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The scrambler module is composed of two components:
•
SCS
–
a software component responsible for managing the interfaces used by external ECMG, EMMI, and
EIS services.
•
SCR
–
a hardware component responsible for encryption (DVB-CSA or AES) of the services.
The functional diagram below shows these components and their relations with the rest of the system.
The SCS module is the master of the scrambling system. It is aware of the ECMG and the scrambler module.
Upon configuration, the SCS card generates a CW, sends it to the ECMG, which returns the ECM. The SCS then
sends the CW to the hardware component scrambling the live content and transfers the ECM to the correct
output card for playout.
Before it is possible to define an output stream with the scrambling properties it is necessary to define the ECM
generator, as the SCS needs to know where to contact the encryption system. Next step is to define an ECM. The
ECM definition associates a CW id and access criteria. The output can now be defined and scrambled. When
configuring the output to be scrambled the ECM selection list implicitly represents the CW and access criteria
while the scrambler indicates the scrambler card.
6.4.1
S
CRAMBLER
M
ODULE
C
ONFIGURATION
The scrambler module runs both the SCS functionality and the scrambler functionality on one single card. The
Scrambler supports both the DVB-CSA and AES scrambling algorithms
–
but only one at a time
DVB-CSA supports the 64-bit and 48-bit entropy algorithm. In order to enable Scrambling algorithm, user needs
to choose either "DVB CSA (48-bit Entropy)" or "DVB CSA (64-bit entropy)".
The scrambler card supports up to 250 scrambled services, with a maximum total bitrate of 850Mbps.
An overview of the scramblers present in the unit is available in the
Conditional Access
node
in the
Navigation
Tree
.
