<s>
In	O
telecommunications	O
and	O
computer	B-Architecture
networking	I-Architecture
,	O
multiplexing	B-Architecture
(	O
sometimes	O
contracted	O
to	O
muxing	B-Architecture
)	O
is	O
a	O
method	O
by	O
which	O
multiple	O
analog	O
or	O
digital	O
signals	O
are	O
combined	O
into	O
one	O
signal	O
over	O
a	O
shared	B-Protocol
medium	I-Protocol
.	O
</s>
<s>
Multiplexing	B-Architecture
originated	O
in	O
telegraphy	O
in	O
the	O
1870s	O
,	O
and	O
is	O
now	O
widely	O
applied	O
in	O
communications	O
.	O
</s>
<s>
In	O
telephony	O
,	O
George	O
Owen	O
Squier	O
is	O
credited	O
with	O
the	O
development	O
of	O
telephone	O
carrier	O
multiplexing	B-Architecture
in	O
1910	O
.	O
</s>
<s>
The	O
multiplexed	B-Architecture
signal	O
is	O
transmitted	O
over	O
a	O
communication	O
channel	O
such	O
as	O
a	O
cable	O
.	O
</s>
<s>
The	O
multiplexing	B-Architecture
divides	O
the	O
capacity	O
of	O
the	O
communication	O
channel	O
into	O
several	O
logical	O
channels	O
,	O
one	O
for	O
each	O
message	O
signal	O
or	O
data	O
stream	O
to	O
be	O
transferred	O
.	O
</s>
<s>
A	O
reverse	O
process	O
,	O
known	O
as	O
demultiplexing	B-Architecture
,	O
extracts	O
the	O
original	O
channels	O
on	O
the	O
receiver	O
end	O
.	O
</s>
<s>
A	O
device	O
that	O
performs	O
the	O
multiplexing	B-Architecture
is	O
called	O
a	O
multiplexer	B-Protocol
(	O
MUX	O
)	O
,	O
and	O
a	O
device	O
that	O
performs	O
the	O
reverse	O
process	O
is	O
called	O
a	O
demultiplexer	O
(	O
DEMUX	B-Protocol
or	O
DMX	O
)	O
.	O
</s>
<s>
Inverse	B-Protocol
multiplexing	I-Protocol
(	O
IMUX	B-Protocol
)	O
has	O
the	O
opposite	O
aim	O
as	O
multiplexing	B-Architecture
,	O
namely	O
to	O
break	O
one	O
data	O
stream	O
into	O
several	O
streams	O
,	O
transfer	O
them	O
simultaneously	O
over	O
several	O
communication	O
channels	O
,	O
and	O
recreate	O
the	O
original	O
data	O
stream	O
.	O
</s>
<s>
In	O
computing	O
,	O
I/O	B-General_Concept
multiplexing	B-Architecture
can	O
also	O
be	O
used	O
to	O
refer	O
to	O
the	O
concept	O
of	O
processing	O
multiple	O
input/output	B-General_Concept
events	O
from	O
a	O
single	O
event	B-General_Concept
loop	I-General_Concept
,	O
with	O
system	O
calls	O
like	O
poll	B-Language
and	O
select	O
(	O
Unix	O
)	O
.	O
</s>
<s>
Multiple	O
variable	B-General_Concept
bit	I-General_Concept
rate	I-General_Concept
digital	O
bit	O
streams	O
may	O
be	O
transferred	O
efficiently	O
over	O
a	O
single	O
fixed	O
bandwidth	B-Algorithm
channel	O
by	O
means	O
of	O
statistical	B-Algorithm
multiplexing	I-Algorithm
.	O
</s>
<s>
This	O
is	O
an	O
asynchronous	O
mode	O
time-domain	O
multiplexing	B-Architecture
which	O
is	O
a	O
form	O
of	O
time-division	B-Protocol
multiplexing	I-Protocol
