Fiber Optics Illustrated Dictionary - Part 65 docx

Fiber
Optics
Illustrated
Dictionary
medium,
if
there
is
only
one).
This
layer
supports
multiple
downstream
and
upstream
channels.
Devices
such
as
network
bridges
are
associated
with
the
MAC
layer
(or
sublayer

in
OSI).
Mechanical
Fiber
Splice
For a mechanical splice to be effective, the fiber
filament ends must be precisely cleaved and aligned
to form a continuous lightpath without gaps
or
par-
ticles that couldcause backreflection (top). The
joint
must be firmly secured within a sturdy supporting
structure
(e.g.,
the
Corning
Cable
Systems
CamSplice™) to maintain theposition ofthefilaments
relative to one another (bottom).
Mechanicalsplicingis onlyrecommended
for
joints
that are well protected from strain
and
temporary
joints such as patch panels that require frequent re-
configuration. Forpermanentsplices, fusion splicing
is generallypreferred.

Media Access Control address, MAC address A
MAC
address
is
an
important
routing
statistic
widely
used
for
managing data network transmissions.
Route-related
devices
typically
keep
alist
or
table
of
MAC
addresses
which
may
be
static
or
dynamic.
Dynamic
MAC

address
lists
may
be
updated
in
a
va-
riety
of
ways
depending
on
the
stability
of
the
con-
figuration
ofa
network
and
the
size
ofa
network.
The
MAC
address
is

used
by
a
network
bridge
to
de-
termine
whether
a
packet
is
to
be
forwarded.
By
copy-
ing
an
incoming
source
address
to
a
MAC
address
table,
the
bridge
builds

up
aport-related"picture" of
device
locations
on
the
network.
Since
there
are
usu-
ally efficiency trade-offs
on
large
networks,
with
machines
being
added
and
removed
and
MAC
ad-
dress
tables
becoming
large
and
unwieldy,

certain
balancing
mechanisms
are
built
into
bridge
manage-
ment.
By
limiting
the
lifespan
ofa
MAC
address,
the
system
can
be
tuned
to
best
serve
the
needs
of
the
network.
Thus,

a
dynamic
MAC
address
that
has
not
been
used
for
a
long
time
will
be
removed
until
a
transmission
is
again
received
from
that
source.
Low-
use
special
purpose
addresses

(e.g.,
emergency
sys-
terns)
that
must
stay
active
can
be
assigned
a static
MAC
address
that
isn't
automatically
deleted.
MediaAccess Exchange
MAX.
A
system-level
net-
work
access
unit
from
Ascend
Communications,
into

which
peripheral
cards
can
be
inserted.
A
MAX
can
support
multiple
host
ports
or
direct
network
connec-
tions,
videoconferencing
units,
and
remote
LAN
con-
nections.
MediaAccess Project
MAP.
An
important
nonprofit,

public interest telecommunications
law
firm
that
looks
out
for
the
First
Amendment
rights
of
individuals
632
before
the
legal
system
and
the
Federal
Communi-
cations
Commission
(FCC).
Over
the
years,
broadcast
agencies

have
been
pro-
vided
free
use
of
the
airwaves
and,
in
return,
have
a
legal
responsibility
to
provide
aportion of
program-
ming
and
resources
for
the
public
good.
They
are
bound

to
uphold
these
obligations
but
may
neglect
them
without
citizen
support
groups
like
MAP,
who
take
the
time
to
lobby
for
the
interests
of
the
little
guy.
In
recent
years

more
free
bandwidth
has
been
broadly
allocated
to
commercial
broadcasters, particularly
satellite
broadcast
frequencies.
It
is
important
that
citizens
safeguard
their
rights,
and
that
it
be
impressed
upon
the
government,
the

FCC,
and
the
broadcasters
that
these
broader
free
permis-
sions
have
inherent
corresponding
responsibilities.
/>MediaAccess Unit
MAU.
In
Token-Ring
local
area
networks
(LAN
s),
a
wiring
concentrator
that
connects
the
end

stations.
The
AU
provides
an
interface
be-
tween
the
Token-Ring
router
interface
and
the
end
stations. Also known
as
Access Unit
(AU).
See
Multistation
Access
Unit.
Media
Interface
Connector
MIC.
An
eight-pin
modular

RJ-45-8
plug.
This
resembles
a
common
RJ-
11
phone
jack
except
that
it
is
wider
to
accommodate
connections
for
eight
wires.
This
is
the
connector
rec-
ommended
for
audio-visual
applications

by
DAVIC
specifications.
medium
Earth
orbit
MEO.
An
orbiting region
around
the
Earth
into
which
certain
types
of
commu-
nications
satellites
are
launched,
mid-way
between
low
and
high
Earth
orbits
into

which
geostationary
satellites
are
typically
launched.
The
lifespans
of
me-
dium-orbit
satellites
are
about
10
to
12
years.
Most
medium-orbit
satellites
travel
about
10,000
to
15,000
km
outside
Earth.
A

region
called
the
Van
Allen
ra-
diation belt between
MEO
and
low
Earth orbits
(LEOs)
is
generally
avoided.
MEO
satellites
are
pri-
marily
used
for
broadcast
applications.
See
high
Earth
orbit,
lCD,
low

Earth
orbit,
Teledesic.
MeetMeA
commercial
FTS2000
capability
initiated
by
dialing
an
access
number
at
a
prearranged
time,
or
as
directed
by
an
attendant,
to
establish
a
group
conference
call.
Additional

conferees
can
join a
con-
ference
in
progress
with
an
Add
On
conference.
It
may
be
necessary
to
make
arrangements
for
a
Meet
Me
call
several
hours
in
advance,
depending
on

how
the
system
is
administered.
See
FTS2000.
Meet-Point
Trunk
Telecommunication
trunks
con-
figured for two-way traffic
in
jointly provided
Switched
Access
Services
(SAS),
to
interconnect
End
Offices
and
Tandems.
mega-
(abbrev.
- M)An
SI
unit

prefix
for
1
million,
expressed
as
10
6
or
1,000,000.
To
confuse
matters,
when
used
in
conjunction with computer-related
quantities,
it
often
means
220,
expressed
as
1,048,576.
The
most
common
of
these

uses
is
in
descriptions
of
computer
storage
capacity
as
megabytes
(MBytes),
in
which
1
MByte
is
1,048,576
bits.
See
kilo
Megaco ProtocolA
network
media
gateway
control
protocol used between elements of a physically
© 2003 by CRC Press LLC
decomposed
multimedia
gateway,

that
is,
between
a
Media
Gateway
and
a
Media
Gateway
Controller.
The
Protocol
was
submitted
as
a
Standards
Track
RFC
by
Cuervo
et
a1.
in
November
2000.
It
provides
a

general
framework
suitable
for
gateways,
multi-
point
control
units,
or
interactive
voice
response
units
to
interact.
The
protocol
definition
has
common
text
with
ITU-
T
Recommendation
H.248.
A
Media
Gateway

converts
media
from
one
type
of
network
to
a
format
compatible
with
another
type
of
network.
The
gateway
may
be
able
to
process
and
translate
audio,
video,
or
T.120
and

can
handle
full
duplex
media
translations,
in
addition
to
playing
and
executing media performances or conferences.
Megaco
Protocol
connection
model
describes
the
logical
entities/objects
within
the
Media
Gateway
and
can
be
controlled
by
the

Media
Gateway
Controller.
See
RFC
3015.
meggerAn
instrument
for
measuring
values
of
very
high
resistance
used,
for
example,
for
insulation
re-
sistance
testing.
See
Wheatstone
bridge.
Melissa
See
virus.
Melles GriotlasersA

line
of
lasers
from
the
Melles
Griot
optical
company.
The
firm
is
a
leading
supplier
of
gas
lasers
and
is
well-known
for
helium-neon
(Re-
Ne)
lasers.
Melles
Griot
also
develops

and
distrib-
utes
semiconductor
laser
technologies
for
research
and
commercial
applications.
In
1999,
the
firm
an-
nounced
acquisition
of
the
Laser
Power
Microlaser
Group,
developers
of
blue,
green,
and
near-infrared

solid-stated
diode-pumped
lasers.
Melpar
model
An
artificial neuron used
at
the
Wright-Patterson
Air
Force
Base
in
Ohio
in
the
early
1960s
to
mimic
human
reasoning
(or
at
least
rodent
reasoning).
The
Melpar model, familiarly called

Artron
by
its
inventors,
was
used
as
the
"brains" ofa
maze-running
bionic
mouse,
physically
resembling
the
input
mice
used
on
today's
computers.
The
bionic
mouse
brain
comprised
10
Artrons,
which
was

suffi-
cient
for
a
trial-and-error
method
of
learning
to
run
the
maze.
With
a
clean
slate,
the
mouse
took
45
min-
utes
to
complete
the
maze;
eight
tries
later,
it

took
only
35
seconds.
See
neural
network.
meltback
In
fusion
splicing
of
fiber
and
other
mate-
rials,
the
receding
away
from
the
point
where
the
fu-
sion
joint
will
occur.

