Subject: [NEXTEL-1] [KD4RAA-K4JDR Rptrs] Progress Energy NPRM Comments - Ham Radio and Harmful Interference

From: [email-masked]
Date: Wed, 05 May 2004 21:01:31 -0400

From:	Todd Ellis <[email-masked]>
Subject:	FW: [KD4RAA-K4JDR Rptrs] Progress Energy NPRM Comments - Ham
Radio and Harmful Interference

-----Original Message-----
From:	Gary Pearce KN4AQ [mailto:kn4aq@a...]
Sent:	Wednesday, May 05, 2004 2:04 PM
To:	KD4RAA Repeater Group; NC-Ham Mailing List; TEARA Mailing List; Triangle Hams

Subject: [KD4RAA-K4JDR Rptrs] Progress Energy NPRM Comments - Ham Radio
and Harmful Interference [note:	this report was originally formatted with
HTML. The HTML has been stripped to be compatible with this mailing list, but the missing fonts,
bold, italics and other formatting will make it somewhat hard to follow
-
KN4AQ)
Progress Energy NPRM Comments -
Ham Radio and Harmful Interference

Progress Energy's comments on the FCC's NPRM on modifying Part 15 to accommodate BPL included some illuminating information on how they see the product and its relationship to ham radio and interference. (Progress 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 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
BPL operations is low. We also believe that a properly designed and operated Access BPL system will pose little interference hazard to non-amateur services such as aeronautical, maritime and public safety.  Should any potential harmful interference with any state-wide communication system become apparent then it should be handled like any other report of harmful interference.
Emphasis added. The implication is that there is an interference hazard to the amateur service.
One big question hams have is: what procedure might be followed if a ham
receives BPL interference? We get a clue in a response to the NPRM proposal for an "automatic shutdown feature" in the event of interference (the NPRM doesn't specify how the automatic shutdown would work). This is from Page 6 of PEC's comments:
In addition, any reported harmful interference complaint should be investigated to determine first, whether or not it is related to the Access BPL system, and whether the interference is truly harmful.
Emphasis added. So, far from finding immediate relief from an interference problem, a ham would have to wait for an investigation. Nothing further is said about the time frame - an hour, a day, a week....
In a reply to interference complaints already filed by area hams, PEC
has shown that they want to engage the question of "harmful interference,"
and hold that the signals they put in the shortwave spectrum may be
interference, but they are not harmful. On Page 8 of their comments,
they put a much finer point on it, while also commenting on the actions of
the North Carolina hams who filed those interference complaints (I am one of
those hams):

Harmful Interference

As Progress Energy continues Phase 2 of its BPL pilot, we have received
several complaints of alleged "harmful interference" from amateur radio
operators ('hams"). The term "harmful interference" is defined in the
FCC's rules as interference that seriously degrades or repeatedly interrupts
another user's transmission. With regard to the hams, it appears that
they consider any interference to be harmful. It also appears that those that
have submitted complaints about Progress Energy's BPL system intentionally seek out interference using very sophisticated and sensitive equipment.
This leads to four factors Progress Energy believes the FCC should
consider when addressing the issue of "harmful interference". First, the interference should have to occur in the normal course of the complainant's operations, rather than be the result of the complainant seeking out the
interference. Secondly, the interference should have to be more than momentary. That is, for example, if driving another 30 yards will virtually eliminate the interference, then it is not harmful. Thirdly, the interference should have to be proven to so greatly interfere with operations such that communications are practically unintelligible.  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
Energy's BPL system intentionally seek out interference using very sophisticated and sensitive equipment.
The implication here is that if we had not gone looking for it, no
interference would have been found, so BPL is not a problem. But PEC is
operating three small trial areas, just a few square blocks each, with
two short overhead power line runs. There are no hams living in the trial
neighborhoods. And hams are generally not familiar with and aware of the
effects of BPL interference.

This is a trial, designed to discover both the promise and problems of
the system under investigation. So we did seek out hams who live near the
trials, and helped them identify the interference they were hearing. And
we operated mobiles in the trial areas themselves as "surrogates" for the missing home stations (inadequate ones at that, given the inefficiency of mobile antennas). We also consider mobile operation to be worthy of protection in its own right.
Our "sophisticated and sensitive equipment" included Icom 706 MKIIG transceivers, and an Outbacker Perth Plus antenna on one vehicle, and a Tarheel screwdriver antenna on the other. Common, routine amateur radio equipment.
With regard to the hams, it appears that they consider any interference to be harmful.
PEC took some liberty in paraphrasing the definition, at least as it appears in Part 97, where it says:
§97.3(a) (23) Harmful interference. Interference which endangers the functioning of a radionavigation service or of other safety services or seriously degrades, obstructs or repeatedly interrupts a radiocommunication service operating in accordance with the Radio Regulations.
We consider signals that appear in spectrum we are entitled to listen
to, covering broad swaths of that spectrum with carriers just 1.1 kHz apart,
with a 100% duty cycle, to be harmful interference.

First, the interference should have to occur in the normal course of the
complainant's operations, rather than be the result of the complainant seeking out the interference.
As I said, this is a small trial. We are seeking to discover the kind of
interference that hams will encounter in the normal course of
operation. We filed complaints, rather than just a cooperative report to
Progress Energy, because PEC and the industry were telling the FCC and the press that there were no complaints coming from hams, implying that BPL systems were not generating interference.
Secondly, the interference should have to be more than momentary. That is, for example, if driving another 30 yards will virtually eliminate the interference, then it is not harmful.
From the point of view of a mobile as "surrogate home station," it would
be difficult to drive the home station 30 yards. From the point of view
of "just a mobile," if the interference zone was just 30 yards, that might
not be so bad. But when driving along a road paralleled by a power line with
BPL, the interference zone is typically more like a mile. When driving perpendicularly away from the power line, we hear the signal for more like 100 yards, sometimes more. Add in stop-and-go traffic, stopping for a red light, pulling into a driveway or parking lot at the 7-11, and the time spent in the interference zone grows.
Thirdly, the interference should have to be proven to so greatly interfere with operations such that communications are practically unintelligible.
This is fantasy, an attempt to push PEC's version of the line as far upfield as they can, so that when a "compromise" is stuck, they might have gained a few yards. Would they be willing to accept that definition of harmful interference if it were applied to the two-way radio systems in 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 the market. A standard in this range would be fine. "Deaf as a block of wood" is not OK.

I believe the definition of "harmful interference" will be a battleground, with all parties weighing in. Eventually the FCC will have to make some calls, and I expect the "losing" side will challenge that.
Ham radio has some operating characteristics that are somewhat unique,
shared only with a few other radio services like shortwave listening. We
routinely comb our bands, be they busy or quiet, looking for signals. Often we are expecting to find weak signals, either from distant parts of the world, or from low power stations anywhere. The presence of a wall of 100% duty cycle carriers, 1.1 kHz apart, even just a few dB above the noise level, is "disruptive" to that operation.

We are the licensed, incumbent service. BPL seeks to gain access to spectrum "through the back door" of Part 15 in a way those rules never intended. We will not apologize for protecting our routine operation from 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@s...
kn4aq@a...
AOL/Yahoo Instant Messanger: KN4AQ
(send e-mail to be put on my "buddy list")

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