Broadband over 'leccy again ...

fatherdougalmag

http://www.pcpro.co.uk/news/71286/the-ec-backs-broadband-over-the-electricity-grid.html

Sponge Bob

As long as they mean Fibre wrapped around the line or inside the line then thats cool.

Sending it down the copper along with the lekky itself just leads to noise pollution on certain frequencies . These are used by Marine Emergency services (amnogst others) and we are an island, last I heard.

oscarBravo

*sigh* Here we go again. They're not talking about fibre wrapping, they're talking about the pipe-dream that is BPL.

It doesn't work. It has never worked. It will never work.[1] Nothing to see here. Move on.

[1] Except in a minor way, in controlled trials in densely-populated urban areas, and as long as there are no licenced radio users nearby.

Sponge Bob

Twas funny when the British tried it in a small area of Manchester and knocked out comms to all their Nuclear Subs

crawler

Please please please close this....it pains me greatly everytime I see this topic! Substations too far, interference etc etc...no, never, not in Ireland.....

Gone West

heh, anywhere else , mabye. But just imagine the scenario if "del-boy telecom" started trials of this here. Nope, wireless is the way to go for ireland.

DonegalMan

oscarBravo wrote:

*sigh* It doesn't work. It has never worked. It will never work

If there is one lesson I have learned in life it is "never say never".

Sponge Bob

I Say "fibre wrap em all"

oscarBravo

DonegalMan wrote:

If there is one lesson I have learned in life it is "never say never".

As a rule, I'd agree with you. Problem is, in this case we're talking about the laws of physics. This is not a software problem to be worked out with clever algorithms. BPL runs up against the brick wall of Shannon's Information Theory every single time.

It's like continuously trialling clever new ways to reduce the latency of a 2-way satellite connection. It's just not going to happen.

dahamsta

oscarBravo wrote:

It doesn't work. It has never worked. It will never work.[1]

[...]

[1] Except in a minor way, in controlled trials in densely-populated urban areas, and as long as there are no licenced radio users nearby.

So what you're saying is that:

It does, in fact, work. It has, in fact, worked. It will, in fact, work.

adam

oscarBravo

dahamsta wrote:

So what you're saying is that:

It does, in fact, work. It has, in fact, worked. It will, in fact, work.

For various infinitesimally small and practically useless values of "work", yes.

In other words, no.

DonegalMan

oscarBravo wrote:

As a rule, I'd agree with you. Problem is, in this case we're talking about the laws of physics.

According to the laws of physics, a bumblebee cannot possibly fly (something to do with ratio of wing area to body mass AFAIR).

Fortunately, nobody ever told the bumblebee that

LFCFan

You can never say never when it comes to technology. Bill Gates said we'd never need more that 64KB of memory. If he'd listened to himself, where would he be today

More than likely BPL isn't a reality but you never know if some clever b*stard out there will come up with a way to make it work.

dahamsta

As I've said before, I remain in the middle of the road when it comes to broadband over electricity networks, both local and wide area. I'm disinclined to blame myself for this fencesitting while supporters continue to sing joyously like cheerleaders discussing "school spirit", and opponents carry placards telling us all that the End Of The World Is Nigh. They remind me very much of Tony Blair and Ian Paisley, one cloyingly and transparently twisting the truth, the other screaming Hams Say No and refusing to discuss matter rationally. Until they do, I'm going to have to continue sitting on that fence.

In the meantime, I'm not going to fight the European Commission's efforts to "investigate the possibility". Maybe those investigations will resolve the matter once and for all, and convince all those vested interests to stfu, once and for all.

adam

oscarBravo

LFCFan wrote:

You can never say never when it comes to technology.

Sometimes you can. For example, it will never be possible to have less than half a second latency with two-way satellite communications using geostationary satellites.

LFCFan wrote:

More than likely BPL isn't a reality but you never know if some clever b*stard out there will come up with a way to make it work.

It's like I said earlier: there are physical limits to what can be achieved. Martin's bumblebee analogy is cute - I've heard it before - but it was first claimed by someone who doesn't understand aerodynamics. Lift is a function of wing surface area, airspeed and air density, not wing surface area alone. In the same way, powerlines are pathetic carriers of data at broadband frequencies, and unfortunately rather good antennae in the HF spectrum.

dahamsta wrote:

In the meantime, I'm not going to fight the European Commission's efforts to "investigate the possibility". Maybe those investigations will resolve the matter once and for all, and convince all those vested interests to stfu, once and for all.

