Manassas Hams Continue BPL Fight > Bottom Line

Bottom Line

The FCC's rules about BPL have their limitations, but a few points are pretty clear:

BPL must meet limits for electromagnetic radiation from the lines. Unfortunately, by radiocommunications standards, these limits are very high, and locally, very strong noise levels will result from "legal" BPL systems. On some frequencies, these limits are about 1000 times higher than the noise levels permitted for computers, as an example. BPL systems operate continuously across several MHz of spectrum; they operate all of the time and they may be built as big as an entire state.

BPL has an unconditional requirement not to cause harmful interfernece to licensed radio services. To meet this requirement, it must must employ *sufficient* filtering that its noise will be below the level of signals being used by licensed radio services. In Manassas, COMTek has tried to "notch" its system by turning off carriers in the Amateur bands, but the notching is not sufficient to protect Amateur communication. The resultant noise, typically "S9" on a radiocommunications receiver's signal strength meter, is rated as "strong" by the international standards for S-meter readings.

Under the FCC's rules, BPL must avoid locally used spectrum. It is certain that in Manassas, there are people who listen to international shortwave broadcast station. None of their spectrum is being notched.

While some BPL companies are still embroiled in ongoing interference problems, things have generally gotten this far only when the company involved has not taken sufficient steps to actually eliminate interference. A company that "fixes" interference with press releases announcing that they have corrected all legitimate claims of interference is starting a downhill slide that, in the long run, cannot succeed.

Is interference from BPL inevitable? Not necessarily, although locally, any spectrum that a BPL system uses cannot be practically used for anything else. Some BPL designs have been deployed without major interference problems.

Motorola uses wireless as its backbone, and uses HomePlug modems on the 240-volt wiring. HomePlug automatically notches most Amateur bands, and Motorola has improved this notchign with additional filters. This additional filtering is an important pro-active step to prevent interference.

Current Technologies and IBEC use 30-50 MHz on the primary distribution lines (the overhead wires seen in most neighborhood). If they carefully choose their use of frequency, in most areas, they could avoid interference to radio services in that spectrum. They operate HomePlug modems to the premises. The notching in the Amateur bands has been shown to be sufficient to protect mobile operation in the area, and, based on the experience in Cincinatti, there have been no reports of interference from fixed Amateur stations in the area. The noise levels in that area are typical for crowded residential areas, and it is highly likely that when HomePlug-based BPL is deployed in low-noise areas, some fixed Amateur stations will experience interfernce. Although Current and IBEC have not (yet) developed solutions, both have assured ARRL that if interference does occur, they will discuss the issue with ARRL and consider solutions at that time. (Fair enough.)

Other BPL technologies have not yet been shown to operate without harmful interference to Amateur Radio. Although they can all "notch" spectrum, the state-of-the-art of notching in most systems deployed today appears to be about 25 dB. When this poor filtering is used on BPL that operates on overhead lines, the resulting interfence occurs along significant lengths of overhead line, degrading the local noise levels by 15 to 30 dB in the notches.

In some BPL systems, it is even worse -- recent ARRL testing in Briarcliff Manor, NY and Allentown, PA show that BPL operators do not always notch the Amateur bands at all, an in both systems, operation at or near the FCC limits is occuring in the Amateur bands in some parts of the BPL installation.

Those who can't fix their interference, or who don't want to do the engineering necessary to address the EMC aspects of BPL, have tried to paint interference reports as being "frivolous," to use their favorite word, or to portray the ARRL as having some agenda against BPL. The fact that some companies have done what they apparently are not doing -- addressed EMC -- doesn't stop the spin. And in reality, ARRL has been very clear that it is not against BPL, but is deeply concerned only about its spectral pollution and interference. ARRL has backed that up with very clear statements when it has found BPL designs or implementations that do not cause major interference problems. It has backed that up over years of working productively with industry -- one example can be seen at:

»p1k.arrl.org/~ehare/rfi/HomePlug···ARRL.pdf

It is ironic that the largest deployment of BPL in the US is building on work done with HomePlug and ARRL long before it was envisioned to use HomePlug for access BPL.

