back to article Ofcom forced to publish tests on dodgy radio kit

Ofcom has been forced to disclose its own tests showing that powerline networking kit does breach the European EMC Directive, but still won't do anything to enforce compliance. Despite claiming there was no evidence that PLT kit built by Comtrend and supplied by BT was breaching EU rules on electromagnetic emissions, the …


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  1. This post has been deleted by its author

    1. Anonymous Coward

      Calm down dear.

      "The people designing, making and selling this kit are worse scum than pedophiles..."

      "...should be jailed for corruption. Hang the lot."

      You do know this isn't the Daily Mail, right?

      1. G7MJV

        I'm a ham

        I think you'll find that there are quite a lot of radio hams and shortwave listeners about

  2. Pahhh

    ..... knock out sensitive radio

    "but as the mains wiring isn't shielded those signals leak out and can knock out sensitive radio users such as HAM operators."

    I have two thoughts on this, firstly:

    1) Really? It surprises me that a low frequency signal thats travelled across half the world will be knocked out by a device that works at very high bandwidth and hence wont travel far

    2) Do I care? I know this is selfish, but really how many HAM operators are there? And more to the point, how many might be near (in fact incredibly near) a supply that might be causing interference?

    Well done Ofcom for exercising some common sense for a change methinks.

    1. Number6


      You're obviously missing some fundamental points here.

      1. Powerline stuff uses a broadband signal and so covers a very wide range of frequencies from very low to VHF.

      2. A signal that has travelled across half the world may well have little residual energy at its destination and will be easily swamped by a local signal. Think nanowatts and picowatts.

      3. If I set up some equipment and knocked out your TV and radio reception then presumably that wouldn't matter either because there's only one of you.

      4. Standards are there for a reason, in order that a multitude of different systems can coexist.

      5. Ofcom appears to be volunteering to be abolished, seeing as it's useless at one of its primary functions.

    2. Anonymous Coward
      Anonymous Coward


      If Ofcom had said they'd measured the kit and while technically in breach of the regulations they were not going to do anything about already installed kit as it would be too disruptive but the manufacturer should not supply anymore infringing kit I'm sure most people would not have been bothered. A judicial review might have forced them to do differently but that's the nature of things.

      However this looks like either a degree of incompetence or duplicity (or both) and shows them up as dodgy bunch. So how are we to trust them when they are supposed to be enforcing standards that really matter.

    3. Monsieurmarc

      Why Care

      Because a suitable saturation of these things will also interfere with Emergency services for instance.

    4. This post has been deleted by its author

      1. Naughtyhorse

        Oh noes not DAB!

        so nationally thats 3 radio hams and both DAB listeners effected!

    5. Steve X

      How many?

      Bear in mind that ham operators worldwide generally have access to small bits of spectrum scattered all over the bands, squeezed between the other legitimate users of those bands. Anything which interferes with ham radio has the potential to interfere with everything else, which includes leisure services like TV & FM radio, emergency services, and other professional users.

      It's Ofcom's job to ensure fair treatment for *all* users, which of course it hasn't done since it was turned into the government's spectrum pimp.

      As with any other law, once the people charged with enforcing it sell out, lots of other unscrupulous folks will jump on the bandwagon and start abusing it because they know they won't be censured. Just because ham users are in a minority doesn't mean that their concerns can be ignored. That way lies tyranny, or anarchy.

    6. MrCheese

      @ Pahhh

      You sir appear to have missed the point by a farily wide mark; if you think corruption, bare-faced lying and the supression of truth demonstrate a modicum of common sense you should apply for a job in the government.

      What will you think of their common sense once we the taxpayer get lumped with another euro-fine for our goverments wilful law breaking?

  3. Sonny Jim
    Thumb Down

    Worse scum than pedophiles?

    I dislike these devices also (UVB-76 ftw) but I wouldn't go that far. It is an absolute travesty that these were even allowed to be sold in the first place and I think things will only change when the first Rescue helicopter/Police car/Army/whatever user finds that they can only hear the beeps and chirps of the interference.

