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[aprssig] Local Event using RELAY?

John Kraus jfkraus3 at cox.net
Thu Mar 31 04:20:10 UTC 2005


At 09:00 PM 3/30/2005, you wrote:
>Ah ha!!!  The light came on for me!  Henk and I are talking apples to Pete's
>oranges...   Apples and Oranges...

This discussion is silly.

The key is to understand that the primary factor that influences whether a 
station is CSMA or ALOHA is, at its most basic, simply a matter of antenna 
height or more succinctly HAAT.

If a station is running near a unity gain antenna at less than 10 ft above 
ground it is almost always functionally ALOHA.  The exception being when it 
is on a high site or is located in a station dense area.

Conversely if it is located at 300ft HAAT or on a mountain it is mostly CSMA.

The key question is will it hurt the network to run a station that is 
functioning almost completely on the ALOHA level in such a manner that it 
can't hear before it transmits? The answer is no if it is set at a 
reasonable beacon rate.

Is it good amateur practice?  This may be open to discussion but it has 
nothing to do with the mode of the net.  Ultimately the question must be 
answered by the individual using their own ethical standards.

I personally don't think it is ideal practice but neither do I think it 
should be considered bad practice.  I see it as acceptable if the 
alternative is not being able to use the network at all. This is 
particularly true for the remote hiker who I feel has a greater right to 
the resource when compared to the routine home and weather beacons.

Ask this question:

If the transmitting station can not hear any station but the digi who will 
be harmed by its transmission in the blind? If the digi and the ALOHA 
collide who loses?

The answer in both cases is nobody.

Nobody is harmed by the blind transmission.

The ALOHA station must accept the loss of this packet as part of "its" 
network design it is expected and unavoidable therefore not harmful.

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