<s>
Each	O
type	O
of	O
radio	O
emission	O
is	O
classified	O
according	O
to	O
its	O
bandwidth	B-Algorithm
,	O
method	O
of	O
modulation	B-Application
,	O
nature	O
of	O
the	O
modulating	B-Application
signal	I-Application
,	O
and	O
type	O
of	O
information	O
transmitted	O
on	O
the	O
carrier	O
signal	O
.	O
</s>
<s>
An	O
emission	O
designation	O
is	O
of	O
the	O
form	O
BBBB	O
123	O
45	O
,	O
where	O
BBBB	O
is	O
the	O
bandwidth	B-Algorithm
of	O
the	O
signal	O
,	O
1	O
is	O
a	O
letter	O
indicating	O
the	O
type	O
of	O
modulation	B-Application
used	O
of	O
the	O
main	O
carrier	O
(	O
not	O
including	O
any	O
subcarriers	O
which	O
is	O
why	O
FM	B-Application
stereo	O
is	O
F8E	O
and	O
not	O
D8E	O
)	O
,	O
2	O
is	O
a	O
digit	O
representing	O
the	O
type	O
of	O
modulating	B-Application
signal	I-Application
again	O
of	O
the	O
main	O
carrier	O
,	O
3	O
is	O
a	O
letter	O
corresponding	O
to	O
the	O
type	O
of	O
information	O
transmitted	O
,	O
4	O
is	O
a	O
letter	O
indicating	O
the	O
practical	O
details	O
of	O
the	O
transmitted	O
information	O
,	O
and	O
5	O
is	O
a	O
letter	O
that	O
represents	O
the	O
method	O
of	O
multiplexing	B-Architecture
.	O
</s>
<s>
The	O
bandwidth	B-Algorithm
(	O
BBBB	O
above	O
)	O
is	O
expressed	O
as	O
four	O
characters	O
:	O
three	O
digits	O
and	O
one	O
letter	O
.	O
</s>
<s>
The	O
letter	O
occupies	O
the	O
position	O
normally	O
used	O
for	O
a	O
decimal	O
point	O
,	O
and	O
indicates	O
what	O
unit	O
of	O
frequency	O
is	O
used	O
to	O
express	O
the	O
bandwidth	B-Algorithm
.	O
</s>
<s>
Character	O
Description	O
A	O
Double-sideband	O
amplitude	B-Device
modulation	I-Device
(	O
e.g.	O
</s>
<s>
AM	O
broadcast	O
radio	O
)	O
B	O
Independent	B-Device
sideband	I-Device
(	O
two	O
sidebands	O
containing	O
different	O
signals	O
)	O
C	O
Vestigial	O
sideband	O
(	O
e.g.	O
</s>
<s>
NTSC	O
)	O
D	O
Combination	O
of	O
AM	O
and	O
FM	B-Application
or	O
PM	O
F	O
Frequency	B-Application
modulation	I-Application
(	O
e.g.	O
</s>
<s>
FM	B-Application
broadcast	O
radio	O
)	O
G	O
Phase	B-Device
modulation	I-Device
H	O
Single-sideband	B-Device
modulation	I-Device
with	O
full	O
carrier	O
(	O
e.g.	O
</s>
<s>
as	O
used	O
by	O
CHU	O
)	O
J	O
Single-sideband	B-Device
with	I-Device
suppressed	I-Device
carrier	I-Device
(	O
e.g.	O
</s>
<s>
Shortwave	O
utility	O
and	O
amateur	O
stations	O
)	O
K	O
Pulse-amplitude	B-Device
modulation	I-Device
L	O
Pulse-width	B-Algorithm
modulation	I-Algorithm
(	O
e.g.	O
</s>
<s>
F8E	O
,	O
F8EH	O
FM	B-Application
broadcasting	O
for	O
radio	O
transmissions	O
on	O
VHF	B-Algorithm
,	O
and	O
as	O
the	O
audio	O
component	O
of	O
analogue	O
television	O
transmissions	O
.	O
</s>
<s>
11K2F3E	O
Narrow	O
FM	B-Application
,	O
11.25kHz	O
bandwidth	B-Algorithm
,	O
±	O
2.5kHz	O
deviation	O
In	O
the	O
United	O
States	O
,	O
all	O
Part90	O
Land	O
Mobile	O
Radio	O
Service	O
(	O
LMRS	O
)	O
users	O
operating	O
above	O
50MHz	O
were	O
required	O
to	O
upgrade	O
to	O
narrowband	O
equipment	O
by	O
1January	O
2013	O
.	O
</s>
<s>
R3E	O
SSB	B-Device
with	O
reduced	B-Device
carrier	I-Device
(	O
AME	B-Device
)	O
speech	O
communication	O
,	O
primarily	O
used	O
on	O
HF	B-Algorithm
bands	O
by	O
the	O
military	O
(	O
a.k.a.	O
</s>
<s>
N0N	O
Continuous	O
,	O
unmodulated	O
carrier	O
,	O
formerly	O
common	O
for	O
radio	B-Device
direction	I-Device
finding	I-Device
(	O
RDF	O
)	O
in	O
marine	O
and	O
aeronautical	B-Algorithm
navigation	O
.	O
</s>
<s>
Continuous	O
Wave	O
(	O
CW	O
)	O
or	O
On-Off	B-Device
Keying	I-Device
(	O
OOK	O
)	O
,	O
currently	O
used	O
in	O
amateur	O
radio	O
.	O
</s>
<s>
A2A	O
Signalling	O
by	O
transmitting	O
a	O
modulated	B-Application
tone	O
with	O
a	O
carrier	O
,	O
so	O
that	O
it	O
can	O
easily	O
be	O
heard	O
using	O
an	O
ordinary	O
AM	O
receiver	O
.	O
</s>
<s>
It	O
was	O
formerly	O
widely	O
used	O
for	O
station	O
identification	O
of	O
non-directional	O
beacons	O
,	O
usually	O
but	O
not	O
exclusively	O
Morse	O
code	O
(	O
an	O
example	O
of	O
a	O
modulated	B-Application
continuous	O
wave	O
,	O
as	O
opposed	O
to	O
A1A	O
,	O
above	O
)	O
.	O
</s>
<s>
F1B	B-Device
Frequency-shift	O
keying	O
(	O
FSK	O
)	O
telegraphy	O
,	O
such	O
as	O
RTTY	O
.	O
</s>
<s>
F2D	O
Data	O
transmission	O
by	O
frequency	B-Application
modulation	I-Application
of	O
a	O
radio	O
frequency	O
carrier	O
with	O
an	O
audio	O
frequency	O
FSK	O
subcarrier	O
.	O
</s>
<s>
Often	O
called	O
AFSK/FM	O
.	O
</s>
