DVB-S2X - S2 Extensions Support

DVB-S2X - S2 Extensions Support

[Αθανάσιος Οικονόμου]

Hi All,

I am not aware if there was a discussion regarding S2X before, so I
would like to hear what are your plans regarding S2X.

There are already several manufacturers with S2X capable receivers and
soon more will follow.

The S2 extensions will bring more code rates and modulations, so I
guess adding those to fe_code_rate and fe_modulation is mandatory.

Something like the following with proper documentation of course.

@@ -313,6 +313,24 @@ enum fe_code_rate {
        FEC_3_5,
        FEC_9_10,
        FEC_2_5,
+       FEC_13_45,
+       FEC_9_20,
+       FEC_11_20,
+       FEC_23_36,
+       FEC_25_36,
+       FEC_13_18,
+       FEC_26_45,
+       FEC_28_45,
+       FEC_7_9,
+       FEC_77_90,
+       FEC_32_45,
+       FEC_11_15,
+       FEC_1_2_L,
+       FEC_8_15_L,
+       FEC_3_5_L,
+       FEC_2_3_L,
+       FEC_5_9_L,
+       FEC_26_45_L
 };

@@ -350,6 +368,10 @@ enum fe_modulation {
        APSK_32,
        DQPSK,
        QAM_4_NR,
+       APSK_8,
+       APSK_64,
+       APSK_128,
+       ASPK_256
 };

Adding new values, means that we should bump the DVB API as well to
5.12 in order usespace applications to be aware of the changes.

That is let's say the easy part, the hard part is how are we going to
query frontend capabilities?

Are we going to introduce a new delsys (SYS_DVBS2X)? Or are we going
to introduce Supports "3nd generation" modulation"
(FE_CAN_3G_MODULATION) ?

Or since the new APSK modulations are optional, we need to add
FE_CAN_APSK_8/64/128/256 to capabilities.

Thanks for your suggestions.

Best Regards,
Athanasios

PS. Here you can read about S2X:
https://www.dvb.org/standards/dvb-s2x
http://www.dvb.org/resources/public/standards/a83-2_dvb-s2x_den302307-2.pdf

Re: DVB-S2X - S2 Extensions Support

[Mauro Carvalho Chehab]

Em Thu, 30 Nov 2017 15:24:47 +0200
Αθανάσιος Οικονόμου         <athoik@gmail.com> escreveu:

> Hi All,
> 
> I am not aware if there was a discussion regarding S2X before, so I
> would like to hear what are your plans regarding S2X.

Ralph started a discussion about that sometime ago.

> There are already several manufacturers with S2X capable receivers and
> soon more will follow.
> 
> The S2 extensions will bring more code rates and modulations, so I
> guess adding those to fe_code_rate and fe_modulation is mandatory.
> 
> Something like the following with proper documentation of course.
> 
> @@ -313,6 +313,24 @@ enum fe_code_rate {
>         FEC_3_5,
>         FEC_9_10,
>         FEC_2_5,
> +       FEC_13_45,
> +       FEC_9_20,
> +       FEC_11_20,
> +       FEC_23_36,
> +       FEC_25_36,
> +       FEC_13_18,
> +       FEC_26_45,
> +       FEC_28_45,
> +       FEC_7_9,
> +       FEC_77_90,
> +       FEC_32_45,
> +       FEC_11_15,
> +       FEC_1_2_L,
> +       FEC_8_15_L,
> +       FEC_3_5_L,
> +       FEC_2_3_L,
> +       FEC_5_9_L,
> +       FEC_26_45_L
>  };
> 
> @@ -350,6 +368,10 @@ enum fe_modulation {
>         APSK_32,
>         DQPSK,
>         QAM_4_NR,
> +       APSK_8,
> +       APSK_64,
> +       APSK_128,
> +       ASPK_256
>  };

That's the easiest part :-)

> Adding new values, means that we should bump the DVB API as well to
> 5.12 in order usespace applications to be aware of the changes.

Yes.

> That is let's say the easy part, the hard part is how are we going to
> query frontend capabilities?
> 
> Are we going to introduce a new delsys (SYS_DVBS2X)? Or are we going
> to introduce Supports "3nd generation" modulation"
> (FE_CAN_3G_MODULATION) ?
> 
> Or since the new APSK modulations are optional, we need to add
> FE_CAN_APSK_8/64/128/256 to capabilities.
> 

We have only 2 bits (maybe a few more bits, if we reuse some
unused ones). Anyway, that's not enough for FE_CAN_foo flags.
So, we'll need to extend the API somehow. I'm answering the other
thread with some raw ideas for discussion.

> Thanks for your suggestions.
> 
> Best Regards,
> Athanasios
> 
> PS. Here you can read about S2X:
> https://www.dvb.org/standards/dvb-s2x
> http://www.dvb.org/resources/public/standards/a83-2_dvb-s2x_den302307-2.pdf



Thanks,
Mauro