Machines
that
perform
auto-
mated
fusion
splicing
are
designed
to
move
the
two
ends
to
be
joined
closer
together
as
they
melt
apart
at
a
speed
that
is
appropriate
for

fusing
the
two
ends
without
excessive
force
or
a
gap.
Different
materials
melt
at
different
temperatures
and
will
recede
to
dif-
ferent
distances
depending
upon
their
diameter,
com-
position,
and

environmental
conditions.
meltback test
In
automated
fusion
splicing,
a
pre-
liminary
setup
test performed
to
determine
how
quickly
and
how
far
a
material
melts
back
when
heat
is
applied
to
the
ends

intended
to
be
fused.
This
data
is
then
used
to
manually
adjust
or
machine
calibrate
the
distance
between
the
grooves
or
chucks
holding
the
two
materials.
Adjusting
fiber
optic
mass

fusion
splicers
is
especially
challenging
as
the
heat
from
the
arc
across
a
linear
array
of
fiber
filaments
may
not
be
consistent,
causing
varying
degrees
of
meltback.
Compensations
in
the

arc
or
in
the
movement
of
the
chuck
(or
both)
as
fusion
takes
place
is
necessary
to
ensure
precise
splicing.
See
fusion
splicing.
memory
In
a
computing
system,
a
storage

area
that
is
dynamically
allocated
and
used
by
the
operating
system
and
various application programs. Most
memory
in
desktop computers
is
random
access
memory
(RAM),
although
some
programs
will
also
allocate hard drive storage
as
"virtual
memory."

Memory
is
one
of
the
most
basic
elements
ofa
com-
puting
system,
along
with
the
central
processing
unit
(the
CPU
often
also
incorporates
memory
internally)
and
the
input/output
(I/O)
bus.

Read
only
memory
(ROM)
is
included
in
many
com-
puters
to
provide
basic
nonvolatile
operating
param-
eters
to
a
system,
particularly
on
startup.
In
the
earli-
est
microcomputers,
a
programming

language
was
sometimes included
in
ROM.
Random access
memory
(RAM)
is
dynamically
allocated
py
the
sys-
tem
and
applications
programs.
RAM
is
further
dis-
tinguished
as
static
or
dynamic
RAM.
Most
desktop

systems
include
about
8
to
64
Mbytes
of
RAM,
and
may
be
extended
up
to
64
or
256
Mbytes.
RAM
typi-
cally
operates
at
about
60
to
80
ns,
although

this
may
change
as
newer,
faster
types
of
memory
are
devel-
oped.
Most
types
of
computer
chip
memory
are
volatile,
that
is,
the
contents
will
disappear
if
the
system
is

not
constantly
powered
and
refreshed.
However,
there
are
some
types
of
chips
that
can
retain
information,
such
as
erasable, programmable, read-only memory
(EPROM)
chips.
The
price
of
memory
fluctuates
dramatically.
In
1986,
a

megabyte
of
RAM
was
$600
U.S.;
by
the
early
1990s
this
had
dropped
to
$25,
then
increased
again
to
$120.
By
early
1998,
the
price
was
down
to
$4
per

megabyte
and
dropped
to
$1
in
2001.
Programmers
tend
to
write
code
that
fills
available
space.
This
results
in
applications
that
require
more
memory
than
many
consumers
have,
setting
off

an-
other
round
of
buying.
In
1978,
the
TRS-80
computer
ran
with
4
Kbytes
of
memory,
and
with
8
Kbytes
it
could
do
word
processing
and
spreadsheet
applica-
tions
quite

well.
By
the
mid-1980s,
the
Amiga
com-
puter
could
multi
task
and
run
graphics
programs
con-
currently
with
stereo
sound
quite
comfortably
in
4
Mbytes
of
RAM.
Systems
in
the

late
1990s
rarely
ran
efficiently
with
less
than
16
Mbytes,
and
most
ven-
dors
recommended
32.
Computers
now
commonly
come
installed
with
256
MBytes
or
more.
MEMS
See
micro-electromechanical
system.

Mensa Single Fiber
Supertrunk
SystemA
commer-
ciallinear,
synchronous,
high
bandwidth,
point-to-
point
optical
transceiver
system
designed
specifically
for
supertrunk
applications,
distributed
by
Synchro-
nous.
It
may
be
used
for
all
analog
or

hybrid
analogi
digital
signals
at
200
MHz.
It
uses
a
1550
om
DFB
laser diode light source modulated
by
a Mach
Zehnder.
The
receiver
is
based
upon
a
high-response
PIN
photo
detector.
The
system
provides

dual-trunk
performance
over
a
633
© 2003 by CRC Press LLC
Fiber
Optics
Illustrated
Dictionary
single
optical
fiber
linle
For international operation,
Band V channels
can
be
directly carried. External
modulation
enables
the
system
to
be
used
with
stan-
dard installed cable
and

is
said
to
eliminate laser
chirp.
The
transmission
link
can
be
optically split
or
repeated.
mercury
vapor
lamp
A
lamp
in
which
mercury
va-
por
flows
back
and
forth
through
a
tube

when
made
horizontal
to
complete
the
electric circuit
and
start
the
lamp.
Ionized
mercury
vapor
is
then
produced
by
the
heat
and
current,
creating
light
through
the
length
of
the
tube.

The
light
is
very
bright,
with
a greenish
glow,
and
is
generally
used
in
industrial
applications.
See
fluorescent
lamp.
mesh
topology
A
type
ofcircular network
backbone
topology
in
which
data
can
travel back along

the
backbone
ifa
node
becomes
unavailable
due
to
a
dis-
ruption,
such
as
line
breakage
or
failure.
The
mesh
nature of
the
topology
stems
from
the
appearance of
the
connections
between
a

node
and
other
nodes
sev-
eral
nodes
away.
Some
vendors
and
users
prefer
this
over a
ring
topology
as
more
than
one
route
can
lead
to
aparticular location
on
the
network.
See

topology.
message
circuit
noise
On
a correctly terminated
cir-
cuit
in
a
network,
the
background noise
that
exists
when
there
is
no
test
signal.
The
noise
may
arise
from
crosstalk,
radio
frequency
interference, power

line
harmonics,
or
thermal
noise.
Noise
is
usually
assessed
by
passing
the
noise
through
selected filters
to
deter-
mine
its
source
and
character.
Message Handling System
MHS.
On
a network,
MHS
provides
a
means

to
store
and
forward
messages
among
MHS
users
or
applications. Unlike traditional
telephone
networks
and
the
early
two-way
radio
com-
munications,
most
data
networks
do
not
need
to
es-
tablish
an
end-to-end

connection
before
carrying
out
communications.
Thus,
the
MHS
provides
a
way
to
handle
the
messaging
traffic
under
dynamic
circum-
stances.
See
XAOO
under X Series Recommenda-
tions.
Message Security Protocol
MSP.
A Secure
Data
Network System (SDNS) protocol
for

providing
XAOO
message security.
With
MSP,
a message
is
given
connectionless confidentiality
and
integrity,
data origin authentication, and access control;
nonrepudiation
with
proofof
origin;
nonrepudiation
with
proofof
delivery.
MSP
is
a
content
protocol,
in
the
application
layer,
and

