User guide

Setting up the SFN Functionality
Note: Reflex, Remote Statistical Multiplexing and Dynamic Remultiplexing are not
affected by the SFN functionality.
The MIPs required for each SFN adapter are supplied by nCC as fully formed
transport stream packets and contain all valid static values for the current configured
SFN modulation mode. The SFN adapter updates all dynamic values within each
MIP as they are inserted into the outgoing transport stream. The insertion of MIPs
within the outgoing transport streams are aperiodic, as defined within ETSI TS 101
191 V1.5.1.
Note: In the MIP received from nCC the periodic flag is set to ‘0’.
The output transport stream bit rate generation of each SFN adapter is frequency
locked to GPS 10 MHz reference (using the MX8400/HWO/GPS Interface Module).
The output transport stream bit rate from each SFN adapter is ETSI EN 300 744
compliant for the configured SFN modulation mode.
Note: ETSI EN 300 744 states the required useful bit rate; 188 byte packet
transport streams.
When 204 byte transport stream packets are required, the design minimizes the
affects of computational rounding errors when generating the required output bit
rate. The output transport stream bit rate is calculated by the MX8400 when
configured for SFN mode of operation.
The modulation parameters are:
• Modulation Index given as number of bits per symbol
• Guard Interval
• Bandwidth in MHz
• FEC
nCC provides the mega-frame size in number of transport stream packets for the
current mode of SFN modulation
H.3 Setting Up the SFN Functionality
H.3.1 MX8400 GPS Card [MX8400/HWO/GPS]
The SFN Adapter functionality contained within the MX8400 Multiplexer obtains its
timing information from An GPS Interface Card (this is a purchasable option –
please contact Customer Services).
Figure H.3 illustrates the nCC Equipment Set up screen for an MX8400 Multiplexer
fitted with various modules. The GPS Interface Module is shown fitted in slot 6.
2/1553-FGC 101 1014 Uen B
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