[aprssig] 9600 APRS net experiment in Central NJ

Jason KG4WSV kg4wsv at gmail.com
Sun Feb 27 08:48:03 EST 2011

On Sat, Feb 26, 2011 at 4:55 PM, Bob Bruninga <bruninga at usna.edu> wrote:
> Now consider what happens if you transmit to the digi on an INPUT ONLY
> channel.  Now your packet is not competing with those 95% to 98% of
> packet QRM

That's packet _traffic_, unless your definition of QRM is "all traffic
that isn't mine."

> from other Digipeaters but only with the 2 to 5% of other uplink packets
> in the same local area who might collide with your input at that closest
> digi.  THis is a HUGE benefit.

I don't see it.  You've still only got one 1200baud output channel.
Doubling the input bandwidth gives you twice as many chances for
collisions.  It also introduces more random timing delays, so the
second digipeat of a packet is less likely to occur simultaneously,
and therefor consume more bandwidth on the output channel in the
immediate area.


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