<s>
Wireless	B-General_Concept
Multimedia	I-General_Concept
Extensions	I-General_Concept
(	O
WME	O
)	O
,	O
also	O
known	O
as	O
Wi-Fi	B-General_Concept
Multimedia	I-General_Concept
(	O
WMM	O
)	O
,	O
is	O
a	O
Wi-Fi	O
Alliance	O
interoperability	O
certification	O
,	O
based	O
on	O
the	O
IEEE	O
802.11e	O
standard	O
.	O
</s>
<s>
It	O
is	O
suitable	O
for	O
well-defined	O
applications	O
that	O
require	O
QoS	O
,	O
such	O
as	O
Voice	B-Application
over	I-Application
IP	I-Application
(	O
VoIP	B-Application
)	O
on	O
Wi-Fi	O
phones	O
(	O
VoWLAN	B-Protocol
)	O
.	O
</s>
<s>
EDCF	O
,	O
according	O
to	O
version	O
1.1	O
of	O
the	O
WMM	O
specifications	O
by	O
the	O
Wi-Fi	O
Alliance	O
,	O
defines	O
Access	O
Categories	O
labels	O
AC_VO	O
,	O
AC_VI	O
,	O
AC_BE	O
,	O
and	O
AC_BK	O
for	O
the	O
Enhanced	O
Distributed	O
Channel	O
Access	O
(	O
EDCA	O
)	O
parameters	O
that	O
are	O
used	O
by	O
a	O
WMM-enabled	O
station	O
to	O
control	O
how	O
long	O
it	O
sets	O
its	O
Transmission	O
Opportunity	O
(	O
TXOP	O
)	O
,	O
according	O
to	O
the	O
information	O
transmitted	O
by	O
the	O
access	B-Device
point	I-Device
to	O
the	O
station	O
.	O
</s>
<s>
The	O
underlying	O
concept	O
of	O
WMM	O
PowerSave	O
is	O
that	O
the	O
station	O
(	O
STA	O
)	O
triggers	O
the	O
release	O
of	O
buffered	O
data	O
from	O
the	O
access	B-Device
point	I-Device
(	O
AP	O
)	O
by	O
sending	O
an	O
uplink	O
data	B-Protocol
frame	I-Protocol
.	O
</s>
<s>
a	O
receipt	O
of	O
a	O
data	B-Protocol
frame	I-Protocol
corresponding	O
to	O
the	O
queue	O
acts	O
as	O
trigger	O
)	O
,	O
and	O
delivery	O
enabled	O
,	O
(	O
i.e.	O
</s>
