<s>
In	O
telecommunication	O
,	O
a	O
digital	B-Protocol
transmission	I-Protocol
group	I-Protocol
is	O
a	O
group	O
of	O
digitized	O
voice	O
or	O
data	O
channels	O
or	O
both	O
with	O
bit	O
streams	O
that	O
are	O
combined	O
into	O
a	O
single	O
digital	B-General_Concept
bit	O
stream	O
for	O
transmission	O
over	O
communications	O
media	O
.	O
</s>
<s>
Digital	B-Protocol
transmission	I-Protocol
groups	I-Protocol
usually	O
are	O
categorized	O
by	O
their	O
maximum	O
capacity	O
,	O
not	O
by	O
a	O
specific	O
number	O
of	O
channels	O
.	O
</s>
<s>
However	O
,	O
the	O
maximum	O
digital	B-Protocol
transmission	I-Protocol
group	I-Protocol
capacity	O
must	O
be	O
equal	O
to	O
or	O
greater	O
than	O
the	O
sum	O
of	O
the	O
individual	O
multiplexer	B-Protocol
input	O
channel	O
capacities	O
.	O
</s>
