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Quieting the Buzz
BPL industry works with hobbyists

Though radio hobbyists and the broadband via power-line industry have been at each other's throats over interference concerns, there are instances where the two groups are working in unison. Both recently descended on Raleigh, North Carolina to explore ways to minimize BPL's impact on nearby radio signals. As this ARRL report explores, hobbyists met with officials from Progress Energy to take a look at Phase II of a trial ongoing in the south of the city.

The trial is taking place in a subdivision, with a half-mile of overhead power line feeder along a highway, a stretch of underground cable, and a few instances where 802.11 wireless gear played the network middle-man. Hobbyists set up shop and measured the levels of interference on the region (albeit before the lines were actually in full use). The conclusion? The Amperion equipment used in the trial is flexible enough to minimize interference if industry is properly motivated.

What's refreshing is that Progress Energy and Amperion are cooperating instead of simply denying the fact interference exists like some in the BPL industry.
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Dan48
Trailer Park Supervisor
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join:2002-12-17
Eh?

Dan48

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Power to THEM!

This is GREAT! A step in the right direction, that will hopefully give all people access to broadband. And it's great that the two sides are finally getting along and working it out. I am please to see this agreement, and hope they keep working things out... I do wonder how long this will last.

-Dan

MoJeeper
The Stig in 2012
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join:2000-10-20
Springfield, MO

MoJeeper

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Re: Power to THEM!

Key word in the article is "IF"

"The Amperion equipment used in the trial is flexible enough to minimize interference if industry is properly motivated."

firefox
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join:2000-12-03
Sunnyvale, CA

firefox

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Re: Power to THEM!

What do you think they need for proper motivation? A hug from the radio guys? Or do you think the profits from supplying broadband to pretty much every home that has a power socket is enough motivation?

MoJeeper
The Stig in 2012
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join:2000-10-20
Springfield, MO

MoJeeper

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Re: Power to THEM!

Uhh maybe the FCC ?

sherman06810
join:2000-10-15
Danbury, CT

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A lawsuit from a widow whose partner died as a result of the EMS being unable to properly dispatch its personnel in a BPL-enabled community.

Any company who operates a voice service prepares power backup and generation primarily for liability. They could care less if your phone service goes out because of a power failure - they only wish to limit their liability should you not be able to call 911.

Jeepster's right, the FCC should step in and do their jobs. Almost every electronic device I buy has the following:

"This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions:
1. This device may not cause harmful interference.
2. This device must accept any interference received, including interference that may cause undesired operation."

Why the FCC hasn't stepped in here and produced a set of maximum interference specifications is beyond me.

- Sherman
XJMark
join:2004-01-10
Seminole, FL

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XJMark

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Re: Power to THEM!

--snip--
Jeepster's right, the FCC should step in and do their jobs. Almost every electronic device I buy has the following:

"This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions:
1. This device may not cause harmful interference.
2. This device must accept any interference received, including interference that may cause undesired operation."
--snip--

The following paragraph pretty much sums it up, and is what I expected, (quoted from the ARRL story)»www.arrl.org/news/featur ··· /1/?nc=1

"It's too soon to draw many firm conclusions from this one test observation. Amperion's tests show that their signals meet Part 15 guidelines, although those guidelines were drawn more to measure the leakage from a computer cabinet than from a long unshielded wire. Amateur observation of this and other BPL trials show that, Part 15 limits notwithstanding, the radiation is clearly enough to cause harmful interference in the immediate vicinity of the power line, which would violate Part 15, whether the signal is within radiation limits or not."

Of particular interest is the following statement: "Amperion's tests show that their signals meet Part 15 guidelines, although those guidelines were drawn more to measure the leakage from a computer cabinet than from a long unshielded wire."

As I suspected, the device was tested for type acceptance as just that, a stand-alone device most likely an unintentional radiator. BPL is a "system" and not a stand-alone device. While one piece of the system may exhibit field strength within limits for an unintentional radiator in a laboratory, out in the real world connected to its infrastructure it is clear that it is operating outside of Part 15 limitations.

