[aprssig] KPC3+ Question

Robert Bruninga bruninga at usna.edu
Wed May 23 12:33:25 EDT 2007 

>   UIDIGI  = WIDE3-3
>   UITRACE = WIDE,30
> 
> Are you saying that it will repeat on the UIDIGI 
> (with substitution) in preference to the UITRACE?
> That would certainly cut down some traffic.

Yes.  That is a cornerstone of the New-N paradigm.  It allows
digipeaters in congested areas to "trap" big hops.  It was that
discovery that made the New-N paradigm finally bring local path
load under control.

Bob, WB4APR

> -----Original Message-----
> From: Robert Bruninga [mailto:bruninga at usna.edu] 
> Sent: 22 May 2007 20:19
> To: jim at stuckinthemud.org; 'TAPR APRS Mailing List'
> Subject: RE: [aprssig] KPC3+ Question
> 
> > Currently WIDE3-3 will get to the single monitoring 
> > point in 3 or less...
> 
> You can do the one thing, and that is to make the first 
> tier of digis outward from the Monitoring site have 
> WIDE3-3 in their UIDIGI list.  This will at least cut 
> the QRM from all users in range of those digis to one hop
> only.  Depending on how many digis can be heard direct 
> at the single monitroing point, this could be 
> significant if say it was 3 of the 8.
>
> > -----Original Message-----
> > From: Robert Bruninga [mailto:bruninga at usna.edu]
> > Sent: 22 May 2007 17:47
> > To: bruninga at usna.edu; 'TAPR APRS Mailing List';
> jim at stuckinthemud.org
> > Subject: RE: [aprssig] KPC3+ Question
> > 
> > You also asked:
> > 
> > > Is there a way of BULIST-ing or excluding certain
stations,
> > to control
> > > what a digi will actually repeat?
> > 
> > Again, assuming you really want only one-way paths to a 
> single point 
> > and want to cutoff everyone else in the remote areas of your
system 
> > from seeing those close to that single point, then there is 
> something 
> > you
> can do.
> > 
> > No matter how all of your 8 digis are arranged, there are
some that 
> > are Immediately adjacent to your one-single-point site 
> where you want 
> > to collect the data.  These 1st tier digis only need to
digipeat a
> > WIDE3-3 packet ONCE.
> > Therefore you can put WIDE3-3 into the UIDIGI LIST settings.

> > Then when a
> > WIDE3-3 station is in that area, their packets are only
digipeated 
> > ONCE.
> > But everyone else beyond that first tier wont see them.  TO
me
> this
> > undermines the intent of APRS...
> > 
> > Repeating myself, if the central single site you want to 
> receive all 
> > this data is more or less centrally located, I would think
that
> > WIDE2-2 would get
> > packets there from all 8 surrounding digis.  If the one 
> single site is 
> > at the end of a very long string of 8 linear digis, then 
> you are going 
> > to have to tell your users to use SS1-1,SS7-7.  So it all
depends...
> > 
> > Bob, WB4APR
> > 
> >  
> > 
> > > -----Original Message-----
> > > From: aprssig-bounces at lists.tapr.org 
> > > [mailto:aprssig-bounces at lists.tapr.org] On Behalf Of
Robert
> > Bruninga
> > > Sent: Tuesday, May 22, 2007 12:25 PM
> > > To: jim at stuckinthemud.org; 'TAPR APRS Mailing List'
> > > Subject: RE: [aprssig] KPC3+ Question
> > > 
> > > > A question for all KPC3+ experts out there.
> > > 
> > > Jim, I'm going to answer based on the lowest common
> > denominator
> > > of interpretation of the information you have provided.  
> > That is, I am
> > > assuming you have not implemented the New-N paradigm
> > settings on these
> > > digis.  Forgive me if you already have...
> > My
> > > answers are more for others who may be following this
> thread.
> > > 
> > > > I have a scenario with eight KPC3+ digi's in a
mountainous
> area, 
> > > > which are set up to get location beacons back to a
central
> point.
> > > 
> > > Probably you mean they are "set up" situationally located
> for
> > RF
> > > such that they can all see the central point, that is one
> > thing.
> > > Again, I will assume a worst case assumption and assume
you
> > may
> > > be talking about "TNC settings"...  In that case, there is
> > practically
> > > nothing you can do in a digipeater to "force" any
> > particular packets
> > > anywhere.  Where the packets go is up to
> > the
> > > originator of the packet.  If it takes 3 hops from one of
> > those
> > > digis to get the data back to the single specific point,
> > then users in
> > > that area will have to use WIDE3-3.
> > > 
> > > > Digi's are hill-top, so I want to stop beacons from
being
> > repeated
> > > > in areas they don't need to be (i.e.
> > > > cut down the redundant RF traffic).
> > > 
> > > Simply implementing the New-N Paradigm in the KPC-3+'s
> > should cut down
> > > on all dupes perfectly.  It eliminates all duplicate
> packets.  Each 
> > > New-N digipeater repeats each packet once and only once.
> > > 
> > > > Control of the route via the sending station is not
> > possible as they
> > > > can be anywhere, which is why I'm looking for a "system"

