<s>
DigiCipher	B-Device
2	I-Device
,	O
or	O
simply	O
DCII	O
,	O
is	O
a	O
proprietary	O
standard	O
format	O
of	O
digital	O
signal	O
transmission	O
and	O
it	O
doubles	O
as	O
an	O
encryption	O
standard	O
with	O
MPEG-2/MPEG	O
-4	O
signal	O
video	O
compression	O
used	O
on	O
many	O
communications	O
satellite	O
television	O
and	O
audio	O
signals	O
.	O
</s>
<s>
The	O
DCII	O
standard	O
was	O
originally	O
developed	O
in	O
1997	O
by	O
General	O
Instrument	O
,	O
which	O
then	O
became	O
the	O
Home	O
and	O
Network	O
Mobility	O
division	O
of	O
Motorola	O
,	O
then	O
bought	O
by	O
Google	B-Application
in	O
Aug	O
2011	O
,	O
and	O
lastly	O
became	O
the	O
Home	O
portion	O
of	O
the	O
division	O
to	O
Arris	O
.	O
</s>
<s>
The	O
original	O
attempt	O
for	O
a	O
North	O
American	O
digital	O
signal	O
encryption	O
and	O
compression	O
standard	O
was	O
DigiCipher	B-Device
1	I-Device
,	O
which	O
was	O
used	O
most	O
notably	O
in	O
the	O
now-defunct	O
PrimeStar	O
medium-power	O
direct	O
broadcast	O
satellite	O
(	O
DBS	O
)	O
system	O
during	O
the	O
early	O
1990s	O
.	O
</s>
<s>
The	O
DCII	O
standard	O
predates	O
wide	O
acceptance	O
of	O
DVB-based	O
digital	O
terrestrial	O
television	O
compression	O
(	O
although	O
not	O
cable	O
or	O
satellite	O
DVB	B-Application
)	O
and	O
therefore	O
is	O
incompatible	O
with	O
the	O
DVB	B-Application
standard	O
.	O
</s>
<s>
Approximately	O
70%	O
of	O
newer	O
first-generation	O
digital	B-Device
cable	I-Device
networks	O
in	O
North	O
America	O
use	O
the	O
4DTV/DigiCipher	O
2	O
format	O
.	O
</s>
<s>
The	O
use	O
of	O
DCII	O
is	O
most	O
prevalent	O
in	O
North	O
American	O
digital	B-Device
cable	I-Device
television	I-Device
set-top	O
boxes	O
.	O
</s>
<s>
DCII	O
is	O
also	O
used	O
on	O
Motorola	O
's	O
4DTV	B-Device
digital	O
satellite	O
television	O
tuner	O
and	O
Shaw	O
Direct	O
's	O
DBS	O
receiver	O
.	O
</s>
<s>
The	O
DigiCipher	B-Device
2	I-Device
encryption	O
standard	O
was	O
reverse	O
engineered	O
in	O
2016	O
.	O
</s>
<s>
DigiCipher	B-Device
II	I-Device
uses	O
QPSK	O
and	O
BPSK	O
at	O
the	O
same	O
time	O
.	O
</s>
<s>
The	O
primary	O
difference	O
between	O
DigiCipher	B-Device
2	I-Device
and	O
DVB	B-Application
lies	O
in	O
how	O
each	O
standard	O
handles	O
SI	O
metadata	O
,	O
or	O
System	O
Information	O
,	O
where	O
DVB	B-Application
reserves	O
packet	O
identifiers	O
from	O
16	O
to	O
31	O
for	O
metadata	O
,	O
DigiCipher	B-Device
reserves	O
only	O
packet	O
identifier	O
8187	O
for	O
its	O
master	B-Device
guide	I-Device
table	I-Device
which	O
acts	O
as	O
a	O
look-up	O
table	O
for	O
all	O
other	O
metadata	O
tables	O
.	O
</s>
<s>
DigiCipher	B-Device
2	I-Device
also	O
extends	O
the	O
MPEG	O
program	O
number	O
that	O
is	O
assigned	O
for	O
each	O
service	O
in	O
a	O
transport	O
stream	O
with	O
the	O
concept	O
of	O
a	O
virtual	B-Protocol
channel	I-Protocol
number	O
,	O
whereas	O
the	O
DVB	B-Application
system	O
never	O
defined	O
this	O
type	O
of	O
remapping	O
preferring	O
to	O
use	O
a	O
registry	O
of	O
network	O
identifiers	O
to	O
further	O
differentiate	O
program	O
numbers	O
from	O
those	O
used	O
in	O
other	O
transport	O
streams	O
.	O
</s>
<s>
There	O
are	O
also	O
private	O
non-standard	O
additions	O
to	O
DVB	B-Application
that	O
add	O
virtual	B-Protocol
channel	I-Protocol
remapping	O
using	O
logical	O
channel	O
numbers	O
.	O
</s>
<s>
Also	O
unlike	O
DVB	B-Application
,	O
all	O
text	O
used	O
in	O
descriptors	O
can	O
be	O
compressed	O
using	O
standard	O
Huffman	B-General_Concept
coding	I-General_Concept
which	O
saves	O
on	O
broadcast	O
bandwidth	O
and	O
loading	O
times	O
.	O
</s>
<s>
DigiCipher	B-Device
II	I-Device
uses	O
Dolby	O
Digital	O
AC-3	O
audio	O
for	O
all	O
channels	O
,	O
although	O
MPEG-1	O
Level	O
2	O
audio	O
is	O
not	O
supported	O
.	O
</s>
