[aprssig] EchoLink APRS-IS Ojbects Mothballed

[Robert Bruninga]

> It does need to look for ACK's, to 
> both limit the retries, and to try 
> and make sure the message gets through.
> How many retries have to be sent on 
> average to each I-Gate to look 
> for improperly configured I-Gates.

For delivering real-time message data, nothing beats the
original APRS decay algorithm,

TX once, then 8 seconds later, then 16, 32, 64, 128 and (in this
application), stop there and quit.  This gives you 5 retries in
a minute and then it shuts up.

Yes, the first 8, and 16 second one will not get through most
Digipeaters 30 sec DUPE filters, but that is OK, since that
means that it DID get digipeated, and that is most of the
problem in throughput.  But at least if the first one does not
get through, then the latency to the next retry is only 8
seconds.

This was how APRS was supposed to work.  Too bad many popular
clients ignored these fundamentals and just implemented
simplistic 1 minunte retries.  As a result, most people have
never seen how rapidly APRS can be used for real time human
communications.  With these simplistic clients it will be 5
MINUTES before they might get a line of text on the 5th retry
instead of 1 minute with the original APRS.

Where it really wins is in the first retry.  8 seconds per line
of text instead of a minute.

Bob, WB4APR