.	O
</s>
<s>
Digital	O
bit	O
streams	O
can	O
be	O
transferred	O
over	O
an	O
analog	O
channel	O
by	O
means	O
of	O
code-division	B-Protocol
multiplexing	I-Protocol
techniques	O
such	O
as	O
frequency-hopping	B-Protocol
spread	I-Protocol
spectrum	I-Protocol
(	O
FHSS	B-Protocol
)	O
and	O
direct-sequence	B-Device
spread	I-Device
spectrum	I-Device
(	O
DSSS	B-Device
)	O
.	O
</s>
<s>
In	O
wireless	O
communications	O
,	O
multiplexing	B-Architecture
can	O
also	O
be	O
accomplished	O
through	O
alternating	O
polarization	O
(	O
horizontal/vertical	O
or	O
clockwise/counterclockwise	O
)	O
on	O
each	O
adjacent	O
channel	O
and	O
satellite	O
,	O
or	O
through	O
phased	O
multi-antenna	O
array	O
combined	O
with	O
a	O
multiple-input	O
multiple-output	O
communications	O
(	O
MIMO	O
)	O
scheme	O
.	O
</s>
<s>
In	O
wired	O
communication	O
,	O
space-division	O
multiplexing	B-Architecture
,	O
also	O
known	O
as	O
space-division	O
multiple	O
access	O
(	O
SDMA	O
)	O
is	O
the	O
use	O
of	O
separate	O
point-to-point	O
electrical	O
conductors	O
for	O
each	O
transmitted	O
channel	O
.	O
</s>
<s>
Examples	O
include	O
an	O
analogue	O
stereo	O
audio	O
cable	O
,	O
with	O
one	O
pair	O
of	O
wires	O
for	O
the	O
left	O
channel	O
and	O
another	O
for	O
the	O
right	O
channel	O
,	O
and	O
a	O
multi-pair	O
telephone	O
cable	O
,	O
a	O
switched	O
star	B-Architecture
network	I-Architecture
such	O
as	O
a	O
telephone	O
access	O
network	O
,	O
a	O
switched	O
Ethernet	O
network	O
,	O
and	O
a	O
mesh	B-Architecture
network	I-Architecture
.	O
</s>
<s>
In	O
wireless	O
communication	O
,	O
space-division	O
multiplexing	B-Architecture
is	O
achieved	O
with	O
multiple	O
antenna	O
elements	O
forming	O
a	O
phased	O
array	O
antenna	O
.	O
</s>
<s>
Examples	O
are	O
multiple-input	O
and	O
multiple-output	O
(	O
MIMO	O
)	O
,	O
single-input	O
and	O
multiple-output	O
(	O
SIMO	O
)	O
and	O
multiple-input	O
and	O
single-output	O
(	O
MISO	O
)	O
multiplexing	B-Architecture
.	O
</s>
<s>
An	O
IEEE	O
802.11g	O
wireless	O
router	O
with	O
k	O
antennas	O
makes	O
it	O
in	O
principle	O
possible	O
to	O
communicate	O
with	O
k	O
multiplexed	B-Architecture
channels	O
,	O
each	O
with	O
a	O
peak	O
bit	O
rate	O
of	O
54Mbit/s	O
,	O
thus	O
increasing	O
the	O
total	O
peak	O
bit	O
rate	O
by	O
the	O
factor	O
k	O
.	O
Different	O
antennas	O
would	O
give	O
different	O
multi-path	O
propagation	O
(	O
echo	O
)	O
signatures	O
,	O
making	O
it	O
possible	O
for	O
digital	B-General_Concept
signal	I-General_Concept
processing	I-General_Concept
techniques	O
to	O
separate	O
different	O
signals	O
from	O
each	O
other	O
.	O
</s>
<s>
These	O
techniques	O
may	O
also	O
be	O
utilized	O
