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[aprssig] Extending javAPRSSrvr's dupeTime

Steve Dimse steve at dimse.com
Tue Sep 23 02:01:49 UTC 2008


On Sep 22, 2008, at 9:36 PM, Pierre Thibaudeau wrote:

> However, these balloons climb to 75000+ft so they are heard by quite a
> number of digi's anyway. Even if they are not digipeated on RF, they
> are going to be sent over the Internet many times.

Yes, but the internet system is designed to handle dups. The root of  
this problem is the long path, fast update rate, and high altitude of  
the transmitting station. Essentially this balloon saturated the RF  
network for hundreds of miles. Because of the congestion, some digis  
were not able to clear their queue of one packet before the next was  
transmitted. Most likely every within 200 miles had real difficulty in  
getting their packets heard over this kind of QRM.

The answer is not to try to fix the APRS IS to handle this abuse, but  
to prevent the abuse in the first place. Most balloon launches  
transmit on a frequency other than 144.39, with IGates set up just for  
the event. There is no need for digis with a balloon launch. If you  
must transmit on 144.39, it must be without any digis in the path and  
with a slow transmit rate. Anything else is abuse, plain and simple.

Steve K4HG







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