On Wed, 16 Dec 2009 11:35:54 -0500, Michael Coslo
wrote:

Jeff Liebermann wrote:

I don't want to comment on the legal part of the puzzle (because I
already have a headache). However, it should be obvious that there's
a potential conflict between unlicensed Part 15 operation, and
licensed part 97 operation on 2.4GHz. Place your bets and blast a way
with kilowatts on 2.4Ghz. Will 800,000 licensed US hams prevail over
perhaps 300 million unlicensed wireless devices? Want to bet on who
will win before an FCC tribunal? If there is a conflict, I'll place
my bets on Part 15.

No one in their right mind is going to be running that much power -
being line of sight, at those frequencies, there isn't any point.

Most of the Wi-Fi installations are setup to go through walls where
power is helpful. Not exactly line of sight. Some of the outdoor
installations are installed by WISPs (Wireless Internet Service
Providers) that sometimes user maximum legal power amplifiers. You
can also buy relatively high power client radios:
http://www.ubnt.com/products/xr2.php
That's +28dBm or 630mw, which is considerably more power than the
typical 50mw radios. There are also bi-directional power amplifiers
allegedly sold only for ham, government, and industrial use only:
http://www.ssbusa.com/kunamp1.html
and the video equivalent:
http://www.bhphotovideo.com/c/product/505472-REG/RF_Video_AMP_5000M_10_AMP_5000M_10_High_Power.html
from of all places a camera store. I've also helped identify and shut
down 3 such overpowered installations.

What's happening is as the 2.4GHz band gets more and more polluted,
some individuals seem to think that the solution is to increase their
TX power level. That's resulting in a very slow power war. The Wi-Fi
device manufacturers have caught on and are now advertising "high
power" devices, which seems to be anything over +20dBm (100mw).
Various pundits have predicted a power war, which fortunately hasn't
happened.

Regarding your hypothetical situation though, The likely outcome is that
the Amateur would be asked to turn down the power.

That's exactly what has happened in one of the situations that I was
involved. He didn't realize he was causing a problem and was very
cooperative. I also monitor the FCC enforcement actions:
http://www.fcc.gov/eb/AmateurActions/Welcome.html
and have not seen anything on 2.4 or 5.6GHz that required official
action. However, I do know of some warnings sent to WISPs over the
last 10 years or so for using too much power. So far so good.

They usually ask the
two parties to work together to get rid of the interference. But the
real onus is on the part 15 device owner. Dunno if you read the F.C.C.
enforcement actions, but the licensed service still "wins".

That's exactly the problem I mentioned. The licensed ham using 2.4Ghz
is within his rights to use 1Kw. He can also legally cause
interference to unlicensed devices without much consideration. So it
is written, and it must be. However, all it's going to take is a few
industry groups (i.e. lobbying interests) to claim that ham radio
operation on 2.4Ghz is somehow detrimental to the economy by impacting
Wi-Fi equipment sales, and I suspect there will be changes that impact
ham radio. Please consider my comments more as a warning than as a
denunciation.

BPL was an
attempt by economic interests to turn technical reality aside for
pecuniary reasons, but it looks like th elicensed services are going to
win that war now also.

BPL is going to die because the electric utility companies are not
seeing any revenue from the exercise, are getting some really bad
press, and really don't need the hassle. The interference issue gets
the press, but the decisions are always made on the basis of dollars.

After the ARRL got hold of the original documents
the F.C.C. used during the run up to BPL, and founf out thet the
commission ignored their own engineers findings, then tried to hide that
fact, it kinda let the air outta that tire.

True. Much credit to the ARRL for being able to do that. Still,
nothing has really changed at the FCC end. BPL systems that are
leaking well over established limits are still "working on the
problem". Most are still running in what is becoming a permanent
"trial" mode.
http://p1k.arrl.org/~ehare/bpl/ex2.html

Meanwhile, a rather large number of HomePlug devices, which is
essentially BPL for home internet, are being sold. They don't leak as
much RF power as real BPL systems, but still manage to make plenty of
noise:
http://www.mds975.co.uk/Content/amateur_radio_BPL_interference.html
Hmmm... It's QRN, not QRM. Oh well.
http://p1k.arrl.org/~ehare/bpl/Testing_HomePlug.htm
At least the ARRL is involved. Some HomePlug devices have
pre-programmed notch filters to reduce power on "sensitive"
frequencies which include ham bands.

- 73 de Mike N3LI -
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558