for	O
space	O
diversity	O
(	O
improved	O
robustness	O
to	O
fading	O
)	O
or	O
beamforming	B-Algorithm
(	O
improved	O
selectivity	O
)	O
rather	O
than	O
multiplexing	B-Architecture
.	O
</s>
<s>
Frequency-division	B-Protocol
multiplexing	I-Protocol
(	O
FDM	O
)	O
is	O
inherently	O
an	O
analog	O
technology	O
.	O
</s>
<s>
One	O
of	O
the	O
most	O
common	O
applications	O
for	O
FDM	O
is	O
traditional	O
radio	O
and	O
television	O
broadcasting	B-Operating_System
from	O
terrestrial	O
,	O
mobile	O
or	O
satellite	O
stations	O
,	O
or	O
cable	O
television	O
.	O
</s>
<s>
A	O
variant	O
technology	O
,	O
called	O
wavelength-division	B-Architecture
multiplexing	I-Architecture
(	O
WDM	O
)	O
is	O
used	O
in	O
optical	O
communications	O
.	O
</s>
<s>
Time-division	B-Protocol
multiplexing	I-Protocol
(	O
TDM	O
)	O
is	O
a	O
digital	O
(	O
or	O
in	O
rare	O
cases	O
,	O
analog	O
)	O
technology	O
which	O
uses	O
time	O
,	O
instead	O
of	O
space	O
or	O
frequency	O
,	O
to	O
separate	O
the	O
different	O
data	O
streams	O
.	O
</s>
<s>
Each	O
terminal	O
communicated	O
at	O
2400	O
baud	O
,	O
so	O
rather	O
than	O
acquire	O
four	O
individual	O
circuits	O
to	O
carry	O
such	O
a	O
low-speed	O
transmission	O
,	O
the	O
airline	O
has	O
installed	O
a	O
pair	O
of	O
multiplexers	B-Protocol
.	O
</s>
<s>
polipo	B-Protocol
)	O
use	O
TDM	O
in	O
HTTP	B-Protocol
pipelining	I-Protocol
of	O
multiple	O
HTTP	B-Protocol
transactions	O
onto	O
the	O
same	O
TCP/IP	B-Protocol
connection	I-Protocol
.	O
</s>
<s>
Carrier	O
sense	O
multiple	O
access	O
and	O
multidrop	B-Architecture
communication	O
methods	O
are	O
similar	O
to	O
time-division	B-Protocol
multiplexing	I-Protocol
in	O
that	O
multiple	O
data	O
streams	O
are	O
separated	O
by	O
time	O
on	O
the	O
same	O
medium	O
,	O
but	O
because	O
the	O
signals	O
have	O
separate	O
origins	O
instead	O
of	O
being	O
combined	O
into	O
a	O
single	O
signal	O
,	O
are	O
best	O
viewed	O
as	O
channel	O
access	O
methods	O
,	O
rather	O
than	O
a	O
form	O
of	O
multiplexing	B-Architecture
.	O
</s>
<s>
TD	O
is	O
a	O
legacy	O
multiplexing	B-Architecture
technology	O
still	O
providing	O
the	O
backbone	B-General_Concept
of	O
most	O
National	O
fixed	O
line	O
Telephony	O
networks	O
in	O
Europe	O
,	O
providing	O
the	O
2m/bit	O
voice	O
and	O
signalling	O
ports	O
on	O
Narrow	O
band	O
Telephone	O
exchanges	O
such	O
as	O
the	O
DMS100	O
.	O
</s>
<s>
Polarization-division	O
multiplexing	B-Architecture
uses	O
the	O
polarization	O
of	O
electromagnetic	O
radiation	O
to	O
separate	O
orthogonal	O
channels	O
.	O
</s>
<s>
It	O
is	O
in	O
practical	O
use	O
in	O
both	O
radio	O
and	O
optical	O
communications	O
,	O
particularly	O
in	O
100Gbit/s	O
