Fiber Optics Illustrated Dictionary - Part 12 doc

Fiber
Optics
Illustrated
Dictionary
demarcate
the
end
of
one
communication
or
section
and
the
beginning
of
the
next
one,
especially
in
situ-
ations
where
many
people
are
sending
information
through
the

same
queue,
such
as
aprint
queue
or
(2)
to
identify
the
type
of
communication
or
the
person
to
whom
it
belongs.
bantam tube A
squat
electron
tube
with
a
normal-
sized
base

that
was
once
commonly
used
in
small
ap-
pliances
or
battery-operated
mobile
devices
like
por-
table
radios.
Modem
transistors
have
since
made
most
types
of
vacuum
tubes
obsolete.
See
acorn

tube.
bar
code
Identification,
information,
and
manage-
ment
code
designed
for
optical
scanning
by
a
read-
ing
device.
Black
and
white
visual
bar
codes
are
fa-
miliar
identifiers
on
consumer

products.
They
assist
the
checkers
in
entering
prices
and
adjusting
inven-
tory
databases.
Bar
codes
are
frequently
inserted
on
postal
letters
and
packages
that
have
been
optically
interpreted.
In
fact,

the
information encoded
into
video
and
audio
discs
is
stored
via
bar
codes.
Bantam portA
connecting
interface
used
on
Tl
sys-
tems
for
interfacing
with
receive
and
transmit
(e.g.,
DS
1
inlout)

or
external
timing
sources,
typically
with
balanced
100-
or
120-ohm
termination.
Amini-Ban-
tam
may
be
used
on
T1
daughtercards
for
support-
ing
an
external
monitor.
In
circuit
testing,
the
sleeve

on
the
Bantam
connection
may
be
used
to
ground
the
circuit.
Port
Configurations -
Bantam
Unlike
RJ-45
(left)
orbayonet-mountports
(middle),
which have distinctive shapes, aBantam port
is
very
simple and unassuming, just a small round hole
(or
dual holesfor receive and transmit connections).
bar generator A
device
used
to
generate

horizontal
or
vertical
bars
on
an
output
device
to
determine
and
adjust
linearity.
Baran, Paul
(ca.
1926- ) A
Polish-born
American
engineer,
Baran
is
acknowledged
as
a
significant
In-
ternet
pioneer.
He
conceived

a
Distributive
Adaptive
Message
Block
Network
(a
concept
dubbed
packet
switching
by
Donald Davies) while working
at
RAND
Corporation
on
U.S.
federal
communications
infrastructure
projects.
The
core
concept
was
to
cre-
ate
a

decentralized
system
through
which
data
could
flow
in
any
direction
such
that
ifa
part
of
the
system
were
lost,
a
portion
of
the
system
and
the
data
would
survive.
Baran

worked
briefly
on
the
historic
UNIVAC
com-
puter
project
before
it
was
taken
over
by
the
RAND
Corporation
and,
after
jobs
elsewhere,
ended
up
at
RAND.
Baran's
networking
ideas
were

verbally
pre-
sented
at
RAND
Briefing
B-265
in
the
summer
of
1961.
He
subsequently
authored
a
series
of
memo-
randa
entitled
"On
Distributed Communications"
which
were
released
beginning
in
1964.
Around

the
102
same
time,
Davies
appears
to
have
been
indepen-
dently
developing
distributed
network
concepts.
In
the
analog
electronics
world
of
the
1960s,
Baran's
idea
was
a
far-fetched
proposal,
far

ahead
of
its
time
(it
was
rejected
as
impossible
by
AT&T).
As
digital
technology
evolved,
however,
Baran's
ideas
became
a
practical
possibility
and
formed
the
essential
inspi-
ration and format
for
distributed networks that

evolved
into
the
Internet.
A
future-oriented
thinker,
Baran
also
predicted
the
e-
commerce
and
online
entertainment
explosions
of
the
year
2000,
long
before
personal
computers,
the
In-
ternet,
and
the

World
Wide
Web
even
existed.
He
pro-
phetically described online comparison shopping
from
home
through
the
use
of
product
images
and
databases
back
in
1967.
Baran
founded
a
number
of
commercial
ventures
and
co-founded

the
Institute
for
the
Future.
He
is
a
trustee
of
the
IEEE
History
Center.
In
April
200
1,
Baran
was
awarded
the
Franklin
Institute's
Bower
Award
and
Prize for Achievement
in
Science. See Davies,

Donald;
Internet.
An
oral
history
of
Baran,
transcribed
in
October
1999,
is
available
online
through
the
IEEE
History
Center.
Barbe, Jane
The
actor
and
singer
whose
voice
has
been
heard
by

millions
as
the
telephone
voice
that
informs
subscribers
about
chan~ed
numbers
("This
number
is
no
longer
in
service

'),
disconnects,
and
other
situations.
Barbe
is
heard
on
Bell
and

National
Bureau of Standards systems
and
many
national
voicemail
systems.
She
has
provided
the
voice
for
Electronic
Tele-Communications,
Inc.
's
Audichron
time,
temperature,
and
weather services
since
the
mid-1960s.
Fans
of
early
television
shows

have
seen
her
on
the
popular
game
show
"I've
Got
a
Secret"
and
"The
Mike
Douglas
Show."
Barclay
box
relayA
historic
telegraphic
relay
which
had
better
sound
amplification
and
portability

than
conventional
models.
Barclay insulator A
type
of
early
glass
utility
pole
insulator
invented
by
John
C.
Barclay.
It
is
a
type
of
spiral
groove
insulator
and
is
numerically
identified
as
CD

150.
See
insulator,
utility
pole.
bare metal,
down
to
the bare metal
The
essentials
ofa
machine
or
system.
The
low
level
systems
func-
tions.
Programming
"down
to
the
bare
metal"
usu-
ally
means

programming
in
assembly
or
machine
lan-
guage
or
hand-wiring
a
prototype
breadboard.
bare wire A
wire
without
any
kind
of
protective
or
insulating
cover.
The
ends
of
insulated
transmission
wires
are
usually

stripped
of
their
covers
to
provide
bare
wire
for
a
good
electrical
contact
at
a
circuit
junc-
tion.
Barge In A
surcharge
phone
service
or
feature
ofa
multiline
subscriber
service
enabling
someone

(hope-
fully
in
authority)
to
barge
into
specified
lines
and
interrupt
a
call
in
progress.
It
is
a
privilege
that
should
not
be
used
indiscriminately
but
may
be
important
in

emergency
situations.
See
buttinsky.
barge out
To
abruptly
leave
a
call
in
progress.
barium ferrite
Barium,
a silver-white, malleable
substance
which,
in
combination
with
iron,
produces
© 2003 by CRC Press LLC
a
substance
that
can
be
used
in

magnetic
recording
media. Methods
of
synthesizing barium ferrite
nanoparticles
through
precipitation
and
spray
pyroly-
sis
are
being
studied.
Barkhausen, Heinrich Georg (1881-1956) A
Ger-
man
physicist
and
educator,
Barkhausen
worked
for
Siemens
&
Halske
and
then
accepted

a
professorship
in
communications
engineering
at
the
Dresden
Tech-
nical
Academy
in
1911.
He
founded
the
first
global
college
for
weak
-current
engineering,
work
that
was
fundamental
to
the
evolution

and
application
of
elec-
tron
tube
technology.
Barkhausen discovered
the
Barkhausen
effect
in
ferromagnetic
materials
and,
in
collaboration
with
K.
Kurz,
described
Barkhausen-
Kurz
oscillations.
See
Barkhausen-Kurz
tube.
Barkhausen effectA
phenomenon
described

in
1919
by
H.
Barkhausen
when
he
was
studying
magnetic
and
acoustic
effects.
He
observed
that
a
slow,
con-
tinuous
increase
in
the
magnetic
field
applied
to
a
fer-
romagnetic

material
would
result
in
discontinuous
increases
in
magnetization
due
to
changes
in
elemen-
tary
magnets
in
the
increasing
magnetic
field.
This
suggested
that
magnetism
was
a
phenomenon
related
to
the

larger
domain
ofa
ferromagnetic
substance
as
opposed
to
being
a
discretely
atomic
function.
The
effect
was
sufficiently
strong
to
be
heard
as
clicking
sounds
when
amplified
through
a
speaker.
Barkhausen-Kurz oscillations

