[aprssig] Why Not "Gate in Vicinity"

Gregg Wonderly gregg at wonderly.org
Wed Dec 28 05:42:33 EST 2011

On 12/25/2011 10:43 PM, Pete Loveall AE5PL Lists wrote:
> You make the mistaken statement that the APRS-IS is a "network" capable of things like "QoS".  It isn't; there is no underlying network protocol.
My perception of what happens with the APRS-IS, is that it is a level 2 
network.  It has source and destination information, and, as you say, no 
end-to-end QOS, because everything is "one-direction" only.  That's just exactly 
what we need, no more, and no less.

Now, on top of that simple flow, we have "APRS messaging" that provides an 
application level "ack" mechanism as long as bi-directional traffic works, but 
still, we don't demand that it work, and the applications are supposed to tell 
the users when their messages do not appear to be received.

So, this simple network, which is very "primitive", and thus quite limited, is 
not the concern or consideration.

What is necessary, is for software at the interface from APRS-IS to RF, to 
maintain some throttling.  1200->300 baud and APRS-IS->1200/300 baud both could 
use this kind of mechanism.  Right now, based on Pete's posts, and the general 
feelings about APRS-IS to RF gating visible in posts here, the acceptable 
APRS-IS->RF gated "bandwidth" is zero.  So, I don't know that we'll really be 
able to have a conversation about this, if key people involved in the most used 
technologies are not interested in making anything happen.

I've been very interested in putting a computer in my vehicle that I would WiFi 
connect my portable devices to.  That computer could then have I-gate software 
and connection sharing configured with a cellular modem connected to the 
internet.  That would provide internet connectivity for the mobile device, while 
it was also connected to this i-gate software computer system.  Next, I would 
use a TNC/software to provide an audio stream in and out of a 2M radio to 
provide my own RF interface.

This is all doable, with the right technical skills, and the money to have the 
extra, $60/month for a cellular modem in the vehicle.  In the grand scheme of 
things, this seems like an excessive investment to accomplish the same thing as 
the APRS-IS could provide to mobile devices.

In the above scenario, we'd still have the "mobile" devices generating traffic 
on 144.390.  The question is whether or not the software systems would be doing 
the right things.   I think it's vital to continue to see how we can include 
other means of connectivity to facilitate the use of APRS for its intended purposes.

Not everything involving Ham Radio needs to limited to just what we can do when 
the public infrastructure is broken.  We do need to be ready to support that 
kinds of operations, and I'm all for be able to operate under those conditions.  
However, we have a lot of other operational capabilities using public 
infrastructure as well as the network technologies that we all have considerable 
experiences with.

The public networks are a conduit that will not always be in place.  But the 
components of that network, are really no different than the i-gate(s) or 
digipeaters we use locally.   When something stops working, we need to have a 
plan for how to deal with that.   In the end, going from

Gregg Wonderly

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