<s>
G.722	B-Algorithm
is	O
an	O
ITU-T	O
standard	O
7kHz	O
wideband	B-Algorithm
audio	I-Algorithm
codec	B-General_Concept
operating	O
at	O
48	O
,	O
56	O
and	O
64	O
kbit/s	O
.	O
</s>
<s>
Technology	O
of	O
the	O
codec	B-General_Concept
is	O
based	O
on	O
sub-band	O
ADPCM	O
(	O
SB-ADPCM	O
)	O
.	O
</s>
<s>
The	O
corresponding	O
narrow-band	O
codec	B-General_Concept
based	O
on	O
the	O
same	O
technology	O
is	O
G.726	B-Algorithm
.	O
</s>
<s>
G.722	B-Algorithm
provides	O
improved	O
speech	O
quality	O
due	O
to	O
a	O
wider	O
speech	O
bandwidth	O
of	O
50	O
–	O
7000Hz	O
compared	O
to	O
narrowband	O
speech	O
coders	O
like	O
G.711	B-Algorithm
which	O
in	O
general	O
are	O
optimized	O
for	O
POTS	O
wireline	O
quality	O
of	O
300	O
–	O
3400Hz	O
.	O
</s>
<s>
G.722	B-Algorithm
sample	O
audio	O
data	O
at	O
a	O
rate	O
of	O
16kHz	O
(	O
using	O
14	O
bits	O
)	O
,	O
double	O
that	O
of	O
traditional	O
telephony	O
interfaces	O
,	O
which	O
results	O
in	O
superior	O
audio	O
quality	O
and	O
clarity	O
.	O
</s>
<s>
Other	O
ITU-T	O
7kHz	O
wideband	O
codecs	B-General_Concept
include	O
G.722.1	B-Algorithm
and	O
G.722.2	B-Algorithm
.	O
</s>
<s>
These	O
codecs	B-General_Concept
are	O
not	O
variants	O
of	O
G.722	B-Algorithm
and	O
they	O
use	O
different	O
patented	O
compression	O
technologies	O
.	O
</s>
<s>
G.722.1	B-Algorithm
is	O
based	O
on	O
Siren	B-Algorithm
codecs	I-Algorithm
and	O
offers	O
lower	O
bit-rate	O
compressions	O
(	O
24	O
kbit/s	O
or	O
32	O
kbit/s	O
)	O
.	O
</s>
<s>
It	O
uses	O
a	O
modified	O
discrete	O
cosine	O
transform	O
(	O
MDCT	O
)	O
audio	O
coding	O
data	B-General_Concept
compression	I-General_Concept
algorithm	I-General_Concept
.	O
</s>
<s>
A	O
more	O
recent	O
G.722.2	B-Algorithm
,	O
also	O
known	O
as	O
AMR-WB	B-Algorithm
(	O
"	O
Adaptive	O
Multirate	O
Wideband	O
"	O
)	O
is	O
based	O
on	O
ACELP	B-Algorithm
and	O
offers	O
even	O
lower	O
bit-rate	O
compressions	O
(	O
6.6	O
kbit/s	O
to	O
23.85	O
kbit/s	O
)	O
,	O
as	O
well	O
as	O
the	O
ability	O
to	O
quickly	O
adapt	O
to	O
varying	O
compressions	O
as	O
the	O
network	O
topography	O
mutates	O
.	O
</s>
<s>
In	O
the	O
latter	O
case	O
,	O
bandwidth	O
is	O
automatically	O
conserved	O
when	O
network	B-Protocol
congestion	I-Protocol
is	O
high	O
.	O
</s>
<s>
G.722	B-Algorithm
is	O
an	O
ITU	O
standard	O
codec	B-General_Concept
that	O
provides	O
7kHz	O
wideband	B-Algorithm
audio	I-Algorithm
at	O
data	O
rates	O
from	O
48	O
,	O
56	O
and	O
64	O
kbit/s	O
.	O
</s>
<s>
This	O
is	O
useful	O
for	O
voice	B-Application
over	I-Application
IP	I-Application
applications	O
,	O
such	O
as	O
on	O
a	O
local	B-General_Concept
area	I-General_Concept
network	I-General_Concept
where	O
network	O
bandwidth	O
is	O
readily	O
available	O
,	O
and	O
offers	O
a	O
significant	O
improvement	O
in	O
speech	O
quality	O
over	O
older	O
narrowband	O
codecs	B-General_Concept
such	O
as	O
G.711	B-Algorithm
,	O
without	O
an	O
excessive	O
increase	O
in	O
implementation	O
complexity	O
.	O
</s>
<s>
Environments	O
where	O
bandwidth	O
is	O
more	O
constrained	O
may	O
prefer	O
one	O
of	O
the	O
more	O
bitrate-efficient	O
codecs	B-General_Concept
,	O
such	O
as	O
G.722.1	B-Algorithm
(	O
Siren7	O
)	O
or	O
G.722.2	B-Algorithm
(	O
AMR-WB	B-Algorithm
)	O
.	O
</s>
<s>
G.722	B-Algorithm
has	O
also	O
been	O
widely	O
used	O
by	O
radio	O
broadcasters	O
for	O
sending	O
commentary-grade	O
audio	O
over	O
a	O
single	O
56	O
or	O
64	O
kbit/s	O
ISDN	O
B-channel	O
(	O
the	O
least	O
significant	O
bit	O
is	O
dropped	O
on	O
56kb	O
circuits	O
)	O
.	O
</s>
<s>
G.722	B-Algorithm
works	O
by	O
having	O
the	O
inbound	O
voice	O
signal	O
pass	O
through	O
a	O
digital	O
filter	O
that	O
splits	O
the	O
audio	O
signal	O
into	O
0Hz-to-4kHz	O
and	O
4kHz-to-8kHz	O
audio	O
bands	O
.	O
</s>
<s>
G.722	B-Algorithm
VoIP	B-Application
is	O
typically	O
carried	O
in	O
RTP	B-Protocol
payload	O
type	O
9	O
.	O
</s>
<s>
Note	O
that	O
IANA	O
records	O
the	O
clock	O
rate	O
for	O
type	O
9	O
G.722	B-Algorithm
as	O
8kHz	O
(	O
instead	O
of	O
16kHz	O
)	O
,	O
RFC	O
3551	O
clarifies	O
that	O
this	O
is	O
due	O
to	O
a	O
historical	O
error	O
and	O
is	O
retained	O
in	O
order	O
to	O
maintain	O
backward	O
compatibility	O
.	O
</s>
<s>
Whilst	O
G.722	B-Algorithm
allows	O
for	O
bitrates	O
of	O
64	O
,	O
56	O
and	O
48	O
kbit/s	O
,	O
in	O
practice	O
,	O
data	O
is	O
encoded	O
at	O
64	O
kbit/s	O
,	O
with	O
bits	O
from	O
the	O
lower	O
sub-band	O
being	O
used	O
to	O
encode	O
auxiliary	O
data	O
.	O
</s>