In
a
vacuum
tube,
oscillation
of
electrons
by
means
of
electrodes
and
the
grid
through
manipulation
of
the
voltage
across
the
grid
and
the
plate
such
that
the
electrons
flow

back
and
forth
between
the
filament
and
the
plate.
This
phenomenon
has
practical
applications
for
the
gen-
eration
of
ultra-high
frequency
waves
and
aided
in
developing
the
principles
of
velocity

modulation.
See
Barkhausen-Kurz
tube,
electron
tube,
klystron.
Barkhausen-Kurz tube, B-K tube A technology
capable
of
generating
microwaves
that
was
developed
around the same time
as
the magnetron, the
Barkhausen-Kurz
tube
is
a
triode
vacuum
tube
with
the
third
element,
the

grid,
operated
at
a
high
posi-
tive
voltage
with
the
plate
at
zero
or
negative
volt-
age.
This
configuration produces
an
oscillating
mo-
tion
of
electrons
between
the
filament
and
plate.

The
tube
dates
back
to
the
work
of
German
scientists
H.
Barkhausen
and
K.
Kurz
who
described
the
technol-
ogy
in
Physik Zeit
V.21,
1920.
By
the
mid-1930s,
there
were
a

number
of
commercial
vendors
of
B-K
tubes,
which
were
used
in
research
and
military
sens-
ing
applications.
See
Barkhausen,
Heinrich
Georg;
Kurz,
Karl;
magnetron.
barometerAn
instrument
designed
to
measure
atmo-

spheric
pressure.
It
is
one
of
the
tools
commonly
used
to
evaluate
and
predict
weather
patterns.
Barometers
are
incorporated
into
a
number
of
other
instruments
as
well,
most
notably
traditional

altimeters.
Newer
altimeters
sometimes
incorporate
Global
Positioning
Service
(GPS)
capabilities.
Barometers
were
important
instruments
in
early
stud-
ies
of
magnetism,
particularly
in
Italy
where
mem-
bers
of
the
Accademia
del

Cimento
used
barometers
in
the
1660s
to
provide
an
airless environment
to
study
whether
the
attractive
properties
of
various
sub-
stances
were
dependent
upon
air.
Unfortunately,
the
difficulties
of
creating
a

vacuum
and
manipulating
the
materials within
the
small
area
hindered
them
!:~:!~\;~i;~:::~:::::~:S~::~::
:~:::l:~
••
early
as
the
1600s,
in
which
a
glow
or
flash
appears
above
the
mercury
in
a
barometric

tube
if
it
is
moved
quickly
or
shaken.
The
phenomenon
is
similar
to
that
exhibited
by
neon
light,
although
this
was not
known
at
the
time.
See
barometer.
barreldistortionA
type
ofvisual

aberration
in
which
the
outward
comers
of
an
image
are
contracted
in-
ward.
This
may
happen
on
a
convex
or
concave
sur-
face
(depending
upon
whether
it
is
backlit
or

frontlit)
and
is
noticeable
on
older,
more
highly
curved
moni-
tors
and
television
screens.
The
opposite
of
barrel
dis-
tortion
is
pincushion
distortion.
See
keystoning.
barretter,
barreter
A device whose resistance
changes
in

relation
to
temperature.
The
hot-wire
barretter
was
devised
in
1901
by
R.
Fessenden
to
improve
the
technology
that
was
then
being
used
to
detect
radio
waves.
The
technology
was
incorporated

into
voltage-regulating
devices
consisting
ofa
wire
filament
connected
to
the
circuit
in
series
contained
within a gaseous
envelope.
In
conjunction
with
a
waveguide,
a barretter
can
be
used
to
measure
elec-
tromagnetic
power.

BARRNet
Bay
Area
Regional
Research
Network.
An
association
ofuniversity
campuses
and
government
research
centers
in
the
San
Francisco
area.
See
BBN
Planet.
Bartholin, Rasmus (1625-1698) A
Danish
physicist
and
mathematician
from
the
erudite

medically
in-
clined
Bartholin
family,
Bartholin
followed
the
ex-
ample
of
his
father
Caspar
and
brother
Thomas
and
studied
in
Italy
from
1653
to
1656.
He
is
best
known
for

his
1669
experiments
with
Ice-
land
spar,
a
transparent
form
of
calcium
carbonate
with
interesting birefringent properties. Bartholin
published his findings
as
Erasmi Bartholini
in
Experimenta
Crystalli
Islandici
Disdiaclastici
and
followed
them
up
with
other
scientific

publications
that
included
information
about
optics.
His
was
an
important
contribution,
inspiring
a
number
of
other
prominent
scientists
to
study
and
mathematically
de-
scribe
double
refraction
and
its
implications
regard-

ing
our
understanding
of
the
nature
of
light.
Bartholin (sometimes transcribed
as
Erasmus
Bartholinus)
had
an
interest
in
astronomy
as
well
and
described
the
path
of a
comet
he
observed
in
1665,
which

is
richly
illustrated
in
Theatrum
Cometum
pub-
lished
in
1666.
See
Iceland
spar,
Nicol
prism.
Barton,Enos Melancthon (1840s-early
1900s)
Bar-
ton
co-founded
Western
Electric
with
telegraph/tele-
phone
pioneer
Elisha
Gray.
He
initially

fonned
a
part-
nership
in
1868
with
George
Shawk.
Shawk
rejected
an
offer
to
partner
with
Gray,
but
Barton
was
inter-
ested
in
Gray's
ideas
and
Gray
&
Barton
was

formed
in
1869,
evolving
into
the
Western
Electric
Company
in
1872.
It
is
the spiritual forerunner of today's
103
© 2003 by CRC Press LLC
Fiber
Optics
Illustrated
Dictionary
Lucent Technologies. Graybar Electric Company,
Inc.,
was
spun
off
from
Gray
& Barton
in
1925

in
order
to
provide
electrical distribution.
See
Gray
&
Barton;
Graybar
Electric
Company,
Inc.
base
I.
Bottom;
lower support portion; portion
to
which
something
is
bonded;
substrate.
2.
In
utility
pole
insulators,
the
base

may
be
smooth
or
may
have
drip
points,
little
knobs
for
the
distribution of
stream-
ing
moisture.
3.In
layered
semiconductor
fabrication,
the
beginning
or
bottom
layer
ofa
component,
which
is
often

a
supporting
substrate.
4.
In
bipolar
semicon-
ductor
components,
a
thin
region
of
one
type
of
semi-
conductor
sandwiched
between
an
emitter
and
a
col-
lector
of
another
type
to

form
a
dynamic
environment.
In
the
base
region,
excitable
(highly
mobile)
electrons
act
as
minority
carriers
moving
between
the
emitter
and
collector.
See
p-njunction.
5.
In
chemistry,
a
sub-
stance

that
gives
up
hydroxide
ions
in
solution.
base
film
Asubstrate
for
holding
magnetic
particles
as
in
audio
and
video
tapes.
The
materials
used
for
base
film
vary
but
generally
have

the
characteristics
of
flexibility,
resistance
to
wear,
and
affinity
for
hold-
ing
the
magnetic
coatings
that
are
applied
to
their
sur-
faces.
Base Information Digital Distribution System
BIDDS.
A
U.S.
Air
Force
telephony
communications

distribution
network
installed
in
the
1980s
with
au-
tomated
functions
such
as
directory
and
operator
as-
sistance,
reporting,
record-keeping,
and
billing.
Base
Information
Transport
System
BITS.
A
U.S.
Air
Force

military
network
system.
Information
about
BITS
is
published
on
the
Web
as
an
aid
to
outside
contractors
planning
and
installing military informa-
tion
technology infrastructures.
base
insulator A
large
support
and
insulating struc-
rure
used

on
transmissions towers
to
insulate
the
tower
from
the
ground.
base
memory
jmgon
The
first
block
of
memory,
con-
sisting of640
kilobytes,
in
the
older
Intel-based
desk-
top
computers.
Base
memory
is

now
more
generally
used
to
describe
the
typical
or
minimum
memory
with
which a
system
is
sold
to
the
enduser.
By
early
2002,
base
memory
configurations of
256
or
512
Mbytes
wercommon.

