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Re: Here I go again... Was: Re: UO-14 , FO-29, FO-20, QRM via ISS



Stan and all,

You have a lot of good questions, but no answers.

Do I have them?

Yes, I have some but all is still "experimental".
All I can say is, I had my experience with MIR as others did also.

As far as APRS software VS DUMB software, it is a toss up.
APRS (((("style"))))  transmissions happen to be very efficient.

On MIR, MIREX was running a Kantronics KPC-9612 for the TNC, and it was
REMOTE LY programmable.

I spent many hours in configuring MIR's TNC for normal friendly usage, thus,
spoiling ISS users with parameters that should be changed. MIR also ran a
full time PBBS or PMS. To do this, there had to be a "remote SYSOP" to do
this too. (one more thing to think about)

There is a lot of work that is involved in getting things to work and
happen.
It takes many volunteers to make it happen.
The end side users, you and I, are the ones benefiting from even having HAM
RADIO on ISS.

Like NOW, as in the old days, we would have to somehow get a message through
to someone onboard MIR or ISS to send instructions to make changes on the
TNC parameters. This sometimes took days or weeks to do. On ISS, the same
rule applies. On MIR, I could send up remotely new parameters, and basically
keep the crew out of the loop. All the crew needed to know is to keep the
power ON!

MIR used to be on SEVERAL frequencies before landing on 145.985 SIMPLEX.
There was much debate with EVERY frequency chosen. There still was debate.
145.550 was the ONE frequency that only had one problem with it on the
ground.
That was in Europe, as it was a SIMPLEX frequency. The only other problem is
that it was not a "Space/Satellite" frequency, so it got changed. Now SAREX
frequencies are being used on ISS. Good, bad or indifferent, all is subject
to "change"

Until this happens, seems that what you see is what you get.

This is a hobby where "experimentation" is allowed.
I guess the ISS packet cops are the guys that are SYSOPS and those involved
in the project.

There should be no KAOS !

GET SMART!

All in jest......

73, All.....

Scott, WA6LIE

----- Original Message -----
From: "Stan Vandiver" <Stan@Vandiver.com>
To: <sarex@AMSAT.Org>; <amsat-bb@AMSAT.Org>
Sent: Tuesday, June 05, 2001 5:06 PM
Subject: Here I go again... Was: Re: [sarex] UO-14 , FO-29, FO-20, QRM via
ISS


Hi all,

This discussion, in one form or another, keeps harking back to the
question of "keyboard versus APRS"... who is clogging the uplink
more?  Who has more "right" to be using this resource?  The
simple answer, I think most would agree, is that we all have equal
"rights" to use the ISS resources.  Who (or who's software) is
causing the most congestion is still undetermined, as far as I can
tell.  Who (or who's software) is causing all the QRM to the other
satellites needs more (or continued) investigation also.

The 2 APRS-automated stations, W3ADO and WA6LIE, are
providing international support to a large audience of users.  I copy
both stations here near Chicago on almost every single pass.  I
think their support of APRS is very effective.  Could they get by
with even fewer transmissions?  Possibly.  But I am not convinced
yet that they are "excessive" either.  (And I don't really like APRS
myself, so I am in no way biased in its favor.)

I also see keyboarders on every pass... including new callsigns
almost daily.  Some use APRS for keyboard QSO's too.  People
are "saying hi" all over the place out there!  Thats great too!

I don't think any individual, or group, or particular software is the
problem.  I still believe it is the overall "noise floor" from all of us
combined (discounting for the moment the possibility of hardware
problems on the ISS).  Any TNC can be set to beacon once per
minute, and any flavor of software will let a user transmit at easily
more than 10 times that rate.  Packet collisions are inevitable, and
there are no good "timing parameters" that can be used to improve
this problem.  The "capture effect" is the only thing that works in a
collision.

Yet I see new people get through all the time... in spite of the 2
major APRS-automated stations, in spite of all the other beaconing
or "machine-gun" stations (real or imagined), and in spite of all the
keyboard regulars.  QRP stations are getting through too, either
due to very lucky timing or due to "capture effect" against other low
or average power level stations.  Low power can sometimes win
over higher power depending on distance to the ISS, aiming of
antennas, etc.  (I guess the Inverse Square Law still applies?!?!)

These APRS stations also send bulletins to try to help the
situation out there, like "Please QRT after pass..."  Miles and
others give helpful advice from the keyboard as well.  But attitude
can sometimes make a difference too... why not say, for example,
"(callsign), Use unproto... its more fun!" rather than "Don't use
connects!"  Hear the difference?  Better to "gently nudge" someone
into a better operating practice than to play "packet/ISS cop".

Bruce Paige has successfully contacted many of the beaconing
stations and convinced them to stop, citing interference to the
other satellites.  And I'm sure Bruce was quite diplomatic about it.
But he could use your help too... all of you who work these other 8
satellites... to try to observe who the offending stations are (when
the ISS is not in range) and to try to educate our fellow hams... in a
nice, helpful manner.