Sadly, that's unlikely. The trials have an unfortunate habit of seeming to work reasonably well. Problem is, a trial of a few houses in an urban housing estate clustered around the transformer where the broadband is being injected demonstrates nothing whatsoever useful about the ability of the technology to deliver anything useful in the wild. Conclusion: inconclusive. More trials needed. Ad nauseam.

dahamsta

oscarBravo wrote:

Sometimes you can. For example, it will never be possible to have less than half a second latency with two-way satellite communications using geostationary satellites.

...with existing technology. Again with the unqualified statements. There's nothing to say that, for example, a light-based satellite communication system won't be invented in the next 5, 10 or 20 years. There might not, but you still can't make a statement like that without qualifying it. If we're going to go down that route, I could say to you that BPL absolutely does work and has worked in practise. Now you can tell me that it interferes with radio communications, and it's quite likely you'll be right, but you can't refute the statement itself. And there's nothing to say that an incredible new shielding mechanism won't come along next week or next month to toss all that out the window.

Please, spare us the unqualified statements. So far this week you've made three of them, and they do nothing for your credibility. (Which previously I had no problem with.)

adam

jd

DonegalMan wrote:

According to the laws of physics, a bumblebee cannot possibly fly (something to do with ratio of wing area to body mass AFAIR).

Fortunately, nobody ever told the bumblebee that

Urban myth
http://www.paghat.com/beeflight.html

bminish

dahamsta wrote:

...with existing technology. Again with the unqualified statements. There's nothing to say that, for example, a light-based satellite communication system won't be invented in the next 5, 10 or 20 years.

Yes, light based sat comms is probably possible, The US navy looked into it for communicating with subs in the 80's. It has of course all of the latency problems that go with satellite since the speed of light still applies.

Now you can tell me that it interferes with radio communications, and it's quite likely you'll be right, but you can't refute the statement itself.

Both the DS2 based system and the mainnet systems being trailed by the ESB in Tuam create severe interference to radio-communications. I have witnessed this first hand. Comreg's EMC people also made measurements that found interference issues. I cannot speak personally for other trial areas.
The first DS2 trial is over and was completely unsuccessful to date, as in did not work at all.
The mainnet trial area I visited uses all underground ESB wiring but of course the houses are not underground so there is still considerable interference being radiated by the system, enough to raise the local HF noise floor outside at the street by over 50 dB when Internet traffic is reasonably heavy.

And there's nothing to say that an incredible new shielding mechanism won't come along next week or next month to toss all that out the window.

Well burying the ESB wiring is a good start but for this to work the houses would also need to be underground. Perhaps that's the solution we have all been waiting for?
Another option might be to replace all wiring both outside and inside the house with coaxial cable.

Please, spare us the unqualified statements. So far this week you've made three of them, and they do nothing for your credibility. (Which previously I had no problem with.)

OscarBravo has seen and tested a power-line Internet connection, it managed about 400 Kbs with pingtimes to boards of 150 to 200 msec when there was no licensed HF users operating in the vicinity. In this trial area there are 11 houses on the system.

You are up against the laws of physics and they do not have a habit of changing to suit PR departments.

.Brendan

DonegalMan

jd wrote:

Urban myth

There are a few variations on how that story came about with no definitive agreement, there's some discussion on it here ... if you're really that interested

oscarBravo

dahamsta wrote:

...with existing technology. Again with the unqualified statements. There's nothing to say that, for example, a light-based satellite communication system won't be invented in the next 5, 10 or 20 years. There might not, but you still can't make a statement like that without qualifying it.

Apologies, and allow me to qualify my previous statement: It will never be possible to have less than half a second latency with two-way satellite communications using geostationary satellites, until someone finds a way around the trivial problem of nothing being able to travel faster than light. Keep me posted.

dahamsta wrote:

If we're going to go down that route, I could say to you that BPL absolutely does work and has worked in practise. Now you can tell me that it interferes with radio communications, and it's quite likely you'll be right, but you can't refute the statement itself. And there's nothing to say that an incredible new shielding mechanism won't come along next week or next month to toss all that out the window.

OK, let me qualify that statement also. BPL has not been demonstrated to provide anything remotely like a useful and reliable broadband service on a widespread basis. BPL has been clearly shown to be extremely vulnerable to radio interference, which EU law says it must swallow. The problems with BPL are solidly grounded in well-understood principles of physics. BPL, in my limited experience - although I'm open to correction by anyone who's put more effort into actually researching this in real-world conditions, which I have - is extremely unlikely to offer anything remotely like a useful solution to the real problems facing broadband rollout in Ireland. In case there's anything unclear about this, what I mean is that in any environment where BPL is likely to work in a limited way, it would be substantially cheaper and easier to provide a much higher-quality service through any of three much more mature, well-understood and scalable broadband technologies.

dahamsta wrote:

Please, spare us the unqualified statements. So far this week you've made three of them, and they do nothing for your credibility. (Which previously I had no problem with.)