> > solution.  
> > > > KPCs are running v9.1.
> > > 
> > > The system solution is to determine what the worst case
path
> > is
> > > (say 3 hops) and have everyone in the area use three hops.
> > This
> > > is easy to convey to users, since all DIGIS under the
New-N
> > paradigm
> > > are supposed to show as the first few bytes of their
> > Position Comment
> > > something like "W3,SSn-N" to tell users that
> > > WIDE3-3 is recommended in that area (and SSn-N is
> supported).
> > > This displays nicely from all New-N digis.
> > > 
> > > Maybe you only want packets to go to the central site, but
> focusing 
> > > too much on that one-way path will exclude users in your
> > "system" from
> > > seeing each other at the extremes.  In my opinion, you
want
> packets 
> > > originated anywhere in the area to
> > be
> > > able to hit all other digis, so that all users in your
> > system see each
> > > other too.  APRS is for all-to-all communications.
> > > Most mobiles receive and display data as well as just
> transmit it.
> > > 
> > > On the other hand,
> > > 
> > > If your "system" is well defined and truly has a specific
> > well defined
> > > and well understood mission, then you can set it up
> > with
> > > a specific SSn-N system (SS can be from 2 to 5 bytes
long).
> > > Then tell all users in the system to use SSn-N where N is
> > the maximum
> > > worst case path from the fartherest extremes of the
system. 
> >  This will
> > > guarantee that all 8 of your digis repeat each packet, but
> > that NONE
> > > of the sourrounding states or areas will see any of them.

> > This might
> > > be unfair for the overall regional APRS communicatinos,
but
> it will 
> > > accomplish what you say you want.  You can even use SS7-7
> without 
> > > regret, because
> > no
> > > matter how big "7" is, these packets will still only hit
> each
> > of
> > > your eight SSn-N digis once and only once.  And not spread
> outward 
> > > beyond your "system".
> > > 
> > > The KCPC3+'s all support both WIDEn-N and SSn-N
> > simultaneously,
> > > so this way you can meet your specific unique objective
for
> > specific
> > > users while also serving the general APRS mobile
> > public
> > > as well.
> > > 
> > > Hope this helps.
> > > 
> > > By the way, if you do implemente the SSn-N system, then
the
> > paths are
> > > the most traceable if the users use the path of
SS1-1,SSn-N.
> This 
> > > will identify the packets when they arrive anywhere by the
> > FIRST and
> > > LAST digis in the path.
> > > 
> > > Bob, WB4APR
> > > 
> > > 
> > > _______________________________________________
> > > aprssig mailing list
> > > aprssig at lists.tapr.org
> > > https://lists.tapr.org/cgi-bin/mailman/listinfo/aprssig
> > > 
> > 
> > 
> > 
> 
> 
> 
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