<s>
TV	B-Algorithm
band	I-Algorithm
devices	I-Algorithm
or	O
TVBDs	B-Algorithm
are	O
unlicensed	O
radio	O
frequency	O
devices	O
operating	O
in	O
the	O
vacant	O
channels	O
or	O
white	O
spaces	O
between	O
US	O
television	O
channels	O
in	O
the	O
range	O
of	O
54	O
to	O
698MHz	O
.	O
</s>
<s>
A	O
Mode	O
I	O
TVBD	B-Algorithm
is	O
portable	B-Application
device	I-Application
that	O
does	O
not	O
have	O
an	O
internal	O
geolocation	O
capability	O
and	O
access	O
to	O
a	O
database	O
of	O
channels	O
in	O
use	O
.	O
</s>
<s>
A	O
Mode	O
II	O
TVBD	B-Algorithm
is	O
a	O
portable	B-Application
device	I-Application
that	O
does	O
have	O
internal	O
geo-location	O
capabilities	O
and	O
can	O
access	O
a	O
database	O
of	O
channels	O
in	O
use	O
.	O
</s>
<s>
A	O
Fixed	O
device	O
is	O
a	O
TVBD	B-Algorithm
at	O
a	O
fixed	O
location	O
whose	O
geo-graphic	O
coordinates	O
have	O
been	O
determined	O
by	O
an	O
internal	O
geo-location	O
capability	O
or	O
by	O
a	O
professional	O
installer	O
.	O
</s>
<s>
A	O
Sensing-only	O
device	O
is	O
a	O
TVBD	B-Algorithm
that	O
determines	O
which	O
channels	O
are	O
available	O
by	O
monitoring	O
for	O
activity	O
.	O
</s>
<s>
A	O
sensing-only	O
device	O
must	O
vacate	O
a	O
channel	O
within	O
two	O
seconds	O
of	O
detecting	O
non-TVBD	O
activity	O
.	O
</s>
<s>
All	O
TVBDs	B-Algorithm
must	O
incorporate	O
a	O
feature	O
to	O
reduce	O
transmitted	O
power	O
to	O
the	O
minimum	O
level	O
necessary	O
to	O
maintain	O
successful	O
communication	O
.	O
</s>
