc
lamp;
Aryton,
Hertha
Marks;
fusion
splice;
Poulsen

arc.
ARC
See
Ames
Research
Center.
arc converter A
device
used
to
convert
direct
cur-
rent
(DC)
into
undamped
or
continuous
wave
radio
frequency
(RF)
signals.
This
technology
was
used
in
early

radiotelegraphy.
Many
aspects
of
global
radio
communications
in
the
early
191
Os
were
based
upon
this
technology.
See
Poulsen
arc.
arc lamp An electrical
lamp
that exploits
the
ten-
dency
of
electrons
to
jump a

gap
in
a
circuit,
which
can
be
harnessed
to
produce
an
intense
light
under
certain circumstances. It was invented by Sir
Humphrey
Davy
in
the
early
1800s
and
came
into
widespread
commercial
use
in
the
late

1870s
when
it
was
incorporated
into
street
lamps.
Arc
lamps
are
important
in
optical
'etching.'
Expo-
sures
from
strong
light
sources
can
be
used
to
chemi-
cally alter substrate materials through a template
mask
so
that

some
of
the
materials
are
removed
and
some
remain.
In
this
manner,
mercury
arc
lamps
have
been
used
in
the
semiconductor
industry
for
circuit
design
through
optical
lithography.
This
is

a
technol-
ogy
that
may
someday
be
superseded
by
higher-pre-
cision
electron-beam
and
laser
etching
techniques.
Archie
Network
archiving
software
developed
by
Peter
Deutsch,
Alan
Emtage,
and
Bill
Heelan. Named
for

the
word
archive,
Archie
is
an
Internet
query
tool
that
tracks
the
contents
of
anonymous
ftp
sites.
It
was
introduced
at
McGill
University,
Canada,
in
1990.
Archie
allows
users
to

retrieve
a
list
ofFTP
locations
by
submitting
file
search
criteria
to
an
Archie
server.
See
Veronica.
Archimedes
(ca.
287-212
BC)
A
Greek
mathemati-
64
cian
and
inventor
born
in
Sicily

who
made
contribu-
tions
to
our
understanding
of
volume
and
displace-
ment,
and
who
created
the
mathematical treatise
"Measurement
of
the
Circle"
in
which
he
described
the
calculation
of
the
ratio

ofacircle's
circumference
to
its
radius.
See
Archimedes'
principle.
Archimedes' principleA
body
immersed
in
fluid
is
buoyed
up
by
a
force
equal
to
the
weight
of
the
fluid
displaced.
(This
principle
is

humorously
illustrated
by
actor
Gary
Oldman
in
a
bathtub
in
the
Cinecom
Entertainment
movie
production
of
"Rosencrantz
and
Guildenstem
Are
Dead.")
architect
One
who
designs
a
layout
or
topology,
such

as
a building
layout,
circuit
board
architecture,
net-
work
routing
system,
etc.
The
architect
frequently
is
also
the
one
who
drafts
the
technical
drawings
asso-
ciated
with
the
layout
and
mayor

may
not
check
elec-
tronics
codes,
building
codes,
or
other
regulations
as-
sociated
with
the
design.
architecture
The
design
and
layout
ofa
process,
sys-
tem,
or
facility.
The
architecture
involves

the
overall
plan
and
topology,
in
addition
to
the
relationships
and
interconnections
between
the
individual
parts.
It
may
also
include
the
direction
of
information paths
or
movement
within
the
system.
Good

architectures
usu-
ally
try
to
incorporate,
or
at
least
balance,
flexibility,
robustness,
efficiency,
and
scalability,
whether
it
be
the
design
ofa
building
or
ofa
microprocessor
chip.
See
topology.
archivalA
format,

medium,
or
protective
system
de-
signed
to
facilitate
preservation.
Archival
papers
and
plastic
sleeves
are
acid-free,
or
free
ofplastics
that
may
change
the
information
or
degrade
rapidly.
Ar-
chival
data

storage
formats
are
nonvolatile
(magnetic
media
such
as
video
tapes,
audio
tapes,
floppy
dis-
kettes,
etc.
are
not
very
stable
over
time
and
may
be
damaged
by
proximity
to
magnets)

and
resistant
to
damage
and
degradation.
In
the
data
industry,
archi-
val
file
formats
are
as
important
as
the
materials
on
which
they
are
stored,
as
the
information
is
useless

if
it
can
no
longer
be
read
or
deciphered.
archiveArepository of
records
or
files.
A
backup
or
duplicate
of
information
made
to
preserve
or
prevent
loss
in
compressed
or
uncompressed
form.

AD
archive
generally
contains
information
that
needs
to
be
kept
over
time,
for
one
reason
or
another
(legal,
histori-
cal,
etc.).
Many
archives
are
seldom
or
ever
accessed.
Computer
data

archives
are
becoming
more
preva-
lent
and
offer
many
search
and
retrieval
advantages
over
traditional paper-based archives.
See
anony-
mous
FTP,
Archie,
archival,
FTP.
archiverA
term
for
software
tools
that
are
designed

to
store
files
in
such
a
way
that
they
take
a
minimum
of
space
and
can
be
retrieved, reconstructed,
and
viewed
at
a later
date.
Software
archivers
often
in-
clude
compression
algorithms

and
switches
to
allow
an
archived
file
to
be
scanned
for
header informa-
tion
without
decompressing
it.
The
degree
of
com-
pression
possible
is
very
dependent
upon
the
inter-
action
between

the
type
of
compression
algorithm
and
the
type
of
data
being
compressed.
Common
soft-
ware
archivers
include
zip,
lharc,
Stuffit,
and
tar.
© 2003 by CRC Press LLC
archiving
The
process
ofstoring infonnation,
com-
pressed
or

uncompressed,
encoded
or
not
encoded,
such
that
it
can
be
accessed
and
viewed
at
some
fu-
ture
date,
if
needed.
Archiving
involves
selecting
a
storage
fonnat,
medium,
and
location
and

carrying
out
occasional
or
scheduled
consolidation
and
orga-
nization
of
the
objects
or
information.
One
of
the
big
issues
with
archiving,
besides
space,
is
the
develop-
ment
of
efficient
search

and
retrieval
methods
that
make
it
possible
to
find
a
desired
piece
ofinfonna-
tion
in
a
vast
amount
of
data.
See
archival,
archive,
database,
FTP.
ARCnet
Attached
Resource
Computer
network. A

popular
pioneering
local
area
network
(LAN)
devel-
oped
by
Datapoint
Corporation
in
1977
for
use
with
thin
coaxial
cable.
Incorporating a
modified
Token-
Ring
passing
scheme,
ARCnet
provides
high-speed
baseband
communications

at
2.5
Mbps
with
either a
bus
or
star
topology.
ARCnet
became
standardized
as
ANSI
878.1.
Although
not
as
widespread
as
it
once
was,
ARCnet
has
been
upgraded
to
include
transmis-

sion
over
copper
twisted pair
wire
and
fiber
optic
cables.
Arcstar
The
brand
name
for
the
Nippon
Telegraph
and
Telephone
Corporation's (NIT)
global
services
including
NTT
Worldwide
Telecommunications
Cor-
poration,
NTT
Europe,

ntta.com
and
Asian
branches.
These
include
managed
bandwidth,
Frame
Relay,
and
Internet Protocol (IP) virtual private networks
(VPNs).
See
Nippon
Telegraph
and
Telephone
Cor-
poration.
ARD
1.
advanced
research
and
development.
2.
See
Automatic
Ring