Of course, while there is no way to fit the transmission lines, power pole transformers, and household wiring of an entire town into an RF lab or anechoic chamber it was clearly not taken into consideration. These infrastructure components make up the entire system and they all become intentional radiators because powerlines are of sufficient length to resonate at those wavelengths.

Part 15 clearly defines intentional and unintentional radiators:

47 CFR 15.3(z) and 15.3(o) describe unintentional and intentional radiators.

15.3(z)
Unintentional radiator. A device that intentionally generates radio frequency energy for use within the device, or that sends radio frequency signals by conduction to associated equipment via connecting
wiring, but which is not intended to emit RF energy by radiation or induction.

15.3(o)
Intentional radiator. A device that intentionally generates and emits radio frequency energy by radiation or induction.

Another interesting point is found in the FCC's own Notice of Inquiry text for ET Docket No. 03-104 Released April 28, 2003.

"8. In addition, the existing Part 15 rules do not provide a clear procedure for measuring emissions from carrier current systems. On May 29, 1998, the Commission adopted a Notice of Inquiry in ET Docket No. 98-80 to examine its Part 15 line conducted emission limits. As part of that proceeding, the Commission requested comments on its existing Part 15 carrier current requirements and measurement issues. The Report and Order in that proceeding harmonized the Part 15 requirements for conducted emission limits with the international standards developed by the International Electrotechnical Commission (IEC), International Special Committee on Radio Interference (CISPR). However, because of the ongoing development of systems using new BPL technology, the Commission also decided in that Report and Order to defer the consideration of carrier current systems and BPL system issues to a separate proceeding."

Interesting, The FCC concedes that "the existing Part 15 rules do not provide a clear procedure for measuring emissions from carrier current systems." That would explain why this BPL nonsense was type accepted to part 15 as stand-alone devices in the first place. Since there's no way to type accept the infrastructure of an entire town you type accept what you can (the individual unintentional radiators) and just deny the rest as just figment of imagination as the BPL lobby has been doing.

The FCC is ultimately responsible for this mess by allowing the type acceptance of these devices knowing full well that a set procedure for measuring carrier current emissions didn't exist.

Part 15 regs. can be found here: »www.access.gpo.gov/nara/ ··· _02.html

EL My Ya
--And Then God Made Orlando
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join:2003-11-15
Columbus, OH

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said by Dan48:
This is GREAT! A step in the right direction, that will hopefully give all people access to broadband. And it's great that the two sides are finally getting along and working it out. I am please to see this agreement, and hope they keep working things out... I do wonder how long this will last.

-Dan

....gotta agree great step.

Microhard3
join:2001-08-03
Huntington Beach, CA

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Ok, I have been "kinda" following this, at some points they say incredible speeds then not so special speeds and then distance issues. Now, the thing is, everyone pretty much hsa a phone line, yet not everyone has the ability to get DSL. This is probably true about this, there is going to have to be infrasturcture build outs and many high costs associated with this. So, here we are the proverbial carrot on a string, what is the incentive of the power companies to take on all this overhead and additional personnel to launch and service this. Is there that many people out there that are going to bail on their cable modems and DSL to run through power lines ....and the questions again how fast and at what costs??

They will purchase the right politicians and silence the ones that don't sign on to do whatever they want to do, if there is money to be made in this you can believe they will do it. So...I wonder if they really are that excited about this?
w2co
join:2003-07-16
Longmont, CO

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Please keep in mind that this is still just a "trial" site that is expanding now to further "experiment" the effects and causes of interference and other things like data rate user load etc. There have been no rulings from the FCC either way yet. Another interesting article follows:

--US Representative Greg Walden, WB7OCE, has called on the FCC to put off any further action in its Broadband over Power Line (BPL) proceeding until the National Telecommunications and Information Administration (NTIA) releases the results of its BPL study and the public has had a chance to comment. Walden is a member of the House Subcommittee on Telecommunications and the Internet.

"I feel that it is important to give the NTIA study thorough consideration before proceeding further with BPL technology, in view of the importance of avoiding interference to federal government HF communications," Walden said in a January 15 letter to FCC Chairman Michael Powell. An Oregon Republican, Walden is one of two Amateur Radio licensees in the US House.

