<s>
Multi-Band	B-Language
Excitation	I-Language
(	O
MBE	O
)	O
is	O
a	O
series	O
of	O
proprietary	O
speech	B-Application
coding	I-Application
standards	O
developed	O
by	O
Digital	O
Voice	O
Systems	O
,	O
Inc	O
.	O
(	O
DVSI	O
)	O
.	O
</s>
<s>
This	O
work	O
gave	O
a	O
start	O
to	O
development	O
of	O
the	O
"	O
multi-band	B-Language
excitation	I-Language
"	O
method	O
of	O
speech	B-Application
coding	I-Application
,	O
that	O
was	O
patented	O
in	O
1997	O
(	O
now	O
expired	O
)	O
by	O
founders	O
of	O
DVSI	O
as	O
"	O
Multi-Band	B-Language
Excitation	I-Language
"	O
(	O
MBE	O
)	O
.	O
</s>
<s>
All	O
consequent	O
improvements	O
known	O
as	O
Improved	O
Multi-Band	B-Language
Excitation	I-Language
(	O
IMBE	O
)	O
,	O
Advanced	O
Multiband	O
Excitation	O
(	O
AMBE	O
)	O
,	O
AMBE+	O
and	O
AMBE+2	B-Language
are	O
based	O
on	O
this	O
MBE	O
method	O
.	O
</s>
<s>
AMBE	O
is	O
a	O
codebook-based	O
vocoder	B-Application
that	O
operates	O
at	O
bitrates	O
of	O
between	O
2	O
and	O
9.6kbit/s	O
,	O
and	O
at	O
a	O
sampling	O
rate	O
of	O
8kHz	O
in	O
20-ms	O
frames	O
.	O
</s>
<s>
The	O
audio	O
data	O
is	O
usually	O
combined	O
with	O
up	O
to	O
7bit/s	O
of	O
forward	B-Error_Name
error	I-Error_Name
correction	I-Error_Name
data	O
,	O
producing	O
a	O
total	O
RF	O
bandwidth	O
of	O
approximately	O
2,250	O
Hz	O
(	O
compared	O
to	O
2,700	O
–	O
3,000	O
Hz	O
for	O
an	O
analogue	O
single	O
sideband	O
transmission	O
)	O
.	O
</s>
<s>
AMBE	O
is	O
used	O
by	O
the	O
Inmarsat	O
and	O
Iridium	O
satellite	O
telephony	O
systems	O
and	O
certain	O
channels	O
on	O
XM	O
Satellite	O
Radio	O
and	O
is	O
the	O
speech	B-Application
coder	I-Application
for	O
OpenSky	O
Trunked	O
radio	O
systems	O
.	O
</s>
<s>
AMBE	O
is	O
used	O
in	O
D-STAR	B-Protocol
amateur	O
radio	O
digital	O
voice	O
communications	O
.	O
</s>
<s>
The	O
NXDN	O
digital	O
voice	O
and	O
data	O
protocol	O
uses	O
the	O
AMBE+2	B-Language
codec	O
.	O
</s>
<s>
APCO	O
Project	O
25	O
Phase	O
2	O
trunked	O
radio	O
systems	O
also	O
use	O
the	O
AMBE+2	B-Language
codec	O
,	O
while	O
older	O
Phase	O
1	O
radios	O
such	O
as	O
the	O
Motorola	O
XTL	O
and	O
XTS	O
series	O
use	O
the	O
earlier	O
IMBE	O
codec	O
.	O
</s>
<s>
Newer	O
Phase	O
1	O
capable	O
radios	O
such	O
as	O
the	O
APX	O
series	O
radios	O
use	O
the	O
AMBE+2	B-Language
codec	O
,	O
which	O
is	O
backwards	O
compatible	O
with	O
Phase	O
1	O
.	O
</s>
<s>
Digital	O
Mobile	O
Radio	O
(	O
DMR	O
)	O
and	O
Motorola	O
's	O
MOTOTRBO	O
use	O
the	O
AMBE+2	B-Language
codec	O
.	O
</s>
<s>
For	O
purposes	O
of	O
comparison	O
,	O
licensing	O
fees	O
for	O
use	O
of	O
the	O
MP3	B-Application
standard	O
started	O
at	O
$	O
15,000	O
.	O
</s>
<s>
Codec2	B-Algorithm
is	O
an	O
open	O
source	O
alternative	O
which	O
uses	O
half	O
of	O
the	O
bandwidth	O
of	O
AMBE	O
to	O
encode	O
speech	O
of	O
similar	O
quality	O
,	O
created	O
by	O
David	O
Rowe	O
and	O
lobbied	O
by	O
Bruce	O
Perens	O
.	O
</s>
<s>
Codec2	B-Algorithm
still	O
continues	O
to	O
evolve	O
,	O
with	O
additional	O
"	O
modes	O
"	O
being	O
developed	O
,	O
refined	O
and	O
made	O
available	O
on	O
a	O
continuous	O
basis	O
.	O
</s>