Down.
ARIADNEt
The
ARIADNE
network,
an
academic
and
research
network
operated
out
of
Athens,
Greece
by
NCSR
Demokritos, a physics
and
sciences
re-
search
association.
/>Ardire-Stratigakis-Hayduk algorithm
ASH.
A
lossless
compression
algorithm,
named

after
its
cre-
ators
at
Western
DataCom,
developed
between
1990
and
1993.
It
was
intended
for
use
over
synchronous
data
communications
with
varying
media
character-
istics.
Unlike
asynchronous
transmissions
protocols,

framed
data
can
contain
a
very
large
number
of
bits
and
does
not
have
to
be
timed
with
start
and
stop
bits.
ASH
provides
a
means
to
provide
good
compression

ratios
on
various
types
of
traffic
in
a multiuser
net-
work.
ASH
incorporates
interesting
concepts
from
artificial
intelligence.
By
using
pattern-matching
and
predic-
tive
algorithms,
data
not
yet
transmitted
and
noniden-

tical
strings
can
be
processed
and
evaluated.
As
part
of
the
compression
methodology,
ASH
uses
an
Oc-
currence
Optimized
Codebook
(DOC)
for
fast-cache
access
to
commonly
occurring
tokens
and
strings.

ASH
safeguards
against
data
expansion
and
latency.
A
patent
has
been
sought
for
the
ASH
technology.
See
Lempel-Ziv-
Welch.
ARDIS
A
commercial
packet-switched
nationwide
wireless
data
communications
service
developed
in

the
mid-1980s
by
Motorola
and
International
Busi-
ness
Machines
(IBM)
and
now
owned
by
Motorola.
It
was
originally
developed
for
field
technicians
and
is
appropriate
for
short
messages
and
quick

database
lookups
for
a
variety
of
applications.
ARDIS
is
some-
what
similar
to
CDPD
except
that
it
is
a
data-only
service.
It
is
used
for
wireless
faxing
and
realtime
messaging with

any
Internet address worldwide.
ARDIS
can
be
accessed
through
laptops,
and
per-
sonal
data
assistants.
See
RAM
Mobile
Data.
ARE
See
all
routes
explorer.
area code Athree-digit
code
in
a
phone
number
that
designates

the
region.
See
North
American
Number-
ing
Plan
(NANP).
See
the
Appendix
for
a
chart.
area code restrictionA
service
for
enabling
the
sub-
scriber
to
deny
telephone
calls
to
specified
area
codes.

It
is
not
a
blanket
restriction
as
in
some
long-distance
call-blocking
services.
The
service
is
useful
in
offices
and
other
environments
where
it
is
othetwise
diffi-
cult
to
monitor
phone

use.
area network
See
local
area
network,
metropolitan
area
network,
wide
area
network.
Area of Service
ADS.
The
geographical
area
sup-
ported
by
a
vendor,
carrier,
or
service
provider.
Arena
1.
The
name

of
an
HTML3
browser
from
the
World
Wide
Web
Consortium
(W3C)
designed
as
a
proof-of-concept demonstration tool
for
HTML+
ideas
preceding
HTML3.
ARES
See
Amateur
Radio
Emergency
Service.
ARF
See
Alternate
Regulatory

Framework.
argon
(symb.
-
Ar)
Argon
is
a
colorless,
odorless
gas
used
in
light
bulbs.
Argon
plasma
arc
lamps
can
pro-
vide
a
continuous
radiation
source
covering
a
broad
spectrum

from
ultraviolet
to
infrared
suitable
for
test-
ing
solar
energy
components
for
use
in
satellite
com-
munications.
See
argon
laser.
argon laser A
type
of
gas
laser
that
primarily
uses
argon
gas.

This
common
type
oflaser
can
be
used
to
produce
green
and
blue
light,
which
is
useful
for
cre-
ating
laser
light
show
effects.
It
is
similar
to
a
kryp-
ton

laser,
except
that
argon
produces a little
more
light.
Argon
is
sometimes
combined
with
krypton
gas
to
produce
an
argon-krypton
hybrid.
Argon
la-
sers
are
typically
water-cooled.
ARI
Automatic
Room
Identification. A
telephony

service
used
especially
in
the
hotel/motel
industry
to
identify
call
locations.
ARm
See
Association
of
Radio
Industries
and
Busi-
nesses.
Ariell
Historically,
the
first
U.K.
satellite project
to
study
the
ionosphere,

launched
in
April
1962.
The
satellite's orbit
decayed
in
1976.
ARIES
1.
Angle-Resolved
Ion
and
Electron
Spec-
troscopy.
2.
The
name
ofa
commercial
satellite
ser-
vice.
See
Constellation
Communications,
Inc.
3.

