2021 Revision to the QO-100 Bandplan

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G8GKQ
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2021 Revision to the QO-100 Bandplan

Post by G8GKQ » Sun Feb 28, 2021 11:22 pm

Following discussions between the AMSAT-DL and the BATC, a revised bandplan for the QO-100 Wideband Transponder has been published.

The changes are only minor. In summary
  • An explicit statement that the playing of recorded music subject to copyright is unacceptable.
  • Guidance on the occasional use of DVB-T and other experimental modes in the lower 1.5 MHz of the "Wide and Narrow" segment.
  • Clarification that 500 kS DVB-S/S2 should not be used in the Narrow DATV segment.
The full .pdf can be read here: https://wiki.batc.org.uk/images/a/a2/QO ... lan_V3.pdf. The graphical version is reproduced below.

Please respect the bandplan and guidance to enable us make the best use of this valuable resource and not risk losing it through unacceptable behaviour.

Thanks

Dave, G8GKQ
BATC Chairman
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G8GKQ
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Re: 2021 Revision to the QO-100 Bandplan

Post by G8GKQ » Tue Mar 02, 2021 2:04 pm

Thanks for all the chat and forum comments on the bandplan. A number of the items discussed during the last few days are not new and were included in the previous version of the bandplan issued one year ago.

The transponder has limited bandwidth and limited power. There are potentially hundreds of thousands of users and we want to make it easy for new users, whilst also enabling advanced experimentation. The bandplan is not perfect for every user group, but is the best compromise that we could reach for all user groups. So please try to work within the rules in consideration of everyone else.

The word "should" is used throughout the bandplan, and it is used to say "what is the correct or best thing to do". So the bandplan provides guidance as to what is the best behaviour for the good of the community. Clearly, we cannot mandate any specific rules - only your National authorities can do that.

Power density could be better defined in the bandplan. We were referring to signal power within a certain bandwidth (for example received dBm per Hz). For similar signal modes (such as all QPSK) this provides a good method of balancing the power and bandwidth constraints. It is less useful for 8PSK and other modes requiring a higher received signal-to-noise ratio. We limited the use of higher power densities (for 8PSK and above) to signals of less than 333 kS to conserve transponder power for other users. We had to draw the line on the maximum bandwidth for the use of these power-hungry modes somewhere. Please interpret this guidance sensibly.

It makes coordination easier if users monitor the internet wideband spectrum monitor and the chat, but we recognise that this is not always practical. We do not want to exclude users without internet connections, as long as they can check the channel is clear before transmitting and monitor their power levels, they are welcome.

Please do not hesitate to suggest improvements to the bandplan, which is a living document. As the available technology advances it needs to evolve, but any changes must take account of the total user community, not just one or 2 users.

Dave, G8GKQ

OE3GBB
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Re: 2021 Revision to the QO-100 Bandplan

Post by OE3GBB » Tue Mar 02, 2021 2:33 pm

Hi Dave,
I think it would be easier to understand if the rule would be stated as:
...the use of higher power densities (for 8PSK and above) to signals of equal or less than 250 kS to conserve transponder power for other users. ...

73 de Gerhard OE3GBB

G4EWJ
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Re: 2021 Revision to the QO-100 Bandplan

Post by G4EWJ » Tue Mar 02, 2021 2:58 pm

>> We do not want to exclude users without internet connections, as long as they can check
>> the channel is clear before transmitting and monitor their power levels, they are welcome.

While there is Scan & Tioune, would it be possible to have a permanent signal from the satellite showing the spectrum monitor and chat display page?

This could be low frame rate at SR66, possibly uplinked from Goonhilly.

Brian

g8gtz
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Re: 2021 Revision to the QO-100 Bandplan

Post by g8gtz » Tue Mar 02, 2021 4:34 pm

would it be possible to have a permanent signal from the satellite showing the spectrum monitor and chat display page?
Whilst it could be useful and possibly part of the beacon channel, the time delay could make it less useful than the internet feed. Also, not sure how we would get on licensing a 24*7 transmission and whether our hosts at Goonhilly would be too keen.

73
Noel

g0mjw
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Re: 2021 Revision to the QO-100 Bandplan

Post by g0mjw » Tue Mar 02, 2021 4:52 pm

What, apart from developing the software, stops the Ryde doing this using the space NIM channel on the Ryde?

Mike

AdrianH
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Re: 2021 Revision to the QO-100 Bandplan

Post by AdrianH » Tue Mar 02, 2021 5:13 pm

Dave thank you for the updates and comments, yes there has been lots of discussion on the Chat forum, me included. I like that there is discussion on the chat as it appears it is the only time some users actually read the operating guidelines.

I have always treated 'should' as a 'must do' statement but I can understand that different nationalities and translations could lead to different meanings. And OK on the clarification on stations without internet access, providing they use a software spectrum to confirm channels are free prior to transmit.

OK on the 8, 16 and 32 psk/apsk signals, now awaiting someone transmitting a 330KS 16 APSK signal, just because they can and says it is allowed! I can stick to 333 QPSK as long at least 1dB less than the beacon, or go to 250KS at 8 PSK perhaps if I have enough power. My longmynd seems to struggle at low SR's with very little decode below 125KS.

I was wondering if the power level indicator will also start to cover 333 signals as well only removing the marker if 250KS or less, looking at the spectrum now I can still see 333 and 500 QPSK signals above the beacon so I suspect it will be a while before all have read updates.

10 mins, copyrights etc have been there from the beginning.

Thanks again for the clarification of the rules.

Adrian

G4EWJ
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Re: 2021 Revision to the QO-100 Bandplan

Post by G4EWJ » Tue Mar 02, 2021 6:43 pm

g8gtz wrote:
Tue Mar 02, 2021 4:34 pm
would it be possible to have a permanent signal from the satellite showing the spectrum monitor and chat display page?
Whilst it could be useful and possibly part of the beacon channel, the time delay could make it less useful than the internet feed. Also, not sure how we would get on licensing a 24*7 transmission and whether our hosts at Goonhilly would be too keen.

73
Noel
Wouldn't the processing and up/down time delays be less than two seconds?

Yes, ideally it would be a second program on the beacon transmission.

Brian

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