base
rate
I.
The
basic
rate
without options
or
value-
added
services.
2.
The
basic
charge
per
minute
for
measured
service.
base
station
I.
A
main
transmitting and/or receiving
station
or
central
switching station,

often
one
which
serves
as
a junction
between
wireless
and
wire
line
communications
paths,
or
between
broadcast signals
and
cable
subscribers.
2.
In
mobile
communications,
a
fixed
station
within
the
transceiver
system.

See
cel-
lular
phone.
3.In
Global
Positioning
Systems
(GPS),
areceiver established
in
a
known
location
to
provide
reference
data
for
differentially
correcting
rover
files.
Baseline
data
can
be
correlated
with
position

data
from
unknown
locations
collected
by
roving
receiv-
ers
to
improve
accuracy.
baseband
I.
A
simple
type
oftransmission
in
which
the
signal
is
sent
without altering
it,
as
by
modula-
tion,

and
which does not require demodulation
104
through
modems
to
alter
the
signal
at
its
destination.
A transmission
that
is
not
segmented
by
frequency
division (multiplexing).
This
basic
signal
is
centered
on
or
near
the
zero

frequency.
See
sideband.
2.
A
one-
channel
or
one
carrier-frequency
data
network
such
as
Ethernet,
that
is
alternately shared
by
the
various
peripherals,
such
as
computers
and
printers,
or
allo-
cated

as
requested.
See
narrowband, Token-Ring.
Contrast
with
broadband.
baseband
modem
This
phrase
is
an
oxymoron,
since
a
baseband
signal
is
one
that
has
not
been
modulated
and
thus
doesn't require a
modem
to

demodulate
it.
However,
baseband
modems
do
sometimes provide
an
interface device
with
some
simple
translation
ca-
pabilities
and
may
physically resemble standard
mo-
dems,
hence
the
name.
Sometimes better
termed
a
short
haul
modem,
it

is
suitable
for
short distances.
baseband repeater A
common
main
station repeat-
ing
system
used
to
retransmit a signal
and,
in
some
cases,
drop
out
selected channel groups,
e.g.,
voice
channels,
before
retransmission.
Over
long
distances
with
several

legs,
heterodyne repeating,
which
is
less
subject
to
loss
or
distortion
from
modulation
and
de-
modulation,
may
be
used
in
conjunction
with
base-
band
repeating
to
exploit
the
better
properties
of

each
method.
See
baseband, heterodyne
repeater.
baseboard raceway A cable conduit or pathway
along
wall
baseboards.
The
raceway
may
run
along
the
baseboards,
or
be
built
into
them,
so
they
won't
be
seen.
Thus, wiring
can
be
installed

and
hidden
without tearing
into
the
inner
walls.
baseline
I.
In
coordinate systems, a
scale,
often
the
horizontal X axis,
that
establishes a reference struc-
ture
on
which
related
data
can
be
depicted.
2.
In
ra-
dar,
a

line
displayed
to
show
the
track ofa scanning
beam.
3.In
typography,
an
imaginary
line
extending
through
a
font
(horizontal
in
Roman
and
Cyrillic
fonts)
for
alignment. Desktop publishing software
is
not
entirely standardized;
some
programs treat
the

base-
line
as
the
bottom
edge
ofnondescending letters,
and
others
treat
it
as
the
first
unit
beneath
the
bottom
edge
of these letters.
4.
In
a Global Positioning System
(GPS),
apair ofstations
for
which
simultaneous
data
have

been
collected.
bash,
bash
shell, Bourne-again shell A popular,
powerful, practical sh-compatible Unix command
interpreter
shell
(command
environment) released
in
the
late
1980s
by
the
Free
Software
Foundation.
Bash
is
based
on
the
Bourne
shell,
with
some
features
from

Korn
(ksh)
and
C
(csh)
shells.
BASIC
Beginner's
All-purpose
Symbolic
Instruction
Code.
An
English-like programming language
de-
signed
at
Dartmouth College
in
the
early
1960s
that
evolved from the Dartmouth Simplified Code
(Darsimco).
BASIC
was
created
to
provide a

pro-
gramming
environment
that
was
faster
and
easier
to
learn
than
FORTRAN
or
lower
level
languages
like
assembler
or
machine
code.
BASIC
was
originally a
compiled language that enabled students
to
write
computer
programs
for

the
Dartmouth
Time-Sharing
System
running
on
a General Electric
(GE)
main-
frame
computer.
© 2003 by CRC Press LLC
The
availability
and
sophistication
of
commercial
software
has
increased dramatically
since
the
early
days
of
BASIC
and
more
powerful

programming
lan-
guages
have
evolved
(e.g.,
C/C++).
Users
no
longer
have
to
program
a computer
to
use
one,
and
the
de-
mand
for
fast,
powerful
software
has
necessitated
the
use
of

other
languages.
Thus,
the
original text-based
BASIC
has
largely
faded
into
computer
history,
sur-
vived
mainly
by
object-based
graphical
versions
(pri-
marily
Visual
BASIC)
that
are
useful
for
writing
utili-
ties

or
prototyping
software interfaces
and
software
flow
(e.g.,
proofof
concept
demonstrations).
With
so
much
off-the-shelf software
now
available,
the
mo-
tivation
for
the
general
consumer
to
learn
to
program
in
BASIC
has

all
but
disappeared,
though
BASIC-
like
macro
programming
languages
can
still
be
found
in
most
paint,
database,
and
word
processing
pro-
grams
for
the
purpose ofautomating
common
tasks.
See
VisualBASIC.
basic access authentication

See
authentication,
ba-
sic
access.
basic cable service
The
base
service
(lowest
level)
offered
by
atelevision cable
company,
consisting of
a
cable
feed
to
the
premises
and
broadcasting
ofa
spe-
cific
package
of
programs.

