[NCham] Progress Energy NPRM Comments - Ham Radio and Harmful Interference

[Gary Pearce KN4AQ]

[note: this report was originally formatted with HTML.  The HTML has been=20
stripped to be compatible with this mailing list, but the missing fonts,=20
bold, italics and other formatting will make it somewhat hard to follow -=20
KN4AQ)

                            Progress Energy NPRM Comments -
                          Ham Radio and Harmful Interference

Progress Energy's comments on the FCC's NPRM on modifying Part 15 to=20
accommodate BPL included some illuminating information on how they see the=
=20
product and its relationship to ham radio and interference.  (Progress=20
Energy operates three BPL trials in the Raleigh, North Carolina area.)

It's been a long time now since they've said that there is no=20
interference.  In Page 4 of their comments, they now say:

Emission Limits and Interference

In general, we believe that the risk of harmful interference from Access=20
BPL operations is low. We also believe that a properly designed and=20
operated Access BPL system will pose little interference hazard to=20
non-amateur services such as aeronautical, maritime and public safety.=20
Should any potential harmful interference with any state-wide communication=
=20
system become apparent then it should be handled like any other report of=20
harmful interference.

Emphasis added.  The implication is that there is an interference hazard to=
=20
the amateur service.

One big question hams have is: what procedure might be followed if a ham=20
receives BPL interference?  We get a clue in a response to the NPRM=20
proposal for an "automatic shutdown feature" in the event of interference=20
(the NPRM doesn't specify how the automatic shutdown would work).  This is=
=20
from Page 6 of PEC's comments:

In addition, any reported harmful interference complaint should be=20
investigated to determine first, whether or not it is related to the Access=
=20
BPL system, and whether the interference is truly harmful.

Emphasis added.  So, far from finding immediate relief from an interference=
=20
problem, a ham would have to wait for an investigation.  Nothing further is=
=20
said about the time frame - an hour, a day, a week....

In a reply to interference complaints already filed by area hams, PEC has=20
shown that they want to engage the question of "harmful interference," and=
=20
hold that the signals they put in the shortwave spectrum may be=20
interference, but they are not harmful.  On Page 8 of their comments, they=
=20
put a much finer point on it, while also commenting on the actions of the=20
North Carolina hams who filed those interference complaints (I am one of=20
those hams):

Harmful Interference
As Progress Energy continues Phase 2 of its BPL pilot, we have received=20
several complaints of alleged =93harmful interference=94 from amateur radio=
=20
operators (=91hams=94). The term =93harmful interference=94 is defined in=
 the FCC=92s=20
rules as interference that seriously degrades or repeatedly interrupts=20
another user=92s transmission. With regard to the hams, it appears that they=
=20
consider any interference to be harmful. It also appears that those that=20
have submitted complaints about Progress Energy=92s BPL system intentionally=
=20
seek out interference using very sophisticated and sensitive equipment.=20
This leads to four factors Progress Energy believes the FCC should consider=
=20
when addressing the issue of =93harmful interference=94. First, the=20
interference should have to occur in the normal course of the complainant=92=
s=20
operations, rather than be the result of the complainant seeking out the=20
interference. Secondly, the interference should have to be more than=20
momentary. That is, for example, if driving another 30 yards will virtually=
=20
eliminate the interference, then it is not harmful. Thirdly, the=20
interference should have to be proven to so greatly interfere with=20
operations such that communications are practically unintelligible.=20
Finally, the sensitivity of the measuring equipment must be standardized.

Emphasis added.

Point by point:
It also appears that those that have submitted complaints about Progress=20
Energy=92s BPL system intentionally seek out interference using very=20
sophisticated and sensitive equipment.

The implication here is that if we had not gone looking for it, no=20
interference would have been found, so BPL is not a problem.  But PEC is=20
operating three small trial areas, just a few square blocks each, with two=
=20
short overhead power line runs.  There are no hams living in the trial=20
neighborhoods.  And hams are generally not familiar with and aware of the=20
effects of BPL interference.