is
implemented
within
originator
and
recipient
MSP
user
agents.
It
is
an
end-to-end protocol that
does
not
employ
an
intermediate
message
transfer
system.
MSP
processing
is
carried
out
prior
to
sub-
mitting

a
message
and
after accepting delivery of a
message.
An
XAOO
message
comprises
a content
and
an
enve-
lope.
With
MSP,
a
new
message
content
type
is
de-
fined
with
a
security
heading
encapsulated
around

the
protected
content.
Three
types
ofX.509
digital
certificates
are
supported
by
MSP.
The
user's distinguished
name
and
public
cryptographic material
are
bound
within
an
X.509
certificate
which,
in
turn,
is
signed
by

a certification
634
authority
(CA).
The
CA
manages
X.509
certificates
and
Certificate Revocation lists.
message
switching A
means
ofswitching
and
mul-
tiplexing
data
packets
by
storing, queuing,
and
for-
warding
the
message
to
the recipient.
See

circuit
switching, packet switching.
Message
Transfer
System
MTS.
Ageneral-purpose,
application-independent, store-and-forward
commu-
nications service within a
Message
Handling
System
(MTS). The
MTS
uses message transfer agents
(MTAs)
to
relay
messages.
See
Message Handling
System.
message
unit
In
packet
networking,
SNA,
a

basic
unit
of
data
processed
by
any
layer.
meta-signaling A
means
to
manage
User Network
Interface
(UNI)
vacant
codes
(VCs)
signaling
and
associated broadcast channels incorporating a user
part
and
a network
part.
Meta-signaling establishes
point-to-point signaling
VC
and
broadcast signaling

VC
(general broadcast
and
selective broadcast).
Metal
Vapor
Laser Variation - Schematic
This schematic illustrates a variation on metal va-
por
lasers
to
make them more efficient without requir-
ing increasingly complex
or
unwieldy tubes.
Voltage
is transmitted through a choke coil (10), a
charging diode
(ll),
anda charging resistor (13) into
the storage capacitor
(12). The switching device (14)
stimulates the capacitor
to
discharge its stored
power
into the circuit in the form
of
a preliminary charge
between the cathode

(2) and the grid (4) which pro-
vides variable impedance. This triggers the main dis-
charge between the cathode and anode
(3).
The
grid
also serves as a discharge "buffer, " improvingthe life-
time
of
the componellt.
[US.
patent#6,229,837, May
2001.}
metal
vapor
laser A
type
of
atomic
gas
laser
that
ef-
ficiently
emits
light
in
the
visible
spectrum.

A
rare-
gas
metal
vapor laser
can
also
emit
light
in
invisible
ranges.
Metal
vapor
lasers
may
be
classified
as
neu-
tral
(e.g.,
gold,
copper
lasers)
or
ionized
(helium-cad-
mium
lasers). Traditionally they

have
been
based
upon
a two-electrode structure
to
create
a discharge
pulse,
though
inventors
such
as
A.
Ozu
have
proposed
variations
that
enable
higher efficiency
with
a grid
electrode
placed
near
the
electron-generating
cathode
to

provide a preliminary discharge.
© 2003 by CRC Press LLC
The
Institute of
Physics
developed
the
first Bulgar-
ian
metal
vapor
laser (He-Cd)
in
1970.
The
Bulgar-
ian
Academy
of
Sciences includes
the
Metal
Vapour
Laser Laboratory
in
Sofia, Bulgaria.
Metcalfe, Robert (1946- )
An
American engineer
and

journalist, Metcalfe
is
the
acknowledged creator
of
Ethernet
at
Xerox
PARC
in
1973,
along
with
David
Boggs.
In
1979
he
founded
the
3Com
Corporation,
and
since
1990
has
been involved with a number of
publishing organizations.
See
Boggs,

David;
Ether-
net.
METEOSAT Meteorology satellite.
meter A metric linear measure of length/distance
equal
to
3.28
feet
or
39.37
inches.
Europe,
Canada,
and
many
other regions
are
standardized
on
metric
measures.
The
u.S. continues
to
use
the
British
units
of

length
(e.g.,
yard)
except
in
scientific
circles,
where
metric
is
used.
Metropolitan Area Network MAN.
An
urban net-
work
of
high-speed
hosts.
See
MAE
East,
MAE
West,
SMDS.
Metropolitan Fiber Systems
MFS.
A Competitive
Access
Provider
(CAP)

founded
in
the
late
1980s.
In
the
1990s
it
established
its
own
backbone, providing
national
network
services.
It
was
subsequently
ac-
quired
by
WorldCom.
Metropolitan ServiceArea
MSA.
An
administrative
designation used
by
many organizations providing

commercial
and
public services
in
urban
areas.
The
u.S.
Government
uses the designation
for
managing
and
analyzing
data
from
the
national census. A
Met-
ropolitan
Service
Area
is
a city
with
at
least
50,000
residents
or

an
urban
area with
at
least
100,000
resi-
dents
within
the
counties encompassing these
areas.
The
Federal Communications Commission
(FCC)
has
used
this
census designation
to
recognize over
300
MSAs
for
the
purposes
of
assigning
telecommun-
ications

licenses
such
as
cellular telephone licenses.
See
Rural
Service
Area.
Meucci, Antonio
An
Italian-born Cuban inventor,
chemist,
stage
designer,
and
engineer,
Meucci
made
many
pioneering discoveries
in
telecommunications
concepts
and
devices, but his findings were not
widely communicated
to
others,
and
hence

not
cred-
ited
as
to
their impact
on
subsequent inventions
such
as
telegraphs
and
telephones,
which
made
telecom-
munications
history.
Meucci developed rheostats, electroplating tech-
niques,
and
experimented with passing electricity
through
the
human
body.
While studying mild
elec-
trical
charges,

he
discovered
the
"electrophonic"
ef-
fect,
which
related nerve responses
to
specific appli-
cations
of
current through a
wire.
By
the
mid-1800s
he
had
developed
several devices
for
creating a
vi-
brating
electric
current
from
spoken
acoustical

im-
pulses.
By
using
a copper strip
and
delicate
animal
membranes
as
diaphragms,
he
created
one
of
the
ear-
liest telephone-like mechanisms.
He
emigrated
from
Cuba
to
the
u.s.
and
applied
for
a caveat for
his

teletrofono
which
was
granted
in
December
1871,
4
years
before
the
patent ofAlexander
Graham
Bell
and
the
caveat of
Elisha
Gray.
It
is
believed that Bell (and
Gray)
may
have had access
to
papers describing
Meucci's invention
and,
due

to
greater
resources
and
celebrity, overshadowed his inventions. See tele-
phone
history.
MeyercodeA
flag
signaling
code,
employing
left
and
right motions
to
create characters or syllables,
and
a
forward
motion
to
indicate
ends
or
pauses.
This
code
was
in

use
until
it
was
superseded
in
the
First
World
War
by
International
Morse
code
and
American
Morse
code.
See
semaphore.
MFJ
See
Modified Final Judgment.
MFS
See
Metropolitan Fiber
Systems.
MFSK
See
multiple frequency shift

keying.
MH
See
Modified
Huffman.
mhoApractical unit
of
the
measure of
conductance,
so
named
because
it
is
ohm
spelled
backwards.
See
admittance,
ohm.
MHS
See
Message Handling
System.
MID
See
Management Information
Base.
Michelson interferometer

See
interferometer.
Micral
The
first
fully
assembled 8008-based micro-
computer,
the
Micral featured 8-bit processing
and
2
Kbytes
of
memory. It was designed
in
France
by
Fran~ois
Gemelle.
The
Micral sold
for
just under
$2000,
and,
like its predecessor
the
Kenbak-l,
was

not
commercially successful
in
the
United States,
an
important market
for
microcomputers. It
was
intro-
duced
in
May
1973
before
the
SPHERE,
Scelbi-8H,
Mark-8,
and
Altair computers.
See
Altair, Kenbak-I,
Mark-8,
MITS,
Scelbi-8H,
Simon,
SPHERE.
micro-electromechanicalsystem