The
cable
company's
pro-
gramming provisions, signals,
and
public, educa-
tional,
and
government
access
channels
are
govern-
ment
regulated under
the
Cable
Act.
Rates
for
basic
cable
services
and
equipment
are
regulated
by
fran-

chising
authorities
that
are,
in
tum, certified
by
the
Federal
Communications
Commission
(FCC).
FCC
rules
are
available through
the
International
Tran-
scription
Service
(ITS).
See
Cable
Act
of
1984.
Basic Call Model
BCM.
See

Intelligent
Networks
Call
Model.
Basic Control System BCS.
An
interrupt-driven
computer satellite control
system.
Basic Encoding Rules
BER.
Standardized
rules
for
data
encoding
that provide
support
for
the
abstract
syntax
description
language
ofAbstract
Syntax
N
0-
tation
One

(ASN.l). BER was developed
in
the
1980s,
arising
out
of
ISO
X.409
and
rewritten
as
ISO
8825
to
provide a separation between ASN.l
and
BER
concepts.
It
was
then
introduced
in
the
1988
CCITT
Recommendations
as
X.209

and
became
a
tool
for
use
in
the development
of
open systems
architectures.
It
became
one
of
three
major
schemes
that
evolved
in
the
early
1990s
for
encoding
and
is
strong
in

the
areas
ofextensibility
and
the
ability
to
recognize
encoding
structure without
knowledge
of
the
originatingASN.l
type.
See
Abstract
Syntax
N
0-
tation
One,
Packed Encoding Rules, LightWeight
Encoding
Rules.
Basic Exchange Radio Telecommunications Ser-
vice
BERTS.
A
system

developed
in
the
1980s
to
pro-
vide
wireless
services
through
radio
signals
to
stan-
dard
local
telephone
loops,
especially
to
rural
areas
or
for
emergency
services.
basic information unit
BIU.
In
packet

networking,
aunit of
data
and
control information consisting ofa
request/response header (RR)
and
a following
re-
quest/response unit
(RU).
Basic
Link
A
voice
grade
circuit providing certain
specified standard levels
for
services, transmission,
and
loss
(8
dB
in
the
300
to
3000
Hz

bandwidth).
See
Assured
Link.
Basic Rate Interface
BRI.
There
are
two
basic
types
of
ISDN
service
available:
BRI
and
PRI.
BRI
is
an
ISDN
service
consisting
of
two
bidirectional
64
Kbps
bearer channels

(B
channels)
for
voice
and
data
and
one
delta
channel
(D
channel)
for
signaling
or
packet
networking
at
16
Kbps
or
64
Kbps.
It
requires
two
conductors through a U
Loop,
from
the

carrier
to
a
terminator
(NT
1)
at
the
customer
premises.
Except
in
the
rare
cases
ofextremely
long
phone
lines
with
load
coils,
most
existing
phone
lines
can
be
used
for

BRI
without significant
changes
to
the
actual
wire.
BRI
is
aimed
at
residential
and
small
business
users.
See
ISDN.
basic sequential access method
BSAM.
A basic
means
of
accessing
data
stored external
to
a proces-
sor.
Other

common
methods
include
basic
direct
ac-
cess,
and
basic
partitioned
access.
basic telecommunications AFederal
Communica-
tions
Commission
(FCC)
general administrative
cat-
egory
distinguished
from
enhanced
service
telecom-
munications.
The
concept
applies
to
telecommunica-

tions
that
are
facilitated
by
computer technologies
without additional processing or protocol conver-
sions.
Basic
phone
service
is
one
example.
This
ser-
vice
is
regulated
under
Title
II
and
mainly
affects
tele-
phone
service carriers rather
than
those

offering
en-
hanced
computer
data
services.
As
such,
basic
tele-
communications
providers
may
be
subject
to
fees
and
regulations
that
don't
apply
to
enhanced
services
pro-
viders
and
are
regulated

in
order
not
to
stifle
compe-
tition with enhanced services providers. Providers
offering both basic
and
enhanced communications
services
have
to
maintain distinctions
between
basic
and
enhanced
services
when
billing clients
and
mar-
keting services
to
potential
customers.
See
Federal
Communications

Commission.
Basic TradingArea
BTA.
An organizational
desig-
nation
for
wireless telecommunications
in
which
the
United States
is
subdivided into almost
500
basic
trading
areas
(BTAs)
which
are
collectively
grouped
into
Metropolitan
Trading
Areas
(MTAs).
The
BTAs

are
used
by
the
Federal Communications
Commis-
sion
(FCC)
as
a basis for assigning
pes
wireless
phone
system
licenses.
basket windingAtechnique
of
winding a
wire
coil,
or
other filamentous conducting material,
such
that
the
paths of
the
various
turns
of

the
winding
do
not
touch
except
at
junctions
where
they
may
cross.
It
is
sometimes
called lattice
winding.
Basket winding
is
used
in
applications
where
a
long
length
of
wire,
or
a greater

degree
of
surface
area,
needs
to
be
organized
into
a
small
amount
of
space.
Basket
wound
antennas
and
other
devices
can
be
quite
aesthetic, resembling
arabesque.
See
basket-wound
tuners.
basket-wound tuners Historically,
various

types
of
basket winding with
fine
threadlike materials
were
commonly used
in
old radios
to
act
as
frequency
105
© 2003 by CRC Press LLC
Fiber
Optics
Illustrated
Dictionary
tuners.
The
windings
were
of
many
shapes,
cylindri-
cal,
circular,
somewhat

spherical.
They
varied
in
com-
plexity
from
a
dozen
turns
or
so,
to
many
hundreds
of
turns,
in
intricate
patterns
in
many
layers.
By
vary-
ing
the
shape,
size,
and

the
thickness
of
the
wires,
dif-
ferent
frequencies
could
be
selected.
A
radio
often
came
with
a
selection
of
basket-wound
tuners
with
electrical
contacts
on
the
base
that
could
be

plugged
in
as
needed.
Basov, Nicolay Gennadiyevich
(1922-2001)
A
Rus-
sian
medical
assistant,
physicist,
and
engineer,
Basov
made
important
contributions
to
the
field
of
quantum
radiophysics
and
pioneered
ammonia-based
beams
(early
laser

research).
By
1957,
Basov
was
design-
ing
and
constructing
optical
quantum
oscillators
that
had
potential
for
gas
and
semiconductor-based
oscil-
lators.
By
the
early
1960s,
along
with
various
collabo-
rators,

Basov
was
creating
injection
semiconductor
lasers
with
gallium
arsenide.
Through
investigations
of
short
laser
pulses,
high-power
single-pulse
Nd-
glass
lasers
were
developed
in
the
mid-
to
late
1960s.
In
1964,

along
with
Townes
and
Prokhorov,
Basov
was
awarded
a
Nobel
Prize.
Under
Basov's
guidance
in
the
early
1970s,
an
original
chemical
laser
was
developed
and
Basov
et
al.
described
infrared

laser
stimulation
of
chemical
reactions.
See
laser.;
laser
history;
Townes,
C.
bass In
audio,
a
low
pitch;
a
deep
audible
tone.
bat
switch
See
toggle
switch.
batch An
assortment
of
data
or

objects
grouped
to
be
processed
during
a
single
run
ofa
program
or
pro-
cess.
See
batch
file,
batch
processing.
batch
fIle
A
data
file
for
grouping,
storing,
and
fa-
cilitating

the
execution
of
complex
sequences
or
fre-
quently
used
computer
commands.
Batch
files
are
a
convenient
way
to
store
configuration
parameters,
frequently
used
groups
of
commands,
a
list
of
appli-

cations
that
are
executed
one
after
another,
commands
intended
for
deferred execution, scripts launched
from
Web
pages,
and
startup
commands
for
a
com-
puter
system.
".BAT"
is
a
familiar
extension
given
to
batch

files
on
MS-DOS-compatible
systems.
Many
systems
provide
job
control
languages
(JCLs)
or
a
va-
riety
of
scripting
languages
for
the
quick
creation
of
batch
files.
Perl
is
an
excellent
multiplatform

pro-
gramming
tool
for
creating
batch
files
use
on
and
off
the
Web.
Batch
commands
have
traditionally
been
created
with
text
editors,
but
graphical
tools
may
be
used.
See
batch,

batch
processing,
JCL,
Perl,
Java.
batch processing
Deferred
or
off-line
processing
of
an
assortment
of
data,
programs,
or
obj
ects
handled
during
a
single
program
or
process
run.
Unless
there
is

a
fault
condition,
batch
processing
usually
assumes
once
the
job
is
initiated,
it
will
run
undisturbed
and
unattended.
Email
is
often
handled
as
a
batch
process,
e.g.,
your
Internet
Services

Provider
may
wait
a
speci-
fied
period
of
time
before
posting
a
group
of
mes-
sages
to
your
account
rather
than
posting
each
one
as
it
is
received.
Payroll
accounts

are
often
run
as
batch
processes,
as
are
many
data
collection
pro-
grams,
such
as
weather
testing,
astronomical
obser-
vations,
etc.
106
It
is
not
uncommon
for
batch
processes
to

run
as
back-
ground
tasks,
executing
while
users
continue
to
use
the
system
for
other
applications.
Batch
processes
can
be
scheduled
to
run
when
network
access
is
low,
thus
not

putting
a
drain
on
system
resources
when
many
users
are
online.
Batch
processes
can
also
be
used
to
schedule
transmissions,
such
as
facsimiles,
during
hours
when
phone
rates
are
low.