ARRL is continuing to work cooperatively with the BPL industy -- at least those parts of it that are willing to address EMC issues with improvements to technology instead of press releases. Two weeks ago, DS2, a major BPL chipset manufacturer, sent two of its engineers to ARRL HQ. DS2 has claimed to have improved the notching in its 200 Mb/s generation 2 chipsets to 40 dB, a 15 dB improvement over the state of the art notching that is resulting in interference problems such as are seen in Manassas.

ARRL and DS2 measured two of the modems DS2 brought with them and they did indeed show this improvement. Although it is not at all certain that all manufacturers that use this chipset can achieve the 40 dB, it's pretty clear that the underlying technlogy is capable of this improvement. It is clear that this will be sufficient to work at least as well as HomePlug to prevent interference to Amateur Radio with in-premise applications. It also will be an improvement for access BPL, and ARRL looks forward to working with DS2 and one or more of their customers to see how well this will work out in deployed access BPL systems. Unfortunately, not all DS2-based manufacturers have chosen to work with ARRL on EMC issues, one of them has been very open and communicative, and ARRL expects to work with them directly.

This improvement may help achieve the general goal -- to reduce the likelihood of harmful interference to a small enough number of cases that it is practical to address the remainder on a case-by-case basis.

All of the spin of those companies who are choosing confrontation over solutions, and there are still a few of them out there, doesn't hold up when compared with proactive and productive work between ARRL and those companies that choose to address their interference problems in their design laboratories instead of in their press-release and legal offices.

Real engineering instead of press releases is resulting in real solutions. Those considering the installation of BPL systems should consider the EMC track record of the involved company first, because the EMC policy of the manufacturer involved with make the difference between their system being the next one to be part of the "BPL fight" or a more positive statement that they have deployed BPL without major interference problems. Being able to say that about more systems would be a happy outcome for all.

Ed Hare, W1RFI@arrl.org
ARRL Laboratory

Basically a good summation of all the issues against Comtek and what is really going on in the rest of the country.

Ed, some questions I have been wondering about, notching frees up the small portion of the HF/low VHF bands that are used by US Hams, but do they also notch the areas used by other countries? Also, what is happening to the other users of this spectrum or do we even care about those people?
--
I am not lost, I find myself every time.

reply to tlcbob
I would agree with you...
IF all parties dealt with the facts and tried to work with the laws of the land and the laws of physics.

The FCC is not taking a proper stance on this matter due to polls, politics and promises. The FCC seems to be (to the technologically knowledgeable), administrated more and more by lawyers and politicians and less and less by technology experts.

Most BPL providers are hoping to win by advertising victory and compliance rather than trying to resolve illegal interference issues. The power companies are not charitable organizations looking to bring broadband to the ruralites...its looking to make more money by throwing bad technology into their power lines, hoping that it will stick- through strong PR and the salivation of the masses.

The majority of BPL providers seem to be playing with and building on the lack of enforcement of the FCC rules. They send out press releases claiming that they are a holy grail technology, have no issues and that anyone who complains has an unwarranted agenda. For the average Joe, this is good news and far too many folks will take anything they read in the paper as rote. They won't know about the FCC, the rules and how interference may affect or potentially affect others. When it becomes a niche technology, the average Joe will forget about it for the next great hype (or hopefully proven technology) while the byproducts and interference of BPL will linger.

The FCC has received very compelling evidence about the violations of most BPL systems, but they stand back and say, "work it out". BPL says, "we did!" and things stay the same.

This is not to say that some BPL providers aren't trying to coexist with other technologies without wiping out their RF spectrum. For those naysayers who say that it's all about the ARRL vs. BPL or the "hams" vs. BPL, there are some very good examples in which this is simply not the case. By looking at them, the naysayers are compelled to agree that the "hams" are not anti-Broadband or anti-BPL, but are taking a legitimate stand against some RF polluting byproducts. We peacefully coexist with cable television even though the signals they use are in one of the the ham bands. If BPL wants to exist, they should play by the rules, and try to fix their technology rather than just brag about it and pretend that the problems do not exist.