See
Australian
Resource
Information
and
Environment
Satellite.
ARINC-429 Digital Information TransferSystem
DITS.
DITS
is
a
digital
point-to-point
hardware
ar-
chitecture
and
data
specification
for
describing
a
digital
bus
for
device
communications
for
the

aeronautics
industry.
The
transmission
hardware
is
based
upon
twisted-pair
wires
with
one
transmitter
connected
to
one
or
more
receivers.
The
data
protocol
is
based
65
© 2003 by CRC Press LLC
Fiber
Optics
Illustrated
Dictionary

upon
32-bit
words
consisting ofa
data
portion
and
a
label
identifying
the
nature
of
the
data.
Development
of
the
DITS
specification
and
ARINC-compatible
products
aided
in
the
commercialization of digital
communications
for
aeronautics

devices
and
facili-
tated
the
development
of
modular,
off-the-shelf
prod-
ucts.
See
ARINC-629.
ARIN
C-629
A
commercial
civilian
communications
protocol
based
upon
a
central
twisted-pair
bus
archi-
tecture
which
can

accommodate
up
to
120
peripheral
devices
or
terminals
at
a
2-MHz
bus
rate.
ARINC-
629
evolved
from
ARINC-429
,
which
was
developed
in
the
1970s.
ARINC
products
are
manufactured
by

Excalibur
Systems,
Inc.
ARINC
Incorporated An organization
formally
es-
tablished
in
1929
by
Louis
Caldwell
and
representa-
tives
of
four
major
airlines
as
Aeronautical
Radio,
Inc.
ARINC
was
established
to
be
the

dominant
nongov-
ernment
single
licensee
and
coordinator
of
radio
com-
munications.
Upon
its
formation,
the
Federal
Radio
Commission
(FRC)
transferred
to
ARINC
the
respon-
sibility
for
aeronautical
ground
radio
stations,

thus
providing
a
within-the-industry
means
of
administrat-
ing
aeronautic
rules
and
regulations established
by
theFRC.
ARINC
continues
to
coordinate
airline
industry
tele-
communications
activities,
communications,
and
in-
fonnation
processing
systems.
It

publishes
standards
of
relevance
to
avionics
systems
and
analog
and
digi-
tal
equipment.
ARISE
1.
See
Advanced
Radio
Interferometry
be-
tween
Space
and
Earth.
2.
American
Renaissance
in
Science
Education.

3.
Applications
Reform
in
Sec-
ondary
Education.
ARISS
See
Amateur
Radio
International
Space
Sta-
tion.
Aristote Association A
French
association of
orga-
nizations
and
frrms
engaged
in
the
development
of
telecommunications
and
data

transmissions
technolo-
gies. The Secretariat
is
located at the Ecole
Polytechnique
in
Paris, France,
with
seminars
and
workshops
held
at
the
Arago
and
Poincare
amphithe-
aters.
/>ARISTOTELES
Applications
and
Research
Involv-
ing
Space
Technologies/Techniques
Observing
the

Earth's
Fields
from
Low
Earth-Orbiting Satellites. A
joint project of
NASA
and
ESA
carrying
out
scien-
tific
research
data
gathering
on
the
Earth's
gravity
and
magnetic
fields.
It
is
equipped
with
a
Global
Posi-

tioning
Service
(GPS)
receiver,
gradiometer,
and
sca-
lar
magnetometer.
Arkay
CT-650
A
commercial
computer
based
upon
a
description
ofa paperclip
computer,
(a
homebrew
digital computer that could
be
constructed out of
materials
found
around
a
home).

ARL
1.
Air Resources Laboratory (NOAA).
/>2.
See
Association of
Re-
search
Libraries.
armature A
portion
ofa
magnetic
circuit typically
consisting of a conducting material,
such
as
wire,
wound
around
a
core,
which
is
moved
within
a
strong
magnetic field
to

create current.
If
the armature
66
revolves,
the
wound
material interacts
with
the
mag-
netic
lines
of
force,
in
asense, cutting
in
and
out,
and
the
current
generated
by
this
interaction
can
be
drawn

out.
The
arrangement
is
used
in
generators
and
alter-
nators, where the current may
be
drawn out
by
brushes.
See
coil.
Armed Forces Communications and Electronics
Association
AFCEA.
An
international nonprofit
professional association
for
communications,
elec-
tronics,
and
intelligence. Founded
in
1946,

the
asso-
ciation
has
over 40,000 individual and corporate
members
in
government,
industry,
and
military
sec-
tors.
AFCEA
publishes
SIGNAL
Magazine,
techni-
cal
papers,
and
books.
/>ARM
See
American
Radio
Museum.
armor
1.
Defensive

or
protective
covering.
2.
A
type
ofheavy-duty waterproofing
or
other shielding used
especially
in
underwater
or
underground
installations.
3.
Heavy
shielding
to
protect facilities,
equipment,
and
personnel
from
radiation
or
chemical
contami-
nation.
4.

In
computer technology, heavy security
measures
taken
to
keep
users
offa
system,
which
may
range
from
inaccessible facilities
to
extra software
measures
taken
to
discourage
unauthorized
intrusion.
armor-plated Aphysical
or
administrative
high
se-
curity
system
which

the
administrators
deem
to
be
virtually impenetrable.
Highly
resistant
to
access
or
tampering.
Bullet-proof.
armored cable
See
aramid
yarn;
cable,
annored.
armoring, ballistic A
strong
armor
layer
(e.g.,
coated
steel)
used
to
protect aerial
components

and
cables
from
shotgun pellet
intrusion.
Ballistic annoring
for
fiber
optic
cables
is
generally
about
0.25
mIn
thick.
Sometimes
dual
armoring
layers
are
used,
in
addi-
tion
to
aramid
fibers.
The
ballistic

energy
from
pellets
hitting
a
cable
is
dis-
sipated
by
the
steel
armoring.
Increased protection
against
larger pellets
is
offered
by
aramid
fibers
that
cushion
the
fibers
from
the
impact
ofa
pellet.

ZETABONTM
is
an
example
ofasteel-annored
cable
distributed
by
Dow
Chemical
Company.
See
aramid;
cable,
armored.
Armstrong, Edwin Howard (1890-1954) Agifted
American
researcher
who
invented
the
superhetero-
dyne
circuit
and
frequency
modulation
(FM).
Arm-
strong

was
not
only
a
good
inventor
but
also
a
good
theoretician;
he
was
one
of
the
few
people
who
un-
derstood,
on
aphysics level,
many
of
the
new
inven-
tions
that

were
making
possible
the
development
of
wireless communications.
In
October
1914,
Armstrong
was
awarded
a patent
for
his
wireless receiving
system
(U.S.
#1,113,149).
In
the
1920s,
he
contested
Lee
de
Forest
in
the

in-
vention
ofregeneration,
but
de
Forest
won
the
suit.
After
many
years
of
painstaking
research
against
con-
ventional wisdom
and
the
negative predictions of
mathematicians
and
engineers,
Armstrong
proposed
a
method
ofwave modulation that varied
the

fre-
quency
rather
than
the
amplitude ofa
wave.
He
was
awarded
a patent
for
FM
radio
signaling
in
Decem-
ber
1933
(U.S.
#
1,941,066).
Armstrong
waged
a
long
and
tragic
legal
battle

with
© 2003 by CRC Press LLC
RCA
over
his
patents
to
the
FM
technology
which
were
posthumously
upheld
in
his
favor.
During
World
War
II,
Armstrong
furthered
the
art
of
radar
transmis-
sion
by

suggesting
the
use
ofFM
signals,
rather
than
the
short
pulse
radar
bursts
that
were
used
at
the
time.
His
ideas
are
now
commonly
incorporated
into
fre-
quency
modulated
(FM)
radio,

television,
and
radar
transmissions.
See
frequency
modulation,
heterodyning.
AROS I. Amateur Radio Observation Service.
2.
Amiga
Research
OS.
A
project
initiated
in
the
mid-
1990s
to
update,
bug-fix,
and
enhance
the
Amiga
Operating
System.
/>ARP