See
batch,
batch
file,
realtime
processing.
Batch Simple
Mail
Transfer
Protocol
BSMTP,
bSMTP,
Batch
SMTP.
A
batch
version
of
the
Simple
Mail
Transfer
Protocol
developed
in
the
early
1980s
by
E.

Alan
Crosswell
to
facilitate
the
reliable
trans-
mission
of
electronic
mail
messages
over
distributed
computer
networks
independent
of
the
transmission
subsystem.
Batch
SMTP
allows
a
series
of
commands
to
be

bundled
and
sent
to
a
remote
machine
for
ex-
ecution'
rather
than
establishing
a
typical
interactive
SMTP
session.
The
processing
of
special
characters
may
also
be
supported
through
batch
processing.

This
protocol
was
presented
to
the
BITNET
community
in
1982
and
installed
on
many
BITNET
mailer
gate-
ways.
See
Simple Mail Transfer Protocol. See
RFC
821,
battery A
group
of
two
or
more
cells
connected

to-
gether
in
such
a
way
that
they
produce
a
direct
elec-
tric
current
(DC).
While
historians
believe
battery
power
may
have
been
used
for
electroplating
by
the
Parthians
as

early
as
the
third
century
BC,
the
first
significant records of
modem
battery
experiments
date
from
the
work
ofC.
A.
Volta.
Battery-generated
electricity
was
widely
used
in
in-
dustrial applications
and
telegraph
and

telephone
communications
in
the
early
1900s.
Edison
was
a
strong
proponent
of
DC
current
and
received
much
opposition
from
Tesla
and
Westinghouse,
who
were
advocating
alternating
current
(AC).
Batteries
are

used
widely
in
portable
devices
and
as
emergency
or
backup
power
for
systems
whose
main
power
source
is
alternating
current.
The
Sampling
of
the
Evolution
of
Batteries
chart
describes
a

few
com-
mon
batteries
and
interesting
technological
adapta-
tions.
See
B
Battery,
cell,
storage
cell,
talking
battery.
battery, rechargeableA
direct
current
(DC)
power
source.
A
rechargeable
battery
is
designed
to
readily

have
its
power
restored,
usually
through
consumer-
priced
battery
chargers
or
through
an
alternating
cur-
rent
(AC)
transformer attached between
the
wall
socket
and
a battery-charging
device.
Rechargeable
batteries
are
commonly
used
on

palmtops,
laptops,
camcorders,
etc.
Most
of
them
need
to
be
fully
dis-
charged
before
being
recharged,
or
a
memory
effect
results
in
only
a
partial
charge.
Some
can
be
trickle-

charged
when
plugged
into
an
outlet
while
being
used.
Larger rechargeable batteries
for
consumer
electronics
usually
supply
from
two
to
five
hours
of
charge.
battery, storageA
type
of
battery
that,
once
charged,
will

hold
that
charge
for
a
practical
amount
of
time
without
constant electrical refreshes
from
another
source,
such
as
alternating
current
(AC).
Car
batter-
ies
are
a
type
of
common
storage battery that
are
© 2003 by CRC Press LLC

bazooka A
device
for
isolating
an
outer conductor
from
other surfaces
and
connecting
an
unbalanced
line
to
abalanced
line.
Bazookas
are
commonly
used
on
the
ends
of
coaxial
cables
that
are
to
be

connected
to
two-wire lines (e.g., copper twisted pair).
See
balun.
BB
1.
See
baseband.
2.
See
broadband.
BNC connectors
are
widely usedfor couplingfiber
optic and coaxial cables
to
switchers and patch pan-
els,
as
they provide a secure connection that
is
not
easily uncoupled
by
bumping or
tugging.
End and
overhead views
of

a number
of
common
BNC
(bayo-
net
mount)
connectors
are
illustrated
as
follows: BNC
to
RCA
plug
(A),
BNC
to
RCAjack
(B),
BNC
to
screw-
type F connector
(C),
BNC
to dual
BNC
male con-
nectors

(e.g.,
'thin'
Ethernet)
(D),
BNC terminator
(E).
E
Dc
BNC
Connectors
BA
See
ASCII;
EBCDIC;
Baudot,
J.M.
Emile.
Bauschingereffect
Straining
a
solid
body
beyond
its
yield strength
in
one
direction decreases
its
yield

strength
in
other
directions.
bay
1.
Harbor,
indentation,
arced
enclosure.
2.
An
opening
in
a rack
or
panel
into
which
modular
com-
ponents
can
easily
be
inserted. Apatch
bay
has
a
se-

ries
of
regular
openings
designed
to
securely
hold
modular
components
while
still
providing
easy
ac-
cess,
ease
ofconfiguration,
and
swapping
in
and
out
as
needed.
See
patch
bay.
3.
Part

of
an
antenna
array.
bayonet baseA
type
ofjack or jack-like
base,
as
on
a
bulb,
which
has
a
small
projection
on
one
side
and
slips
into
a receptacle
with
a turn
so
the
proj
ection

catches
within
a
small
trough
and
secures
the
inserted
object.
bayonet
nut
connector, bayonet navy connector
BNC.
A quick-connect bayonet-locking
connector,
commonly
used
for
coaxial cables
for
network
or
video
transmissions.
It
is
intended
to
provide

a
con-
stant
impedance.
The
outer
shell
has
a
sma,ll
bayonet
that
inserts
in
a helical
channel
in
the
receptacle
to
aid
in
firmly
securing
and
aligning
the
connector.
This
is

good
for
securing
connections
that
must
not
be
in-
terrupted or
for
securing
cables
against
which
there
may
be
tension.
See
connector,
F
connector,
RCA
connector.
recharged
when
the
engine
is

running.
They
have
a
useful
life
of
about
three
to
five
years
if
not
com-
pletely
discharged
too
often
(by
leaving
lights
on,
for
example).
Storage
batteries
are
often
used

as
backup
systems
for
alternating current
(AC)
systems.
See
battery,
fechargeable.
battery backup A
direct
current
(DC)
backup
sys-
tem
which
kicks
in
if
something
happens
to
the
pri-
mary
power
system.
For

example,
many
phones
now
have
memory
storage
for
names
and
numbers,
or
ex-
tra
features
like
speakerphones
or
text
display,
that
require
more
power
than
is
provided
by
the
current

coming
from
the
phone
line.
These
phones
may
have
a
battery
or
AC
power
cord
to
help
power
the
extra
features
which
also
functions
as
a
backup
battery
to
protect

the
contents
of
the
electronic
phonebook
if
the
phone
line
power
is
interrupted
by
a
power
fail-
ure,
or
if
the
phone
is
disconnected
and
moved
from
one
location
to

another.
Most
computer
systems
have
small
batteries
on
the
motherboard
to
protect
the
contents
of
certain
types
of
chips
that
hold
information
such
as
configuration
parameters.
Lithium
batteries
are
commonly

used
and
should
be
replaced
every
5
to
7
years
or
so.
Many
microwaves, clock radios,
and
VCRs
have
backup
batteries
so
that
the
time
is
not
lost
during
a
power
outage.