MEMS.
Technol-
ogy
for
integrating electromechanical
functions
into
integrated circuits. MEMS-based actuators
are
used
in
single-
and
multimode fiber optic switches.
microbend
In
fiber
optic
cables, a small inconsis-
tency,
nick,
or
slight bend that might
be
introduced
into
the
fiber during manufacture or installation
or
may occur after installation

due
to
wear
and
tear.
Microbends
may
introduce
small
changes
in
the
op-
tical transmissions path as the light "bounces"
through
the
fiber,
but
are
not likely
to
significantly
degrade
the
signal.
However,
if
the
fiber
is

especially
slim or
the
wavelengths especially
long,
microbend
losses may occur.
If
there are a large number
of
microbends,
the
accumulated effect
of
the
disruption
over distance, especially
in
a cable with a
small
core
radius, may
be
significant. See loss, macrobend,
macrobend
loss.
MicroCal Module A
new
type
of

integrated circuit
(IC)
designed
to
facilitate self-monitoring
in
virtu-
ally
any
type
ofwireless equipment, including base
stations, mobile handsets,
and
subscriber
units.
The
MicroCal Module
scans
the entire bandwidth, gath-
ering
data
which
is
then
fed
back
to
acentral mainte-
nance
center.

The
module,
designed
by
Micronetics
Wireless, was awarded a
u.s.
patent
in
1996.
Micronetics
is
working
with
anumber ofcompanies,
including Nortel
and
Motorola,
to
integrate
the
mod-
ule
into
wireless infrastructure equipment.
Microcom Networking Protocol
MNP.
Aseries of
proprietary error control
and

data compression
pro-
tocols
designed
for
dialup
modems,
which
are
often
635
© 2003 by CRC Press LLC
Fiber
Optics
Illustrated
Dictionary
used
in
conjunction
with
industry standard
ITU-
T-
recommended error
control
mechanisms.
For
example,
MNP-4
works

with
modems
that
trans-
mit
at
data
rates
up
to
14,400
bps.
MNP-4
is
often
implemented
in
conjunction
with
the
VA2
error
con-
trol
protocol standard
from
the
ITU-
T.
See

Microcom
Networking Protocols chart.
See
Y.42.
microfiche Asomewhat standardized
optical
archive
system
using
thin
transparent
sheets
of
image-carry-
ing
plastic
for
storing scanned printed
matter,
espe-
cially
newspapers,
books,
journals,
etc.
Since
micro-
fiche
information
is

miniaturized
to
fit
as
much
data
on
asheet
as
possible,
it
is
typically
not
human-read-
able without magnification. Microfiche machines
backlight
and
magnify
the
data.
Some
photocopiers
are
designed
to
enlarge
and
print microfiche infor-
mation,

although
the
copies
are
often
not
very
clear.
Digital storage techniques
are
replacing microfiches
and
the
quality
is
improving over earlier
scans.
Un-
fortunately,
like
microfiche
archives,
the
originals
are
often
destroyed
for
lack
ofstorage space

and
funds.
Microfiches
are
common
in
libraries, post-secondary
institutions,
and
government archives
but
are
being
gradually superseded
by
scanned
digital
images.
micromachined membrane deformable
mirror
MMDM.
A
compact
component
for
correcting
aber-
rations
in
optical

systems,
such
as
distortion
that
may
be
caused
by
passing
through
an
aperture
or
lens.
In
contrast
to
traditional
glass
lens
correction devices,
a
MMDM
is
a thin membrane coated
to
give
it
a

highly-reflective surface.
Gold
and
aluminum coat-
ings
are
common.
The
speed
ofresponse ofMMDMs
is
faster
and
astigmatism
is
somewhat lower
than
other popular technologies (e.g.,
OKO
mirrors).
By
application ofcurrent through actuators incorpo-
rated into
the
membrane system,
the
shape
of
the
membrane

can
be
controlled through
an
attracting
electrostatic
force.
The
system
is
commonly set
up
with a flat spherical MMDM which
is
shaped
as
needed.
MMDMs
have been found practical
in
the
visual
spectrum
and
have
been
studied
for
their effect
at

su-
percooled temperatures.
See
wavefront control.
microphone Adevice
for
apprehending
sounds
and
transmitting
them
electrically
or
acoustically
to
a
re-
ceiver
or
audience. A
very
simple microphone
can
be
created
by
wrapping stiffpaper
into
a
funnel

shape,
attaching
it
to
a string
or
wire,
and
stretching it
to
a
receiver- another
funnel
on
the
other
end.
If
the
lis-
tener puts
an
ear near
the
receiving
funnel
while
the
speaker
talks

into
the
microphone
funnel,
the
sound,
while
not
loud,
can
be
heard
across
a
room.
Add
elec-
tronics
to
amplify
the
signal,
and
you
have
a basic
microphone.
Some
microphones
also

include echo
acoustics
to
make
the
sound
of
a voice
more
reso-
nant.
Many
singers
use
this
type
of microphone
to
enhance their singing
on
recordings.
Microphones
are
widely used
in
camcorders, film
cameras,
tape
recorders,
and

video recorders.
Two
microphones
are
needed
for
true
stereo
sound.
Microphones
can
be
used
as
peripherals
with
com-
puters
for
the
creation
of
music
and
other sound
samples, or
for
videoconferencing.
See
sampling,

videoconferencing.
Microsoft BASIC A
BASIC
interpreter
first
released
for
the
Altair computer
in
1975.
Paul
Allen
had
seen
the
feature article
on
building
the
Altair
in
the
Janu-
ary
1975
issue
of
Popular Electronics,
so

he
and
Gates
talked about
it
in
Harvard Square,
and
con-
ceived
the
idea
of
writing a
BASIC
interpreter
for
the
new
kit-based
machine.
They
contacted
MITS,
made
a proposal,
and
set
to
work creating a

BASIC
that
could
fit
into
4K
of
memory.
The
entrepreneurs
had
previous experience
in
looking
at
code
for
interpret-
ers
for
various languages based
on
their business
ac-
tivities
together
through
high
school,
and

8K
BASICs
Microcom Networking Protocols
Name Notes
MNP-l
Asynchronous
mode,
half
duplex
transfer
operation.
MNP-2
Simple
error
correction
scheme,
asynchronous
mode,
full
duplex
operation.
MNP-3
Error
correction
incorporated,
synchronous
mode.
MNP-4
Error
correction

incorporated,
increased
throughput.
Often
included
with
Y.42
modems,
along
with
MNP-5
data
compression.
MNP-5
Simple
data
compression
scheme.
Often
included
with
Y.42
modems,
along
with
MNP-4
error
control.
MNP-6
Statistical

duplexing
and
Universal
Link
Negotiation.
Full
duplex
emulation.
MNP-7
Data
compression
scheme
included.
MNP-8
MNP7
for
modems
which
emulate
duplex
operation.
MNP-9
Data
compression
scheme
included.
Incorporates
Y.32
technology.
MNP-1O

Dynamic
fall-back
and
fall-forward
adjusts
modulation
speed
with
link
quality.
636
© 2003 by CRC Press LLC
were
available
for
the
PDP-8.
They
developed
the
BASIC
in
a
simulation
environment,
since
it
wasn't
practical
to

write
it
on
the
Altair
itself.
Allen
created
a simulation environment
for
8080
programming
code
and
modified
a
symbolic
debugger
to
understand
the
8080
instructions.
Gates
laid
out
a
design
for
the

BASIC
interpreter
modeled
on
the
BASIC
he
had
en-
countered
on
a
timesharing
system
at
Dartmouth
and
began
coding
it, with assistance later
from
Allen.
Monte
Davidoff
contributed
some
of
the
math
rou-

tines,
especially
those
for
floating
point
operations.
On
the
plane
to
Albuquerque
to
demonstrate
the
soft-
ware,
Allen
created
a bootstrap
loader
so
the
Altair
would
be
able
to
read
the

data
into
memory,
using
a
teletypewriter
as
an
input
mechanism.
(Gates
later
streamlined
the
bootstrap
loader.)
On
the
first
run
at
the
demonstration
at
MITS,
the
BASIC
didn't
work.
On

the
second try it did. This
was
a substantial
achievement,
given
the
short,
hands-off
development
period
and
environment.
This
first
BASIC
was
later
ported
to
many
machines.
Not
long
after
the
Altair
kicked
off
the

microcom-
puter industry, Microsoft BASIC Level II
was
bundled
with
the
TRS-80
Model
I
in
ROM
in
1976,
replacing
Level
I
BASIC,
and
included
with
the
Com-
modore
PET.
Microsoft
also
contributed
some
rou-
tines

to
the
Integer
BASIC
designed
by
Wozniak
for
the
Apple
Computer,
resulting
in
AppleSoft
BASIC.
Later,
in
1984,
Microsoft
BASIC
was
incorporated
into
ROM
on
the
ffiM
Personal
Computer
XT.