See
Address
Resolution
Protocol.
ARPA
Advanced
Research Projects
Agency.
See
Defense
Advanced
Research
Projects
Agency.
ARPANET
Advanced
Research Projects
Agency
Network.
The
historical
basis
of
the
Internet,
ARPA-
NET
was
originally
discussed

by
the
ACM
in
1967,
presented
to
ARPA
the
next
year
and
put
into
opera-
tion
in
1969.
The
frrst
widespread
demonstration
of
ARPANET
occurred
at
a
Computer
Communications
conference

in
1972,
and
ayear
later
ARPANET
traf-
fic
had
grown
to
millions
of
packets
of
data
transfer
per
day.
By
1975,
the
ARPANET
had
been
transferred
to
the
Defense
Communications

Agency
(later
the
Defense
Information
Systems
Agency).
In
1982,
ARPA
endorsed
TCP/IP
as
its
protocol
suite.
In
1983,
ARPANET
split
into
MILNET
and
ARPA-
NET
(mandated
to
use TCP/IP), which together
formed
the

Internet.
Each
was
given
a
network
num-
ber,
and
gateways
were
installed
to
provide
packet
forwarding
between
them.
ARPANET
was
officially
discontinued
in
1990,
largely
due
to
the
evolution
of

the
Internet.
See
ARPA,
BITNET,
lANA,
NSFNET,
NEARNet,
SPAN.
ARQ
See
automatic
retransmit
request.
array A
type
of
data
organization structure
com-
monly
used
in
programming.
An
array
consists
of
an
ordered

list
or
matrix
of
information
which
can
be
visualized
as
2D
or
3D
tables
of information
con-
tained
in
cells
which
often
have
common
character-
istics,
such
as
the
size
of

the
data
cell
(although
the
data
in
the
cells
may
vary
in
length).
Arrays
form
the
structural
basis
for
many
types
of
databases,
includ-
ing
tables
and
lists.
Many
software

programs
have
built-in
array-handling
functions
to
automate
com-
mon
ways
in
which
arrays
are
manipulated.
array antenna I. An
antenna
with
a
number
of
di-
recting,
reflecting,
or
other
elements
arranged
in
a

more-or-Iess
regularly spaced, often symmetrical
pattern.
See
antenna.
2.
One
antenna
in
an
array
of
antennas
that
are
organized
and
connected
in
such
a
way
as
to
significantly
boost
power,
range,
and
per-

formance.
These
powerful
antenna
systems
are
used
for
picking
up
weak
signals
as
in
astronomy
and
mili-
tary
applications.
ARRL
See
American
Radio
Relay
League.
ARRL Monitoring SystemA
policing
system
of
the

American
Radio
Relay
League
to
monitor
and
main-
tain
the
correct,
licensed,
and
responsible
use
of
ama-
teur
radio
frequencies
and
procedures.
For
the
most
part,
the
amateur
radio
community

successfully
seeks
to
be
self-policing,
but
there
are
times
when
unau-
thorized
use
reaches
problematic
levels
or
originates
in
countries
that
are
not
regulated
by
the
U.S.
Fed-
eral
Communications

Commission
(FCC),
at
which
time
the
ARRL
will
document
the
problems
and
call
for
assistance
from
appropriate
domestic
and
inter-
national agencies. See American Radio Relay
League.
ARRN
Amateur
Radio
Repeater
Network.
ARS
See
Automatic

Route
Selection.
ARSR
See
Air
Route
Surveillance
Radar.
articulation Clear
utterance
or
playback
of
sounds
-
the
degree
to
which reproduced
or
transmitted
sounds
are
clear
enough
to
be
understood
by
a

lis-
tener.
Mumbling
is
poor
speech
articulation.
When
people
say
"Testing,
testing,

"
on
a
sound
system,
they
are
testing
not
only
circuit
functioning
and
vol-
ume
but
also

the
clarity of
the
sound
and
capability
of
conveying
a
message.
Articulation
does
not
have
to
be
high
fidelity
to
be
understood.
It
depends
in
part
upon
the
ability of
the
recipient

to
perceive
and
un-
derstand
the
message,
and
may
not
have
to
match
perfectly
the
original.
This
is
an
important
aspect
of
data
communications
as
well.
When
conversations
are
converted

from
analog
to
digital,
through
a
pro-
cess
called
sampling
and
quantization,
it
is
important
to
determine
how
much
of
the
information
is
needed
in
order
for
the
communication
to

be
understood
by
the
recipient.
This
information
can
be
applied
to
com-
pression
and
decompression
systems
for
speeding
up
transmissions.
See
fidelity,
intelligibility.
articulation index
AI.
A
scale
from
0
to

1
that
pro-
vides
an
obj
ective
reference
for
the
intelligibility of
voice
signals
expressed.
AI
is
quantified
in
terms
of
the
percentage
of
speech
units
understood
by
a
lis-
tener

when
the
units
are
presented
out
of
context.
The
index
is
a
useful
measure
for
testing
and
comparing
voice
transmission
and
speech
compression/decom-
pression
technologies.
See
articulation.
artificial intelligence
AI.
Insights

or
behaviors
at-
tributed
to
an
entity,
usually a
machine,
that
is
not
traditionally
perceived
by
humans
as
having
the
ca-
pability
to
think
in
ways
that
involve
problem-solv-
ing,
insight,

and
other
uniquely
human
characteris-
tics.
The
field
ofartificial intelligence
has
spawned
many
useful
approaches,
languages,
techniques,
and
programming
algorithms.
Expert
systems,
neural
net-
works,
robotics,
vision
systems,
and
natural
language

processing all have their origins in
AI
research.
People
interested
in
artificial
intelligence
come
from
a
diverse
range
of
backgrounds.
The
origins
ofartificial
intelligence,
as
they
apply
to
computers,
trace
back
to
the
1950s,
though