The FCC released a BPL Notice of Inquiry in ET Docket 03-104 last April.

In comments filed last August, the NTIA expressed "broad concern" about BPL. The agency--which administers spectrum allocated to federal government users--has said the FCC "must ensure that other communications services, especially government operations, are adequately protected from unacceptable interference."

The NTIA, which is part of the US Department of Commerce, subsequently undertook evaluations of BPL field test sites, in part to gauge the technology's interference potential. Walden noted that the NTIA's field work was scheduled to wrap up this month, and that its observations and conclusions would be released sometime during the first quarter of this year.

Walden told Powell that, given its interference potential to federal and nongovernment radio services in the HF and low-VHF range, the issue of BPL is "of great concern to me." He did not indicate in his letter that he was an Amateur Radio licensee.

"It is important that the commission give serious consideration to both the NTIA study and the subsequent round of public comment on the study results," Walden asserted. While agreeing with the goal of increased competition in broadband delivery, Walden encouraged the FCC to "give sufficient attention" to concerns raised regarding BPL's potential to interfere with other radio services.

"Allowing the public sufficient time to evaluate the NTIA study is clearly in the best interest of all," Walden concluded. He asked Powell to respond "outlining how you intend to proceed on this important matter."

Yes folks "how they (the FCC) intend to proceed" has yet to be announced. The interference is there as in the other studies done in other lands, and nothing the engineers do can stop this. As the saying goes "you can't change physics" and is true today.
mr weather
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join:2002-02-27
Mississauga, ON

mr weather

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Good first step

As a ham radio operator I'm glad to see some groups actually trying to achieve a middle ground. However, I'm certain any precautions to minimize interference will cost extra money. Many utilities in the United States are private, shareholder owned entities where the business is driven by the bottom line. If the shareholders aren't happy with their ROI I'm sure they'll find ways to cut costs. All those extra safeguards to reduce RFI? Get rid of them. It doesn't adversely affect the subscriber's service and saves us money!

It was this thinking that helped contribute to the Great Blackout of 2003. The utilities reduced their right-of-way tree trimming budgets -- to save a buck in the short-term. The power lines sagged from the load, touched the overgrown trees and failed! Voila, instant crisis that'll probably cost them more $$ in the long term.

mitchell
join:2002-06-21
Darlington, SC

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mitchell

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Re: Good first step

The Amateur Radio Operators in the Raleigh NC area, are some of the most pro-active and technically astute folks I've ever met. Progress Energy also is a company that 'tries to be morally correct' in most dealings with the public. Interesting enough is that the majority of folks from Progress Energy side were trained by hams that worked for the company before they (the old guard) retired. So maybe some of the common sense is left in Progress Energy.

Hopefully a good middle ground can be worked out and a suitable ground can be found in this test period.

Mitch
moonpuppy (banned)
join:2000-08-21
Glen Burnie, MD

moonpuppy (banned)

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Re: Good first step

said by mitchell:

Hopefully a good middle ground can be worked out and a suitable ground can be found in this test period.

Mitch

Amen to that.
N0JCG
join:2003-07-18
Minneapolis, MN

N0JCG

Member

Observations

Yes, this is a positive development. I have a few observations.
1. Progress Energy is admitting the obvious; that BPL will affect HF communications. I commend them for this.
2. Like all other BPL implementations, the HF noise is roughly 300 feet either side of an affected power line (about a football field; either side).
3. BPL must fill this space with harmful interference, but the frequency band is adjustable at the discretion of the BPL operator.
4. It's kind of like a water balloon; you squish it in one area and it pops out another. Where do we let it 'pop' out? SW broadcast? Aeronautical mobile? Marine? Maybe there is a range that the NTIA will give up. How do we manage that? Maybe BPL should have a "call sign". Then a licensed user can ask for 'space'; although how, and how often?
5. Local HF transmitters will affect the bit rate of BPL: BPL will have to live with it.
6. How many BPL operators will be as Forward thinking as Progress?

