<s>
Digital	B-Device
Satellite	I-Device
System	I-Device
is	O
the	O
initialism	O
expansion	O
of	O
the	O
DSS	O
digital	O
satellite	O
television	O
transmission	O
system	O
used	O
by	O
DirecTV	O
.	O
</s>
<s>
Only	O
when	O
digital	O
transmission	O
was	O
introduced	O
did	O
direct	O
broadcast	O
satellite	O
(	O
DBS	O
)	O
television	O
become	O
popular	O
in	O
North	O
America	O
,	O
which	O
has	O
led	O
to	O
both	O
DBS	O
and	O
DSS	O
being	O
used	O
interchangeably	O
to	O
refer	O
to	O
all	O
three	O
commonplace	O
digital	O
transmission	O
formats	O
-	O
DSS	O
,	O
DVB-S	O
and	O
4DTV	B-Device
.	O
</s>
<s>
At	O
the	O
time	O
of	O
DirecTV	O
's	O
launch	O
in	O
1994	O
,	O
the	O
DVB-S	O
digital	B-Device
satellite	I-Device
system	I-Device
in	O
use	O
in	O
the	O
majority	O
of	O
the	O
world	O
had	O
not	O
yet	O
been	O
standardised	O
,	O
the	O
Thomson	O
developed	O
DSS	O
system	O
was	O
used	O
instead	O
.	O
</s>
<s>
While	O
functionally	O
similar	O
in	O
DVB-S	O
–	O
MPEG	B-Algorithm
2	I-Algorithm
video	O
,	O
MPEG-1	O
Layer	O
II	O
or	O
AC3	O
audio	O
,	O
QPSK	O
modulation	O
,	O
and	O
identical	O
error	O
correction	O
(	O
Reed	B-Error_Name
–	I-Error_Name
Solomon	I-Error_Name
coding	I-Error_Name
and	O
Viterbi	O
forward	B-Error_Name
error	I-Error_Name
correction	I-Error_Name
)	O
,	O
the	O
transport	O
stream	O
and	O
information	O
tables	O
are	O
entirely	O
different	O
from	O
those	O
of	O
DVB	O
.	O
</s>
<s>
DirecTV	O
is	O
now	O
using	O
a	O
modified	O
version	O
of	O
DVB-S2	O
,	O
the	O
latest	O
version	O
of	O
the	O
DVB-S	O
protocol	O
,	O
for	O
HDTV	B-Device
services	O
off	O
the	O
SPACEWAY-1	O
,	O
SPACEWAY-2	O
,	O
DirecTV-10	O
and	O
DirecTV-11	O
satellites	O
;	O
however	O
,	O
huge	O
numbers	O
of	O
DSS	O
encoded	O
channels	O
still	O
remain	O
.	O
</s>