Ada
Love-
lace
proposed
in
the
1800s
that
"thinking
machines"
could
be
programmed
to
create
music
or
art.
Pioneer
researchers
include
A.
Turing,
J.
McCarthy,
and
N.
Wiener.
See
expert

systems;
Intelligent
Networks;
Lovelace,
Ada;
robotics.
Artron artificial
neuron.
The
familiar
name
for
an
electronically
simulated
neuron
used
in
a
maze-run-
ning
robotic
mouse
in
the
early
1960s.
See
Melpar
model,

neural
network.
67
© 2003 by CRC Press LLC
Fiber
Optics
Illustrated
Dictionary
AS
1.
See
Applicability
Statement.
2.
See
autono-
mous
system.
as
is
Atenn
applied
to
products
that
are
bought
and
sold
with

no
implied
or
stated
warranties.
Condition
may
be
guessed
by
inspecting
and
trying
the
equip-
ment,
but
there
is
no
way
to
know
the
completeness,
remaining
useful
life,
or
technical

functionality
of
the
equipment.
See
fair,
good.
AS&C
1.
Advanced
Systems
&
Concepts.
A
division
of
the
U.S.
Department
of
Defense
associated
with
the
Deputy
Under
Secretary
of
Defense
(DUSD).

ASCO,
the
DTRA
Advanced
Systems
&
Concepts
Office,
encourages
seed
projects
for
technologies
developed
to
counter
threats
to
national
security.
2.
Alann
Surveillance
and
Control.
AS-Interface,
Actuator
Sensor
Interface,
AS-i.

An
open
network
protocol
for
automating
actuator
and
sensor
control
for
industrial
applications.
It
can
op-
erate
as
a
controller
or
as
a
stand-alone
automation
support
bus.
It
may
also

be
used
with
higher
level
field
buses
to
enable
remote
input/output
operations.
A
single
AS-i
v2.0
master
can
support
up
to
124
ac-
tuators/outputs
and
124
sensors/inputs.
See
actuator,
INTERBUS,

PROFffiUS.
ASA
1.
See
Acoustical
Society
of
America.
2.
Assis-
tant
Secretary
of
the
Army.
ASARS
See
Advanced
Synthetic Aperture
Radar
System.
ASC
1.
advanced switching communications.
2.
Aeronautical
Systems
Center.
A
U.S.

facility
lo-
cated
at
Wright-Patterson
AFB.
Science
and
technol-
ogy
programs
are
carried
out
in
the
Wright
and
Arm-
strong
Laboratories.
Ascend InverseMultiplexing
AIM.
An
in-band
net-
working
protocol
from
Ascend

Communications
that
manages
interconnections
between
two
remote
in-
verse
multiplexers.
Ascend Password Protocol
APP.
A
network
User
Datagram
Protocol
(UDP)
used
in
servers
to
respond
to
password
challenges
from
external
authentication
servers.

APP
Server
utilities
are
available
from
As-
cend
for
a
wide
variety
of
computer
platforms.
ASAI
See
Adjunct
Switch
Application
Interface.
ASAPI
Advanced
Speech
API.
An
open,
cross-plat-
fonn
speech

applications
programming
interface
de-
veloped
by
AT&T.
ASCA
See
Advanced
Satellite
for
Cosmology
and
Astrophysics.
Ascend Password Protocol
APP.
A
User
Datagram
Protocol
(UDP)
network
security
protocol
defaulting
to
port
7001.
ascending node

Intersection
of a satellite's
orbital
plane
with
the
Earth's
equatorial
plane.
Ascn
(as-kee)
The
American
Standard
Code
for
In-
formation
Interchange
was
developed
by
the
Ameri-
can
National
Standards
Institute
(ANSI).
Also

known
as
ASCII
International
Telegraph
Alphabet
5,
ASCII
is
the
most
widely
used
computer
character
set
en-
coding
scheme
currently
employing
seven
bits,
thus
making
a
total
of
128
possible

characters/symbols.
ASCII
is
mainly
suitable
for
English
language
com-
munications.
Since
it
is
very
limited
in
its
letters
and
68
symbols,
many
extensions
to
ASCII
have
been
incor-
porated
into

key
mappings
on
various
computers
to
include
symbols
and
western
European
characters.
Sometimes
called
extended
ASCII
(even
though
the
extensions
aren't
standardized),
these
8-bit
encodings
provide
256
possible
characters,
but

the
higher
128
characters
are
not
usually
compatible
across
plat-
forms.
See
EBCDIC,
Unicode.
See
the
Appendix
for
an
ASCII
chart.
ASCn
editorA
text
editing
tool
that
handles
basic,
simple

characters
standardized
as
ASCII
text,
which
are
cross-compatible
and
transferable
over
almost
all
seven-bit-compatible
systems,
which
includes
most
computer
networks.
Since
the
ASCII
standard
does
not
support
style
attributes
(bold,

underline,
oblique,
etc.),
it
cannot
be
used
for
extensive
formatting.
Due
to
the
limitations
and
simplicity
of
its
character
set,
ASCII
editors
are
very
fast.
They
are
also
good
for

writing
computer
source
code,
which
typically
needs
speed
and
compatibility
more
than
style
tags.
If
you
require
style
tags
and
indentation
for
text
for-
matting,
and
want
to
transfer
the

documents
across
applications
or
platforms,
the
best
supported
format
that
includes
them
is
Rich
Text
Fonnat
(RTF),
also
known
as
Interchange
Format
(developed
by
Micro-
soft
and
supported
across
its

products).
It's
not
100%
compatible
across
platforms,
but
it's
pretty
close
and
can
be
read
and
written
by
most
word
processors
(with
import
and
export
menu
options).
Another
good
format

for
transferring
more
complex
documents
is
generic
Adobe
PostScript,
which
includes
not
only
text
and
style
support,
but
image
positioning,
layout
effects
and
more,
or
its
cousin,
Adobe
Acrobat's
Por-

table
Document
Format
(PDF).
When
designing
Web
pages
with
links
to
download-
able
files,
there
should
be
more
than
one
format
avail-
able.
If
all
Web
site
managers
were
to

include
these
three:
an
ASCII
version,
an
RTF
version
(which
can
be
read
into
virtually
any
popular
word
processor),
and
a PostScript
or
PDF
version,
then
the
needs
of
low-end
and

high-end
users
would
be
well
met,
and
at
least
one
of
the
files
would
be
accessible
to
virtu-
ally
everyone
using
the
Web.
See
appendix
for
an
ASCII
chart.
ASDSP

application-specific
digital
signal
processor.
See
digital
signal
processor.
ASE
Application
Service
Element.
An
element
of
an
application
layer
protocol
in
the
Open
Systems
in-
terconnection
(OSI)
layered network
model.
It
is

combined
with
other
elements
to
form
the
complete
protocol.
See
Open
Systems
Interconnect.
ASFP
See
Application
Specific
Fiber
Platform.
ASH
See
Ardire-Stratigakis-
Hayduk.
Asia
DAB
Committee,Asia
DAB
ADC.
A
nonprofit

association
working
in
conjunction
with
the
World
DAB
Forum
to
promote, support,
and
coordinate
the
implementation
of
digital
radio
broadcasting
tech-
nologies
in
Asia.
Digital
Audio
Broadcasting
(DAB)
promises
to
significantly

change
and
improve
the
quality
and
richness
of
programming
information
available
to
consumers.
See
Digital
Audio
Broadcast-
ing
Forum.
/>© 2003 by CRC Press LLC
Asian Mobile Satellite System
AMSS.
Asatellite-
based
mobile
phone
system
of
Asia-Pacific
Mobile