    Cue the standard argument process:

    "I live in a 6 million year old house with 5 meter thick walls, I couldn't possibly run CAT-5/6, that would just be what a MENTAL would do"

    "I am a radio HAM and I'd like to strongly physically violate anyone who either uses these devices"

    and so on and so forth

  4. The BigYin

    Simple test

    Did public money pay for the research?

    Then the report and raw data must be made public.]

    End of discussion.

  5. Anonymous Coward


    At last - proof I don't need to worry about meeting the EMC directive...

    AC for obvious reasons

  6. Naughtyhorse

    "Tony Blair defence":

    aka lying in their teeth about it, then when caught refusing to apologise.

  7. Will Godfrey Silver badge


    Further evidence that OffCom is in the pocket of BT. This jamming kit should be outlawed.

  8. Anonymous Coward
    Anonymous Coward

    Your leaving out points 3 and 4

    3: The kit also interferes with FM. Lots of people use that.

    4: Its in breach of the regulations, and they've been caught lying by saying otherwise.

    They appear to be saying its OK to break the regulations if you have the right friends.

    They have been cracking down on Pirate FM radio stations for years for creating minimal interference Of course when BT do it, its fine.

    IMO, There supposed to be a regulator. Its not OFCOM's job to decide what is and isnt in the public interest.

  9. Pypes


    At least we now have proof that ofcom are a bunch of crooks who are on the make, even if nothing will get done about it.

    Also, not enforcing the law because they reasoned it's "not in the public interest" as the world and it's dog was already using this kit? That's a hell of a precedent for a government body to set, lets hope they apply the same reasoning to the tera-bytes of films sitting on my hard drive.

    1. Anonymous Coward
      Anonymous Coward


      "At least we now have proof that ofcom are a bunch of crooks...."

      Who isn't in this country?

      This is yet more proof of how corrupt "Great" Britian is.

  10. solongandty

    AC needs a reboot

    Something is wrong in your world if screwing someone's RF spectrum is worse than your comparison

  11. Refugee from Windows
    Thumb Down

    Picking and choosing which bits to enforce

    Killing off this kit would upset one very big Telco - it's the size of that company that's probably kept it all quiet. The argument was that this isn't radio equipment, but it sure is a potential wrecker of the spectrum below whatever nominal data rate it's trying to achieve.

    1. Hayden Clark Silver badge

      BT must have a big bribe budget

      If they can afford Ofcom, the Data Protection Registrar and the Information Commissioner!

  12. Monsieurmarc


    This kind of interference not only disrupts amateurs it can disrupt emergency services, baby monitors and many others.

    Further sales of these devices should be suspended there are plenty of alternatives available.

  13. Alex Walsh

    does this

    mean that homeplugs are iffy in any way? I've got a lot of them you see :)

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      1. Tim Parker

        Re : All PLA devices breach EN55022

        Personally I would like the see the data for all the adaptors that have such already submitted, and ask the regulator to obtain data for any that are missing. I originally got, and still use, a few HomePlug AV adaptors before I was aware of some of the issues. These are from Zyxel and Devolo but, although i've seen a couple of test results from other manufacturers (e.g. Comtrend), i've not been able to find any test or certification data for these.

        This issue is something i'm thinking about and could effect my usage of the adaptors, or how they are setup on the wiring, but i'd like to know more before I spend time or money sorting things out.. e.g. what notching is present in the devices.

        If anyone is issuing another FOI then i'd be interesting in getting as much information as possible on as wide a range of adaptors as possible - how likely is that ?

        1. This post has been deleted by its author

  14. Anonymous Coward
    Anonymous Coward

    DVB-T too

    Over the road from me got the kit just before last Christmas. When they're streaming video (it regularly goes on in the evening) I instantly lose a couple of DVB multiplexes, the ones carrying BBC1-2 and CH4. Fortunately I can just switch back to analogue, but not for too much longer. I shall probably move before the switch off happens though.

    1. SImon Hobson Silver badge

      Then complain about it !

      >> When they're streaming video (it regularly goes on in the evening) I instantly lose a couple of DVB multiplexes, the ones carrying BBC1-2 and CH4. Fortunately I can just switch back to analogue ...

