[sarex] Re: Future ISS amateur radio modes

Robert Bruninga bruninga at usna.edu
Thu May 3 11:27:55 PDT 2007

> Looks like option 3 would work [2m monoband for 
> school contacts] with the eventual 28, 145, 430 
> and 2400 MHz options planned for installation. 
> That will provide 4 bands for 4 different modes.

I may be nitpicking your words, but that particular phrasing
still sounds like self-limiting mono-band operation, which not
only limits to exactly 4 modes, but overlooks the fact that with
the long lead time of systems on ISS, there are years of overlap
between the design and eventual operations of some systems.
Allowing for "monoband" operations on any of these other bands
is simply multiplying the current coordination issues across 4
more bands and making them a roadblock to future independent
growth and development which should have less dependence on
daily immediate crew involvement for every mode.  Not
perpetuating the same problems to other bands.   What I would
like to see ARISS say is something along these lines:?

1) Monoband 2m operation exclusively for school contacts only.
No other uplinks or downlinks or any other modes will be planned
without consideration of the requirement for direct crew
involvement of every operation and every mode change for
operation on 2m.

2) 430 MHz as a dedicated downlink band (no uplinks)
3) 28 MHz and 1200 MHz as dedicated UPLINKs
4) 2400 MHz TBD.

Number 1 makes 2m a lost band for any other modes or experiments
except for the indicated limitations and inherent unreliablity.
But does preserve the status quo.

Number 2 and 3 combined give an unlimited number of future modes
and systems than can operate independenly, without interferrence
and without intense coordination. (not just 4).  And more
importantly can be planned and worked on the ground
independently as well.

By dedicating at least one band to exclusive downlinks and
another band for exclusive uplinks, ALL mutual system
interferrences are avoided as well as any requirement for crew
involvement.  Plus, all future Amateur Radio Operations and
equipment, and planning can work independently, in any sequence
at any time, and be preempted, replaced, or whatever as
independent systems.  That is the only way to avoid the problems
of mutual interference, intense crew involvement for every mode
change, and intense coordination for daily operation.

Even thinking of perpetuating even a hint of future monoband
operations on any of the other precious bands is very
shortsighted, and builds in exactly the kind of intense crew
involvement, intense coordination, and intense and detailed
interleaved planning... All of which can be avoided by never
even considiering any future monoband designs or operations.

Blocking any of these other bands with any future plans for
monoband operations I fear is short sighted...  

What we really need to see is for ARISS to commit to dedicated
uplink and downlink bands and the prohibition of any monoband
operations in those bands.  Without that, then there is no clear
independent path for any future missions, experiments or
operations, which does not bring us back to the present
situation of the potential for incompatible, conflicting,
crew-involved , interrelated, cordination intense processes.

Or something along those lines...


> -----Original Message-----
> From: sarex-bounces at AMSAT.Org 
> [mailto:sarex-bounces at AMSAT.Org] On Behalf
> Of Robert Bruninga
> Sent: Wednesday, May 02, 2007 11:07 AM
> To: sarex at AMSAT.Org
> Subject: [sarex] Re: Future ISS amateur radio modes
> > Once the planned hardware is aboard and installed, having 
> each system 
> > dedicated to a specific operation will minimize the need for
> > changes and crew interaction.
> But this can only be true if all systems operate with clear 
> isolation of
> all uplinks from all downlinks on separate bands.
> It is impossible to have independent systems operating with
uplinks in
> the same band which may be used for downlinks.
> Until ARISS commits to a permanent dedicated downlink band
which then
> guarantees other known bands for non-interfering uplink bands,
> planning is stymied by crew-required mode changes and lack of
> independence of systems.
> Current use of 2m for both uplink and downlink, prevents its 
> use by any
> other system for any other purpose without crew intervention
on every
> such use.  There are really only three choices...
> 1) make 2m the downlink band for simplicity of reception
around the
> world.  Even the least advantaged country should be able to at
> borrow an ARISS UHF uplink radio for a school contact.
> But it does require Doppler tuning in the blind on the uplink.
> Tuning a radio +/10 KHz is not a hard skill to learn.
> 2) Make UHF the downlink band so that recipients can simply
tune the
> Doppler to best sound, and then uplink on 2m is fixed 
> frequency with no
> problems.  Less interference with UHF radars...
> 3) Continue status-quo, and use 2m for both uplink and
downlink for
> school contacts and either require crew intervention with
every mode
> change for use of 2 meters for anything else, or require all
> systems to not use 2m for anything, so they can be independent
of crew
> issues.
> Until there is a permanent commitment to one of these three
> possibilities, uplinks and downlinks can not be planned
> conflicts, and crew intervention is required in every mode
change on
> every system that might want to share 2m for anything.
> Of 60+ amateur satellties, few (with more than one mode on
> board) use monoband operation.  There is a good reason for
> Uplinks and downlinks are in different bands for operating 
> independence
> of modes. Just what we need on ISS.
> Just a thought.
> Bob Bruninga
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