[aprssig] Future Concept for APRS

Matti Aarnio oh2mqk at sral.fi
Sun Sep 20 14:53:01 EDT 2009


Oops.. this got rather long...
But do read, there is a Request For Comments inside here.

On Sun, Sep 20, 2009 at 11:26:26AM -0400, Bob Bruninga  wrote:
> >>> ... I propose ... digipeater... intelligence
> >>> ... local area "mapped"... define spatial 
> >>> rules... they could...  make joint decisions
> >>
> >> BoB:  All Excellent ideas if one were 
> >> designing a commercial system with a 
> >> business model and a [specific] service 
> >> one wanted to define and deliver.  But 
> >> impossible in a flexible amateur network:
> >
> > Benjamin in Finland: Yes. All those ideas are 
> > very reasonable, if there is to be any future 
> > for APRS.
> >
> > Get rid of all last-century hacks, and for 
> > Joe's sake, try to start to think at least 
> > a teeny-weeny bit professionally.
> 
> I admit that European and USA amateur radio differ drastically in mission
> and intent.  In the USA there is legal support for emergency and public
> service communications, whereas in Europe (in general) there are no such
> provisions and amateur radio is more of a competition contest of QSO, and
> wildly competing individual interests.

Remember that for radio amateur, an RF path with 1/10 000 change of getting
the QSO is GREAT THING, but for professional emergency use, the change of
failing the QSO must be at that level, or lower!

Emergency communication is also not considered amateur radio, and most of
our regulator rules on this continent have  a) dimm view at other than
ham radio in ham bands,  b)  look that emergency comms are not ham radio..
Regulators in Finland have taken a bit more lenient approach on this
recently.  Still due to typo, our current regulations state that you can
practice emergency communication on ham bands, but you can not actually
do it in real emergency.   Presumably the powers that are will tell us
frequencies to work on,  but then we have no antennas pre-made for it,
nor radios tuned and practiced to work there...

> > You can spend all your time opposing 
> > changes, but let me tell you one
> > very simple fact:
> >
> > It is not going to make our operations 
> > any different. This is what you call 
> > freedom, I suppose? We will filter, we 
> > will restrict, we will take all possible 
> > measures to keep our network functional. 
> 
> Ah, then you have to nail down exactly what everyone in your network wants.
> I guess if all anyone wants is a vehicle tracking system driving cute
> internet displays, then that is pretty EASY to optimize  (at the loss
> of flexibiitly for other applications)...

Not everyone, but:
  a) network viability must be preserved
  b) careless flooding with non-local traffic must be discouraged,
     or preferrably actively prevented, because foreigners are not
     discourable quite so easily, and other regulators may have even less
     existing power over their subjects (or are a bit too libertarian in
     their thinking - don't care about anything except bottom line,) than
     our own regulator.
  c) Regulatory issues on non-ham originated traffic are a pain
     (And reason why there are no Tx-IGates in UK.)

Network viability preservation says that if you do send more than N messages
per minute, we must not digipeat your packets.  Not digipeating same packet
heard from another local digi a few seconds before (viscous digipeating) is
also a viability preservation issue. 

Digipeating packets with indicated position far from local system is also
very questionable.  When a chap in south Sweden sends a beacon of WIDE7-7,
and I hear it repeated 5 to 10 times in Helsinki, it means that  a) there
is 2m tropo in baltic!   b) bloody flools really should know better and not
do that kind of thing in the first place.  A WIDE3-3 is quite enough!

I have heard (literally, I had FM audio open in addition to TNCs "listening")
when a WIDE3-3 from northern sweden (ESRANGE Kiruna) made it thru 3 hops
along entire Finland.

Using messages (unreliable at best, and charset issues unresolved outside
US-ASCII) is for a Finn a very bad joke.  Our mobile networks have supported
so called "short message service" since beginning of digital services, and
here we have  a)  no charset problems,  b)  commercial reliability, and
c) commercial service rates that are so cheap, that even hams will not
bother to play with unreliable ham-radio packet networks.

So, if here somebody wants to use messaging with somebody, they are within
the service area of same digipeater.  No non-local traffic.


We do agree among ourselves, that UIDIGI type digipeaters must be killed.
Real Smarts take a few magnitudes more memory, than what an embedded modem
from 20 years back can have installed.

Also, all products with DEAD SOFTWARE (= no sources are available for any
reason, development stopped) are to be deprecated.  When algorithms are
wrong, they must be fixed, or things trashed for good.

A KISS TNC can barely be accepted without source code, but DIGI is so much
more complex thing that there really is no excuse for non-source systems.

If you transmit positionless packets, in our thinking they will not be
digipeated unless you have recently enough sent a position that is within
our local service coverage.  All packets are IGated from RF to APRSIS
regarless.

A 2m FM Radio, KISS TNC and a fanless nano-ITX computer running Linux can
do wonders.  All running from 13.8V battery rail, etc.  Heck, there is no
absolute need for the KISS TNC even, the Linux computer can run soundmodem
on audioport with PTT trigger on parallel or serial port.
(Nano-ITX machines have real ports, while desktop PCs don't have anymore.)

> > Remember, it is our network, not yours. 
> > We will even write new software if what is 
> > currently available is not up to _our_ standards.
> 
> I wish I could write new software too, since very few APRS clients meet
> my expectations...


There is another way you could approach on this:

  Write Requirement Specifications for APRS clients.

  Write updated consistently edited APRS master document.


Can you figure out what is wrong with your current heaps of APRS-1.0.1
amendment text files ?    You have now so many amendment notes that
I have lost count!   After about 5 erratas, you really should have had
the APRS WG restarted to edit  APRS-1.1,  APRS-1.2,  etc.

Of course now you do not have an WG disagreeing with you, and correcting
most obvious inconsistensies.


Here locally we have been hashing some Requirement Specifications for
an APRS DIGI/IGATE as we see it.  You all are welcome to comment on it:

  http://repo.ham.fi/svn/aprx/trunk/doc/


I am not best writer that there is, and obviously I am not native english,
but your well considered comments are welcome.  Preferrably look at PDF,
always quote SVN version, page masthead version number, page number and
line number.  (That is: complete context.)



> >> we came up with the new-N paradigm to 
> >> give a national consistent system, 
> >> instead of individual incompatible feifdoms
> >
> > Yes. National, not international. Most 
> > of the interference up here comes from 
> > abroad. From Sweden and from Russia.
> 
> I agree, that is a problem.  And depending on the normal cooperation of hams
> across those borders may or may not need the national solutions.  But that is
> why I inidicated that the New-N paradigm works as a national system in the
> USA where there is very little if any "communicatios boarders"...
> 
> Are those bothersome packets coming in with hops greater than 2?  If so, then
> simply implementing the New-N paradigm recommendation of 2 hops in most areas
> would seem to solve most of the problems.

The problem is not well behaving local users.  Correct parametrization lets
them fit on our single radio channel quite nicely,  but most stuborn few who
think that "it is my radio channel" can flood "new-n" system quite efficiently
over a few thousand km range when tropo conditions are upon us.  Otherwise
couple hundred km of open water is nice isolation barrier.   Somehow these
stuborns ones tend to have high elevation antennas and high power radios...

Correctly behaving digi system keeps serving local users while stupid ones are
left powerless to harm networks that are not their local.

> I do not oppose any "national" solutions to "national" problems.  That is
> kinda how humanity os organized, so it makes sense to let those boundaries
> and local problems dictate the action required.
> 
> Good luck.
> Bob, Wb4APR


73 de Matti, OH2MQK




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