[aprssig] Just my 2 cents worth on smart beaconing

Keith VE7GDH ve7gdh at rac.ca
Tue May 24 17:18:23 EDT 2011

Wes AI4PX wrote...

> Kenwood has released a new firmware that up's the max speed setting 
> in the smart beacons. Great. But I think there is some misunderstanding
> in the "fast speed" setting. And your mileage may vary...  This speed
> setting should not be of any interest for people in cars and trucks

I don't understand why you think drivers of cars or trucks wouldn't be
interested in the SmartBeaconing fast speed setting. Anyone that uses it
should be interested in all of the SmartBeaconing settings and have
appropriate settings entered. This includes the fast speed and fast rate.
Any mobile station not using SmartBeaconing should have a good reason
for not doing so.

> I set my "fast beacon" rate to 45mph... If my 'fast beacon" was
> set to 70 mph, I'd never get into time/distance beacon mode!

I would recommend setting the fast speed to your normal highway
speed and the fast rate between 60 and 120 seconds. I go with 60
seconds because where I live, it would be impossible to travel at
that speed for more than 2-3 minutes at a time. I set the slow speed
and rate to 5 kmh and 600 seconds. Corner pegging takes care of
the rest.

If I lived somewhere with roads and speed limits that permitted travelling
at highway speeds for long periods of time, I would consider a fast rate of
120 or even 180 seconds.

> If you set your fast beacon rate to say 70mph, you will never get into
> time/distance beacon mode in town. Think about the curves in most
> roads in your town that would needlessly trigger a beacon... so many
> that I'd be willing to bet it would be akin to QRM. I guess a lot of
> people want to see dots on a map for every curve in the road but what
> us folks watching you want to see is to see when you turn onto a side
> street.

The fast speed and beacon rate aren't meant for "in town". They are
meant for highway speeds, or at least what would be your normal fast
rate of travel. There are SmartBeaconing settings to limit the rate of
beacons due to corner pegging. If anyone is using SmartBeaconing
and it produces results akin to QRM, I would suggest that their settings
were way out of wack.

I wouldn't consider a beacon caused by a curve or a 90  degree turn to
be needless - if normal and appropriate SmartBeaconing settings were used.

Looking at AI4PX-9, you don't seem to beaconing at an excessive rate. What 
settings are you using?


> Smart beaconing should allow us to /reduce/ our beacon rates because we
> tend to transmit only when there is a notable change.

It allows you to automatically beacon at a higher rate when you speed up, and
at a lower rate when you slow down, plus corner pegging.

> The internet jockeys forget or don't know about dead reckoning because aprs.fi
> doesn't display guestimated positions and I'm going to guess that they will want
> to transmit more often since their car would appear stuck in one position until
> the next TX.

I just don't get that. I know that it's supposed to be a criticism of something,
but I'm not sure of what.

> In realistic terms, I'd love to know a)that you are moving, b) that you are
> still moving, c)when you change roads. Heck, if you program the turn slope
> right, smart beaconing will TX when you turn into a parking space at the
> local burger joint.

SmartBeaconing does all of that.

> But please, set your "fast beacon" just a hair above the fasted speed you'd
> expect to make a turn we'd need to know about.  Remember, we want to know
> about TURNS not CURVES in the highway.

I would disagree with that. I would recommend setting the fast speed at your
normal highway speed, not the speed that you would take a curve at. If it is a
gentle curve, beaconing at the fast rate should be fine. If it's a cloverleaf or 90
degree turn, corner pegging with normal settings will catch it.

I think that you are all for SmartBeaconing, but I'm not entirely sure that I
would agree with your suggestions, although AI4PX-9 doesn't  too out of whack.

73 es cul - Keith VE7GDH
"I may be lost, but I know exactly where I am!"

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