CheeseWare
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join:2003-04-24
Burnaby, BC

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CheeseWare

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Re: Observations

If being forward-looking is really at stake here, I would argue that investors (&Progress) should look at stringing fibre on the access segment, now that Chairman Powell has finally agreed that BPL makes no sense in rural areas. What problem are we trying to solve BTW? Sounds a whole lot cheaper, less risky, and operable to have a fiber solution. If Chairman Powell still wishes to encourage entrepreneurship and deliver the internet to the AC outlets, he really does not need to encourage further messing on the access segment. Entrepreneurs can't change the law of physics in regards to emissions on unshielded wires no matter how creative they get or how much financing they can raise.
N0JCG
join:2003-07-18
Minneapolis, MN

N0JCG

Member

Re: Observations

I agree, fiber is the ultimate solution. BPL would be a spectrum management nightmare. Why bother?
N0JCG

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BTW, if the housing development in question was new, why didn't the developer put in fiber?

CheeseWare
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join:2003-04-24
Burnaby, BC

CheeseWare

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Re: Observations

This smells very fishy... Maybe the AC outlets will have the internet (but they still do not need to mess with the access segment). Perhaps somebody in sales did not explain the difference in between the home and the access segment. Or perhaps they are shielding and burrying all the wires. Or maybe they are actually using underground fiber but are saying that they are using BPL with the intent to demonstrate no harmful interference. I will bet on that last explaination.;)
Ad astra
join:2004-01-13
Watertown, CT
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said by N0JCG:
2. Like all other BPL implementations, the HF noise is roughly 300 feet either side of an affected power line (about a football field; either side).

Can't agree with that. Reception of the BPL signal at a moderate level at a distance of just under a mile away shows clearly that the interference potential would not be confined to the immediate vicinity of the line carrying BPL, at least in the case of overhead lines.
said by N0JCG:
4. It's kind of like a water balloon; you squish it in one area and it pops out another. Where do we let it 'pop' out? SW broadcast? Aeronautical mobile? Marine? Maybe there is a range that the NTIA will give up. How do we manage that?

For the 3.5 Mhz wide employed channel used by Amperion in this test, there are a total of two slots below 30 MHz where that channel may be placed that would avoid overlapping amateur allocations and zero places that simultaneously avoid the amateur and broadcast allocations.

There's one additional slot in the 30-50 MHz region in which Ameprion's hardware can operate that wouldn't overlap police/fire/public safety allocations; provided that is the NTIA agrees it's okay for BPL to share with the DoD.

Frequency management for the BPL architecture described would seem not to be a delicate jigsaw puzzle, but rather a game of musical chairs with someone always being left out.

rf_engineer
join:2003-08-04
USA

rf_engineer

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Re: Observations

said by Ad astra:
For the 3.5 Mhz wide employed channel used by Amperion in this test, there are a total of two slots below 30 MHz where that channel may be placed that would avoid overlapping amateur allocations and zero places that simultaneously avoid the amateur and broadcast allocations.

There's one additional slot in the 30-50 MHz region in which Ameprion's hardware can operate that wouldn't overlap police/fire/public safety allocations; provided that is the NTIA agrees it's okay for BPL to share with the DoD.

Frequency management for the BPL architecture described would seem not to be a delicate jigsaw puzzle, but rather a game of musical chairs with someone always being left out.

Also consider that they have to use different frequencies between repeater segments. Frequencies can be reused further down the line, but it's my understanding that you need to have several repeater segments before a frequency can be reused. So it's very likely you'll see that 3.5 Mhz downstream and 2.5 Mhz upstream channel hit every chunk of 2-30 Mhz somewhere in a given neighborhood.

Something I wonder about is what kind of bit density they are getting. If it's something like 2 bits per hertz, it won't take long to saturate a 3.5 Mhz channel with traffic, especially when you're carrying traffic from other segments in the neighborhood back to the feedpoint and you take into account the "overhead tax".