      But you shouldn't have to switch back to analogue (which won't be an option for anyone at all in a couple of years). The point of EMC regulations is so that people shouldn't have this sort of problem. And to all those imbeciles with a "it's only a few old beardies, why should we care ?' attitude - FFS it's isn't just Radio Amateurs that are affected, it's just that Radio Amateurs are the only ones prepared to kick up a fuss about it. FYI, even our CAA (Civil Aviation Authority) has expressed concerns as some of the newer kit risks interfering with aviation radio systems. Still think it's a storm about nothing ?

      I'm actually not at all surprised that TV reception has been shown to be affected. While the kit itself may only be designed to generate frequencies up to a few tens of MHz, when driving something that's as badly matches as some random bit of T&E with multiple joints and branches, it's highly likely that spurious emissions will go several order of magnitude higher in frequency. So that's the TV bands splattered over, and above that is one of the aviation bands.

      One of the excuses OfCon has used for inaction is that "few have complained, and most of them are radio hams". It also seems that many people (radio hams included) haven't bothered complaining because they don't expect anything will be done about it. So please, anyone who has been affected at all, please complain to OfCon so they can no longer use that excuse.

      Apart from the immediate problems caused, this case is important for the precedent it sets. As others have jokingly said, does it now mean that if you give a load of them away quickly enough, you'll be let off as it would inconvenience the public to have them banned ? Well enjoy the repercussions of that if it comes to pass and your TV goes off.

      On a ore serious note, perhaps some of use should set up some public demonstrations. Set up something similar but designed to knock out TV. We'd soon see the "I don't care, it's only a few old beardies" attitude change then !

      1. Anonymous Coward
        Anonymous Coward

        But who to?

        Thank you for a well considered reply. Here is a relevant extract dug up from Ofcom's site:

        "The BBC are now responsible for investigating complaints of interference to domestic radio and television.

        "Potential causes of interference inside the home can include central heating thermostats, fridge-freezers and some dimmer switches, for example on halogen lights. Under some circumstances, radio or other electrical equipment outside your home can also cause interference.

        "Before reporting interference to the BBC, you should check your TV or Radio installation to ensure it is operating correctly. In some cases, faults such as poor aerial connections, can cause be the cause of the interference.

        So, clearly it's not Ofcom's problem then, and from that it would seem the fault is most likely to be of my own doing. Despite possessing an engineering degree, I feel quite put off before I have even started.

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  16. GatesFanbois

    Well done Ofcom

    I use powerline networking and it's much easier than running cat5 thrpugh walls and floors. So thanks Ofcom for keeping my life easy. If this does screw up things for radio geek then meh. Get a new hobby.

    1. Dave Bell


      You seem to have not noticed the reports, scattered through the thread, of these powerline networks interfering with other licenced uses such as TV broadcasts.

      Radio Amateurs have to pass tests of technical knowledge, and take care to maintain their transmitters so as not to interfere with other users. So they have test equipment which can detect and measure the effects. They are also scattered across the country.

      Radio Amateurs are, in matters such as this, somewhat like the miner's canary, which were more susceptible to noxious gases. When the canaries fall over, you know something is wrong.

      Ofcom are idiots. This seems to go far beyond the usual discretion found in all law enforcement.

  17. Andy3


    Ofcom is an evidence-based regulator that suppressed evidence and refused to regulate. The interference from these devices can radiate over several hundred yards and make weak-signal comms impossible. Closer in it swamps even strong signals. You only need one pair of these things in your village to wreck your radio listening.

    The EMC reports that Ofcom have now been forced to disclose prove that these PLT devices vastly breach the rules and laws regarding EMC compliance, but Ofcom chose to suppress these reports and deny everything.

    They lied to the public, to MPs, to Ministers and to MEPs in the process.

    Ofcom is not well-liked by our current government, and I hope strong action is taken to bring those responsible to justice.

  18. Andy 97

    QK QK QK

    Look, I am sorry that a minuscule number of hobby radio people are having a problem using CW or wax discs or something, but things have moved on.

    Time to embrace the new century gentlemen.