Telecommunications
Satellite
Pte.
Ltd.
The
system
was
supplied
by
Hughes
Space
and
Communications
International,
Inc.
It
operates
in
the
L-band
to
pro-
vide
a
mobile
infrastructure
for
communications
in
Asian-Pacific

regions
from
Japan
to
Pakistan.
Asia
is
a
world
leader
in
many
aspects
of
wireless
com-
munications.
ASI
1.
Advanced
Study
Institute.
2.
artificial
sens-
ing
instrument.
3.
Astronomical
Society

of
India.
ASIC
See
application-specific
integrated
circuit.
ASK
See
amplitude-shift
keying,
modulation.
Ask Jeeves A
prominent
and
specialized
freely
ac-
cessible
search
engine
on
the
Web,
Ask
Jeeves
uses
natural
language
processing

to
search
information
based
upon
sentence-like
queries.
Finding
information
on
the
Internet
can
be
a
daunt-
ing
prospect
and
many
lexical
search
engines
search
on
keywords
or
conditional
statements
and

provide
thousands
or
millions
of
hits
on
the
queried
topic.
In
contrast,
Ask
J
eeves
will
parse
out
English-like
que-
ries
and
provide
a
selective
group
of
good
hits
from

a variety of
search
sources
based
upon
intelligent
search
algorithms,
a
process
central
to
data
mining.
See
data
mining;
search
engine,
Web.
See
appendix
for
a
search
engine
chart.
ASL
Adaptive
Speed

Leveling.
A
U.S.
Robotics
mo-
dem
term
for
adjusting
the
speed
ofa
serial
transmis-
sion,
depending
upon
line
conditions,
to
optimize
the
transfer
of
data.
ASN
1.
Abstract
Syntax
Notation.

See
ASN.l
2.
See
Autonomous
System
Number.
ASN.l
Abstract
Syntax
Notation
1.
An
ISO/ITV-T
standard
machine-
and
implementation-independent
language
defined
in
1988
for
the
description
of
data,
to
facilitate
the

exchange
of
structured
data
among
applications
programs.
ISO
8824,
lTV
TS
X.208.
ASP
1.
Abstract
Service
Primitive.
In
ATM
network-
ing,
an
implementation-independent
description
of
user/provider
interactions,
as
defined
by

the
Open
Systems
Interconnection
(OSI).
2.
Adjunct
Service
Point.
A
network
feature
of
peripherals
designed
to
respond
intelligently
to
processing
requests.
3.
admin-
istrative
service
provider.
SCSA
term.
4.
analog

sig-
nal
processing.
5.
See
AppleTalk
Session
Protocol.
6.
See
Application Service
Provider.
7.
See
ATM
switch processor.
8.
Attached Support Processor.
9.
Association
of
Shareware
Professionals.
ASPIndustry ConsortiumAn
informational
global
advocacy
group
supporting
Application

Service
Pro-
viders
(ASPs),
their delivery associates,
and
their
customers,
founded
in
May
1999.
The
group
provides
research
information,
education,
and
strategic
guid-
ance.
The
ASP
Consortium
currently
serves
hundreds
of
members

in
more
than
two
dozen
countries.
It
is
managed
by
Virtual,
Inc.,
a
high-tech
industry
inte-
grated
management
and
marketing
firm.
consortium.
org/
aspect ratio
The
relationship of
the
proportions
of
the

width
to
the
height,
usually
ofa
rectangular
form.
A
two-to-one
aspect
ratio,
for
example,
is
commonly
written
as
2:
1.
The
aspect
ratios
of
televisions
and
monitors
are
similar,
but

cinematic
films,
which
are
shown
in
theaters
with
panoramic
screens,
have
a
much
greater width-to-height ratio.
This
is
why
letterboxed
films
have
a
dark
strip
on
the
top
and
bottom
to
preserve the full width

of
the
image.
Unletterboxed
films
have
been
modified
to
remove
part
of
the
picture
from
the
sides.
See
anamorphic.
ASPI
See
Advanced
SCSI
Programming
Interface.
ASQ
1.
Administrative
Science
Quarterly.

2.
Ameri-
can
Society
for
Quality.
ASQ
sponsors
ASQNet.
/>Appli-
cant
and
Student
Query.
A
system
to
automate
the
verification
of
student
admissions
information.
4.
Ap-
plication
Status
Query.
A

Web-based
tool
for
allow-
ing
applicants
to
check
their
status,
developed
by
DLAHROC.
/>Automated
Status
Query.
ASR
1.
Access
Service
Request.
A
request
sent
to
a
local
exchange
carrier
(LEC)

for
access
to
the
local
circuit.
2.
See
Airport
Surveillance
Radar.
3.
Auto-
matic
Send/Receive.
A
system
that
can
send
and
re-
ceive
messages
unattended.
4.
See
Automatic
Speech
Recognition.

assemblerA
program
that
converts
symbolic
assem-
bly
language
program
code
into
machine
instructions
that
can
be
directly
executed
by
a
computer
CPU.
On
early
microcomputers,
in
the
1970s,
most
serious

pro-
gramming
was
done
with
an
assembler.
assembly language A
low-level
symbolic
computer
language
which
structurally
and
mnemonically
fits
somewhere
between
machine
code
and
higher
level
languages
such
as
C,
BASIC,
Java,

and
Perl.
Lan-
guages
like
BASIC
and
Perl
are
typically
run
in
in-
terpreted
mode
(although
compilers
exist
for
almost
everything,
if
you
really
want
one).
When
compiled
and
assembled,