per	O
channel	O
fiber	B-Application
optic	I-Application
transmission	I-Application
systems	I-Application
.	O
</s>
<s>
Orbital	O
angular	O
momentum	O
multiplexing	B-Architecture
is	O
a	O
relatively	O
new	O
and	O
experimental	O
technique	O
for	O
multiplexing	B-Architecture
multiple	O
channels	O
of	O
signals	O
carried	O
using	O
electromagnetic	O
radiation	O
over	O
a	O
single	O
path	O
.	O
</s>
<s>
It	O
can	O
potentially	O
be	O
used	O
in	O
addition	O
to	O
other	O
physical	O
multiplexing	B-Architecture
methods	O
to	O
greatly	O
expand	O
the	O
transmission	O
capacity	O
of	O
such	O
systems	O
.	O
</s>
<s>
it	O
is	O
still	O
in	O
its	O
early	O
research	O
phase	O
,	O
with	O
small-scale	O
laboratory	O
demonstrations	O
of	O
bandwidths	B-Algorithm
of	O
up	O
to	O
2.5	O
Tbit/s	O
over	O
a	O
single	O
light	O
path	O
.	O
</s>
<s>
This	O
is	O
a	O
controversial	O
subject	O
in	O
the	O
academic	O
community	O
,	O
with	O
many	O
claiming	O
it	O
is	O
not	O
a	O
new	O
method	O
of	O
multiplexing	B-Architecture
,	O
but	O
rather	O
a	O
special	O
case	O
of	O
space-division	O
multiplexing	B-Architecture
.	O
</s>
<s>
Code-division	B-Protocol
multiplexing	I-Protocol
(	O
CDM	O
)	O
,	O
code-division	B-Protocol
multiple	I-Protocol
access	I-Protocol
(	O
CDMA	B-Protocol
)	O
or	O
spread	B-Architecture
spectrum	I-Architecture
is	O
a	O
class	O
of	O
techniques	O
where	O
several	O
channels	O
simultaneously	O
share	O
the	O
same	O
frequency	O
spectrum	O
,	O
and	O
this	O
spectral	B-Algorithm
bandwidth	I-Algorithm
is	O
much	O
higher	O
than	O
the	O
bit	O
rate	O
or	O
symbol	O
rate	O
.	O
</s>
<s>
One	O
form	O
is	O
frequency	B-Protocol
hopping	I-Protocol
,	O
another	O
is	O
direct	B-Device
sequence	I-Device
spread	I-Device
spectrum	I-Device
.	O
</s>
<s>
Advantages	O
over	O
conventional	O
techniques	O
are	O
that	O
variable	O
bandwidth	B-Algorithm
is	O
possible	O
(	O
just	O
as	O
in	O
statistical	B-Algorithm
multiplexing	I-Algorithm
)	O
,	O
that	O
the	O
wide	O
bandwidth	B-Algorithm
allows	O
poor	O
signal-to-noise	O
ratio	O
according	O
to	O
Shannon-Hartley	O
theorem	O
,	O
and	O
that	O
multi-path	O
propagation	O
in	O
wireless	O
communication	O
can	O
be	O
combated	O
by	O
rake	O
receivers	O
.	O
</s>
<s>
A	O
significant	O
application	O
of	O
CDMA	B-Protocol
is	O
the	O
Global	O
Positioning	O
System	O
(	O
GPS	O
)	O
.	O
</s>
<s>
A	O
multiplexing	B-Architecture
technique	O
may	O
be	O
further	O
extended	O
into	O
a	O
multiple	O
access	O
method	O
or	O
channel	O
access	O
method	O
,	O
for	O
example	O
,	O
TDM	O
into	O
time-division	B-Protocol
multiple	O
access	O
(	O
TDMA	O
)	O
and	O
statistical	B-Algorithm
multiplexing	I-Algorithm
into	O
carrier-sense	O
