1) A kind of PACSAT BBS or HamNet access
as described above...
About the point 1, a short term solution for IP/Hamnet over QO-100, what do you think about my proposal to port my NPR protocol to QO-100 WB, like described in my previous post? Do you find that it would be useful or not?
2) A successor for P4-A which would replace the Analog Linear Transponder Downlink by a regenerative digital transponder with a single DVB-S2 downlink.
About the point 2, it is similar to what P4B, in the USA, planned to do a few years ago.
In my opinion, it is far from optimal (it's only my opinion):
- A pure "bend pipe", like QO-100, is much better for experimenters like us, in order for evey motivated OM to experiment new things on his own.
- The number of simultaneous TX stations is (very) limited.
Part of the Uplink would be still "linear" as it is for SSB/CW/etc., but just like a remote SDR which will stream the "passband" down as I/Q data on the DVB-S2 downlink.
Another topic about "point 2" I’ve not understood the "narrow band SDR" that you propose, inside the satellite. If you want to capture 100kHz RF bandwidth at uplink side, then you need more than 24bits x 100kHz= 2.4Mbps for IQ samples of each channel, for 12bits IQ sample resolution, to the downstream. This induces a huge RF bandwidth need at downlink (~2MHz with QPSK) compared to a pure “bend pipe” solution (~100kHz). Therefore, unless I have not understood something, I don’t think that it’s a good idea.
73, Guillaume F4HDK