RFI Matters

As an amateur radio operator, I’m concerned that this device may cause radio frequency interference (RFI)  in the high frequency (HF) bands. Commercial BPL installations are required by the FCC to use “notch filters” to prevent RFI in the HF bands. What steps have you taken in this regard?

Your potential customers should know that they could be legally required to shut their Livewire modems down if they cause problems for nearby ham radio operators.

Here’s a little reading for you:

http://www.pcpro.co.uk/realworld/350648/does-powerline-networking-nuke-radio-hams

There’s no such thing as PREVENTING RFI in the HF band.   It’s only MITIGATED and reduced in certain notches.

 What steps have you taken in this regard?

It’s not a “You,” this is all stipulated by the HomePlug alliance which has been working with the HAM-heads for a while.

 they could be legally required to shut their Livewire modems down if they cause problems for nearby ham radio operators.

Oh, really?   I’m not familiar with such a law.   I know that HAM Radio Operators are required by law to avoid interfering with specific installations, but I am not aware of a law that requires ANY Class-B / Part 15 approved device to be Shut Down unless it’s not performing according to the original certification requirements.

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Tony’s right, Gyrogeerloose o.o

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From FCC Part 15 Regulations:

§ 15.5 General conditions of operation.

(a) Persons operating intentional or unintentional radiators shall not be deemed to have any vested or recognizable right to continued use of any given frequency by virtue of prior registration or certification of equipment, or, for power line carrier systems, on the basis of prior notification of use pursuant to § 90.63(g) of this chapter.

(b) Operation of an intentional, unintentional, or incidental radiator is subject to the conditions that no harmful interference is caused and that interference must be accepted that may be caused by the operation of an authorized radio station, by another intentional or unintentional radiator, by industrial, scientific and medical (ISM) equipment, or by an incidental radiator.

© The operator of a radio frequency device shall be required to cease operating the device upon notification by a Commission representative that the device is causing harmful interference. Operation shall not resume until the condition causing the harmful interference has been corrected.

(d) Intentional radiators that produce Class B emissions (damped wave) are prohibited.

Paragraph (a) doesn’t apply.    That’s just stating the FCC can change law and certificates are revokable.  In other words;  Grandfather Clauses don’t exist.   Also, HomePlug systems aren’t considered “Power Line Carrier;” that definition applies to UTILITIES ONLY.

(b):  … HARMFUL interference … 

refers to section 15.3(m):  Harmful Interference: Any emission, radiation or induction that endangers the functioning of a radio navigation service or of other safety services or seriously degrades, obstructs or repeatedly interrupts a radio communications service operating in accordance with this chapter. 

HAM Radio is not a radionavigation service or safety service.   Whether or not “Amateur Radio” is conisdered a service is debatable.   But the major point, I suppose is ©:  " upon notification by a Commission representative " …   I doubt that would ever happen…

And as the 15.3(gg) states, In-Home BPL is classed as “UNINTENTIONAL” radiator, so paragraph (d) doesn’t apply.

Paragraph (a) and (d) may have been added for the sake of completeness, although it seems true that they do not apply in this case.

It is not debatable that amateur radio is a service. It is in fact defined in the FCC Regulations as such, and is licensed and regulated according to Part 97.

Notification by a Commission representative sounds more momentous than it really is; it need only be a letter from the local FCC field office. Any operator in any service may file a complaint of harmful interference, but how the FCC responds depends on the strength of supplied evidence and the potential scope of the damage.

One would hope that the designers of the system have taken all the necessary precautions against causing harmful interference, but the experience of BPL has made that less of a certainty than it was once considered.

 …  and is licensed and regulated according to Part 97.

Indeed.  I was having trouble finding that one!  

This is all a very interesting exercise.    I am only really arguing the position that, since BPL *is* regulated and its allowance and usage is codified, it’s unlikely that an amateur radio operator would have the grounds necessary to trump the usage of an FCC certified in-home BPL kit.  I will agree after these points that it’s certainly POSSIBLE, but I don’t believe it PLAUSIBLE.

I have no doubt that there will be continue to be arguments in hearing rooms over UTILITY BPL as the interference is so widespread on such systems.  