multiple	O
access	O
(	O
CSMA	O
)	O
.	O
</s>
<s>
Multiplexing	B-Architecture
is	O
provided	O
by	O
the	O
Physical	B-Application
Layer	I-Application
of	O
the	O
OSI	O
model	O
,	O
while	O
multiple	O
access	O
also	O
involves	O
a	O
media	B-Protocol
access	I-Protocol
control	I-Protocol
protocol	O
,	O
which	O
is	O
part	O
of	O
the	O
Data	B-Protocol
Link	I-Protocol
Layer	I-Protocol
.	O
</s>
<s>
The	O
Transport	O
layer	O
in	O
the	O
OSI	O
model	O
,	O
as	O
well	O
as	O
TCP/IP	O
model	O
,	O
provides	O
statistical	B-Algorithm
multiplexing	I-Algorithm
of	O
several	O
application	O
layer	O
data	O
flows	O
to/from	O
the	O
same	O
computer	O
.	O
</s>
<s>
Code-division	B-Protocol
multiplexing	I-Protocol
(	O
CDM	O
)	O
is	O
a	O
technique	O
in	O
which	O
each	O
channel	O
transmits	O
its	O
bits	O
as	O
a	O
coded	O
channel-specific	O
sequence	O
of	O
pulses	O
.	O
</s>
<s>
Other	O
widely	O
used	O
multiple	O
access	O
techniques	O
are	O
time-division	B-Protocol
multiple	O
access	O
(	O
TDMA	O
)	O
and	O
frequency-division	O
multiple	O
access	O
(	O
FDMA	O
)	O
.	O
</s>
<s>
Code-division	B-Protocol
multiplex	O
techniques	O
are	O
used	O
as	O
an	O
access	O
technology	O
,	O
namely	O
code-division	B-Protocol
multiple	I-Protocol
access	I-Protocol
(	O
CDMA	B-Protocol
)	O
,	O
in	O
Universal	O
Mobile	O
Telecommunications	O
System	O
(	O
UMTS	O
)	O
standard	O
for	O
the	O
third-generation	O
(	O
3G	O
)	O
mobile	O
communication	O
identified	O
by	O
the	O
ITU	O
.	O
</s>
<s>
The	O
earliest	O
communication	O
technology	O
using	O
electrical	O
wires	O
,	O
and	O
therefore	O
sharing	O
an	O
interest	O
in	O
the	O
economies	O
afforded	O
by	O
multiplexing	B-Architecture
,	O
was	O
the	O
electric	O
telegraph	O
.	O
</s>
<s>
Émile	O
Baudot	O
developed	O
a	O
time-multiplexing	B-Protocol
system	O
of	O
multiple	O
Hughes	O
machines	O
in	O
the	O
1870s	O
.	O
</s>
<s>
Several	O
researchers	O
were	O
investigating	O
acoustic	O
telegraphy	O
,	O
a	O
frequency-division	B-Protocol
multiplexing	I-Protocol
technique	O
,	O
which	O
led	O
to	O
the	O
invention	O
of	O
the	O
telephone	O
.	O
</s>
<s>
In	O
telephony	O
,	O
a	O
customer	O
's	O
telephone	B-Architecture
line	I-Architecture
now	O
typically	O
ends	O
at	O
the	O
remote	B-Architecture
concentrator	I-Architecture
box	O
,	O
where	O
it	O
is	O
multiplexed	B-Architecture
along	O
with	O
other	O
telephone	O
lines	O
for	O
that	O
neighborhood	O
or	O
other	O
similar	O
area	O
.	O
</s>
<s>
The	O
multiplexed	B-Architecture
signal	O
is	O
then	O
carried	O
to	O
the	O
central	O
switching	O
office	O
on	O
significantly	O
fewer	O
wires	O
and	O
for	O
much	O
further	O
distances	O
than	O
a	O
customer	O
's	O
line	O
can	O