In the event that friendly advice doesn't work, I think a real case
could be made for malicious interference too.  Does a ham have
the "right" to transmit every minute, 24 hrs per day, on a satellite
uplink frequency?  I may be wrong, but my opinion is NO.  But the
offenders must be identified first... and a case against them would
have to be built to get attention from the FCC.  I don't think it needs
to come to that, but I for one am glad that the FCC is back in the
enforcement business.  (Go Riley!!!)  ;-)

More of us could and should spend more time listening to the
uplink in our area too.  The downlink is not the only place to
analyze the challenges and/or problems in working the ISS
digipeater.  We may help identify who is causing all the QRM even
if we don't work these other satellites.

Rather than encouraging anyone else to become a "super-beacon"
and "Voice of the ISS".... let me ask, "Can the ISS TNC be
configured to transmit its own APRS position data?"  Once the
TNC can get the attention it needs (like a callsign!)... can the
NASA folks supply the beacons needed to satisfy BOTH of these
large user groups, position beacons for the APRS'ers and
information beacons for the keyboarders (or other casual listeners,
like school kids perhaps)?  In the event that the ISS TNC can't
transmit the APRS positions, what is the likelihood that we could
get NASA to keep a full-time computer on the packet station that
could fulfill this need with software?  How about GPS?

To have the ISS do this task would help to free up the uplink for live
users, no matter what flavor of software they use.  And then
perhaps *ALL* automated operations could be discouraged instead
of applying "selective exceptions".

Again, Bob is asking for "one packet per pass" (this time for a
solitary super-beacon)... while the 2 APRS support stations
continue to send numerous packets per pass.  I still find this hard
to chew on.  "What's good for the goose is good for the gander."  If
Bob wants reduced transmit rates, he (and Scott) should lead by
example. To seemingly elevate APRS as being "more important"
rubs many people the wrong way, including me.

Also, I wonder how many "retries" W3ADO and WA6LIE have to
transmit before they get their desired data successfully digipeated?
 How much congestion from these 2 stations might be caused from
their unsuccessful attempts?  The ISS test we had awhile back
showed I only have about a 20-25% success ratio with "one packet
per pass" (and with considerably more ERP than what Bob told me
they're using at W3ADO).  For these APRS-automated stations to
get so many successful digipeats seems to indicate that they are
using an even higher transmit rate (4-6 sec intervals noted by
W3ADO at times during the test), or else higher ERP, or both.
Bob (and I think everyone) acknowledges that higher ERP is
better... get your transmission completed and then back off.

More beacons are not the answer... not even one high-powered
one... not even at a low transmit rate. Analyzing the conditions (ie,
listening to the uplink and identifying QRM'ing individuals on the
other sats) and coming up with workable solutions (ie, notifying
offending unattended stations and getting the ISS to do all beacon
functions) will go a lot further to resolving these issues, IMHO.

I realize that nothing is going to be solved overnight... but I would
think (and hope!) that NASA is still "taking requests" on how to
improve the ARISS project with future plans and upgrades.

Finally, am I correct in assuming that "courteous operation" in the
future will be for all of us (keyboard and automated alike) to "stand
by" when ground stations have connected to the ISS mailbox and
are attempting to send the crew a message?  Think about this
awhile folks... it may be you, or your kids in the classrooms, that
are trying to leave a message!  If the ISS TNC or software can't
send the APRS info in beacons... are W3ADO and WA6LIE going
to continue digipeating at these rates... interfering with people's
attempts to leave a message in the mailbox?  And will the rest of
us also say, "who cares if this person gets their message saved?"
as we continue to bang away on the keyboard "chatting" with other
users of the digipeater.  Of course, digipeaters can be disabled
too... leaving us all out of the fun!  These are still things to consider.

Stepping back down from my soapbox... thank you for your time.

Vy 73,

Stan/W4SV
Hanna, Indiana


On 2 Jun 2001, at 10:31, Bob Bruninga wrote:

> Yes, but we only need One station doing it and that one station should
> be using HIGH power so that it only needs to transmit the Bulletin
> once per pass.  Thus, only one packet added to the uplink congestion
> to get the word out.
>
> If we had 10 people offering such helpful beacons, each transmitting
> say once every minute (so that at least one got through from his 50 W
> station) then we would be adding 100 congesting packets to the uplink
> for the same effect.  Also, all 10 stations would have to manually
> activate and deactivate these beacons before and after a pass.  Each
> one that forgets just adds QRM to the other 8 satellites...
>
> That is why I loaded the 1 line Bulletin on the W3ADO East coast ISS
> tracking uplink station and asked Scott to add it to his West coast
> uplink station.  This will keep the uplink loading to a minimum when
> we need to get such information out to everyone.  Also, these stations
> are automatic and only transmit during ISS passes, never inbetween.
>
> de WB4APR, Bob

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