Radio Frequency in the Power Lines

[ThomasLMcLean]

I have just received this from the ARRL and thought that this group may have an interest in it. I personally believe that RF is one of fine audio's biggist problems.

The FCC released its Notice of Inquiry (NOI) on the deployment of
''Broadband over Power Line'' (BPL) technology on April 28 and now is
accepting comments. A form of carrier-current communication better
known as power line carrier (PLC), the technology has raised
concerns of substantial interference to the Amateur Radio HF bands.

BPL would couple high-frequency RF to parts of the power grid and
use existing power lines as the transmission medium to deliver
broadband and Internet access. In the NOI, the FCC acknowledges the
interference risk from BPL.

ARRL Lab Manager and RFI guru Ed Hare, W1RFI, has cautioned that
deployment of BPL could affect every amateur in communities where
it's employed with a significant increase in noise levels. More
information is on the Web at www.arrl.org/tis/info/HTML/plc/.

The complete NOI is available on the FCC Web site. The FCC now is
accepting electronically filed comments via its Electronic Comment
Filing System ECFS Express page. To initiate a comment, click next
to ''Broadband over the traditional telephone network.''

Good Listening;

[phase_accurate]

My feeling is that this technology was already dead before even fully born, at least in Europe !!
Some service providers already withdraw their plans for implementing this technology.

Furthermore I still have problems to understand how the heck stupid managers can force engineers to develop new communications technology for today and tomorrow - when tommorrow's technology is already existing for decades in an even more powerful version: GLASS-FIBRE

Regards

Charles

[nemestra]

Whilst I agree with Charles that fibre is by far the best medium you don't see anyone installing fibre to the home. Businesses will get (and pay handsomely for) fibre to their buildings but the 'last mile' problem for domestic users is as economically difficult as ever.

Cable companies ( at least in the UK ) have spent billions digging in coax - almost to the point of bankrupting themselves. ADSL offers a slightly easier solution as the wires are already in place. Power line technology will not easily go away because there are massive potential financial benefits.

On a technological front it will be a nightmare. Providers are simply hoping that no one will make too much of a fuss when they deploy it. If after a few trials not too many people complain then they have a winning technology in their opinion. If only a few radio amateurs complain - well they are not a very important group are they?

Trials are still continuing, see:

http://www.theregister.co.uk/content/22/29992.html
http://www.theregister.co.uk/content/22/29669.html
http://www.theregister.co.uk/content/archive/27221.html

The classic quote on power line, also from The Register is:

http://www.theregister.co.uk/content/archive/17775.html

>>>
The technology encountered particularly fierce opposition for radio hams. The Low Power Radio Association (LPRA) described powerline technology, which was been tested in the north of England in 1998, as causing "alarming levels of interference".

"Eavesdropping aliens and the industrial archaeologists of the future may well wonder why we built a phased array across the north of England to beam credit card numbers and digital images of naked ladies into the atmosphere," Nick Long of the LPRA memorably said at the time.
>>>

Unfortunately this technology like so many other recent ones could yet produce another big increase in radio spectrum pollution. <sigh>

James

[phase_accurate]

In Germany it is not only the HAMs who complain it is also the army, ambulance ,.......


The expected increase of the noise-floor throughout the shortwave range is about 10 dB (as far as I remember), i.e. tenfold in terms of power.

Regards

Charles

[nemestra]

Originally posted by phase_accurate
In Germany it is not only the HAMs who complain it is also the army, ambulance ,.......


Charles

That's good! These are important groups who are objecting. It might make a difference. However, as with all economically driven scenarios, it may be cheaper to 'move' the problem users than fix the real issues. The army, ambulance etc. may be persuaded to move to other bands, modulation modes etc. such as TETRA or a secure digital scheme.

James

[ThomasLMcLean]

I believe that we all agree that this concept is technically dumb with many much better approaches available. It will also contribute to a higher RF field in and arround our homes. In audio this will tend to increase background noise and the non-specific mud in the signal. We clearly don't need or want it.

We do need to pass this opion on to the FCC in a visit to their wed page (See No. 1).

Comlpain now or forever hold your peace.

