[aprssig] APRS legality

Robert Bruninga bruninga at usna.edu
Thu Jan 29 12:10:27 EST 2009

>> I see 241 stations on local RF in the
>> DC/Baltimore area:
>> - 56 are digi's     (2-way)
>> - 44 are objects    (2-way)
>> - 50 are home stns  (2 way)
>> - 18 are home WX    (2-way)
>> - 60 are D7/700/710 (2-way)
>> -  2 are remote WX (1 way)
>> -  4 are Mic-E's   (1-way)
>> -  3 are NMEA      (1-way)
>> -  4 are trackers  (1 way)
> Even after all these years, Bob, you 
> manage to impress me. So now  
> objects are two-way APRS stations?

Because most of them that are transmitted from home stations are
two-way participants in the two-way APRS network.  And if they
follow the APRS SPEC, the transmitter of a tactical object needs
a receiver so that it can allow the object to be taken over by
another station.  That concept of anyone with new information on
an object to be able to take it over was fundamental to the
two-way APRS network and the proper handling of objects.  When
an object sender sees another station take over the object, it
is supposed to stop transmitting it.  Hence a tactical object is
by definition two-way.

However, I do stand corrected.  I did not distinguish between
the permanent objects and the tactical objects.  Not all of the
above 44 objects are tactical.  Some are permanent and are being
originated by digipeaters which do not support the take-over
protocol because the objects are permanent.  All of the New-N
paradigm FREQUENCY objects are permanent objects and so are not
two-way objects. So I will revise the above statistics to:

>> - 15 are tactical  objects (2-way)
>> - 29 are permanent objects (1-way)

> Even aside from this absurdity, I reject 
> these numbers as immaterial, the vast 
> majority of these stations, even though 
> they have receivers, are not expecting 
> transmissions, 

Huh?  Every one of the 214 two-way APRS stations (out of the 241
total) above are expecting transmissions and receive, process,
record and display those transmissions.  They receive positions,
weather, traffic, bulletins and messages from everyone else on
the net.  Else why even have APRS if no one is receiving,
processing, and displaying this info?

> and are not monitored by a human for such. 

Then why are these two-way stations even on the air?  Why do
these two-way stations, with receivers, processors, parsers,
even have displays?  ANSWER:  Because they are owned by APRS
operators that use those displays to receive, display and use
information of human value.

> They are sending their data in the blind, 
> every bit as much as if they did not have
> a receiver.

No, the only stations sending in the blind are the one-way
transmitter-only trackers, one-way remote WX stations and
one-way telemetry devices such as rain gages or flood gages,
because they are one-way telemetry devices.  The vast majority
of all the other two-way APRS stations are involved in two-way
communications on the two-way (one-to-all) APRS system.

> My statement that most people use APRS 
> one way is based on your own experience. 
> Every time you come back from a trip 
> you complain about there being no humans 
> on 144.39. True, because most people are 
> using 144.39 in a one-way fashion. 

There are many one-way devices on APRS, but they are a small
minority.  The vast majority are two-way stations participating
in the two-way (one-to-all) APRS system.  My complaints that you
hear from me after a long trip are:

1) Practically none of the DIGIpeaters along the vast I-81
interstate system put out any local (direct) FREQUENCY OBJECTs
so that travelers can find where the human operators in that
area hang out.

2) Very few of the mobiles with two-way APRS radios have Voice
Alert enabled so that you can contact them when in simplex range
or be alerted to their presence so that you can make a two-way

3) Some of those two-way mobiles are TRANSMITTING voice alert,
but then have their volume turned down and are not listening for
a call.  Transmitting Voice Alert is a *CQ*.  In my mind it
violates the principles of amateur radio to be calling CQ and
then not listening for a response.

4) uninformed individuals transmitting-only one-way on voice
alert (CQ)!  Thus irritating to any voice alert station that
comes in range, and killing the value of this excellent contact
capability in that area by forcing everyone to turn their volume

> How many of the 228 two-way stations you  
> claim above are participating in your 
> "rapid-real-time human digital  
> communications" system at this moment?

All of them as best I can tell.  Their systems are reeciving all
the time and are up-to-date with the immediate real-time
tactical picture.  When the human checks his screen, his system
is fully up-to-date and real-time, having received all of the
two-way data from all the other 2-way participants in the net up
to that instant. 

> I maintain people have a right to use 
> 144.39 as a one-way vehicle  
> tracking system if they choose. 

Me too!  I don't think I have ever said they were illegal nor
that they could not use the APRS system.  I use one-way trackers
all the time for tracking non-amateur mobiles and objects at
special events.  But the other 364 days of the year, the one-way
devices are of little value to our local net.

> I tire of this. I got involved because 
> of statements from you like
> On Jan 19, 2009, at 2:21 PM, Robert Bruninga wrote:
>> 2) Transmit-only-trackers!  These transmit-
>> only devices were killing the APRS concept of 
>> rapid-real-time human digital communications 
>> (APRS) by attempting to turn the national 
>> network into nothing more than a vehicle 
>> tracking system.  (APRS was never intended 
>> to be a "tracking" system.

Yes, I stand by that statement.  But I never said they could not
use it, nor that their transmissions were illegal.  In fact, I
agree with you that they are legal one-way devices.  But I also
stand by the statement, that the movement of APRS away from
two-way stations, towards one-way transmit-only devices, is
in-fact killing the APRS network as a two-way tactical system in
the minds of the uninformed (other 95% of amateur radio
operators who have never even tried APRS because they could care
less about being tracked). 
> It doesn't matter what you intended.  If these 
> trackers are killing anything (how can 
> something that is 8 of 240 (or 3% by 
> your own numbers), kill????)

Because lets say that 95% of ALL other amateur radio operators
(who have never used APRS) that I talk to, without exception,
think of APRS as only a vehicle tracking system of which they
sometimes vehemently say they have no interest in being tracked.
They are unaware of all the potential information they could be
receiving *from* APRS if they would use it as a two-way or
receive-only system.

> ... then it is because that is what these hams want.  

Yes, 3% of these APRS operators WANT to be one-way trackers with
no interest in what is around them.  But the other 95% of
non-APRS amateur radio operators that I have talked to, ***DO
NOT WANT TO BE TRACKED*** nor to be driving around with a
one-way transmit-only device.  They see amateur radio as a
COMMUNICATIONS system between operators.  Therefore they do NOT
even consider APRS, because they have been mislead by too many
people that APRS is a one-way transmit-only system.  That
concept is just dead wrong. (though popularly held).

> You are free to lament about missed 
> opportunities all you want, and encourage 
> people to do more real-time things, 
> but please do not try to tell people 
> that the way they choose to use 144.39 
> is any less valid than the way you 
> choose to use it.

I never do.  But what I do vehemently react to is your continued
prostelitizing to all that will listen that APRS is a one-way
system.  It was not, it is not, and the vast majority of
stations on the air are not.  Therefore I will argue till the
day I die, that APRS is a two-way system (one-to-all, and
all-to-one), and encourage operators to use it that way.  Else
it is just a dumb tracking system of little interest to the
greater amateur radio community that has NO INTEREST IN BEING
TRACKED!  One-way trackers and telemetry are welcome where they
are most useful, but they do not DEFINE APRS.


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