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

Tue Aug 20 09:11:41 PDT 2019

I'm hanging on to a Primestar Dish to try when that day comes...

On Tue, Aug 20, 2019 at 11:47 AM Michelle Thompson via Ground-Station
<ground-station at lists.openresearch.institute> wrote:

> 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."
>
>

-- 
Thanks,
Mike Sprenger
(37.9167N  81.1244W is the Summit)
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