C
and
assembly
language
are
con-
verted
into
machine
language,
which
typically
con-
sists
of
the
binary
digits
one
and
zero
and
is
very
dif-
ficult
(for
normal
folks)
to

read
and
debug.
By
coding
in
assembly
language
(which
is
difficult
for
most
folks)
and
then
using
an
assembler,
a
soft-
ware
utility
to
convert
to
machine
code,
the
program

can
often
be
optimized
to
run
faster
and
may
be
more
difficult
to
reverse-engineer.
See
symbolic
code.
assigned frequency
See
Federal
Communications
Commission.
assigned numbers A
sequential
numbering
system
administrated
by
IAN
A

to
organize
and
assist
in
the
search
and
retrieval
of
Request
for
Comments
(RFC)
documents.
See
lANA,
Request
for
Comments.
Association Control Service Element
ACSE.
An
International
Standards
Organization
(ISO)
applica-
tion
layer

service
for
establishing
a
connection,
as
part
of
the
Open
Systems
Interconnection
(OSI)
model.
Association for Computing Machinery
ACM.
A
well-known trade association serving
more
than
80,000
computing
professionals
in
over
100
countries.
Members
participate
in

the
exchange
of
ideas,
dis-
coveries
and
information
in
many
areas
of
academia,
government,
and
industry.
The
ACM
was
founded
in
1947.
/>69
© 2003 by CRC Press LLC
Fiber
Optics
Illustrated
Dictionary
Association for Cooperation
in

Telecommunica-
tions Research
in
Switzerland
ACTRlS.
A
telecom-
munications research initiative
for
precompetitive
research
in
telecommunication technologies,
formed
in
1995
by
the
Pro
Telecom
partners,
an
association
of
Swiss telecommunications companies.
ACTRIS
is
centered
in
the

Multimedia Communications Lab
in
Basel, Europe's largest experimental platform.
It
serves major
Swiss
telecom companies,
as
well
as
those
in
neighboring countries.
The
main
objectives
are
to
promote research
and
education
in
telecommu-
nications.
Association for Education
in
Journalism and Mass
CommunicationAEJMe. Aprofessional association
ofpost-secondary journalism
and

mass
communica-
tions
educators
and
administrators.
/>Association for Educational Communications and
Technology
AECT.
An
organization committed
to
providing communication
among
professionals
with
a
common
interest
in
using
technology
for
education.
/>Association for Information and Image Manage-
ment
AIIM
International. AIIM
was
established

in
1943
as
the
National Microfilm Association.
It
sup-
ports users of document and content technologies
with information about technologies
and
suppliers.
AIIM
seeks
to
provide
practical,
unbiased
educational
information
to
its
global membership through
con-
ferences, articles,
and
member participation.
!
Association for Information Systems AlS. A
pro-
fessional

organization
serving
as
a
global
resource
for
academics specializing
in
information systems,
founded
in
1994.
AlS
publishes
The
Journal
of
the
AIS
and
The
Communications
of
the
Association for
/nfo177zation
Systems.
/>Association for Interactive Media
AIM.

A
Wash-
ington,
D.
e based nonprofit
trade
association dedi-
cated
to
promoting consumer confidence
and
govern-
ment support of interactive media products
and
re-
lated
technologies. !
Association for Literary and Linguistic Comput-
ing ALLe.
An
association
for
supporting
the
use
of
computer technologies
for
studying languages
and

literature,
founded
in
1973.
ALLC
publishes
the
Lit-
erary andLinguistic Computing
journal through
Ox-
ford
University Press.
The
association sponsors
an
annual convention
in
cooperation
with
the
Associa-
tion
for
Computers
and
the
Humanities
(ACH).
Association for Maximum Service Television

MSTY.
Aprofessional association of
local
television
stations established
in
1956
to
undertake studies
to
support development
of
Federal Communications
Commission
(FCC)
television technical standards.
In
1962,
MSTV
provided a voice
for
new television
technologies
in
the All-Channel Receiver
Act.
In
1987,
the
association brought together broadcast

or-
ganizations
to
petition
the
FCC
to
look
into
high-defi-
nition
television
(HDTV)
and
participated materially
in
the
Advisory Committee
on
Advanced Television
Services
(ACATS).
In
1996,
the
Consumer
Electronics
70
Manufacturers Association
(CEMA)

and
MSTV
cre-
ated
the
Model
HDTV
Station Project, licensed
as
WHD-
TV,
to
educate broadcasters
on
the
implemen-
tation
of
digital television services.
MSTV
seeks
to
preserve
and
improve the technical
quality of free, universal, community-based televi-
sion
service
to
the

American public.
MSTV
provides
its
members with information
on
new technologies
and
policies, particularly digital television advance-
ments and implementation information. See Ad-
vanced Television
Test
Center, Advisory Committee
on
Advanced Television Services, Digital Television
Station Project,
Inc.
!
Association for Women
in
ComputingAWe. A
not-
for-profit professional association founded
in
1978
to
promote
the
advancement ofwomen
in

comput-
ing.
!
Association ofCollege and University Telecommu-
nications Administrators
ACUTA.
An
international
nonprofit educational association serving colleges
and
universities
and
representing vendors serving
the
educational market.
ACUTA
sponsors
the
award
for
Institutional Excellence
in
Telecommunications
and
publishes news and a quarterly journal.
!
Association ofCommunications Technicians
ACT.
An
organization

to
support technicians
working
in
the
field of communications.
ACT
is
a member
of
the
PClAFederation
of
Councils, representing commer-
cial
and
private
mobile
radio service communications
industries.
Association of Competitive Telecommunications
Suppliers
ACTS.
ACanadian-based association
rep-
resenting telecommunications equipment manufac-
turers
and
suppliers
in

order
to
support
and
encour-
age
market competition.
Association of Computer Professionals
ACP.
A
U.K based nonprofit organization providing courses
that lead
to
recognized qualifications, founded
in
1984.
!-acp/
Association
of
Computer
Support
Specialists
ACSS.
Atrade organization assisting
and
represent-
ing
those
who
install, support, maintain,

test,
and
re-
pair computing systems. Members include vendors
and
manufacturers
who
provide customer support,
as
well
as
independent consultants
and
those
who
pro-
vide
equipment
and
services
to
support
these
special-
ists.
/>Association of Computer Telephone Integration
Users and SuppliersACTIUS. Atrade organization
in
the
United Kingdom which promotes awareness

and
acceptance
of
computer-telephone integration
(CTI) technology through campaigns
and
educa-
tional
programs.
Association ofIndependents
in
Radio
AIR.
Anon-
profit organization representing and promoting
the
interests ofa diverse membership ofaudio produc-
ers,
audio artists, radio broadcast stations,
and
me-
dia arts centers. AIR sponsors online discussion
groups, group health benefits,
and
the AIRSPACE
journal.
See
Producers Advocacy Group.
!
© 2003 by CRC Press LLC