If
your
appliance
flashes
12:00
after a
power failure,
it
probably doesn't have a backup
battery.
baud, baud rateA
unit
signifying
a
rate
of
trans
mis-
sion
of
data
indicating
the
modulation
rate,
named
after
French
engineer
J.M.E.

Baudot.
The
term
is
commonly
used
to
describe
modem
data
transfer
rates
(e.g.,
9600
baud),
although
it originated
from
tele-
graph
signaling
speed
in
the
1920s.
Note
that
the
rate
of

transmission
is
not
necessarily
equal
to
the
rate
of
acquisition
of
the
data.
Line
interference,
handshak-
ing' error
correction,
and
other
factors
can
cause
the
actual
rate
of
data
received
to

be
less
than
the
raw
transmission
speed
associated
with
the
amount
of
data
transmitted.
Baudot, J.
M.
Emile (1845-1903) A
French
engi-
neer
and
inventor,
Baudot
made
many
contributions
including
a
means,
in

the
1870s,
to
insert
synchroni-
zation
signals
between
baseband
signals
so
time
di-
vision
multiplexing
(TOM)
could
be
used
to
combine
signals
into
a
bundle.
He
developed
the
Baudot
code

for
telegraphic
communications.
Baudot code,
Murray
code A data
code
used
in
asynchronous
transmissions,
named
for
its
inventor
J.
M.
Emile
Baudot.
It
was
widely
incorporated
into
teletypewriter communications beginning around
1870.
Baudot
code
was
based

on
a
marks
and
spaces
character-representation scheme employing five
equal-length
bits
to
symbolize
upper
case
letters. A
simple
method
of reversing
the
polarity of
the
line
was
in
use
for
about
half a
century
before
it
was

su-
perseded
by
frequency
shift
keying
(FSK
modulation
techniques).
The
character
set
was
very
limited
and
eventually standard codes such
as
EBCDIC
and
ASCII
superseded
Baudot
code
except
for
special-
ized
communications,
as

fo~
the
hearing
impaired.
107
© 2003 by CRC Press LLC
Fiber
Optics
Illustrated
Dictionary
BBC
1.
Broadband Bearer Capability. Abearer class
field that
is
part
of
an
initial address message.
See
ISDN.
2.
See
British Broadcasting Corporation.
BBL
1.
broadband loop.
2.
BROADBANDLOOP
Project. An

ACTS
project
to
define and test cost-ef-
fective broadband access network concepts facilitat-
ing the migration
of
fiber optic transmissions into
local loops.
The
project demonstrates the upgrade
of
passive optical networks
to
high bandwidth capacity
and the upgrade
of
wire-based networks
to
handle
broadband services
to
the customer premises.
The
target group
for
the
project
is
European residential

subscribers
and
small-
to
medium-sized businesses.
See BIDS,
BONAPARTE,
BOURBON, BROAD-
BANDLOOP,
UPGRADE,
WOTAN.
BBN
Bolt, Beranek,
and
Newman,
Inc.
Ahigh-tech-
nology company
in
Cambridge,
MA
which devel-
oped, maintained, and operated
the
historically sig-
nificant
ARPANET
and later the Internet gateway,
CSNET
CIC,

and NSFnet NNSC. See BBN Planet.
BBN
Planet A subsidiary
of
Bolt, Beranek, and
Newman, Inc., which operates a national Internet
access network. See
BBN.
DBS
See
bulletin board system.
DBT
broadband technology.
Dc
See
Committed Burst
Size.
BC
1.
backward compatible
2.
beam coupling.
3.
bi-
nary
code.
4.
broadcast.
BCC
1.

Bellcore Client
Company.
2.
See
block
check
character.
DCD
See
binary coded decimal.
DCM
See
Basic Call
Model.
DCOB
Broadband Connection-Oriented Bearer. In
ATM
networks, information
in
the SETUP message
that
indicates
the
type ofservice requested
by
the
call-
ing
user.
The

appropriate bearer class depends
on
the
Sampling
of
the Evolution
of
Batteries and Promising BatteryTechnologies
Type
Developer
Notes
B battery
electrochemical N
ogami
et
a1.
Daniell
battery
J.
F.
Daniell
Edison
cell
gravity/crowfoot
cell
Grove
battery
Abattery
A
chemical

battery
used
in
early telegraph systems,
1
volt.
A variable
storage
nickel
hydrate (positive)
and
iron
oxide
(negative)
cell
with
an
electromotive
force
lower
than
that
ofa
lead
cell.
This
is
a historic battery
that
was

used
in
automobiles
due
to
its
ruggedness.
A voltaic
wet
cell
for
providing
small
currents at a constant
emf.
Primary,
1.96
volts
per
cell.
Zinc,
platinum.
Used
by
S.
Morse.
Historically
used
as
talk batteries

in
telephone installations
and
as
low
voltage batteries
for
electron
tube
filaments.
Modem
versions
are
now
commonly
used
for
cameras,
calculators,
and
other
small
portable
appliances.
Historical provider of
low
voltage power
to
the
plates

(anodes)
in
electron
tubes
and
to
communications relay circuits.
Introduced
in
the
early
1920s,
C batteries provided bias voltage
to
electron
tubes
for
the
control
of
the
grid circuit
and
were
often
used
in
conjunction
with
B batteries

to
extend
the
life
of
the
B
battery.
C batteries
are
now
commonly
used
with
small
portable
devices
such
as
flashlights
and
portable boomboxes.
Announced
by
Bell
in
1954,
there
are
now

a number
of
variations
on
this
technology
from
different developers. Kyocera
introduced a multicrystal silicon solar battery
in
1996
that
has
a
conversion efficiency
rate
of
17.1
%, considered
good
in
the
solar
industry.
A battery
chemistry
based
on
lithium polymer
which

may
provide
longer
life
for
power-hungry
mobile
phones,
laptops,
etc.
Biological
systems
in
the
form
of
synthetic melanins
that
appear
to
have
the
form
of
an
amorphous semiconductor "threshold
switch" operating
at
threshold significantly
lower

than
inorganic
thin
films.
These
also
exhibit electroluminescence
at
the
point of
switching
energy
states, described
in
1973.
Abattery
with
its
electrodes immersed
in
an
organic solvent
electrolyte solution
with
the
electromotive
force
generating
by
dopinglundoping processes associated with

the
electrodes,
1982.
McGinness
et
al.
Bell
Labs
organic
C battery
silicon
solar
lithium
nouveau
108
© 2003 by CRC Press LLC
specification of
the
network.
BCOB-A
(Type
A)
connection-oriented, con-
stant bit
rate,
timing required
BCOB-C
(Type
C)
connection-oriented,

variable
bit rate, timing not required
BCOB-X
(Type
X)
transparentAAL, traffic
type
and
timing requirements
UNI
3.0
and
UNI
3.1
must support
Type
A
and
Type
C or
Type
X
as
a substitute
for
the
first
two
types
for

virtual connections (VCs). Internet Protocol over
ATM
signaling must permit
Type
C and
Type
X
bearer capability
in
specified combinations.
Type
C
and
Type
X
both
apply
to
multiprotocol connections.
BCP
See
Best
Current Practice.
BCRS
See
Bell
Canada Relay
Service.
BCS
1.

basic control system.
2.
Batch Change
Supplement. A development tracking system for
documenting
system features
from
proposal
to
fm-
ished
product.
3.
See
beam control system.
4.
See
Boston
Computer
Society.
5.
See
British Computer
Society.
BDF
block
data
format,
also
referred

to
as
data
block
format
(DBF).
Ageneric phrase
for
ablock ofdigital
data
with
a specific format with respect
to
the
size
and
order of
the
data items within
the
block.
BDT
See
Telecommunications
Development
Bureau.
Be
1.
See
burst

size,
excess.
2.
See
Be,
Inc.
Be,
Inc. Acomputer software
company
founded
by
Jean-Louis
Gassee,
head
of
R&D
at
Apple
Computer
during
the
Apple
II
years.
Be
developed
and
released
the
BeOS