I hadn't pegged you for a pathological pedant, but I would have hoped that most people understood my opening remarks in this thread to mean what I just said in this post. I'll make a point of catering to pedantry in the future.

oscarBravo

Actually, you know what's funny? Reading back over the thread, I did qualify my opening remarks, and what's more, I did so precisely to head any potential pedantry off at the pass.

dahamsta

I'll hold my hand up high and admit that it's been a while since I did physics, and I didn't realise until after I'd posted last night that electromagnetic radiation travels at the speed of light. It was stupid of me and I apologise for making such a silly comment.

oscarBravo, you did qualify that particular statement in a rather silly way, which is what bugs me. Like I said, it's this kind of behaviour from both supporters and opponents that annoys me. It's a contentious subject that results in flame wars without fail, and you know this.

Martin wasn't the only one to find your pigeonholing of IrelandOffline annoying, I might add. I appreciate that you took it back, but it seems to me that it wouldn't have happened in the first place if you hadn't responded with a jerk of the knee. That's all I'm asking.

adam

oscarBravo

dahamsta wrote:

I'll hold my hand up high and admit that it's been a while since I did physics, and I didn't realise until after I'd posted last night that electromagnetic radiation travels at the speed of light. It was stupid of me and I apologise for making such a silly comment.

No problem. I only hope that this debate gets one point across: when I'm talking about physics being the obstacle here, I'm actually talking about real physical limitations like this one, as opposed to issues of processing power or materials technology or whatever. It's hard to explain exactly why BPL is doomed to failure without a detailed understanding of the physical issues involved. My understanding is, I'll be honest, somewhat limited, but it's informed by people who've forgotten more about this stuff than you or I will ever learn.

dahamsta wrote:

oscarBravo, you did qualify that particular statement in a rather silly way, which is what bugs me. Like I said, it's this kind of behaviour from both supporters and opponents that annoys me. It's a contentious subject that results in flame wars without fail, and you know this.

I think the main reason it's contentious is this: there are three sides to the debate. There are the supporters of the technology, who tend to be those with a vested financial interest in its success. There are the detractors, who tend to be those who understand the reasons why it can't achieve what's being claimed for it. What's unfortunate from a third party perspective is that the detractors also have an apparent vested interest, in that BPL creates difficulties for them. What the third parties need to understand is that those difficulties are symptomatic of the very real flaws that exist in this technology, and that nobody's come up with even a theoretical answer to. I'm not just talking about the fact that it causes interference, or is vulnerable to interference. I'm talking in particular about distance and throughput limitations that make Eircom's DSL implementation look like FTTH.

The third side to the debate is the third-party perspective I've already alluded to. These are the people who just want broadband, and who treat the claims of the first two groups with equal skepticism. Their attitude is, understandably, "we'll wait and see". I would have been part of that group, but I made the effort to research the issues - hands-on - and I'm convinced that BPL is not a useful technology in an Irish context, if anywhere.

There's another tangential issue to this. I don't know how much money ESB has spent testing this stuff, or how much more they intend to spend, but it's non-trivial. I also know that there is no carrier-neutral fibre anywhere in County Mayo, which is a major contributor to the difficulties we're experiencing in broadband-enabling this county. Don't believe me? How many 3.5GHz licences were applied for in Mayo? I'll save you the trouble of looking it up: none. ESB could bring fibre to Ballina or Castlebar for roughly €100k. They're not going to do it. They're probably going to keep playing with this silly kit in Tuam, though.

dahamsta wrote:

Martin wasn't the only one to find your pigeonholing of IrelandOffline annoying, I might add. I appreciate that you took it back, but it seems to me that it wouldn't have happened in the first place if you hadn't responded with a jerk of the knee. That's all I'm asking.

Fair comment. All I'll add is that any seemingly rash comments from me are symptomatic of an incredibly deep sense of frustration. The broadband problems in this country wouldn't actually be all that hard to fix, but talk of either subsidising an existing monopoly or playing with dead-end BPL toys distracts from the real issues and deepens my frustration even further.

cgarvey

OK, now that that's out of the way, let's get back on topic.