In
addition
to
the
computer-specific
8-bit
operating
sys-
tems,
BASIC
was
ported
to
run
on
the
popular
CP/
M
-80
operating
system
designed
by
Gary
Kildall.
At
this
point,
Microsoft

BASIC
was
still
a text-based
program.
Microsoft
BASIC
version
2.0,
the
first
graphics-based
BASIC
for
the
Macintosh,
was
not
announced
until
fall,
1984,
a
decade
after
the
text
version
shipped.
In

1985,
Microsoft
provided
a
windowing
version
on
floppy
diskettes
for
the
Amiga
1000.
Later
Microsoft
BASIC
evolved
further
into
Microsoft
Visual
BASIC,
which
differed chiefly
in
that graphically entered
structures
could
be
used

to
automatically
generate
code.
See
BASIC,
Visual
BASIC.
Microsoft
Data
Warehousing
Framework
A
Microsoft
commercial
open,
scalable
architecture
for
creating,
using,
and
managing
integrated
data
ware-
housing
applications.
Microsoft
Data

Warehousing
Alliance
DWA,
MDWA.
A
trade
association
for
those
using
and
sup-
porting
Microsoft
Data
Warehousing
Framework
in-
formation
technology
(IT)
applications
and
standards.
Microsoft Incorporated
One
of
the
earliest
compa-

nies
supporting
the
microcomputer
market,
Micro-
soft
was
founded
by
Paul
Allen
and
Bill
Gates
in
1975
following
their
partnership
as
Traf-O-Data,
which
they
formed
around
1972.
Although
Gates
and

Allen
had
worked
on
programming
projects
together
dur-
ing
high
school
in
Seattle,
they
formalized
Microsoft
in
1975
in
order
to
market
a
version
of
interpreted
BASIC
for
the
Altair

computer.
The
trade
name
was
registered
in
1977.
Paul
Allen
learned
of
the
Altair
computer
in
a
Popular
Electronics
article
he
saw
in
Harvard
Square.
Since
the
Altair
so
closely

paralleled
an
earlier
microcom-
puter
hardware
idea
of
his,
he
contacted
Gates
to
let
him
know
"someone else
is
doing
it."
They
then
talked
in
the
Square
about
writing
BASIC
for

the
new
machine.
They
contacted
MITS,
the
makers
of
the
Altair,
and
Allen,
Gates,
and
Davidoff
created
a
BA-
SIC
based
on
Gates'
and
Allen's experience
with
BASIC
interpreters
at
Dartmouth.

Six
weeks
later,
Allen
flew
south
and
successfully
demonstrated
BA-
SIC
to
MITS
in
New
Mexico,
setting
the
groundwork
for
their
software
development
company.
The
entrepreneurs
moved
their
operations
first

to
the
Sun
downer
Motel
across
the
street
from
MITS,
and
later
to
an
eighth
floor
office
in
Albuquerque,
New
Mexico.
Allen
took
a position
as
VP
of
Software
at
MITS,

while
keeping
in
regular
contact
with
Micro-
soft
and
Gates.
They
hired
high
school
friends
to
help
out.
Meanwhile,
Gates
began
enhancing
BASIC
and
porting
it
to
new
platforms that
were

introduced.
When
Gates briefly went back
to
Harvard,
Ric
Weiland
and
Marc
McDonald
formed
the
core
at
Microsoft.
Marc
McDonald designed
and
coded
Stand-alone
Disk
BASIC,
in
consultation
with
Bill
Gates.
In
the late 1970s, Microsoft
BASIC

was
adapted
to
run
on
a popular text-oriented
operating
system
called
CP/M,
developed
in
various
versions
by
Gary
Kildall
of
Digital
Research
between
1973
and
1976.
After
three
years
in
New
Mexico,

Microsoft
relocated
to
Bellevue,
Washington,
near
the
co-owners'
fam-
ily
members.
At
this
location
it
was
easier
to
recruit
programmers
as
well.
Microsoft
now
has
a
campus
in
Redmond,
Washington,

and
has
grown
to
be
a
large,
financially
successful
enterprise.
While
it
has
had
occasional
forays
into
hardware
de-
velopment,
the
primary
focus
of
the
company
has
been
software,
and

a substantial
portion
of
the
rev-
enues
are
derived
from
operating
systems
and
busi-
ness-related
applications.
Paul
Allen
left
the
company
to
invest
in
a
number
ofother
ventures,
and
formed
the

Paul
Allen
Group
to
oversee
his
various
invest-
ments.
Allegations
ofunfair
business
practices
were
leveled
at
Microsoft
on
numerous
occasions
during
the
late
1980s
and
the
1990s,
and
the
company

be-
gan
to
be
scrutinized
by
the
U.S.
Justice
Department.
These
proceedings
are
ongoing
and
are
still
not
com-
pletely
resolved.
Bill
Gates
was
the
long-standing
CEO
until
January
2000

when
he
resigned
in
lieu
of
Steve
Ballmer
who
took
the
positions
of
president
and
CEO.
Gates
continued
as
chairman
and
chief
software
architect.
See
Allen,
Paul;
Altair;
Gates,
William;

MITS;
Traf-O-Data.
Microsoft Mobile Explorer
MME.
A
multi
standard
microbrowser
emulation
environment
optimized
for
low-resource
devices
such
as
mobile
telephones
ca-
pable of displaying HTML-like
markup
language
pages.
See
browser,
PDA
microbrowser.
microwave A radio
wave
transmission

frequency
(1000+
MHz)
generally
used
for
radar
and
radio
re-
peaters.
Microwaves
also
provide
the
cooking
power
637
© 2003 by CRC Press LLC
Fiber
Optics
Illustrated
Dictionary
for
microwave
or
radar
range
ovens.
The

generation
of
microwaves
was
initially
achieved
with
magne-
trons
and
Barkhausen-Kurz
tubes
in
the
early
1920s.
Microwaves
were
sometimes
called radio-optical
waves
in
the
early
days
of
their
development
due
to

their
position
on
the
electromagnetic
spectrum
be-
tween
light
waves
and
conventional
radio
waves,
and
because
some
of
their
characteristics,
such
as
propa-
gation,
were
similar
to
light
waves.
Microwave

relay
systems
were
in
use
as
early
as
the
1930s
by
AT&T.
The
original
magnetrons
were
de-
veloped
into
cavity
magnetrons
and
traveling-wave
tubes.
Microwave
generators
and
relays
are
now

an
important
aspect
of
satellite
communications.
Micro-
waves
are
also
finding
increasing
use
in
connecting
local
area
wireless
networks
(LAWNs).
While
they
are
not
used
for
the
primary information-carrying
aspects
within

the
network,
they
are
useful
for
inter-
connecting
line-of-site
separated
LAWNs,
or
LANs,
between
buildings.
Connection requires a license
from
the
Federal Communications Commission
(FCC).
See
magnetron,
microwave
antennas,
short
wave,
traveling-wave
tube.
Microwave
Antenna

Structures
Parabolic antennas constructed
from
mesh
orsolid
materials
are
usedfor
very
short
(microwave)
radio
waves.
The
curvature
of
the
dish
and
the
relatedplace-
ment
of
transmitting orreceivinghorns
are
important
to
the
quality
of

the
signal transmitted or
received.
[Classic
Concepts
photos; used
with
permission.}
microwave antenna
Due
to
the
very
short
wave-
lengths
used
in
microwave
transmissions,
the
physi-
cal
arrangement of microwave antennas
is
quite
different
from
those
for

UHF,
VHF,
and
FM
broad-
casts.
Microwave
transmissions
are
directional
for
both
up-
and
downlinks,
quite different
from
the
roughly
isotropic,
omnidirectional
character
of
tra-
ditional
television
and
radio
broadcast
waves.

