[aprssig] Multi control station situational awareness - For mobiles? or homes without power?

Greg D ko6th.greg at gmail.com
Tue Dec 3 22:26:22 EST 2019

Hi all,

Wow, excellent discussion.  And, thanks Andrew for your insight into the
problem, if not your actual code.  Would this be a view of the data from
within YAAC, or a separate application?

To summarize some of the thoughts....  First, a bit of clarification on
what I'm envisioning are parameters that the solution should include. 
The scale, for starters.  Right now we're looking at check-ins
(contributions) from the field of view of our club's repeater, which
covers the outage area our members reside in pretty well.  That area is
some 40 miles in diameter, or 120-ish square miles.  The terrain is the
Sierra Nevada foothills, so lots of valleys.  Our repeater has battery
backup power, good for several weeks, which worked perfectly.  At the
north end, about 25 miles from the club repeater is a high level Digi,
which appears to also have backup power (it was operating continually as
far as I could tell).  Its coverage is even larger, and can usually be
counted on to hit an iGate somewhere, though not all iGates in the area
are bi-directional.  But because of the terrain, not everyone can hit
that Digi with any reliability, and the few fill-in digis are usually
not outfitted with backup power (mine isn't).  I believe both net
control stations can hit it, and there's enough coverage that we could
use APRS as a viable transport.

We discussed the use of mesh netwoks, such as the mentioned TARPN, and
AREDN which is similar.  These networks don't currently exist in this
area, and again with the physical area and terrain, would take some time
and money to create.  Doubtful that such an undertaking would be
supported for the need we have identified. 

Hosting a dial-up node is not going to be good, as I was pretty much
alone in having a working land-line phone, and that it was working was a
huge surprise to me, as it's gone down (no dial tone) for every
unplanned outage over the past about 3 years.  Creative idea, however.

Packet BBS was not an option we had though of.  There are (or, were?) a
few packet BBS systems in the state, and I think one within earshot of
me is still operating.  Haven't used it for a while.  That certainly
could be a way to pass a file around from one control operator to
another.  But being an informal net, we didn't set up a specific
operator schedule.  Instead we just let each other know when we came and
went; often both were available at the same time.  So, the idea of
passing a file around would take some coordination, but could be
possible.  We had thought to use Winlink for this.  If nothing else, my
TNC is an MFJ-1278T with a huge mail storage card installed.  It's
mostly wasted technology, as I run the TNC in KISS mode... This is a
worthwhile thing to investigate, if we can figure out the RF paths. 
Thanks for the idea! 

Overall size of the data collected is important to consider.  My
hand-written notes from the 3 events totaled about 4 pages, single
sided.  So, this is way more than will fit in an HT, good size for text
files, and trivially small for an enterprise-class application (SARtrack).

The two (current) net control operators included one ham who is about 10
crow-flies miles from the other (me), but not on a line-of-sight basis. 
He has radios and backup power (battery + generator), and was on them
for all 3 of the major outages.  No internet during the outages.  I was
the other operator, and my situation is less dire, as I was only out
during the first of the three outages.  For the other two, I had both
power and Internet, and could view the PG&E website for their updates. 
For the first outage, I was totally offline until power came back.  No
generator here (nor a desire to have one); I have battery backup power,
and can hit the repeater with just my Kenwood D-74 and the main beam
antenna.  Computers here were not used during the outage, but I have a
variety of platforms from the proverbial Raspberry Pi to laptops that
are within capacity of the batteries.  And in a pinch I could tap into
the battery in my EV.

A question about Objects...  How much information can one object
contain?  I was thinking 1 packet-worth, but apparently that's not
true?  I think that it would be good for folks to be able to see the
objects as they are generated, but as Stephen says, creating one on an
HT-sans-PC is not going to happen.  Data input from the population at
large is expected to be primarily voice through the repeater.

So, next steps.  On the guess that I'd survive the last planned outage,
we set up a Google Docs file to use as a test bed to see what sorts of
information should be captured and now the baton passing could work
between stations.  The outage ended up being canceled for our area, so
we didn't have a chance to test it in action.  We did a little
pre-outage postings with it, and it seemed like it would work well.  So,
that's action along the file-transfer leg of the discussion.

For the live RF-based path, I'm very interested in Andrew's work.  I use
YAAC on a Raspberry Pi in my car, and could certainly take the new code
out for a test drive (pun intended and not).  Let me know what I can do
to help.

Thanks to all for the excellent discussion, and the great ideas to try!

Greg  KO6TH

spam8mybrain via aprssig wrote:
> Bob,
> I could have something available for option#2 in a week or so, freely
> available. I've been working on this sort of usecase for some time
> now, but I haven't been in charge enough to deploy it.
> And I'm still working on adding supplemental information to the
> reports from one-way trackers, like how many injured/exhausted
> bicyclists riding in a SAG vehicle.
> Andrew, KA2DDO
> author of YAAC
> -------- Original message --------
> From: Robert Bruninga <bruninga at usna.edu>
> Date: 12/3/19 19:08 (GMT-05:00)
> To: aprssig at lists.tapr.org
> Subject: Re: [aprssig] Multi control station situational awareness -
> For mobiles? or homes without power?
> There sounds like two paths emerging.
> - Come-as-you are with APRS radios in the mobile as the end terminal unit
>    Everybody has one
> - Invent something new with PC's, clients, Pi's, displays, for use at home
> (or front seat mobile?
>   Nobody has one
> -----Original Message-----
> From: aprssig <aprssig-bounces at lists.tapr.org> On Behalf Of Shawn Stoddard
> Sent: Tuesday, December 3, 2019 7:01 PM
> To: aprssig at lists.tapr.org
> Subject: Re: [aprssig] Multi control station situational awareness - How's
> this supposed to work?
> Great sanity check. You’re thinking the same path I am.
> On Tue, Dec 3, 2019, at 15:40, Greg Troxel wrote:
> > I would urge you to step back and consider your requirements, think
> > about the protocol that will be used at a high level, and then figure
> > out how to use specific techniques to implement that protocol.
> >
> > If what you want to do is publish infomration about status of
> > particular places, then APRS probably is the best fit.
> >
> > If you are trying to synchronize the list of checked-in stations among
> > N NCS stations, then I think you want some sort of database sync
> > protocol which is going to send messages among the participants, and
> > you may or may not want to carry that over APRS.
> >
> > I think you implied this, but from the "train like you'll fight" I
> > would suggest using the over-the-air sync all the time, and not use any
> > direct-to-APRS-IS internet-based injection.   Gatewaying to APRS-IS is
> > great for others to probably be able to see what's up, but I think you
> > should plan on no internet, and thus operate that way routinely,
> > because otherwise you are likely to be depending on it more then you
> > think.
> >
> > ALl of this is going to push you to protocols that are very terse and
> > push just the data, with all formatting and UI local.  This means
> > writing a local implementation of the UI for the protocol.
> >
> > 73 de n1dam
> >
> > 

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