This is a trial, designed to discover both the promise and problems of the=
=20
system under investigation.  So we did seek out hams who live near the=20
trials, and helped them identify the interference they were hearing.  And=20
we operated mobiles in the trial areas themselves as "surrogates" for the=20
missing home stations (inadequate ones at that, given the inefficiency of=20
mobile antennas).  We also consider mobile operation to be worthy of=20
protection in its own right.

Our "sophisticated and sensitive equipment" included Icom 706 MKIIG=20
transceivers, and an Outbacker Perth Plus antenna on one vehicle, and a=20
Tarheel screwdriver antenna on the other.  Common, routine amateur radio=20
equipment.

With regard to the hams, it appears that they consider any interference to=
=20
be harmful.
PEC took some liberty in paraphrasing the definition, at least as it=20
appears in Part 97, where it says:

=A797.3(a)
(23) Harmful interference. Interference which endangers the functioning of=
=20
a radionavigation service or of other safety services or seriously=20
degrades, obstructs or repeatedly interrupts a radiocommunication service=20
operating in accordance with the Radio Regulations.

We consider signals that appear in spectrum we are entitled to listen to,=20
covering broad swaths of that spectrum with carriers just 1.1 kHz apart,=20
with a 100% duty cycle, to be harmful interference.

First, the interference should have to occur in the normal course of the=20
complainant=92s operations, rather than be the result of the complainant=20
seeking out the interference.

As I said, this is a small trial.  We are seeking to discover the kind of=20
interference that hams will encounter in the normal course of=20
operation.  We filed complaints, rather than just a cooperative report to=20
Progress Energy, because PEC and the industry were telling the FCC and the=
=20
press that there were no complaints coming from hams, implying that BPL=20
systems were not generating interference.

Secondly, the interference should have to be more than momentary. That is,=
=20
for example, if driving another 30 yards will virtually eliminate the=20
interference, then it is not harmful.

 From the point of view of a mobile as "surrogate home station," it would=20
be difficult to drive the home station 30 yards.  From the point of view of=
=20
"just a mobile," if the interference zone was just 30 yards, that might not=
=20
be so bad.  But when driving along a road paralleled by a power line with=20
BPL, the interference zone is typically more like a mile.  When driving=20
perpendicularly away from the power line, we hear the signal for more like=
=20
100 yards, sometimes more.  Add in stop-and-go traffic, stopping for a red=
=20
light, pulling into a driveway or parking lot at the 7-11, and the time=20
spent in the interference zone grows.

Thirdly, the interference should have to be proven to so greatly interfere=
=20
with operations such that communications are practically unintelligible.

This is fantasy, an attempt to push PEC's version of the line as far=20
upfield as they can, so that when a "compromise" is stuck, they might have=
=20
gained a few yards.  Would they be willing to accept that definition of=20
harmful interference if it were applied to the two-way radio systems in=20
their service trucks?

Finally, the sensitivity of the measuring equipment must be standardized.

The Icom 706 MKIIG has a good receiver, but it is not the best performer on=
=20
the market.  A standard in this range would be fine.  "Deaf as a block of=20
wood" is not OK.


I believe the definition of "harmful interference" will be a battleground,=
=20
with all parties weighing in.  Eventually the FCC will have to make some=20
calls, and I expect the "losing" side will challenge that.

Ham radio has some operating characteristics that are somewhat unique,=20
shared only with a few other radio services like shortwave listening.  We=20
routinely comb our bands, be they busy or quiet, looking for=20
signals.  Often we are expecting to find weak signals, either from distant=
=20
parts of the world, or from low power stations anywhere.  The presence of a=
=20
wall of 100% duty cycle carriers, 1.1 kHz apart, even just a few dB above=20
the noise level, is "disruptive" to that operation.

We are the licensed, incumbent service.  BPL seeks to gain access to=20
spectrum "through the back door" of Part 15 in a way those rules never=20
intended.  We will not apologize for protecting our routine operation from=
=20
this encroachment.

73,
Gary KN4AQ
ARRL NC PIO, Wake County ARES




__________________________________________________________________________
        Gary Pearce KN4AQ        editor, SERA Repeater Journal
        Cary, NC                 www.sera.org
        919-380-9944             kn4aq@sera.org
        kn4aq@arrl.net
         AOL/Yahoo Instant Messanger: KN4AQ
         (send e-mail to be put on my "buddy list")