The
638
common
multibranched
Yagi-Uda
style
antennas
and
fan
dipole
antennas
are
inexpensive
and
appropriate
for
VHF
and
UHF
reception,
but
directional
parabolic
antennas
are
the
norm
for
microwave
signals.

The
diameter
ofa
parabolic
dish
antenna
is
a
mul-
tiple
of
the
length
of
the
microwaves
received
and
typical
dishes
range
in
size
from
about
2
to
about
10
feet

across,
with
the
curvature
of
the
dish
determin-
ing
the
position
of
the
feed
hom
which
focuses
the
beams.
The
first
transcontinental
microwave
communication
system
began
operations
in
1951
through

a
system
of
relay
stations
between
San
Francisco
and
New
York
City.
Within
three
years,
there
were
more
than
400 additional stations scattered across North
America.
See
antenna,
parabolic
antenna,
UHF
an-
tenna,
VHF
antenna.

microwave
multi-point
distribution
system
MMDS.
MMDS
is
a
system
for
distributing
cable
TV
programming
through
microwave
communications,
more commonly known
now
as
wireless cable.
MMDS
works
in
the
frequency
range
of2.50
to
2.686

GHz,
and
MMDS
service
providers
are
increasing
in
number.
The
signals
are
downlinked
from
the
satel-
lite
to
the
local
transceiver,
and
broadcast
from
there
to
subscribers
within
about
a

50-mile
radius,
depend-
ing
upon
terrain.
The
subscriber
receives
the
signal
on
a
consumer-priced
antenna
mounted
on
or
near
the
home,
which
is
linked
through
a
cable
to
a "black
box"

connected
to
(and
sometimes
sitting
atop)
the
TV
receiver.
This
box
decompresses compressed
digital
signals
and
unscrambles
signals
intended
to
prevent unpaid/unauthorized viewing
of
the
pro-
grams.
The
MMDS
system
is
in
the

process
of
chang-
ing
from
analog
to
digital
technology,
opening
up
op-
portunities
for
digital
multiplexing
through
highly
linear
radio
frequency
(RF)
subsystems,
thus
provid-
ing
more
television
channel
choices

for
viewers.
microwave
radar
Radar
systems
employing
micro-
waves
have
been
extremely
important
in
navigation,
tracking,
surveillance,
guidance,
and
communications
systems.
Much
of
the
early
research
in
microwave
radar
was

conducted
at
the
Massachusetts
lnstitute
of
Technology
(MIT)
radiation
laboratory
in
the
early
1940s.
Mid-Span Meet An
interconnection
point
between
two
co-carriers.
The
Mid-Span
Meet
is
the
point
up
to
which
the

carriers
provide
cabling
and
transmis-
sions.
MIDI
See
Musical
Instrument
Digital
Interface.
MIDI
time
codeMTC.A
standard
developed
to
iden-
tify
timing
information
associated
with
a
stream
of
Musical
Instrument Digital Interface
(MIDI)

data.
See
SMPTE
time
code.
MIDP
See
Mobile
Information
Device
Profile.
Midwestern
Higher
Education
Commission
MHEC.
MHEC
was
founded
as
an
interstate
agency
in
1991
to
promote
resource
sharing
in

higher
edu-
cation.
As
a
subgroup,
it
includes
a
Telecommunica-
tions
Committee
that
takes
a
regional
approach
to
improving
access,
services,
and
costs
of
telecommu-
nications
services.
© 2003 by CRC Press LLC
Milan Declaration on Communication
and

Hu-
man Rights
This
declaration
was
put
forth
in
1998,
based
in
part
on
a
number
of
global
rights
documents,
including
the
Universal Declaration
of
Human
Rights,
the
International
Covenant
on
Civil

and
Po-
litical
Rights,
the
American
Convention
on
Human
Rights,
the
European
Convention
for
the
Protection
of
Human
Rights
and
Fundamental
Freedoms,
the
Beij
ing
Platform
of
Action,
and
other

important
ac-
knowledgments
of
human
rights.
The
Declaration
asserts
the
intrinsic
relationship
be-
tween
freedom
of
opinion
and
expression
and
the
technologies
and
venues
available
for
their
commu-
nication.
It

declares
that
"The
Right
to
Communicate
is
a
universal
human
right
which
serves
and
under-
pins
all
other
human
rights
and
which
must
be
pre-
served
and
extended
in
the

context
of
rapidly
chang-
ing
information
and
communication
technologies,

"
It
affirms
the
need
for
equitable
access
to
all
com-
munications
media
coupled
with
the
mandate
to
pre-
serve

and
sustain
cultural
rights
and
diversity.
It
un-
derlines
the
importance
of
not
reducing
all
informa-
tion
users
to
the
category
of
consumers
and
affirms
their
role
as
communications
producers

and
contribu-
tors.
It
calls
for
international
recognition
of
commu-
nity
broadcasting
as
a
vital
contributor
to
human
free-
doms.
See
People's
Communication
Charter.
The
text
of
the
Milan
Declaration

is
available through
the
World
Association
of
Community Broadcasters
(AMARC).
/>Mill Streetplant
This
historically
significant
power
plant
began
providing
three-phase
alternating
current
(AC)
in
1893.
Partly
due
to
the
advocacy
ofT.
Edi-
son,

most
early
power
plants
provided
direct
current,
so
the
Mill
Creek
No.1
hydroelectric
plant
was
a
pre-
cedent-setting
installation,
and
many
other
similar
AC
power
suppliers
followed
its
example.
milli-

(abbrev.
-
m)
An
SI
unit
prefix
for
1
thousandth,
10-
3
or
0.001.
Thus,
a
milliamp
is
1
thousandth
of
an
ampere.
MILNET
Military
Net.
The
ARPANET
was
a

his-
toric
computer
network
put
into
operation
in
1969.
In
1975,
ARPANET
was
transferred
to
the
Defense
Communications
Agency.
Then,
in
1983
it
was
split
into
MILNET
for
military
usage,

and
ARPANET,
which
evolved
into
the
Internet.
MILNET
is
used
for
nonclassified
U.S.
military communications.
See
ARPANET,
Internet.
MilstarAjoint
U.S.
ArmylNavy/Air
Force
satellite
system
for
providing
jam-resistant
communications
for
wartime
requirements

for
high-priority
military
users.
It
is
a
global
constellation of
5-ton
geostation-
ary
satellites
orbiting
at
about
22,250
nautical
miles.
The
first
Milstar
satellite
was
launched
in
February
1994,
the
second

in
November
1995.
Six
launchings
are
intended
to
support
four
satellites
that
are
active
at
anyone
time.
The
satellites
have
operational
life-
times
of
about
10
years.
Milstar
was
designed

to
link
ground,
marine,
and
air
command
authorities.
The
satellites
relay
communi-
cations
from
terminal
to
terminal,
anywhere
on
Earth.
By
transmitting
from
satellite
to
satellite,
ground
hops
are
reduced

and
security
heightened.
Milstar
termi-
nals
provide a variety of data services, including
voice,
data,
facsimile,
or
teletype
communications.
MIME
See
Multipurpose
Internet
Mail
Extension.
MIN
See
Mobile
Identification
Number.
Miner,
Jay
( 1930-1994)
Agifted
design
engineer

responsible
for
designing
the
hardware
for
the
Atari
800
computer,
the
Amiga
computer,
and
the
Lynx
color
handheld
game
machine.
In
1982,
Miner
joined
Hi
Toro
to
develop
the
Lorraine

computer,
which
was
subsequently
sold
as
the
Amiga
by
Commodore
Busi-
ness
Machines.
A
proponent
of
open-mindedness
and
creativity,
Miner
included
his
dog's
pawprint
inside
the
case
of
the
Amiga

1000.
After
the
Amiga,
he
cre-
ated
the
Atari
Lynx,
a
fast
color
handheld
game
ma-
chine.
Jay
Miner
was
affectionately
known
as
Padre,
the
Father
of
the
Amiga,
to

the
computing
commu-
nity.
Following
a
serious
illness
and
kidney
trans-
plant,
Jay
Miner
devoted
his
remaining
working
life
to
developing
medical
devices,
such
as
pacemakers,
to
aid
society.
Surprisingly,

despite
the
fact
that
he
understood
that
the
creation of
the
Amiga'
was
a
re-
markable
achievement,
Miner
didn't
anticipate
the
revolution
in
the
video
industry
launched
by
his
cre-
ation.

