[Xastir] IGating

[James Ewen]

On 8/24/07, Steve Friis <wm5z at comcast.net> wrote:

> Way cool. Since the RF pollution is so high here, I am trying to lower
> it some to that low power stations can be heard, or at least stand a
> chance.

Steve,

Another incorrect supposition. Adding i-gating to your station will
not lower the amount of noise on the RF network directly.

> As it has been, there was not much chance for the low power
> stations in this area getting heard. My hope is that once heard and
> gated here, then the need to repeatedly be digipeated will be lowered.

By running an i-gate you will be able to help those low powered
stations located close to you to get to the APRS-IS internet stream.
You will not help lower the amount of traffic on RF though.

The amount of traffic on the local RF network is a product of the
number of stations in your area, the frequency of the beacons from
those stations, the path used by those stations, and finally the RF
digipeater network in your area.

It sounds like you have made the supposition that once a packet from
the RF network gets i-gated, that the packet stops on the RF network.
The RF network has no way of knowing anything about the internet. If
your local RF network has too many overlapping digipeaters that don't
support the new n-N paradigm, used by local users that use old
RELAY,WIDE paths, who beacon too often and with their power set too
high, then the low powered guys don't stand a chance.

You can fix any or nearly all of the above, which will make things a
little better for the low powered trackers, but the best thing to do
is to try and fix all of it. Of course that's easier said than done.

Adding more i-gates does not hurt the network, especially if you don't
send anything from your station to the rf network. Having redundant
i-gates in an area helps with the reliability of stations getting to
the APRS-IS. This can possibly help reduce the RF overload IF people
see that using a shorter path still gets them heard on the APRS-IS,
and that is their ultimate goal. If those stations use a shorter path,
or lower power, then the RF load gets reduced as a side effect.

You are in a very well developed area, and most likely you have
digipeaters located on mountain tops that can hear very large areas,
as well as users using long paths. This all adds up to too many
stations being heard on a limited RF channel.

Keep your station acting as an i-gate, but keep your outgoing path
short, and beacon frequency low so you don't add to the RF congestion.

James
VE6SRV