(Be
Operating System)
in
1997.
It
is
a
fast,
integrated-database, multiplatform
OS
aimed
at
the
audio
and
graphics/video
computer-using
markets.
In
addition
to
BeOS,
Be
now
provides integrated client-
side
software,
development,
and
customization

tools
for
Internet device
and
service providers
and
con-
sumer electronics companies.
In
the
early
2000s,
Be
was
acquired
by
Palm.
See
BeOS.
BE
1.
base embossed. A designation
for
glass
and
ceramic
utility
pole
insulators
with

embossings
on
the
lower
edge,
usually
of
the size, company, and/or
patent
date.
2.
Bose-Einstein.
beacon
1.
A
signal,
locator,
or
guidance
beam
or
tone.
2.
A transmitter that
aids
in
monitoring radiant
en-
ergy
propagation.

beacon alert
An
alert
frame
in
a
Token-Ring
or
Fi-
ber Distributed
Data
Interface
(FDDI)
device signal-
ing
a
serious
problem,
such
as
a physical interrup-
tion
of
the
signal
or
Media Access Unit
(MAU).
The
frame

includes information
on
the
location
of
the
break
or
the
station that
is
down.
beam
1.
n.
A
ray,
shaft,
or
other directed energy or
illumination,
as
an
electron
tube,
radar,
or light
beam.
2.
v.

To
direct
or
aim,
as
in
a broadcast
beam.
beam antenna
An
antenna that transmits and/or
re-
ceives
within
a
narrow,
confined directional
range.
beam control system
BCS.
A
means
for
directing a
beam.
It
may
also
have
control capability

for
turning
a beam
on
and
off.
A
BCS
is
usually used
for
di-
recting common electromagnetic beams such
as
microwave
radio
signals
or
a
beam
of
light, but
it
may
also
be
used
for
high-precision
control

in
atomic
physics
testing
systems
(e.g.,
study
of
neutrinos).
The
more
sophisticated
the
technology,
the
more
likely
that beam control
is
automated with computer
hard-
ware
and
software. Logging
of
beam
characteristics
and
activities over
time

may
also
be
incorporated
into
aBCS.
beam divergence
1.
As
a
beam
travels
through
the
air,
various factors
may
cause
it
to
spread
out.
This
divergence
may
result
in
attenuation or dispersion of
the
signal strength of a transmission over distance.

2.
The
path ofa
beam
may
progressively
move
away
from
the
axis
of
the
original trajectory, resulting
in
divergence.
beam
position
monitor
BPM. A mechanism
for
keeping track of
the
position
of
an
emitted/transmit-
ted
beam
of

light (e.g., laser light) or other electro-
magnetic
energy
(e.g.,
radio
waves).
A
beam
position
monitor
is
commonly
used
in
systems
where
the
di-
rection
of
the
beam
can
be
controlled.
beam power
tube
An
electron
tube

with
a
beam
that
is
directed
and
concentrated
in
certain specific
direc-
tions
by
a special electrode. Used,
for
example,
in
radio
frequency
(RF)
transmitters.
beam splitter A
device
that produces
two
or
more
separate
beams
from

one
incident
beam.
Mirrors
and
prisms are commonly used
to
direct or split light
beams.
Coherent laser light
is
favored
for
most
beam
splitting applications.
Once
the
beam
is
split,
the
split
beams
are
usually
of
a lower intensity than
the
origi-

nal
beam,
in
proportion
to
how
many
times
the
beam
has
been split. Beam splitting
is
used
in
a number
of
industrial instruments and consumer
devices
and
is
also
used
for
testing
and
diagnostic purposes.
In
interferometers, a beam
is

split
into
two
or
more
beams
in
order
to
compare the relationship
of
the
beams
when
they
are
recombined.
The
interference
patterns
from
the
beams
can
provide information
on
influences
from
heat,
vibrations, gases,

etc.
bearer
channel
See
B channel.
beat
Short percussive tone,
one
instance ofarepeti-
tive
sequence, a reaction
from
the
impact of
one
ob-
ject
or
process
on
another,
the interaction of
two
dif-
ferent frequencies when certain portions
of
their
cycles interact.
See
beat

frequency,
beat reception,
zero
beat.
beat
frequency
The
frequency resulting
when
two
different frequencies beat together
on
anonlinear cir-
cuit.
The
beat frequency
is
equal
to
the
difference
between
the
two
separate frequencies, typically
ex-
pressed
in
cycles persecond (hertz).
When

the
beats
are
very
close
to
the
same
frequencies,
they
can
be
set
to
generate
an
audible tone which
may
change
when
subjected
to
the
influence ofmagnetic materi-
als.
See
heterodyne.
beat
frequency oscillator
BFO.

Alow-current
gen-
erator ofbeat
frequencies
in
anonlinear
circuit.
BFOs
are
used
in
a number
of
practical applications
from
metal
detectors, which
use
search
and
reference
os-
cillators,
to
older single sideband
radio
receivers.
beat
reception
The

combining
of
two
different
fre-
quencies, usually
the
external, incoming
frequency,
109
:?!.
:1
:
© 2003 by CRC Press LLC
Fiber
Optics
Illustrated
Dictionary
and
an
internally
generated
frequency
which
are
then
easier
to
amplify
or

othelWise
condition
as
a
single
frequency
than
the
incoming
frequency
would
be
by
itself:
See
heterodyne.
For
contrast,
see
zero
beat
re-
ception.
beating A
wave
phenomenon
that
occurs
when
two

or
more
periodic
waves
of
different
frequencies
com-
bine
to
form
a
periodic
amplitude
pulsation.
In
au-
dio,
beating
can
quite
often
be
heard
and
felt
as
an
undulating
pulse

by
those
in
listening
range.
See
beat
frequency,
heterodyne.
Beaufort notation
In
meteorology,
a
code
used
for
indicating
the
state
of
the
weather.
Beaver Falls Glassworks A
lesser-known
historic
utility pole glass insulator fabrication company
founded
by
William
Modes

in
Pennsylvania
in
1869.
See
insulator,
utility
pole.
BEC
1.
See
Best
Effort
Capability.
2.
Bose-Einstein
condensation.
BECN
See
Backward
Explicit
Congestion
Notifica-
tion.
beehive
insulator A
type
of
early
glass

utility
pole
insulator,
characterized
by
its
beehive
shape.
See
in-
sulator,
utility
pole.
BEEP A
generic
application
protocol
framework
for
connection-oriented,
asynchronous
network
interac-
tions.
In
conjunction
with
other
protocols,
BEEP

can
provide
reliability,
privacy,
and
authentication
op-
tions.
Through
transport
mappings,
BEEP
specifies
how
messages
are
carried
over
the
underlying
trans-
port
mechanisms.
Profiles
may
be
defined
for
BEEP.
F

or
example,
the
RAW
profile
is
a
backwardly
com-
patible,
efficient,
readily
implemented
profile
for
sup-
porting legacy Syslog Protocol processing.
The
COOKED
profile
is
intended
for
new
implementa-
tions
of
Syslog
Protocol
handler,

at
the
expense
of
more
overhead.
See
RFC
3081,
RFC
3195.
beeper
Colloquial
term
for
a portable
device
that
alerts
the
user
with
an
audible
tone.
Commonly
in-
corporated
into
pagers,

a
beep
signifies
that
there
is
a
message
awaiting
the
user,
or
some
action
to
be
taken
as
a
result
of
the
alert
signal.
Beginning of
Message
BOM.
In
ATM
networking,

an
indicator
contained
in
the
fIrst
cell
ofa
segmented
packet.
The
BOM
segment
is
followed
by
Continua-
tion
of
Message
(COM)
and
End
of
Message
(EOM)
segments.
A
header
is

associated
with
the
segments
and
they
are
passed
to
the
Physical
Layer
for
trans-
mission.
A
two-bit
Segment
Type
(ST)
field
identi-
fies
the
type.
Deilby layerA
microcrystalline
or
amorphous
layer

that
is
formed
on
the
surface
of
metals
by
polishing.
Being
There
1.
A
consumer-priced,
Macintosh-based
videoconferencing product
from
Intelligence
at
Large,
which
provides
video,
audio,
whiteboard,
and
file
sharing
utilities

over
AppleTalk
and
TC/IP
local
area
and
wide
area
networks.
2.
The
title
ofa
classic
Peter
Sellers
movie.
bel
symb.
-
B.
A
unit
of
relative
power
or
strength
of

a
signal,
which
is
not
commonly
used
because
it
is
so
large.
It
is
used
in
conjunction
with
amplitude,
usu-
ally
by
its
tenth
measure,
the
decibel.
Named
after
110