In
a
computing
industry
where
hardware
archi-
tectures
go
out
of
date
in
a
few
months,
the
viability
of
the
Amiga
hardware
for
more
than
a
decade,
par-
ticularly
for

graphics
and
sound,
is
a
tribute
to
its
ef-
ficient
and
insightful
design.
See
Amiga
computer,
Commodore
Business
Machines.
minifloppy A
generic
term
for
a
number
of
floppy
diskette
technologies
that

store
almost
ten
times
as
much
data
as
a
regular
3.5-in.
floppy,
but
which
are
designed
by
some
manufacturers
to
be
downwardly
compatible
with
1.4-Mbyte
drives.
The
price
of
stor-

age
on
these
high
capacity
floppies
is
substantially
cheaper,
and
they
may,
in
time,
supersede current
floppies.
minimal shift keying
MSK.
A
type
of
modulation
technique
similar
to
quadrature
phase
shift
keying
(QPSK),

except
that
the
rectangular
pulse
in
QPSK
is
a
half-cycle
sinusoidal
pulse
in
MSK.
See
modu-
lation,
phase
shift
keying.
minimize button,iconize button
Graphical
user
in-
terfaces
on
several
different operating
systems
in-

clude
a
small
gadget
on
application
or
display
win-
dows
which,
when
clicked,
will
shrink
the
window
down
to
an
icon.
Thus,
the
program
is
available
and
can
quickly
be

retrieved
by
double-clicking
the
mini-
mized
icon
without
shutting
down
the
process
and
rerunning
the
program.
Ministeredes Postes etTelecommunicaciones
The
telecommunications
authority
for
the
Democratic
and
Popular
Republic
of
Algeria.
Online
communications

are
in
French.
Ministerio de Comunicaciones
The
telecommuni-
cations
planning
and
regulatory
authority
of
the
Re-
public
of
Columbia
in
South
America.
/>Ministry
of
Information Technology
and
Telecom-
munications
MITT.
The
Mauritius ministry that
handles

the
formulation and implementation
of
639
© 2003 by CRC Press LLC
Fiber
Optics
Illustrated
Dictionary
government
policies
in
telecommunications
and
in-
formation
technology.
Telecommunications
are
gov-
erned
by
the
Mauritius Telecommunications
Act
1998.
Online
services
are
designed

and
published
by
the
National
Computer
Board.

Ministry
of
Posts and Telecommunications
MPT.
The
Japanese
radio
regulatory
administration,
MPT
oversees
radio
communications,
based
upon
the
Ra-
dio
Law
of
1950.
The

MPT
grants
radio
station
and
operator
licenses,
monitors
and
inspects
stations
and
radio
frequencies,
and
sets
technical
standards
for
ra-
dio
equipment.
/>Ministry
of
Telecommunications
The
telecommu-
nications
authority
of

the
Lebanese
Republic
under
the
direction
of
the
Minister
of
Post
and
Telecommu-
nications.
/>Ministry of Telecommunications and E-Com-
merce
The
authority
in
Bermuda
that
oversees
tele-
communications,
broadcasting,
and
frequency
admin-
istration.

MinitelA
French
Telecom
service
that
provides
free
terminals
for
chat
and
electronic
telephone
directory
videotext services. It
is
similar
to
the German
Bundespost's interactive videotext system.
See
Minitel.
MIP
See
Multichannel
Interface
Processor.
MIPG
See
Multiple-Image

Portable
Graphics.
MIPS
million
instructions
per
second.
A
measure
of
processor
speed
used
in
system
design
and
cross-sys-
tem
comparisons.
MIPS
describes
the
average
num-
ber ofmachine instructions that a central
process-
ing
unit
(CPU)

performs
per
unit
of
time
of 1
sec-
ond.
This
is
a
narrow
definition
of
performance,
as
many
other
factors
influence
overall
speed
and
effi-
ciency.
The
Digital
VAX-ll/780
is
defined

as
a
base-
line
at
1
MIP.
By
the
late
1990s,
most
consumer
desk-
top
models
delivered
about
3
to
10
MIPS
and
high-
end
minicomputers
and
mainframes
ranged
from

10
to
50
MIPS,
with
supercomputers
comprising
the
top
of
whatever
was
state
of
the
art
at
any
particular
time.
See
benchmark.
Mir A
landmark
"permanent"
Earth-orbiting
space
station
used
for

observation,
experimentation,
and
scientific
research
about
living
and
working
in
space.
U.S.
and
Russian
Mir
missions
began
early
in
1995,
with
the
core
module
launched
in
February
1986.
Mir
consisted

ofa
number
of
connected
modules,
dock-
ing
components,
solar
screens,
life
support
systems,
and
scientific
instruments.
The
Mir
capsule
could
hold
two
or
three
people
fairly
comfortably,
and
up
to

six
for
short
periods
of
time.
Travellers
to
and
from
Mir
connected
through
the
NASA
space
shuttle.
Amateur
radio
enthusiasts
enjoyed
regularly
listen-
ing
to
Mir
signals,
and
some
have

sent
transmissions
to
the
orbiting
station.
A
great
deal
was
learned
about
the
wonders
and
chal-
lenges
of
living
in
space
from
Mir.
Information
and
photographs related
to
Mir
missions
can

be
seen
through
the
Office
of
Space
Flight
Web
site.
After
orbiting
the
Earth
for
more
than
15
years,
the
space
station
entered
the
Earth's
atmosphere,
in
a
640
controlled

decline,
on
March
23,
2001.

/osf/mir
MIR
See
multimedia
information
retrieval.
mirror A
highly
reflective,
usually
polished
surface
that
readily
reflects
light
while
absorbing
very
little
of
it.
Water
and

glass
have
mirroring
qualities,
but
some
of
the
light
is
refracted
or
absorbed,
making
the
image
foggy
or
ghostly
rather
than
crisp
and
detailed.
Highly
polished
metal
and
silvered
glass

make
ex-
cellent
mirror
surfaces.
Dielectric
mirrors
are
most
effective
within
a
narrow
range
of
wavelengths
and
angles
of
incidence.
Mirrors
were
used
for
line-of-sight signaling
long
before
electrical
telecommunications
methods

were
available.
Hikers
still
regularly
carry
them
for
emer-
gency
signaling
in
the
wilderness.
Mirrors
are
also
used
in
many
types
of
computer
devices,
especially
those
which
incorporate
laser
beams,

such
as
laser
printers.
The
mirror
serves
to
direct
the
beam
inside
the
mechanism
onto
the
appropriate
areas,
such
as
a
printing
drum.
In
fiber
optics,
it
was
discovered
by