[jackinnj]

Originally posted by nemestra
On a technological front it will be a nightmare. Providers are simply hoping that no one will make too much of a fuss when they deploy it. If after a few trials not too many people complain then they have a winning technology in their opinion. If only a few radio amateurs complain - well they are not a very important group are they
James

Power lines are already a PIA if there is a slight misconnection. The problem for the power distributors is that it is very expensive to fix one of these RFI problems, but they do interfere with many, many communications services. The best things ham radio ops can do is to sniff out the location of the problem for the power company and identify the location. We have a little patch of Northern New Jersey where a.m. radio is "unlistenable" due to interference from the power lines for the electrified railroad.

The ARRL is also making a stink about the use of small, micropower 432MHz transmitters -- used by retailers for inventory control, etc.

[jackinnj]

seems that the FCC is waking up to the problems of using the power grid as a "last mile solution" -- that's the case in the US where FCC Commissioner Abernathy's enthusiasm has waned, at least according to the ARRL

Now the Japanese have concluded that it would interfere with emergency communications services, etc.

physicists, radio astronomers are starting to raise a stink -- it would put an end to radio astronomy.

probably good news for serious audiophiles that this source of intentional interference is getting sidetracked.

[jackinnj]

The following appeared in the ARRL weekly blast email -- seems that the onus is now on the user of ham or audio gear, emergency services, etc. NOT the provider. This will be a disaster for those of you who like your power lines quiet:

<em> FCC OKAYS BPL PROPOSAL

The FCC has unanimously approved a Notice of Proposed Rule Making (NPRM)
to deploy Broadband over Power Line (BPL). The NPRM is the next step in
the BPL proceeding, which began last April with a Notice of Inquiry that
attracted nearly 5200 comments--many from the amateur community. The FCC
did not propose any changes in emission limits for unlicensed Part 15
devices, but said it would require BPL providers to apply "adaptive"
interference mitigation techniques to their systems. An ARRL delegation
that attended the February 12 FCC open meeting in Washington later
expressed disappointment in the FCC action.

"The Commission clearly recognized that the existing Part 15 emission
limits are inadequate to stop interference," Sumner said," but it's
placing the burden of interference mitigation on the licensed user that's
supposed to be protected," said ARRL CEO David Sumner, K1ZZ.

Sumner said that if the FCC really believed current Part 15 emission
limits were sufficient, it would not have had to require that BPL
providers institute interference mitigation systems. The FCC has not yet
released the actual NPRM, and a presentation by the FCC's Office of
Engineering and Technology (OET) revealed only its broad outlines. Sumner
said the League would not take a formal position until it reviews the full
NPRM.

Anh Wride of the OET staff spelled out the scope of the NPRM, which only
addresses so-called "access BPL"--the type that would apply radio
frequency energy to exterior overhead and underground low and
medium-voltage power lines to distribute broadband and Internet service.
She said the OET staff believes that interference concerns "can be
adequately addressed." Wride said the FCC's BPL NPRM:

* Applies existing Part 15 emission limits for unlicensed carrier-current
systems to BPL systems. Part 15 rules now require that BPL systems
eliminate any harmful interference that may occur "and must cease
operation if they cannot," she noted.

* Requires BPL systems to employ "adaptive interference-mitigation
techniques, including the capabilities to shut down a specific device, to
reduce power levels on a dynamic or remote-control basis and to include or
exclude specific operating frequencies or bands."

* Subjects BPL providers to notification requirements that would establish
a public database that would include the location of BPL devices,
modulation type and operating frequencies.

* Proposes guidelines to provide for consistent and repeatable measurement
of the RF emissions from BPL and other carrier-current systems.

Mirroring his colleagues' enthusiasm, FCC Chairman Michael Powell called
BPL "tremendously exciting," although he conceded that BPL has "a long way
to go." Powell also said the FCC's OET has worked very hard to try to "get
their hands around" the issue of interference and that the FCC would
continue its vigilance in that area.

The FCC has posted additional information, including a public notice
<http://hraunfoss.fcc.gov/edocs_publi...C-243879A1.doc> on
its Web site. The Commission is expected to issue the complete Notice of
Proposed Rule Making within a few days and will invite comments on it
sometime after publication.

Additional information about BPL and Amateur Radio is on the ARRL Web site
<http://www.arrl.org/tis/info/HTML/plc/>. To support the League's efforts
in this area, visit the ARRL's secure BPL Web site
<https://www.arrl.org/forms/development/donations/bpl/>.