[aprssig] New-N paradigm and LOCALINFO Freq Objects

Lynn W. Deffenbaugh (Mr) ldeffenb at homeside.to
Tue Sep 24 16:00:47 CDT 2013

On 9/24/2013 4:11 PM, Robert Bruninga wrote:
> 1) It uses a hop, meaning it will blindly collide with  users in the
> VERMLN area because the digi (nor VERMLN) that is sourcing this packet
> into the network CANNOT HEAR ALL THE USERS of VERMLN.  Hence the network
> suffers reliability.  Hence the rule, only source these at the digi
> direct.

Call me dense, but I don't understand this statement in light of others 
that you have made about digis and whether or not they wait for a clear 
channel.  I understand that the sourcing digi can't hear what's going on 
at VERMLN, but I don't see how the request for a VERMLN explicit hop in 
the path will result in any more collisions than a path-less source.

The sourcing digi is going to transmit the packet whenever it thinks the 
local channel is not busy.  This may or may not collide with packets 
going on over at VERMLN regardless of the path of that packet.

If VERMLN didn't copy the packet due to local activity, then that 
particular 10 minute announcement doesn't get out in his area.  No 
collisions there, at least, none caused by the path of the packet.

If VERMLN actually copied the packet (meaning his local area activity 
didn't collide with it), then he will wait for his own local channel to 
be clear before performing the explicitly requested digipeat, no DWAIT 
delays, but still will delay if the channel is busy.  No collisions, and 
in fact, the same behavior as if VERMLN was sourcing the packet directly.

So I'm not seeing how a VERMLN path or no path is changing the 
collisions even though the sourcing digipeater cannot hear the users of 
VERMLN?  The path won't affect the original transmission timing and 
therefore it may or may not collide regardless of that path.

Of course, this whole discussion only applies if the coverage areas of 
both the sourcing digi and VERMLN are fully within the coverage area of 
the voice repeater being advertised!

Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32

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