practically	O
go	O
.	O
</s>
<s>
This	O
is	O
likewise	O
also	O
true	O
for	O
digital	O
subscriber	B-Architecture
lines	I-Architecture
(	O
DSL	O
)	O
.	O
</s>
<s>
Fiber	B-Architecture
in	I-Architecture
the	I-Architecture
loop	I-Architecture
(	O
FITL	B-Architecture
)	O
is	O
a	O
common	O
method	O
of	O
multiplexing	B-Architecture
,	O
which	O
uses	O
optical	B-Architecture
fiber	I-Architecture
as	O
the	O
backbone	B-General_Concept
.	O
</s>
<s>
Cable	O
TV	O
has	O
long	O
carried	O
multiplexed	B-Architecture
television	O
channels	O
,	O
and	O
late	O
in	O
the	O
20th	O
century	O
began	O
offering	O
the	O
same	O
services	O
as	O
telephone	O
companies	O
.	O
</s>
<s>
IPTV	O
also	O
depends	O
on	O
multiplexing	B-Architecture
.	O
</s>
<s>
In	O
video	O
editing	O
and	O
processing	O
systems	O
,	O
multiplexing	B-Architecture
refers	O
to	O
the	O
process	O
of	O
interleaving	O
audio	O
and	O
video	O
into	O
one	O
coherent	O
data	O
stream	O
.	O
</s>
<s>
The	O
audio	O
and	O
video	O
streams	O
may	O
have	O
variable	B-General_Concept
bit	I-General_Concept
rate	I-General_Concept
.	O
</s>
<s>
Software	O
that	O
produces	O
such	O
a	O
transport	O
stream	O
and/or	O
container	O
is	O
commonly	O
called	O
a	O
multiplexer	B-Protocol
or	O
muxer	B-Architecture
.	O
</s>
<s>
A	O
demuxer	B-Architecture
is	O
software	O
that	O
extracts	O
or	O
otherwise	O
makes	O
available	O
for	O
separate	O
processing	O
the	O
components	O
of	O
such	O
a	O
stream	O
or	O
container	O
.	O
</s>
<s>
In	O
digital	B-Application
television	I-Application
systems	O
,	O
several	O
variable	B-General_Concept
bit-rate	I-General_Concept
data	O
streams	O
are	O
multiplexed	B-Architecture
together	O
to	O
a	O
fixed	O
bit	O
rate	O
transport	O
stream	O
by	O
means	O
of	O
statistical	B-Algorithm
multiplexing	I-Algorithm
.	O
</s>
<s>
This	O
may	O
involve	O
several	O
standard-definition	B-Device
television	I-Device
(	O
SDTV	B-Device
)	O
programmes	O
(	O
particularly	O
on	O
DVB-T	O
,	O
DVB-S2	O
,	O
ISDB	B-Protocol
and	O
ATSC-C	O
)	O
,	O
or	O
one	O
HDTV	B-Device
,	O
possibly	O
with	O
a	O
single	O
SDTV	B-Device
companion	O
channel	O
over	O
one	O
6	O
to	O
8MHz-wide	O
TV	O
channel	O
.	O
</s>
<s>
The	O
device	O
that	O
accomplishes	O
this	O
is	O
called	O
a	O
statistical	O
multiplexer	B-Protocol
.	O
</s>
<s>
In	O
several	O
of	O
these	O
systems	O
,	O
the	O
multiplexing	B-Architecture
results	O
in	O
an	O
MPEG	O
transport	O
stream	O
.	O
</s>
<s>
The	O
newer	O
DVB	O
standards	O
DVB-S2	O
and	O
DVB-T2	B-Protocol
has	O
the	O
capacity	O
to	O
carry	O
several	O
HDTV	B-Device
channels	O
in	O
one	O
multiplex	O
.	O
</s>
<s>
On	O
communications	O
satellites	O
which	O
carry	O
broadcast	B-Operating_System