For someone like markopoleo, he will he back with his blinders on, stoking the fire at the feet of the BPL industry. Would he bother to comment on, or offer convincing counterpoints to the liked of Ed Hare W1RFI who is closer to this issue than perhaps anyone on BBR? No way...yet he hopes, like many of the BPL providers, that if he says something enough times that it will somehow come true. Maybe that stuff works in Hollywood studios, but not in the real world.

Unfortunately, the casual reader may mistake markopoleo's posts as reasonable, without knowing the facts, details and his history of baseless claims. This is the only reason why there are continued responses to folks like him.

Rob

reply to W1RFI
The bottom line is......

How much money is the ARRL receiving from the fixed line telecommunications companies for its "BPL Defence fund"?

It's interesting to me that this whole thread went dead as soon as the question of telecomms companies funding the ARRL BPL defence fund was mentioned.

I looked at the annual report like you suggested. It starts off by attacking BPL (fullstop, not just the Cincinnati system) and admits to having 50 (fity) anonymous sources of funding, whilst providing no details of how much those anonymous donations amount to.

It's also interesting that you immediately decry my question by labelling it a "conspiracy theory" it isn't, it's just a question that deserves an answer.

And once that question is answered I have another. Why isn't the guy who's driving round Cincinnati looking for interference on his ham radio concentrating on his driving, rather than 10-4ing his good buddies? There's plenty of evidence that using mobile comms whilst driving is very dangerous. It's time a law was brought in to ban it...... In fact, as there's no problem with notching out frequency for static ham radio, perhaps I'll get in touch with the UPLC guys and see if we can organise a campaign to ban irresponsible behaviour like this when driving

You keep asking me to provide evidence to back up my question. What kind of logic is that. If I knew the answer, I wouldn't be asking.

What's so uncomfortable to you about my question "how much money does the ARRL receive from telecomms companies". It's just fine for you and I to say we don't know the answer, maybe someone else does. And while we're at it, what's the deal between the ARRL and Motorola?

My point about using mobile comms whilst driving is, as you rightly say, just as applicable to cell phone users. I'm not excluding them. The evidence of the increase in accidents directly applicable to using mobile comms whilst driving is out there. I'm serious, most European countries have the ban in place in order to save lives, why not in America? The fact that this would also help to deal with the BPL interference argument is just a bonus.

I make no secret about my motives for wanted BPL technology to be given a chance. I want cheaper broadband, I want cheaper energy prices, I want the information I need to help me reduce the energy I use, I want to cause less pollution and I want to see a big improvement in the supply and management of our dwindling natural energy reasources.

I even want these things for you to.

OK, my hands are up. You seem like a reasonable person and seem to know your subject. I apologise for being a jerk with some of the comments I've made. In my defence I have to say I have talked to telecomms execs who think their industry is providing funding and support to the anti-BPL lobby, they’ve never backed it up and it's probably not true. It also isn't important.

My problem is this. I am a big fan of BPL, I think it's going do a lot of good, particularly in places in the world that don't have the resources or infrastructure the USA has. Yet when I try to talk to people about BPL I always get them come back saying it can't work because it interferes with amateur ham radio users. If I search for broadband over power line on the net, I will always hit a story about how it pollutes the airwaves, usually before anything else. I don't find the articles about the potential economic benefit, the demand side management potential and the reduction in Co2 possibilities, nothing. Just some good 'ol boy and his crackling radio signal.

I keep reading about how radio hams are the only people who can communicate after a natural disaster and it just isn't true. The most reliable and accessible communications infrastructure for the emergency services is invariably the communications systems belonging to Critical Infrastructure Industries (CII) i.e. the utilities companies. Take a look at the UTC response to the FCC review of the impact of the hurricanes on communications networks »www.fcc.gov/eb/hkip/PubCom/utc.pdf

The utilities companies are the guys with the experience of keeping this stuff working, not just for a relative few good intentioned amateurs, but for the entire emergency response effort.