Nothing stated here defeats this argument:    HAM Radio interferes with BPL.    I could therefore ask my field office to issue an injunction to stop my neighbor from transmitting in the same band while I am streaming NetFlix over my HomePlugs.  :smileyvery-happy:

TonyPh12345  said:

“Nothing stated here defeats this argument:    HAM Radio interferes with BPL.    I could therefore ask my field office to issue an injunction to stop my neighbor from transmitting in the same band while I am streaming NetFlix over my HomePlugs.”

I think you’re missing the whole point of paragraph b)

“…subject to the conditions that no harmful interference is caused and that interference must be accepted that may be caused by the operation of an authorized radio station…” (emphasis added)

The regulations are quite clear that official radio services have priority over Part 15 devices.

However, it doesn’t have to come down to someone turning off their device. RFI is generally manageable when people are willing to recognize and mitigate it. And Amateur Radio operators are generally knowledgeable about mitigation techniques and willing to help, even when they’re not legally obligated to do so. But it’s crticial that makers and users of Part 15 devices be aware of the existence of RFI, its causes, and cures. I think tha’s all the OP was trying to say.

Wow.  It’s amazing how many First-Time Posters this thread is attacting. 

Welcome, ya’ll!  :)

Midnight:  You’re right.   I totally missed that.

I agree with you about the cooperative aspect of all this.    I was taking on the argument (which, IMHO, was actually a veiled threat of sorts) that “The Man” will knock on your door and snatch your LiveWires!  

Tony, thanks for your thoughtful response to the points raised by me and others I presume to be fellow Hams.

The fact is “The Man” doesn’t have very many men, and the regulations are really predicated on cooperation and reasonable accommodation among all parties involved when RFI occurs. The Amateur service is largely self-regulated and self-enforced, and the FCC expects Amateur operators to be likewise self-reliant and cooperative in dealing with interferece between the Amateur Service and other services or Part 15 devices. Hams use Part 15 devices also, of course, so we all have the same vested interests in promoting the peacuful co-existence of all legitimate emitters.

More generally on the subject of RFI, I think I speak for most Hams when I say our concerns are two-fold. In the first instance, we believe that manufacturers often produce devices that are far noisier than they need to be. It’s usually quite inexpensive to mitigate RFI, but manufacturers are looking at the multiplied costs, and they often cut corners. Secondly, there is a need for awareness and cooperation among all parties when RFI occurs. Hams have specialized knowledge that we can’t really expect the general public to have; but the main thing needed by both parties is what we were all taught in Kindergarten.  :smiley:

So now, back to the veiled threat you perceived. I don’t know the OP’s intent, but it seems to me that he accurately stated what could be the worst-case consequence for someone purchasing a poorly-implemented Part 15 device. That could be seen not as a threat, but as an injuction to a manufacturer to protect the interests of their customers. And for what it’s worth, a quick persual of available information seems to indicate that in-home power-line broadband networks are not particularly problematic wrt RFI, in contrast to the commercial equivalent.

Thanks for educating me!

My experience with the FCC has been that in the “Old Days,”  20 or more years ago, the FCC was staffed by lots of competent, consciencious engineers and scientists.   More now:  it’s a typical government beurocracy that only weighs comments and arguments of outsiders (who are typically representing only their own interests.)  

Without that In-House expertise, there’s a problem remaining purely objective…

MidnightJava wrote:

 

So now, back to the veiled threat you perceived. I don’t know the OP’s intent, but it seems to me that he accurately stated what could be the worst-case consequence for someone purchasing a poorly-implemented Part 15 device. That could be seen not as a threat, but as an injuction to a manufacturer to protect the interests of their customers. 

Java, that was exactly the intent of my post–I was suggesting to the manufacturer that if they  hadn’t taken steps to prevent interference with the amateur radio bands, the owner of one of these devices could find him/herself forced to shut it down if no other method could be found to alleviate the problem. It was also intended as advice to potential customers, just so they knew what they might be getting into.

That said, further research has shown me that these devices have been properly engineered and should not cause problems for amateur radio operators unless they are actually using one in their own homes.