For wideband transponders that transmit several narrowband carriers, or one or few wideband carriers, the concept of time slicing — as defined in the DVB-S2 standard (EN 302 307-1 Annex M) — allows the receivers to pre-select specified streams already in the physical layer (PL) carrying one or more services. The DVB-S2x standard (EN 302 307-2 Annex E) also specifies a format for time slicing.
For broadcast interactive or professional applications (e.g., IPTV services, direct-to-home (DTH) offerings, occasional use (OU), etc.), which can use a wideband carrier to allow efficient transponder usage, time slicing permits the operation of demodulators with high-speed input processing and standard FEC and output processing.
The conventional DVB-S2 multistream operation also uses multiplexing techniques in the baseband frame layer, but the header of the underlying physical layer only carries information about modulation, coding parameters, and the presence of pilots.
Once the FEC processing is over, the receiver can discard unused data. In time-slicing mode, the PL header contains additional stream-specific information, which supports certain portions of the multiplex at the physical layer processing within the receiver.
Only required information is forwarded to the FEC and output processing. With time slicing, a cost-effective receiver can be realized for wideband applications.
