European manufacturers of collision avoidance hardware for sailplanes are
proposing to use 433 MHz for the signals from their aircraft mounted transmitters.

These would use a propriatary (secret) signal protocol to transmit position,
altitude, velocity, and other tracking information to other aircraft with their
equipment on board.

While it is a sense of "radiolocation", it is not radar in the sense of current
radiolocation activities on the band.

Note that the transmitters and receivers will be located in aircraft (not just
sailplanes), and will cover a wide area. As collision avoidance equipment they
would likely be considered safety of life, and not get along well with shared
frequencies.

I have not heard of this in the amateur community, and I doubt that the ARRL
knows about it, though they have been objecting to ground based robots operating
on those frequencies.

It sounds like a camel nose in the tent.

Alan
wa6azp



From: Westbender
Newsgroups: rec.aviation.soaring
Subject: Flarm in the US
Date: Thu, 12 Aug 2010 18:10:50 -0700 (PDT)

On Aug 12, 4:48=A0pm, Dave Hoppe wrote:
I'm waiting for one more response regarding flarm frequency and
approval status in the US.

And here it is:

Dave,

no problems, I'm very glad to help you!

It is a free frequency (SRD). In Europe we use 868Mhz, in the US it
will be 433Mhz. PowerFLARM automatically chooses the right frequency
for the place you are at - this means you can also use yours in europe
e.g. on competitions without having to change settings.

FCC approval is on its way and is going to be done before first units
start shipping.

Cheers
Marc

On Aug 14, 12:42 am, (Alan) wrote:



I have not heard of this in the amateur community, and I doubt that t
he ARRL
knows about it, though they have been objecting to ground based robots op
erating
on those frequencies.


Good morning, Alan.

The League is aware of the issue. I am confident that the appropriate
action will be taken.

73

Lloyd, KC5FM

Looks like a useful application of the shared band. On what grounds should
we (secondary user ourselves) object?

--
73, de Hans, K0HB
--
"Just a boy and his radio"
--
Proud Member of:
A1 Operators - http://www.arrl.org/a-1-op
MWA - http://www.W0AA.org
TCDXA - http://www.tcdxa.org
CADXA - http://www.cadxa.org
LVDXA - http://www.lvdxa.org
CWOps - http://www.cwops.org
SOC - http://www.qsl.net/soc
TCFMC - http://tcfmc.org
--
Sea stories here --- http://k0hb.spaces.live.com/
Request QSL at --- http://www.clublog.org/logsearch/K0HB
All valid QSL requests honored with old fashioned paper QSL!
LoTW participant


I have not heard of this in the amateur community, and I doubt that the
ARRL
knows about it, though they have been objecting to ground based robots
operating
on those frequencies.






--- news://freenews.netfront.net/ - complaints: ---

On 8/16/2010 6:34 AM, Radio KØHB wrote:
Looks like a useful application of the shared band. On what grounds
should we (secondary user ourselves) object?


I have not heard of it before the thread here either.. But I seriously
suspect the ARRL DOES know about it epically if there has been an FCC
filing.

Recently the ARRL responded to a bunch of Waiver requests filed with the
assistance of APCO (which is an orgination representing public safety
communications officers.. IE: ME in the days when I was working, though
I am rather pleased to say I never joined. Though this had nothing to do
with it at the time (they do a better job of representing bosses.
epically the ones that spell boss backwards, but that's another story
not radio related)

There is a Recon Robot.. Recently shown on the TV show Flashpoint that
operates in the 70 cm ham band. It's only 0.3x watts so to be honest
the poetntial for interference to my 70cm operation (I can push 50 watts
there) is minimal.. But my concern is if the robot is providing eyes and
ears to police in a hostage situtation.. And I listen to the frequency
it's using and hear nothing but noise (the 0.3x being below my noise
floor) what happens when I key my 50 watt transmitter. or "Joe" (Generic
name) keys his hundreds of watts transmitter and totally wipes out the
signal from that tiny-bot?

Same concern here. This is a safety product. Now if you want to use a
shared frequency for something where it's possible to key up and "Say
Again" I have no issues with that.

But when robots are talking to either other robots, or people. at low
power, and I'm sure these Collision avoidence jobs will be low power
cause they only need to talk to a receiver hundreds of yards away, not
hundreds of miles.

What happens when the neighborhood ham keys up and wipes the system out?

This is a 'critical' service and such services should NEVER be on a
shared frequency. NEVER.. Because if you put them there sooner or later
the secondary (or primary depending on the nature of the sharing) will,
not being able to hear the low power signal, KEY UP with much more
power and drown you out.

--
Nothing adds Excitement like something that is none of your business.

Alan wrote:
European manufacturers of collision avoidance hardware for sailplanes are
proposing to use 433 MHz for the signals from their aircraft mounted transmitters.

These would use a propriatary (secret) signal protocol to transmit position,
altitude, velocity, and other tracking information to other aircraft with their
equipment on board.

While it is a sense of "radiolocation", it is not radar in the sense of current
radiolocation activities on the band.

Note that the transmitters and receivers will be located in aircraft (not just
sailplanes), and will cover a wide area. As collision avoidance equipment they
would likely be considered safety of life, and not get along well with shared
frequencies.

I have not heard of this in the amateur community, and I doubt that the ARRL
knows about it, though they have been objecting to ground based robots operating
on those frequencies.

It sounds like a camel nose in the tent.

It sounds like reinventing the wheel to me.

There are already systems being implemented on aviation frequencies to do
this.

See for example:

http://en.wikipedia.org/wiki/Automat...ance-broadcast

http://en.wikipedia.org/wiki/Traffic...oidance_system

Also cheap (for aircraft) portable systems:

http://www.zaon.aero/

Any such system must get blessed by both the frequency regulators (FCC in the
US) and the aviation regulators (FAA in the US) and I wouldn't give this
thing a snowball's chance in Hell of getting approval in the US or any
other country of any significance.


--
Jim Pennino

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