<s>
In	O
computer	B-Architecture
networking	I-Architecture
,	O
carrier-sense	B-Protocol
multiple	I-Protocol
access	I-Protocol
with	I-Protocol
collision	I-Protocol
avoidance	I-Protocol
and	I-Protocol
resolution	I-Protocol
using	I-Protocol
priorities	I-Protocol
(	O
CSMA/CARP	B-Protocol
)	O
is	O
a	O
channel	O
access	O
method	O
.	O
</s>
<s>
CSMA/CARP	B-Protocol
is	O
similar	O
in	O
nature	O
to	O
the	O
carrier-sense	O
multiple	O
access	O
with	O
collision	O
detection	O
(	O
CSMA/CD	O
)	O
channel	O
access	O
method	O
used	O
in	O
Ethernet	O
networks	O
,	O
but	O
CSMA/CARP	B-Protocol
provides	O
no	O
detection	O
of	O
network	O
collisions	O
.	O
</s>
<s>
Instead	O
of	O
detecting	O
network	O
collisions	O
,	O
CSMA/CARP	B-Protocol
attempts	O
to	O
avoid	O
collisions	O
by	O
using	O
a	O
system	O
of	O
transmission	O
priorities	O
.	O
</s>
<s>
When	O
a	O
station	O
wants	O
to	O
transmit	O
on	O
a	O
CSMA/CARP	B-Protocol
network	O
it	O
first	O
listens	O
for	O
network	O
traffic	O
and	O
if	O
the	O
medium	O
is	O
clear	O
instead	O
of	O
immediately	O
transmitting	O
as	O
a	O
station	O
would	O
in	O
CSMA/CD	O
it	O
waits	O
a	O
predefined	O
amount	O
of	O
time	O
.	O
</s>
<s>
This	O
waiting	O
period	O
is	O
called	O
the	O
interframe	B-Protocol
spacing	I-Protocol
(	O
IFS	O
)	O
and	O
it	O
varies	O
by	O
the	O
type	O
of	O
data	O
being	O
transmitted	O
.	O
</s>
<s>
This	O
system	O
allows	O
CSMA/CARP	B-Protocol
to	O
avoid	O
many	O
collisions	O
that	O
would	O
occur	O
if	O
it	O
was	O
not	O
used	O
.	O
</s>
<s>
In	O
addition	O
to	O
having	O
a	O
different	O
IFS	O
per	O
priority	O
,	O
a	O
station	O
in	O
a	O
CSMA/CARP	B-Protocol
network	O
will	O
add	O
a	O
"	O
random	O
backoff	O
"	O
to	O
its	O
waiting	O
period	O
,	O
to	O
reduce	O
the	O
collision	O
probability	O
between	O
stations	O
that	O
have	O
to	O
transmit	O
packets	O
in	O
the	O
same	O
priority	O
.	O
</s>
<s>
The	O
ITU-T	B-General_Concept
G.hn	I-General_Concept
standard	O
,	O
which	O
provides	O
high-speed	O
local	O
area	O
networking	O
over	O
existing	O
home	O
wiring	O
(	O
power	O
lines	O
,	O
phone	O
lines	O
and	O
coaxial	O
cables	O
)	O
includes	O
support	O
for	O
CSMA/CARP	B-Protocol
,	O
although	O
only	O
during	O
certain	O
periods	O
of	O
time	O
called	O
"	O
Shared	O
Transmission	O
Opportunities	O
"	O
(	O
STXOP	O
)	O
.	O
</s>
<s>
During	O
the	O
rest	O
of	O
the	O
time	O
,	O
G.hn	B-General_Concept
uses	O
a	O
time-division	O
multiple	O
access	O
channel	O
access	O
method	O
to	O
ensure	O
quality	O
of	O
service	O
.	O
</s>
