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Overview • Operating Modes
APEX1000 All-Purpose Edge QAM Software Version 2.4.x • Installation and Operation Manual
15
573408-001-a
Switched Digital Video
Switched Digital Video (SDV) is a system feature that allows channels on the broadcast
line-up to be dynamically switched on and off the HFC network as a function of real time
subscriber viewing, such as
channel changes
. In an SDV environment, channels that are
not being watched by any subscribers on a given segment of the HFC network (in a
given
service group
) can be temporarily removed from the HFC network to make room
for other channels that subscribers
do
want to watch. In a network which is properly
working, SDV channels and traditional broadcast (linear) channels are indistinguishable to
the subscriber. However, using SDV, an MSO can offer a given set of channels that use
half (or less) of the HFC bandwidth, as compared to the linear broadcast method.
As previously discussed in
, there are also two major industry
architectures that address SDV,
RPC
and
RTSP
.
RPC Mode SDV
The figure below illustrates the RPC Mode SDV architecture:
TWC
Conductor
Network
Encryptor
DAC
IP/GigE
Switch
Router
APEX
GSRM
CCMIS
(via ALOHA
or DOCSIS)
SDV
Manager
STB Client
(Core or
Advanced)
EPG Data Carousel (via DSG or ALOHA)
RDS
I/F
SSP-SIS
IGMPv3
Joins
MPEG via
UDP/IP/GigE
MCMIS
MCMIS
MPEG
over
QAM
DAC to
Conductor I/F
SDV
Rate
Clamp
IP/GigE
Switch
Router
SDV Server/Edge
(EDIS_SDV)
GSRM/Edge
(EDIS_Edge)
MPEG over GigE
Central Location (i.e. Headend) Remote Location (i.e. Hub)
MPEG over QAM
MPEG over various transports/media
Control Signaling
MCMIS
(Mini Carousel)
Content
Distribution
(typically GigE
over DWDM)
Note: Shown with Motorola components, as well as the Time Warner Conductor
required to support the TWC guide/SDV client (MDN/ODN) running in the set-top.