DVB-S/S2 with 5% ROF
Spectral efficiency boost without changing legacy headend equipment
The DVB-S standard for satellite transmission still plays a major role in the Direct-to-Home (DTH) satellite TV industry. Millions of deployed DTH set-top boxes (STBs) still use satellite transmission technologies based on the DVB-S waveform to broadcast more than 30,000 TV channels.
Boosting spectral efficiency to enable more TV channels per MHz often means upgrading all installed STBs for compatibility with newer standards such as DVB-S2/S2X, requiring substantial investment.
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ROF limitations of DVB-S
The DVB-S standard specifies a single Roll-Off Factor of 35%. The DVB-S2 standard specifies Roll-Off Factors as low as 20%. With a simple OTA software upgrade, SatExpander modulators and modems can support DVB-S/S2 waveforms with 5% Roll-Off Factor.
Once implemented, you will experience an increase in capacity or, alternatively, you will be able to transmit the same data traffic using less bandwidth. And you can achieve this efficiency boost without the need to replace legacy Head End equipment (STB/IRDs), and without affecting your transmit/receive link budget.
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Up to 28% spectral efficiency gain
Low ROF (5% instead of 35%) can boost spectral efficiency by as much as 28%, compared with standard DVB-S, in both single carrier and multiple carrier modes of operation. In Single Carrier Mode (Full Transponder):
Broadcast Applications – Additional TV Content
Data Applications – More bits per Second
No Need to replace legacy head end equipment (STB/IRDs)
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Receive side STB/IRD should be able to support ~35Msps for maximum spectral efficiency gain. IRDs/STBs that support a lower symbol rate (< 35Msps) can still benefit from improved spectral efficiency.
Up to 20% in bandwidth savings
When your goal is to reduce OPEX or to free up bandwidth for additional carriers, DVB-S with 5% ROF support from SatExpander can deliver up to 20% in bandwidth savings.
​Even in Multiple Carrier mode, where low ROF can cause ACI (Adjacent Carrier Interference), potentially reducing signal quality in adjacent carriers, SatExpander tests show that ACI is a minor factor. DVB-S with 5% ROF still delivers significant benefits in multiple carrier conditions.
DVB-S2 with 5% ROF
As DVB-S2 standard minimal ROF is 20%, the same conditions and motivation described above for DVB-S with 5% ROF apply as well, although with lower relative efficiency gain.