I’ve got no beef with radio hams, I admire the seriousness with which you treat your hobby, but that’s what it is, a hobby. Some of us energy people are trying to find ways to build additional revenue streams to attract the investment we need to handle demand growth and the aging transmission and distribution infrastructure, we're talking about a requirement for Trillions of dollars over the next 20 years. If we can integrate high-speed communications with the energy grid, it's going to make it possible to gain that investment. I'm sorry if these are things people don't want to consider but I have to.

The other potentially more important part of what BPL might do for is in the area of global warming. Lots of intelligent people believe that if you give consumers clear real-time information about their energy usage, they'll turn the lights off and the heating down when they don't need them, it's as simply as that.

There are other even more intelligent people out there that are seriously worried that if we don’t start to turn back the tide of Co2 emissions real soon, we’re likely to get plenty more Katrina's.

So from my point of view, we have a nascent technology that may be of immense use to our society and our economy, we know it's not perfect and we sure know it's not easy. We've heard the argument from the ARRL and we've spent a lot of time and money trying to deal with the issue, we think we're there now. So how about giving us a break and just going off air for a while to allow some of the other important discussions to take place.

Two final points on this post.

My suggestion about the difference between mobile and static radios is that I understand we can now use "notching" to cut out interference on any particular frequency that is causing a problem in the local area. This obviously won't work if the receiver is constantly changing locations and frequencies. I'm out of my depth here but that's my understanding.

The final point is regarding my anonymity, it's simple. You radio ham guys scare me. I'm afraid I'll open my curtains one morning and they'll be an anti-BPL rally on my lawn

reply to Straight question

In my defence I have to say I have talked to telecomms execs who think their industry is providing funding and support to the anti-BPL lobby, they’ve never backed it up and it's probably not true. It also isn't important.

My problem is this. I am a big fan of BPL, I think it's going do a lot of good, particularly in places in the world that don't have the resources or infrastructure the USA has. Yet when I try to talk to people about BPL I always get them come back saying it can't work because it interferes with amateur ham radio users. If I search for broadband over power line on the net, I will always hit a story about how it pollutes the airwaves, usually before anything else. I don't find the articles about the potential economic benefit, the demand side management potential and the reduction in Co2 possibilities, nothing. Just some good 'ol boy and his crackling radio signal.

I've got no beef with radio hams, I admire the seriousness with which you treat your hobby, but that's what it is, a hobby. Some of us energy people are trying to find ways to build additional revenue streams to attract the investment we need to handle demand growth and the aging transmission and distribution infrastructure, we're talking about a requirement for Trillions of dollars over the next 20 years. If we can integrate high-speed communications with the energy grid, it's going to make it possible to gain that investment. I'm sorry if these are things people don't want to consider but I have to.

The other potentially more important part of what BPL might do for is in the area of global warming. Lots of intelligent people believe that if you give consumers clear real-time information about their energy usage, they'll turn the lights off and the heating down when they don't need them, it's as simply as that.

So from my point of view, we have a nascent technology that may be of immense use to our society and our economy, we know it's not perfect and we sure know it's not easy.

We've heard the argument from the ARRL and we've spent a lot of time and money trying to deal with the issue, we think we're there now. So how about giving us a break and just going off air for a while to allow some of the other important discussions to take place.

My suggestion about the difference between mobile and static radios is that I understand we can now use "notching" to cut out interference on any particular frequency that is causing a problem in the local area. This obviously won't work if the receiver is constantly changing locations and frequencies. I'm out of my depth here but that's my understanding.

The final point is regarding my anonymity, it's simple. You radio ham guys scare me. I'm afraid I'll open my curtains one morning and they'll be an anti-BPL rally on my lawn.