[Xastir] UDP frames

[Jason Winningham]

On Jan 10, 2005, at 11:33 AM, Curt Mills wrote:

> It might be more useful with an
> 802.11 network set up for a smaller event, where officials could
> keep track of the event on laptops with 802.11 cards, and the actual
> trackers would be on ham APRS.  In that case you don't need UDP
> though.

Maybe come up with a well-known UDP port, then let APRS tracker 
applications treat UDP/IP port 255.255.255.255:xyz as an interface.  
802.11 "trackers" (PDAs, etc) could deploy with non-ham mobile assets, 
802.11 access point stations could link them to an RF gate, either a 
gate at each AP, or maybe network the IP back to a single gate for RF 
distribution?  802.11 trackers would update only when in range, e.g. 
checkpoints, mile/kilometer markers, etc.  Gate 802.11 to RF and vice 
versa, and everyone gets the big picture, and non hams can use APRS on 
802.11.

I like it. Is there a port, well-known or othwerwise, in use for APRS?  
Maybe we could just define one, and define the format, which should 
probably be just AX.25 (sans sentinels) dropped in the UDP payload.

Of course, there's the callsign issue when gating to RF.  Also IP 
addressing: subnet broadcast, all subnets broadcast, global broadcast, 
or multicast?

Heck, I could probably get hardware so set one up here just to play 
with.  Anybody know how far you can reasonably cover an area with an 
802.11 card/amp/interface combination?

In my enthusiasm for a project more interesting that what I'm doing 
right now (:, what am I missing?

-Jason
kg4wsv