MIT
scientists
that
dielectric
films
would
behave
more
like
a
metal
if
they
were
layered
in
a particular
way,
a
capability
that
they
subsequently
applied
to
the
development
of
improved
lightguides

that
had
the
potential
to
sup-
port
the
transmission
ofa
wide
range
of
optical
wave-
lengths,
while
retaining
the
polarity of
the
transmit-
ted
beams.
The
new
technology,
described
in
2000,

was
also
capable
of
reflecting
light
through
small
ar-
eas for increased miniaturization.
See
coaxial
omniguide,
heliograph.
mirroring A
means
of
providing
system
backup
se-
curity
or
redundant
access
by
replicating
data
in
dif-

ferent
locations.
The
system
can
enable
the
user
to
access
the
mirror
location
if
the
original
data
storage
location
becomes
oversubscribed
or
corrupted.
Or,
the
system
can
be
restored
with

information
from
the
mirror.
Redundancy
is
a
very
common
property
of
computer
systems.
Some
will
mirror
whole
directory
structures
and
files
as
a
matter
of
course.
Some
hard
drive
systems

are
set
up
to
constantly
mirror
infor-
mation
over
several
devices.
While
mirroring
almost
inevitably
costs
a
little
more
in
terms
of
memory
or
storage
space
and
in
processing
time,

it
is
usually
worthwhile.
See
mirror
site,
RAID.
MIS
See
Management
Information
Services.
missile,
fiber-guided A
guided
missile
that
flies
in
a
high
trajectory
with
a camera housed
in
its
nose,
which
is

connected
to
the
launcher
by
a
fine
spool-
ing
fiber
optic
cable.
The
cable
enables
a
remote
hu-
man
pilot
to
view
the
progress
of
the
flight
and
guide
it

to
targets
within
a
10-mile
range
using
ajoystick
as
the
guidance
controller.
This
weapon
was
initially
released
in
the
early
1990s
by
the
U.S.
Army
as
the
FOG-M
(Fiber
Optic

Guided
Missile)
but
not
widely
fielded.
See
multiplexed
optical
scanner
technology.
MITS
Micro
Instrumentation
and
Telemetry
Sys-
tems.
The
historic
creators
of
the
Altair
microcom-
puter,
MITS,
under
the
direction

of
Ed
Roberts,
origi-
nally
sold
radio
transmitters
(telemetry
devices)
for
model
planes.
These
products
did
quite
well
and
got
© 2003 by CRC Press LLC
the company under
way,
but when the company
moved
into
the
area
ofcalculator
kits,

there
was
a
lot
ofcompetition
from
bigger
names
like
Texas
Instru-
ments,
and
the
Altair
was
in
essence
an
effort
to
stave
off
bankruptcy.
MITS
developed
the
MITS
816
in

1972,
and
later
the
historic
kit
for
the
Altair
8800
in
1974.
While
the
Altair
is
not
the
first
microcomputer,
it
is
to
be
credited
as
the
first commercially success-
ful
microcomputer.

In
spite
of
the
success of
the
Al-
tair,
the
company
was
sold
to
Pertec, amanufacturer
of peripherals.
See
Altair, Intel
MCS-4,
Kenbak-l,
Mark-8,
Micral,
Scelbi.
MJ
modular
jack.
Any
jack designed
to
interconnect
readily

with
various
standardized receptacles
in
a
cir-
cui
t
system.
See
RJ.
MLPP
multilevel precedence
and
preemption (e.g.,
as
in
ISDN
Q.85
and
A.735
community of interest
services).
MMC
1.
minimum
monthly
charge.
2.
See

Mobile
Multimedia Communication project.
3.
See
MultiMediaCard.
MMCA
See
MultiMediaCard Association.
MMCF
See
Multimedia Communications
Forum.
MMCX
See
Multimedia Communication
Exchange.
MMDC
1.
See
Massachusetts Microprocessor
De-
sign
Center.
2.
See
Multi-Media
and
Digital
Commu-
nications

lab.
3.
See
Multi-Service, Multi-Carrier,
Distributed Communications.
4.
See multimedia
desktop
collaboration.
5.
See
Multimedia Develop-
ment
Center.
6.
See
multimodel
data
compression.
7.
See
Multiple
Module
Data
Computer.
MMDM
See
micromachined
membrane
deformable

mirrors.
MMDS
See
microwave multipoint distribution
sys-
tem.
MME
1.
See
Microsoft Mobile Explorer.
2.
See
Mobile
Meteorological Equipment.
3.
See
Multime-
dia
Message
Entity.
MMF
1.
See
Mobile Management Forum.
2.
See
multimode
optical fiber
MMI machine-to-machine interface.
Since

this
can
easily
be
confused with
the
abbreviation
for
man-
machine
interface,
which
was
also
traditionally
MMI,
it
is
preferable
to
use
HMI
for
human-machine
inter-
face.
MMIC
See
Monolithic Microwave Integrated
Cir-

cuit.
MMM
See
multimedia mail.
MMMS
See
Multimedia Mail
Service.
MMMSec
See
Multimedia
Mail
Security.
MMS
1.
marketing
measurement
system.
2.
memory
management
system.
3.
meteorological measurement
system.
4.
module
management
system.
5.

multime-
dia
survey.
MMSI
1.
Manchester Museum ofScience & Indus-
try.
2.
See
Maritime
Mobile Service
Identity.
MMSP
See
modular multi-satellite preprocessor.
MMSS
Maritime
Mobile-Satellite Service.
MMTA
See
Multimedia Telecommunications
Asso-
ciation.
MMU
1.
Manned
Maneuvering
Unit.
A
human

ma-
neuvering unit used
in
untethered space walks
originating
from
the
u.S. space shuttle missions.
2.
memory
management
unit.
Computer circuitry
of-
ten
built
into
central processing
chips
to
handle
ad-
ministration ofblocks
of
storage.
MMUSIC
See
Multiparty Multimedia
Session
Con-

trol.
MMX Multimedia Extension. Matrix
Math
Exten-
sion.
See
Pentium
MMX.
MNLP
See
Mobile Network Location
Protocol.
MNP
See
Microcom Networking Protocol.
MNRP Mobile Network Registration
Protocol.
mobile assisted handoffMAHO. A
process
in
which
the
handoff
of
a voice channel
by
a
mobile
station
is

assisted
by
the
base station
by
providing information
on
the
surrounding
radio
frequency
(RF)
signal
en-
vironment.
Mobile
Broadband
System
MBS.
Awireless cellu-
lar
network
developed
as
one
of
the
European
RACE
II Integrated Broadband Communications (IBC)

proj
ects.
The
purpose
of
the
proj
ect
was
~o
develop
third-generation, integrated mobile
systems
as
part
of
a universal, cost-efficient, voice/data personal
communications
system.
MBS
transparently transports Asynchronous
Trans-
fer
Mode
(ArM)
cells
over
the
air interface
at

60
GHz
at
data
rates
up
to
34
Mbps
(with higher
rates
pos-
sible
through
multicarrier transmission).
Two
recom-
mended sub-band frequencies
for
MBS
are
62
to
63
GHz
and
65
to
66
GHz.

MBS
is
supported over B-ISDN systems
and
differs
from
traditional cellular
by
its
bursty
nature
and
dy-
namically adjusting data transmission
rates.
A
new
channel structure
and
protocols
have
been
developed
in
conjunction with
the
project
to
exploit
the

packet
characteristics
of
B-ISDN connections.
See
Inte-
grated Broadband
System,
Research
into
Advanced
Communications
in
Europe.
MobileDataBaseStation
MDBS.
In
CDPD
mobile
communications, a system which provides data
packet relay
functions
between
the
Mobile
End
Sys-
tem
(M-ES)
and

the
Mobile Data Intermediate
Sys-
tem
(MD-IS).
See
Cellular Digital Packet
Data.
Mobile
Data
Intermediate
System
MD-IS.
In
CDPD
mobile communications, a
system
which
pro-
vides routing
and
location management functions,
utilizing a
Home
Domain
Directory
(HOD)
database.
The
MD-IS

communicates with
the
Mobile
End
Sys-
tem
(M-ES)
through
the
Mobile Data
Base
Station
(MDBS).
See
Cellular Digital Packet
Data.
Mobile
End
System
M-ES.
In
CDPD
mobile
com-
munications,
the
system
through
which
the

subscriber
accesses wireless network services.
M-ESs
include
modems
installed
in
laptops,
palmtops,
personal
digi-
tal
assistants
(PDAs),
etc.
See
Cellular Digital Packet
Data.
Mobile Identification
Number
MIN.
Each
wireless
phone
is
assigned
an
identification number
by
the

carrier.
The
MIN
is
not
attached
to
the
individual,
as
the
phone
may
change
hands
or
the
individual
may
change
locations.
Mobile Information Device Profile
MIDP.
Aspeci-
fication supported
by
a number
of
major wireless
641

© 2003 by CRC Press LLC