Capt'n Midnight

http://www.siliconrepublic.com/news/news.nv?storyid=single4666

If this is done by underground cables it might work, but what happens if someone decides to get a radio licence after this is deployed in their area ?

The scary bit is if they deploy spread spectrum on the High Voltage lines. If it has to be done then fibre to step down transformers on each estate , so you are only modulating the 230V with a narrower bandwidth and just enough power to go very short distances.

http://elecdesign.com/Articles/ArticleID/8487/8487.html

Next-generation BPL, he said, will transmit at the higher end (the 30- to 50-MHz range) of the BPL spectrum, where previous-generation systems used spread-spectrum and caused more interference problems with ham reception (in the HF spectrum). Another piece of the solution, he said, is to use a "triple play" broadband architecture combining fiber, power lines, and Wi-Fi. Interference is minimized by using BPL to transmit over short distances, rather than trying to send the signal miles and miles.

"We use fiber to bring high speed into neighborhoods, then take it off a node and inject it into the high-voltage line. Then we use a repeater every 500 feet on utility poles, so we only need to have enough power to go 500 feet," he explained.

Sponge Bob

Expect some very strange critters to appear on that Baby Alarm 10 miles away .

will transmit at the higher end (the 30- to 50-MHz range)

bminish

Capt'n Midnight wrote:

If this is done by underground cables it might work, but what happens if someone decides to get a radio licence after this is deployed in their area?

The Tuam Maninet trial is an estate with underground wiring, however one has to remember that the PLT signals are also present on all of the house wiring in all of the houses fed by the inject points. This is the main source of egress (& ingress), especially considering that typical Irish (European?) lighting circuits split the neutral (daisychained between light fixtures ) and the live (routed via the light switches ) this creates multiple (&effective) loop antennas in each house.

I can't talk much (yet) about the ingress tests (impact of licened radio use on PLT) except to say that findings to date appear to be similar to ingress tests elsewhere

( PDF of FCC filing )
http://gullfoss2.fcc.gov/prod/ecfs/retrieve.cgi?native_or_pdf=pdf&id_document=6515383154

http://www.target-eng.com/bpl/bplweakness.html

Capt'n Midnight

You are not wrong about the lights !

Where is the neutral earthed and would it make any difference ?

Maybe insist on a filter in the fuse box so only sockets can get it, not much point in having the cooker/imersion/light. (though we've been promised TCp?ip fridges for over a decade.)

eircomtribunal

oscarBravo wrote:

I don't know how much money ESB has spent testing this stuff, or how much more they intend to spend, but it's non-trivial.

Shouldn't we try to find out how much gov money, in the form of a DCMNR grant to the ESB (under Dermot Ahern) went into this?

P.

dahamsta

Fair points oscarBravo.

On the subject of the "three parties" involved and how they all work together - or don't, actually - I think that a lot of the confusion is caused by the typical techie issue of finding it difficult to break something down without either insulting the intelligence of fellow techies, or bamboozling non-techies.

The ARRL's response to BPL was typical of this in my mind, they were obviously seriously concerned with the issue but their hysterical response only served to confuse non-techies, and piss off everyone else. Individuals like me can get away with that sometimes, but it's solves nothing in the greater scheme of things. If they had kept interference on the agenda and highlighted other major issues with BPL, as you've done here, that wouldn't have happened. To me, they still look like a bunch of nerds doing exactly the same as the companies they've attacked: pushing their own limited agenda.

In a perfect world they could do that with success because, let's be honest, they have a limited agenda. But this isn't a perfect world.

BTW, I think it's fair to point out that, to the best of my knowledge, the ESB didn't do Tuam out of choice, but because they were directed to by the Minister. AFAIK they've been against BPL since very early on, which I respect to a degree (because I respect the ESB to a degree), but it also creates an issue with trials, obviously. Which is why I asked those questions in my PM.

Finally, I think it's worth pointing out again, for those that may have missed it, that the EU isn't advocating BPL, but BPL research. I realise that it still involves money being spent in what many consider a wasteful manner, but some may think that the EU is going all-out for BPL. They're not.

adam

bminish

eircomtribunal wrote:

Shouldn't we try to find out how much gov money, in the form of a DCMNR grant to the ESB (under Dermot Ahern) went into this?

P.

Well you could but it would probably be better to wait until the whole sorry mess is over. The ESB trials are nearly over, they have put good engineering staff on the trials who have worked hard at it and have tried multiple vendors equipment in various configurations and scenarios. It has been a comprehensive trial conducted in an unbiased manner.

.Brendan