<s>
Cellular	B-Protocol
frequencies	I-Protocol
are	O
the	O
sets	O
of	O
frequency	O
ranges	O
within	O
the	O
ultra	O
high	O
frequency	O
band	O
that	O
have	O
been	O
assigned	O
for	O
cellular-compatible	O
mobile	B-Application
devices	I-Application
,	O
such	O
as	O
mobile	O
phones	O
,	O
to	O
connect	O
to	O
cellular	O
networks	O
.	O
</s>
<s>
Most	O
mobile	O
networks	O
worldwide	O
use	O
portions	O
of	O
the	O
radio	O
frequency	O
spectrum	O
,	O
allocated	B-Algorithm
to	O
the	O
mobile	O
service	O
,	O
for	O
the	O
transmission	O
and	O
reception	O
of	O
their	O
signals	O
.	O
</s>
<s>
Some	O
European	O
countries	O
(	O
and	O
Japan	O
)	O
adopted	O
TACS	B-Protocol
operating	O
in	O
900MHz	O
.	O
</s>
<s>
Initially	O
,	O
systems	O
based	O
upon	O
the	O
AMPS	O
mobile	O
phone	O
model	O
were	O
popular	O
,	O
including	O
IS-95	O
(	O
often	O
known	O
as	O
"	O
CDMA	B-Protocol
"	O
,	O
the	O
air	O
interface	O
technology	O
it	O
uses	O
)	O
and	O
IS-136	O
(	O
often	O
known	O
as	O
D-AMPS	O
,	O
Digital	O
AMPS	O
,	O
or	O
"	O
TDMA	O
"	O
,	O
the	O
air	O
interface	O
technology	O
it	O
uses	O
)	O
.	O
</s>
<s>
In	O
Russia	O
and	O
some	O
other	O
countries	O
,	O
local	O
carriers	O
received	O
licenses	O
for	O
450MHz	O
frequency	O
to	O
provide	O
CDMA	B-Protocol
mobile	O
coverage	O
area	O
.	O
</s>
