[aprssig] Re: Tracker Smart Pathing
jdw at eng.uah.edu
Thu Mar 23 05:59:08 CST 2006
On Mar 22, 2006, at 7:13 PM, Wes Johnston wrote:
> Note that no matter what my path is, people very close to me hear
> my packet.
I really think that, for most people and applications, the practical
definition of "very close" will turn out to be "useless".
> Hey, a way to limit mobile's sending the same position while parked
> all day is to use the dupe checker with an extended timer... like
> 255 seconds.
> The problem with this is that the digi doesn't know the difference
> between a static position and an aprs client sending a message and
That's why just twiddling parameters on UIDIGI will _never_ result in
a smart digipeater. Most digis on the air (KPC3, TNC-2, etc) are
Commodore 64 era microcontrollers. Today you can get a flash based
microcontroller with more horsepower than that old C64 and _way_ more
processing power than the digi's microcontroller for $3 or $4.
> I'm just not sure that the job of decoding the multitude of aprs
> packet types and deciding yea or nay can or should be done at the
> digipeater level. Isn't this why we have a 7 layer OSI model?
Depends on who you mean by "we". APRS users only have 3 of those
layers - physical, data link, and application.
Having said that, the smart digi could also operate at the APRS
application level and do lots of things for us.
> However it would be handy if the digi used to stop redundant parked
> car packets was smart enough to not stop message type packets...
> but now I get into a moral delima.
Why? There is no moral dilemma to dropping packets of the joker who
forgot to turn off his $GPGGA spewing TNC when he parked. Let one
through every 5 or 10 or 15 minutes (tunable based on network load,
maybe station type?). A digi that's going to be smart enough to drop
"redundant" position reports _must_, IMO, be smart enough to let
message traffic pass normally.
More information about the aprssig