Alexander
Graham
Bell.
See
decibel.
Belden A
major
commercial
manufacturer
of
com-
munications
media
which
has
been
responsible
for
influencing
cable
standards
for
many
telecommuni-
cations
systems.
bell
1.
An
audio

device,
often
of resonant
hollow
metal,
designed
to
emit
sound
when
struck,
vibrated
by
a
column
of
air,
or
vibrated through electrical
stimulation.
2.
A
digitally
reproduced
simulation
of
a
physical
bell,
created

either
by
sampling
a
physical
bell
and
playing
back
the
sound,
or
by
analyzing
the
type
of
sound
wave
patterns
produced
by
aphysical
bell
and
simulating
them
mathematically.
A
computer

requires
built-in
electronics
or
a
peripheral
sound
card
in
order
to
send
sounds
to
a
speaker,
especially
ifit's
good
quality
16-bit
stereo
sound.
Digital
music
syn-
thesizers
often
have
a

wide
array
of
bell
sound
patches
from
which
to
choose.
3.
A
phone
bell
that
is
acti-
vated
by
line
current
from
the
switching
office
to
in-
dicate
that
there

is
an
incoming
call
on
the
line.
Alexander
Graham
Bell-
Inventor,
Educator
Alexander Graham Bell continued to think
of
him-
self
as a teacher
for
the
deaf
long after he became
famous andfinancially independentfrom sales
of
his
technological inventions.
He
and
Helen Keller were
friends. Many
of

the members
of
hisfamily were known
as excellent orators. This portrait was photographed
by
Moffett Studio when Bell was approximately 69
years
of
age. [National Archives
of
Canada, Dept.
of
ExternalAffairs collection.}
Bell,
Alexander Graham (1847-1922) A
Scottish-
born
American
inventor,
who
was
one
of
the
origi-
nal
founders
of
the
National

Geographic
Society.
He
emigrated
to
Canada with
his
family
and
subse-
quently
found
employment
in
Boston.
He
studied
aviation,
electricity,
fresh
water
distillation,
etc.,
but
he
is
chiefly
credited
with
the

invention
of
the
tele-
phone.
In
fact,
A.
Meucci
had
tested
animal
mem-
branes
as
vibrational
devices
many
years
earlier
and
a
number
of independent
inventors
in
Europe
and
America
were

working
on
ways
to
transmit
tones,
and
in
some
cases
voice,
over
telegraph
lines.
Three
sig-
nificant
contemporaries
of
Bell
who
achieved
success
© 2003 by CRC Press LLC
in
some
of
these
technologies
were

Philip
Reis,
Elisha
Gray,
and
Thomas
Edison.
In
March
1876,
two
years
after
working
out
the
origi-
nal
concept,
Bell
and
his
assistant
Watson
reported
having
transmitted
Bell's
spoken
voice

over
electri-
cally
charged
wires,
a
story
that
caught
the
world's
imagination
and
ushered
in
the
telephone
age.
Bell's
patent
was
filed
just
hours
before
a
caveat
to
file
was

entered
at
the
same
office
by
Elisha
Gray,
for
a
simi-
lar
harmonic
telegraph.
Bell's
talking
phone
was
not
demonstrated
publicly until
some
time
later.
One
in-
teresting
historical
note
is

that
Bell's patent
did
not
mention
the
use
ofa
liquid
medium,
yet
the
rudimen-
tary
telephone
that
was
later
demonstrated
did
use
a
liquid
medium,
a
structural
detail
that
was
mentioned

in
the
Gray
caveat.
Model
of
the
First
Telephone
A model reconstruction
of
what Bell has described
as
theftrsttelephone invented
by
him
in
1875,
referred
to
as
the
"Gallows Telephone"
due
to
its
shape.
{Li-
brary
of

Congress
Detroit Publishing Company
Col-
lection.
Published
ca.
1920.J
There
was
significant
critical
interest
in
the
invention.
On
31
Aug.
1876,
Anna
Joy
wrote
to
Bell,
asking
him
"Was
an
experiment
tried

at
your
office
for
transmit-
ting
sound
by
Electricity?
If
so
when
was
it
tried?
Who
were
the
parties
engaged?
What
was
the
result?"
to
which
Bell
gave
an
uncharacteristically

cryptic
re-
ply:
"~Sept.lst,
1876./TheManag.oftheP.&A.
T.
Co.
has
forw.
to
me
your
note
of
the
31
st
ult.
and
I
beg
to
state
tho
expo
were
made
with
my
app.

for
the
tel.
transm.
of
vol.
s.
under
the
direct.
of
Sir
William
Thompson
at
the
office
of
the
Pac.
&
At.
Tel.
Co.
-
but
at
what
date
I

am
unable
at
the
pres.
mom.
to
state.
/Y
rs.
truly /
A.
Graham
Bell"
In
April
1877,
Bell
acknowledged a request
from
Boston
professionals
for
a 'practical
demonstration
of
my
Electric
Telephone'
and

made
arrangements
to
publicly describe
his
invention three
weeks
later.
Given
all
the
hedging
and
the
murmur
of
controversy
over
the
veracity
of
the
original
claim,
one
wonders,
in
retrospect,
if
Bell

's
famous
message
to
Watson
was
fabricated
or
exaggerated
because
the
ambitious
Bell
was
anxious
to
get
the
patent
before
someone
else,
feeling
he
was
on
the
verge
of
success.

In
1880,
Bell
devised
a
means
to
transmit
phone
sig-
nals
through
light,
a forerunner
to
fiber
optic
com-
munications that languished
for
almost
100
years
~~~~c~rr~i~~:~:~~
technology
made
the
concept.
Bell's Historic
Telephone

Invention
Alexander
Graham
Bell making a historic call by
opening the
New
York
to
Chicago long-distance line
on
18 October 1898. {National Archives
of
Canada
image.J
A historic report
in
the Detroit
News
on
'Bell sFirst
Telephone.
'{Library
of
Congress Detroit Publishing
Company Collection,
ca.
1920.
Photo
by
Underwood

&
Underwood,
Inc.J
In
1882,
Bell
was
granted
United
States
citizenship
though
he
continued
to
maintain
a
summer
home
in
Nova
Scotia,
Canada.
Bell
achieved
enormous
financial
success
and
could

have
ceased
working
at
a
young
age,
but
he
contin-
ued
to
research
aeronautic
kites
(he
succeeded
in
get-
ting
a
manned,
motorized
aircraft aloft
in
1908),
hy-
drofoils,
and
various technologies

to
aid
the
deaf,
most
notably
the
audiometer.
For
much
of
his
life,
he
listed
his
occupation
as
teacher of
the
deaf.
111
© 2003 by CRC Press LLC