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[aprssig] RE: 6m MS network Performance Monitoring!

Robert Bruninga bruninga at usna.edu
Fri Jan 4 17:53:52 UTC 2008


> Why use packet when the other modes like WSJT 
> and PSK31 are a zillion times more efficient 
> for this type operation?

PSK-31 is ideal for weak signal, useless for 300 ms Meteor
windows.  Im not sure about WsJT modes.  But packet is ideal for
Meteor Scatter.  9600 baud is perfect, but 1200 baud should be
sufficient and is 100% compatible with what people have.  My
experience is taking what people have and applying it in a new
way is what can motivate a large movement.... And we need these
receivers at lots of Igates to make this work.  I measured my 6m
100W rig and it only draws 500 mA on receive.

> The concept I've advocated for years is to 
> put this frequency to real use and then 
> picking up the openings would be a side 
> benefit with no extra cost...

But our specific objective here is not occasional band openings,
or working DX.  It is simply taking advantage of MS as a
*reliable* 24/7 capability to get simple data out of an area.
(and have fun learning about MS while we are doing it and
waiting for that disaster to occur)...

I think Propnet works well as a band opening detection system.
I want to focus on the MS aspect... And take advantage of a
whole lot of 100W surplus FM radios.  That is why packet seems
best, where as WSJT needs linear SSB radios.

Oh, and since these 6m MS Igate receivers will all be listening,
then there is nothing to prohhibit someone from putting a 100W
APRS 6m station in his truck and driving around beaconing once a
minute.  His packet is just another packet into the APRS system.
The Igate doesn't care what propogation mode got it to  that
receiver.

But Bill Diaz makes a good point.  And that is that such 6m
Igates would best use some PRE-DUPE-FILTERING.  When the band
opened, the APRS-IS would not like to see 45 dupes per minute
from each Igate!  I am hoping that maybe if this project takes
off, that a special 6m Igate will be written to do the unique 6m
MS stuff:

1) Have its own dupe filter before sending to APRS-IS
2) Keeps statistics on dupe to monitor the band
3) schedule reverse message transmissions.
4) Cooperate with other in-range 6m MS igates
5) Monitor the APRS-IS for own packets for performance
monitoring.

Something like that...
Bob, WB4APR


Just my 2 cents.
Bob, WB4APR





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