[Ground-station] Brazilian RF pirates on old Military GEO comms sats.

[Michelle Thompson]

Kent, anything that works to transmit 5GHz up and collect all the 10GHz
down is needed.

Have you tested our dual band feed yet for potential improvements and
variations?

-mdt

On Mon, Aug 19, 2019 at 17:21 KENT BRITAIN <wa5vjb at flash.net> wrote:

> You are thinking FM, very very few signals though Oscar 100 are narrow
> band FM.
>
> But the drug dealers have been using the edges of the Satellite
>  TV transponders for at least 40 years.   Easy to do back in the old
> Galaxy iV days.
>
> "Bent Pipe" is where you have a frequency converter , and IF with a
> passband filter, and
> an up converter to a broad band amp.    Any signals in the frequency
> converter passband
> are repeated.         Control signals would really need to be on a
> separate receiver.
> Michelle is thinking about a system where the digital signals are converted
> to baseband data.  Then remodulated and retransmitted.    Input and output
> do not even
> need to be the same modulation format.   In fact there are several
> advantages to using
> different digital modulations up and down.   With GSM cell phones, the
> phone-tower and
> tower-phone are two different modulation formats.
>
> A complex, but very flexible system.
>
> Michelle, any antennas I should be looking at?
>
> The European Space agency says my latest S-Band antenna just pasted Fit
> Check,
> now to make up another 11.
>
> 73 Kent WA5VJB/G8EMY
>
>
>
>
>
> On Monday, August 19, 2019, 7:02:03 PM CDT, KC9SGV <kc9sgv at gmail.com>
> wrote:
>
>
> Hi Kent,
> At the risk of having foot in mouth disease here....😀
> Maybe just activating the transponder in a previous transmission via a PL
> tone or DTMF code, which would then keep it activated for say, 15 minutes.
> Maybe the engineers among us here can come up with some feasible solution.
>
> Some FM LEO sats have to be activated like this first.
> Also, aviation phone patch calls have to be activated like this first.
> Indeed, DTMF codes from cell phone keys, acoustically coupled into a keyed
> VHF radio mike, can activate the system.
> This code can be changed periodically.
> Just throwing out ideas there.
>
> Bernard,
> KC9SGV
>
>
>
> Sent from my iPad
>
> On Aug 19, 2019, at 12:11 PM, KENT BRITAIN <wa5vjb at flash.net> wrote:
>
> Bernard
>
> I have made a QSO though Oscar 100.
> How would you have a PL tone on a CW or SSB signal in a transponder
> bandwidth?
> Not to mention the fun of detecting it in a multi signal bandwidth.
>
> Kent WA5VJB/G8EMY
>
>
>
> On Monday, August 19, 2019, 11:36:08 AM CDT, KC9SGV via Ground-Station <
> ground-station at lists.openresearch.institute> wrote:
>
>
> Agreed.
> QO-100 runs without a required sub audible PL tone.
> Maybe a random, alternating PL tone is all we need.
> Change it every month or so.
> Advise the users via a mail list like this.
>
> KC9SGV
>
>
> Sent from my iPad
>
> On Aug 19, 2019, at 10:29 AM, Michelle Thompson <
> mountain.michelle at gmail.com> wrote:
>
> Authentication is part of the air interface, and not just in the hardware,
> so any home brew would have to comply. Otherwise, you just don’t get
> through.
>
> We assume auth/auth management is part of operations and is the operator’s
> responsibility. It’s up to the operator to decide to use all the functions.
> They’d have to make sure they had enough people on the job to not slow down
> new users. You addressed exactly this potential bottleneck.
>
> It can be run wide open, with no checks, and then be changed depending on
> status (e.g. emergency traffic only may mean only credentialed people can
> use it).
>
> Spoofing is hard. It is not impossible, but in general, for security to
> work, you just have to make it hard enough for attempts to drop to zero. It
> doesn’t have to be mathematically perfect, or eliminate every way to break
> in.
>
> If all any malcontent can do is raise the noise floor, then we have been
> extremely successful. That seems achievable with what we’ve assumed as the
> baseline security design. Needs testing!
>
> -mdt
>
> On Mon, Aug 19, 2019 at 08:15 KC9SGV <kc9sgv at gmail.com> wrote:
>
> Hi,
>
> Well trod ground, certainly.
> Recent ham radio systems like Echolink, Winlink, IRLP, etc. come to mind.
> To access these systems, the individual ham is authenticated and
> authorized.
> If this is done by hand, individually....good luck with that.
> A full time job for somebody with the resultant delays in authorization.
>
> Authentication is not to stop the enterprising, criminal element to usurp
> an old "CW only" operator's call sign and operate digitally through the
> satellite, even with an on-board data base.
> Such old "CW only" operator will never have the reason to suspect his
> callsign is being used nefariously....
>
> Most of the client ground station hardware will be home brewed anyway,
> with no authentication chips in place.
>
> Maybe, authentication via cell phone before each QSO, is what is needed.
> The way on-line banks now authenticate customers for on-line banking
> transactions.
>
> Bernard,
> KC9SGV
>
> Sent from my iPad
>
> On Aug 19, 2019, at 9:36 AM, Michelle Thompson <
> mountain.michelle at gmail.com> wrote:
>
> This is one of the biggest reasons our designs are regenerative repeaters
> with authentication and (optional) authorization.
>
> Background info is in the repo, but the essential mechanism is what LotW
> uses combined with white and black lists. Requires a database in the
> payload and enough horsepower to afford the overhead.
>
> Fortunately, it’s well trod ground. It would be even better with a working
> authentication/authorization demo, but we just got a good channelizer
> working. We are much closer to a working end to end demo than we were just
> a few weeks ago.
>
> *Enabling legacy traffic through the aggregator is a special case. The
> aggregated traffic is tagged, but the individual traffic channels (FM hts,
> p25, d-star) would not necessarily be individually authenticated.
>
> -mdt
>
> On Mon, Aug 19, 2019 at 07:02 John Klingelhoeffer via Ground-Station <
> ground-station at lists.openresearch.institute> wrote:
>
> Unless we configure an appropriate authentication system, I am afraid we
> will suffer a similar fate.  So much for open transponders.
>
> On Sun, Aug 18, 2019 at 1:07 PM KC9SGV via Ground-Station <
> ground-station at lists.openresearch.institute> wrote:
>
> I agree and understand that.
> So let us concentrate on getting our very own, very legal ham GEO sat up
> for Region 2 ASAP.
> Hopefully these old 1970's technology military comms sats are not
> completely abandoned by the various Western militaries.
> For fun, revisit the movie "Space Cowboys" with Clint Eastwood now on
> Netflix.
> Somewhat related.
>
> Bernard,
> KC9SGV
>
>
> Sent from my iPad
>
> On Aug 18, 2019, at 12:16 PM, Timestep <help at time-step.com> wrote:
>
> It's easy world wide communication.  However the USA Government will track
> you down...........
>
> Regards
>
> Dave  G 4IUG
>
> --
> -Michelle W5NYV
>
> "Potestatem obscuri lateris nescis."
>
> --
> -Michelle W5NYV
>
> "Potestatem obscuri lateris nescis."
>
> --
-Michelle W5NYV

"Potestatem obscuri lateris nescis."
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