<s>
In	O
digital	B-Application
video	I-Application
broadcasting	I-Application
(	O
DVB	B-Application
)	O
,	O
a	O
data	B-Device
and	I-Device
object	I-Device
carousel	I-Device
is	O
used	O
for	O
repeatedly	O
delivering	O
data	O
in	O
a	O
continuous	O
cycle	O
.	O
</s>
<s>
An	O
individual	O
object	B-Device
carousel	I-Device
is	O
also	O
called	O
a	O
service	O
domain	O
in	O
some	O
documents	O
.	O
</s>
<s>
To	O
be	O
precise	O
,	O
a	O
service	O
domain	O
is	O
a	O
group	O
of	O
related	O
DSM-CC	B-Algorithm
objects	O
.	O
</s>
<s>
In	O
broadcast	O
systems	O
,	O
there	O
is	O
no	O
difference	O
between	O
an	O
object	B-Device
carousel	I-Device
and	O
a	O
service	O
domain	O
except	O
for	O
the	O
terminology	O
:	O
an	O
object	B-Device
carousel	I-Device
is	O
a	O
service	O
domain	O
,	O
and	O
vice	O
versa	O
.	O
</s>
<s>
Data	B-Device
and	I-Device
object	I-Device
carousels	I-Device
are	O
most	O
commonly	O
used	O
in	O
DVB	B-Application
,	O
which	O
has	O
standards	O
for	O
broadcasting	O
digital	O
television	O
content	O
using	O
carousels	O
.	O
</s>
<s>
The	O
standard	O
format	O
for	O
a	O
carousel	O
is	O
defined	O
in	O
the	O
Digital	O
Storage	O
Media	O
Command	O
and	O
Control	O
(	O
DSM-CC	B-Algorithm
)	O
toolkit	O
in	O
ISO/IEC	O
13818-6	O
and	O
is	O
part	O
of	O
the	O
Digital	O
Audio	O
Video	O
Council	O
(	O
DAVIC	O
)	O
DVB	B-Application
standard	O
for	O
digital	B-Application
video	I-Application
broadcasting	I-Application
.	O
</s>
<s>
The	O
DSM-CC	B-Algorithm
standard	O
specifies	O
two	O
types	O
of	O
carousel	O
,	O
a	O
data	B-Device
carousel	I-Device
and	O
an	O
object	B-Device
carousel	I-Device
.	O
</s>
<s>
The	O
object	B-Device
carousel	I-Device
extends	O
the	O
more	O
limited	O
data	B-Device
carousel	I-Device
and	O
specifies	O
a	O
standard	O
format	O
for	O
representing	O
a	O
file	O
system	O
directory	O
structure	O
comprising	O
a	O
root	O
directory	O
or	O
service	O
gateway	O
and	O
one	O
or	O
more	O
files	O
and	O
directories	O
.	O
</s>
<s>
Files	O
and	O
directories	O
are	O
encapsulated	O
in	O
a	O
DSM-CC	B-Algorithm
object	B-Device
carousel	I-Device
in	O
several	O
layers	O
.	O
</s>
<s>
Objects	O
are	O
encapsulated	O
in	O
modules	O
,	O
which	O
are	O
carried	O
within	O
download	O
data	O
blocks	O
,	O
within	O
DSM-CC	B-Algorithm
sections	O
encoded	O
in	O
MPEG	O
private	O
sections	O
which	O
are	O
assembled	O
from	O
packets	O
.	O
</s>