Association
of
Radio Industries
and
Businesses
ARIB.
A research
and
development organization,
headquartered
in
Tokyo,
Japan, that studies radio
waves
and
developing
radio
systems
and
industries
in
telecommunications
and
broadcasting,
in
order
to
promote public welfare. A number
of
committees

work
under
ARIB,
including
the
Infrared
Communi-
cations
Systems
Study Committee.
Association
of
Research LibrariesARL. Anot-for-
profit organization of
the
leading research libraries
in
North
America.
The
ARL furthers
and
promotes
the
evolution
of
research libraries
and
scholarly
com-

munication.
/>Association
of
Science-Technology CentersIncor-
porated
ASTC.
An organization
of
science centers
and
museums
dedicated
to
fostering
the
public
un-
derstanding ofscience through innovation
and
excel-
lence.
ASTC
was
founded
in
1973
and
has
members
worldwide in more than three dozen countries.

/>Association
of
Wireless System Integrators
AWSI.
An
organization
to
support
integrators
working
in
the
field
ofwireless communications.
ACT
is
a member
of
the
PCIA
Federation
of
Councils, internationally
representing commercial
and
private mobile radio
service communications industries.
ASSP
1.
acoustics speech and signal processing.

2.
application-specific standard product. An inte-
grated circuit designed
for
a specific application.
ASSP Magazine Apublication of
the
IEEE
devoted
to
signal processing.
ASSTA
See
Australian
Speech
Science
and
Technol-
ogy
Association Incorporated.
Assured LinkA
telephone
link
meeting
certain
mini-
mum
transmission,
loss
(5.5

dB
in
the
300-
to
3000-
Hz
bandwidth range), and service standards
for
a
communications circuit
for
voice grade analog
sig-
nals
and
sometimes
one-way digital signals.
See
Ba-
sic
Link.
AST
See
Automatic
Scheduled
Testing.
astatic galvanometer A device developed
by
Will-

iam
Thompson
(Lord Kelvin)
in
1858
to
overcome
the
limitations ofearlier instruments that
were
sub-
ject
to
interference
from
the
Earth's magnetic
field.
Unlike previous galvanometers employing one
needle,
the
astatic galvanometer
uses
two
needles,
each
with
a separate
coil.
The

needles
are
oriented
so
that
north
and
south
poles effectively cancel
out
the
Earth's
magnetic
interference.
See
galvanometer.
ASTC I.
See
Association
of
Science-Technology
Centers.
2.
Australian
Science
and
Technology
Coun-
cil.
An

association
of
professionals involved
in
tech-
nical
and
business communications. 3. Australian
Society
for
Technical Communication
Inc.
A
non-
profit society ofprofessionals involved
in
commu-
nicating technical information.
ASTER Advanced Spaceborne Thermal Emission
and
Reflection Radiometer. A
Jet
Propulsion
Labo-
ratory
(JPL)
satellite imaging instrument project.
Since
1998,
ASTER

has
been obtaining moderate
to
coarse
detail
maps
of
Earth's temperature, emissiv-
ity,
reflectance,
and
elevation characteristics.
The
satellite that first carried
ASTER,
the
EOS
AM-I,
is
part of
NASA's
Earth Observing
System
(EOS).
The
ASTER
instrument
was
subsequently launched
in

December
1999
aboard
Terra
to
provide
high
spa-
tial
resolution instruments
as
one
of
five
sensing
sys-
tems.
See
Earth Observing
System.
See
the
NASA
ASTER
Web
site for information on ASTER's
progress. />astigmatismAn aberration associated
with
lenses
in

which irregularities
in
the
shape
or
general curvature
of
the
lens
cause
more
than
one
line
of
focus
or
in
which a portion
of
the preferred line of focus
is
blurred.
Astigmatism
is
inherent
in
a number
of
laser

beam-
generating technologies
such
as
laser
diodes.
Since
the
semiconductor-based emission facet of a laser
diode
is
typically rectangular,
it
causes
an
astigmatic
beam
(a
beam with
an
elliptical cross-section) that
is
usually corrected
with
one
or
more
lenses.
ASTRAL Alliance for Strategic Token-Ring
Ad-

vancement
and
Leadership. A vendor-supported
or-
ganization formed
in
the
mid-I990s
to
support
mi-
gration
to
High
Speed
Token-Ring
LAN
technology.
The
group
prepared a number
of
white papers
and
a
draft standard
for
100
Mbps
Token-Ring

transmis-
sions.
With
the
emergence ofEthernet
as
a widely-
adapted
technology,
interest
in
Token-Ring
networks
was
waning
in
the
late-1990s.
See
High
Speed
To-
ken-Ring.
Astro-D
See
Advanced Satellite
for
Cosmology
and
Astrophysics.

Astrolink A commercial global satellite
communi-
cations service scheduled
to
come
online
in
2001.
Astrolink International Limited
is
an
independent
Lockheed
Martin
venture.
Lockheed
Martin
has
been
active
in
global communications frequency utiliza-
tion conferences
and
on
various
ATM-
and
lTU-T-
related technical

and
standardization
committees
and
working groups.
Astrolink
is
targeted
at
providing multimedia
appli-
cations over virtual private networks
(VPN)
with
a
focus
on
secure transmissions
and
connectivity
be-
tween
private
and
public networks.
The
Astrolink
system
consists
of

nine
geostationary
satellites:
five
to
provide global coverage,
four
to
come
online
later.
They
will
be
operating over Ka-
band
frequencies
with
approximately
6-Gbps
capac-
ity
per satellite
using
continuous
beam
uplinks
and
multi
frequency

TDMA.
astronomical unit
AU.
A unit
of
length defined
as
the
distance
from
the
Earth
to
the
Sun,
a
measure
that
is
generally given
as
about 149,579,000 to
149,599,000 kilometers. The variation
in
the unit
comes
about
due
to
the

variation
in
the
Earth's
move-
ment
in
relation
to
the
Sun
and
the
measuring sys-
tem
and
criteria
used
to
establish
the
distance.
ASU application-specific
unit.
asymmetric
1.
Not symmetric, lopsided, irregularly
proportioned, unbalanced, one-directional, having
one
side larger or longer than

the
other.
Asymmetric Digital SubscriberLine
ADSL.
A
data
communications service over traditional
phone
wires
71
© 2003 by CRC Press LLC