television	O
networks	O
and	O
radio	O
networks	O
,	O
this	O
is	O
known	O
as	O
multiple	O
channel	O
per	O
carrier	O
or	O
MCPC	O
.	O
</s>
<s>
Where	O
multiplexing	B-Architecture
is	O
not	O
practical	O
(	O
such	O
as	O
where	O
there	O
are	O
different	O
sources	O
using	O
a	O
single	O
transponder	B-Architecture
)	O
,	O
single	O
channel	O
per	O
carrier	O
mode	O
is	O
used	O
.	O
</s>
<s>
In	O
FM	O
broadcasting	B-Operating_System
and	O
other	O
analog	O
radio	O
media	O
,	O
multiplexing	B-Architecture
is	O
a	O
term	O
commonly	O
given	O
to	O
the	O
process	O
of	O
adding	O
subcarriers	O
to	O
the	O
audio	O
signal	O
before	O
it	O
enters	O
the	O
transmitter	O
,	O
where	O
modulation	B-Application
occurs	O
.	O
</s>
<s>
(	O
In	O
fact	O
,	O
the	O
stereo	O
multiplex	O
signal	O
can	O
be	O
generated	O
using	O
time-division	B-Protocol
multiplexing	I-Protocol
,	O
by	O
switching	O
between	O
the	O
two	O
(	O
left	O
channel	O
and	O
right	O
channel	O
)	O
input	O
signals	O
at	O
an	O
ultrasonic	O
rate	O
(	O
the	O
subcarrier	O
)	O
,	O
and	O
then	O
filtering	O
out	O
the	O
higher	O
harmonics	O
.	O
)	O
</s>
<s>
Multiplexing	B-Architecture
in	O
this	O
sense	O
is	O
sometimes	O
known	O
as	O
MPX	O
,	O
which	O
in	O
turn	O
is	O
also	O
an	O
old	O
term	O
for	O
stereophonic	O
FM	O
,	O
seen	O
on	O
stereo	O
systems	O
since	O
the	O
1960s	O
.	O
</s>
<s>
In	O
spectroscopy	O
the	O
term	O
is	O
used	O
to	O
indicate	O
that	O
the	O
experiment	O
is	O
performed	O
with	O
a	O
mixture	O
of	O
frequencies	O
at	O
once	O
and	O
their	O
respective	O
response	O
unravelled	O
afterwards	O
using	O
the	O
Fourier	B-Algorithm
transform	I-Algorithm
principle	O
.	O
</s>
<s>
In	O
computer	B-General_Concept
programming	I-General_Concept
,	O
it	O
may	O
refer	O
to	O
using	O
a	O
single	O
in-memory	O
resource	O
(	O
such	O
as	O
a	O
file	O
handle	O
)	O
to	O
handle	O
multiple	O
external	O
resources	O
(	O
such	O
as	O
on-disk	O
files	O
)	O
.	O
</s>
<s>
Some	O
electrical	O
multiplexing	B-Architecture
techniques	O
do	O
not	O
require	O
a	O
physical	O
"	O
multiplexer	B-Protocol
"	O
device	O
,	O
they	O
refer	O
to	O
a	O
"	O
keyboard	O
matrix	O
"	O
or	O
"	O
Charlieplexing	O
"	O
design	O
style	O
:	O
</s>
<s>
Multiplexing	B-Architecture
may	O
refer	O
to	O
the	O
design	O
of	O
a	O
multiplexed	B-General_Concept
display	I-General_Concept
(	O
non-multiplexed	O
displays	O
are	O
immune	O
to	O
break	O
up	O
)	O
.	O
</s>
<s>
Multiplexing	B-Architecture
may	O
refer	O
to	O
the	O
design	O
of	O
a	O
"	O
switch	O
matrix	O
"	O
(	O
non-multiplexed	O
buttons	O
are	O
immune	O
to	O
"	O
phantom	O
keys	O
"	O
and	O
also	O
immune	O
to	O
"	O
phantom	O
key	O
blocking	O
"	O
)	O
.	O
</s>