Transmaster
Don't Blame Me I Voted For Bill and Opus
join:2001-06-20
Cheyenne, WY

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Transmaster

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One of My worries

One of the concerns I have with the ease in which one can interfere with BPL is This. You have a BPL wired community
and a couple of Ham Radio operators. These stations are operating and interfere with the BPL consumers. Now FCC
in it's part 15 rules tells these consumers they must except any interference, tell that to the Ham that has
angry people beating his door down because these liver-lip
fools got kicked out of the latest Turkey lurkey of lounano
game, after said Ham fires off a 1500 watt CQ DX.

Radio Active
My pappy's a pistol
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join:2003-01-31
Fullerton, CA

Radio Active

Premium Member

I wonder what this report actually means...

The ARRL article »www.arrl.org/news/featur ··· /1/?nc=1 has some very good documentation in terms of what, when, where, how, etcetera...

But the parameters were not fully explored/documented. Here's why.

There was not a full "data load" test... only what I would characterise as "sync test" and was only at a "quiescent" state, with no "real" data being exchanged. This should be explored more fully before we "conservative" hams can give our support to this technology (not that "our blessing" is needed for the "powers that be" to move forward ).

What will happen when each branch is fully "lit up" and active? This is a question that has not been fully answered.

In terms of scientific testing, this has not produced quantifiable or repeatable results (IMHO). It fails to conform to the term "scientific method".

I would like to hear rf_engineer follow up on this point...

Don't get me wrong-I am gratified to see preliminary results that seem to prove wrong my doomsday attitude regarding BPL... I want exhaustive, complete testing to be done. This test is neither exhaustive nor complete.

We are getting close to a solution. More must be done to perfect this "broadband alternative." I await this with much interest.

Cheers.
w2co
join:2003-07-16
Longmont, CO

w2co

Member

A seeming shift away from "Broadband Nirvana"

NEWINGTON, CT, Jan 23, 2004--In a seeming shift away from "Broadband Nirvana," FCC Commissioner Kathleen Q. Abernathy this week specifically cited Amateur Radio concerns about the interference potential of Broadband Over Power Line (BPL). In remarks prepared for delivery at her alma mater, the Catholic University of America's Columbus School of Law, Abernathy said BPL should not be widely deployed before dealing with ham radio's interference fears.

"I recognize that Amateur Radio licensees have raised concerns about harmful interference," Abernathy said, "and that is something that will have to be addressed before any mass market deployment can occur." She addressed the convocation "The Journey to Convergence: Challenges and Opportunities" January 22 on the school's Washington, DC campus.

Abernathy said that if engineers can find a way to prevent harmful interference to other radio services, BPL would represent "a tremendous advance for consumers, because it could bring broadband to any home that has electricity."

In her speech, "Overview of the Road to Convergence: New Realities Collide with Old Rules," Abernathy called BPL "another promising technology" that electric utilities have already successfully field tested. As an "add-on service to the existing electrical grid," she said, BPL might be a cost-effective alternative to provide broadband service to rural and other "underserved communities."

Missing from her remarks was any mention of interference worries that the Federal Emergency Management Agency (FEMA) and the National Telecommunications and Information Administration (NTIA) have expressed to the FCC in the BPL proceeding.

Abernathy drew fire from the Amateur Radio community last September after she expressed unabashed enthusiasm for BPL in a talk before the United Powerline Council's annual conference. In that talk, she'd suggested that BPL was a step along the pathway to "Broadband Nirvana."

The ARRL led the barrage of strong objections in the wake of Abernathy's characterization. ARRL CEO David Sumner, K1ZZ, told Abernathy that technical showings submitted in response to the FCC's Notice of Inquiry in ET Docket No. 03-104 "clearly establish that BPL is a significant source of radio spectrum pollution" that "cannot be implemented without causing harmful interference to over-the-air radio services."

Abernathy's office later conceded that her "Broadband Nirvana" speech may have failed to make sufficiently clear the commissioner's concerns about potential BPL interference. Sumner called Abernathy's subsequent clarification "most welcome and reassuring news."

More than 5100 comments--many from the Amateur Radio community--have been filed in response to the FCC's BPL NOI and are available for viewing via the FCC's Electronic Comment Filing System (ECFS).