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(Fwd) Re: HT uplink test via ISS? Keyboarders uplink



Oh geez... I forgot TWICE.  Need to pay more attention.  Sorry!  This was 
my first "reply" (out of 2)... plus my original post.

------- Forwarded message follows -------
From:           	Stan Vandiver <Stan@Vandiver.com>
To:             	Bob Bruninga <bruninga@usna.edu>
Subject:        	Re: [sarex] HT uplink test via ISS?  Keyboarders uplink test  too.
Send reply to:  	Stan@Vandiver.com
Date sent:      	Thu, 24 May 2001 03:26:29 -0000

On 23 May 2001, at 16:29, Bob Bruninga wrote:

> 1) I have not seen evidence that there are many unattended APRS packets.

Is there a way for us to tell whether an APRS packet is unattended or not?

> 2) I do see evidence that there are many TNC BEACONS set on automatic, and
> although some of these use Gridsquares or include a positions report, the
> packets are clearly not generated by APRS software.  Look at the header... 

OK, investigating... I see the header differences.  My Kantronics sends 
beacons addressed to BEACON (via the digipeat path), along with whatever 
BTEXT is programmed.  It still shows as a <UI> frame though, same as an 
UNPROTO or APRS.

Still, UNPROTO can be used as an unattended "beacon" of sorts.  This is 
exactly what I did for the test, using a script to set the transmit times.  I 
could just as easily programmed it to transmit every minute, and I could 
have addressed the packets to my grid square, name, or whatever... other 
than BEACON.  I don't think most folks are operating scripts like this 
though.  Are the beacon addresses of other brand TNC's different?  Is it 
"easier" for APRS users to setup beaconing properties such as this without 
resorting to some type of script?  

Of the numerous packets that I logged this morning, only 3 were addressed 
to BEACON.  And 2 of these were from the same station.  If trying to 
identify unattended beaconing stations, I think that time stamps are needed 
to determine the "regularity" of the packets.  My Kantronics transmits 
beacons to the exact second of the interval that I specify (although it sends 
at "odd seconds"... probably from whenever I give it the cmd).  My script 
function will will only let me transmit straight up on the minute, although 
perhaps other TNC software will allow scripts to be programmed to the 
second.  Again, I don't think most people who are sending unattended 
beacons will go to this much trouble to "hide themselves" so people won't 
know they're operating unattended.  

So, in other words... I don't think I can say there are a lot of unattended 
stations, unless it is the APRS systems.  But I don't mean to imply that 
there are a lot of unattended APRS systems either... I just don't know.  Is 
there a way to tell?  We might sort it out better if we did a lot of logging and 
watched the timestamps. All the packets I see addressed to grid sqares 
and names seem to be live operators... as far as I could tell from the ISS 
test log anyway.  

I have been keeping almost daily logs since I first got on the ISS and may
could check this out further... but don't hold me to it.  Thats a lot of work,
and I don't have a lot of spare time.  I wouldn't want to "selectively" sort my
logs as it might seem prejudiced... but I can only hope that my ISS test logs
are typical.  Others may please comment if your findings are different.

> think more than 80% of all packets are not APRS nor APRS generated. Look at
> the logs.

Well, I'm not gonna count individual packets today... I've done enuff of my 
own analysis for the time being.  ;-)  But counting STATIONS... I showed 
APRS users accounting for about 50% (or slightly less) for 4 out of the 5 
passes during the test this morning.  Keyboard activity picked up on the 
last pass when folks started waking up.  Here's some numbers:
Pass 1: 10 stations, 4 using APRS 
Pass 2: 11 stations, 5 using APRS 
Pass 3: 7 stations, 3 using APRS 
Pass 4: 8 stations, 4 using APRS 
Pass 5: 16 stations, 4 using APRS  

> Conversly,a few MANUAL keyboarders can maintain a packet throughput that can
> effectively saturate the ISS uplink...  Manual keyboarders can generate about
> a packet every 3 seconds...

Absolutely... this is certainly possible.  But I can't carry on a QSO that 
way... all talk and no listen.  I typically wait for many seconds before 
MAYBE getting a response from a QSO... sometimes hearing many other 
stations before I get a response.  If transmitting, I may have to retry several 
times to get through, but still I don't transmit that often.  It is always 
possible that my packet got through, even if I did not see the return from the 
ISS.... so I try to wait awhile to see if there is a response between each of 
my retries.  Isn't this the "common sense" way to QSO?  

Bob, I'll hazard another *guess* here.  If you're seeing a lot of 3 sec 
"machine gun" stations out there (like you reported when you were trying to 
do the shirt pocket demo while away from home recently)... I would first try 
to rule out badly set TNC parameters or other unintentional problems... but 
then I would definately suspect malicious interference (such as you also 
once indicated hearing voice stations talking on the ISS uplink).  If that's the 
case, then I don't know what to tell ya.  

> We both agree that there are too many automatic unattended beacons, but
> the data proves that the vast majority of these are not APRS...

How much data is there?  Its a lot of work tallying these numbers... even for
only 5 passes.  How do you compute your information and estimates?

> So we need to be careful about casting aspersions...

Yep, I'm trying to be careful.  I've just provided some honest numbers in this
and another post earlier about what I'm hearing here in Indiana.

> Similarly, WinAPRS and both kenwood
> radios will only send one message packet a minute...

I refer you to the following 3 transmissions... seeming to use WinAPRS. I 
don't know if the "format" is that of an APRS "message packet"... but the 
effect is certainly the same.  3 packets in one minute, 2 seeming to be 
"messages."  But, as I mentioned in my earlier post, this station was 
keyboarding and not really involved in the test, and I don't think 3 packets 
per minute necessarily excessive for trying to make a QSO.  (But I don't 
know how many times this ham transmitted to get those 3 through.)  

AB2CJ>APW243,NOCALL*/1 [05/23/01 07:55:17]: <UI>::KB2WQM-3 
:Greetings {000

AB2CJ>APW243,NOCALL*/1 [05/23/01 07:55:47]:
<UI>:=4053.35N/07313.38WyPHG3190/Win APRS 2.4.3 -NESUFKINGS 
PA-243-<530>

AB2CJ>APW243,NOCALL*/1 [05/23/01 07:55:59]: <UI>::KB2WQM-3 
:Greetings {000

> The ISS PACKET system is designed for
> live activity.  Only stations with operators should be on the uplink
> during normal operations.

I agree with that wholeheartedly.

I will not be meaning to snub anyone... but I am working double-shifts Thur 
and Fri... so I will only be able to comment further as time permits.  I am 
sometimes able to check mail from work, but depends on the work!  ;-(  

I'm looking forward to your thoughtful replies...

73 to all,

Stan/W4SV

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