    1. This post has been deleted by its author

      1. peter 45

        Not to mention

        Your wireless doorbell

        Your wireless heating controller

        Your remote car lock

        Your clock/watch synchronised to the MSF signal

        your kids remote control car.

        Welcome to the 19th century

        1. Fr Barry

          Not to mention

          mid Atlantic communications to/from aircraft

          your wifi

  19. Anonymous Coward

    Essential Requirements and Standards

    There's this dance you can do (and which it appears the sellers of this kit are doing):

    The harmonised standards you can use to demonstrate conformity with the essential requirements are effectively a shortcut. Meet the standards and you have what's termed a presumption of conformity for the apparatus. If you don't meet the standards (either because you haven't tested to them, or you actually fail them), then you can write some weasel words (the technical term is "extended justification") to explain why you don't need to meet the standard - perhaps your apparatus is only ever going to be used in a screened room, or on a desolate hillside miles from the nearest neighbour to [potentially] interfere with.

    Sometimes these weasel words are just that, other times they are wholly justifiable.

    So, it isn't always as clear cut as "meets standards==pass, doesn't==fail". Which isn't to say that it isn't clear-cut in this case - I haven't seen the margin of fail, or the extended justification.

  20. Andy3

    Wax discs?

    In response to the ignorant and selfish Andy97 and GatesFanbois. Since when did radio amateurs use wax discs? I'm afraid your childish posts just reveal your lack of knowledge. AR is not an old-fashioned hobby. Many of us use cutting-edge digital techniques and digital signal processing is in common usage. Communication via satellite and moonbounce is in regular usage.

    We have rules and laws which were put in place to keep the radio spectrum clean, and these need to be obeyed. Ofcom is the UK regulator but they failed to enforce the rules, thus allowing the widespread pollution of the RF spectrum to take place.

    It doesn't matter how many people are affected, it matters that the law is being openly broken.

    Perhaps you wouldn't mind being told by the police that they weren't going to investigate the burglary of your home because hey, only one person was affected and anyway the burglars only took your TV and a few quid?

  21. JeffyPooh

    "Time to embrace the new century gentlemen..."

    These sorts of mindless comments reveal a deep and profound ignorance of the facts. Anyone that actually understands the importance of the HF and VHF radio spectrum would not make such foolish statements. There is absolutely no excuse for allowing any form of "power line" communications scheme where it leaks noise into the local radio spectrum.

  22. Harry

    The argument was that this isn't radio equipment,

    There are still laws applicable and even if it isn't in ofcom's remit to prosecute, then it should at the very least have referred the problem to the Home Office with the request that somebody else be appointed to prosecute. Or perhaps ofcom's remit should have been expanded to include enforcement of devices that aren't radio equipment but nevertheless unlawfully transmit unintentional radio signals in excess of the permitted levels.

    If nothing else, the company concerned could probably be prosecuted either for bearing the CE mark which does not comply with an applicable law, since the CE mark is the manufacturer's legal assertion that the device complies with all applicable laws.

  23. Pahhh

    Something doesnt ring right...

    Thanks for the thumbs down, somehow I think a lot of you are full of bull....

    Firstly, if ANY of these devices had any chance of interfering with emergency services then I was be AMAZED if OFCOM didnt pounce on this. So I will take those comments as irrelevant noise (ha! cheap pun)

    Secondly, PLC are sold in the US. This is the country that has crazy regulations on RF inteference. Thats why anything anything sold to the US has a metal cage around it just in case some RF might interfer with something.

    Yes of course PLC will emmit. They couldnt work if they didnt. I just cant believe that its such a big problem that it warrants the banning of PLCs.

    1. Anonymous Coward

      Metal cage is fine... long as the whole thing is witin the metal cage, the PLC has what is essentailly a huge great ariel attached to it which is not contained within the metal cage.

    2. Monsieurmarc


      You are correct these things are available in the U.S.

      The FCC was sued for redacting data that would of shed doubt on their decision to allow their use.

      Sounds familar.

    3. SImon Hobson Silver badge

      Time to stop digging ?

      >> Secondly, PLC are sold in the US. This is the country that has crazy regulations on RF inteference. Thats why anything anything sold to the US has a metal cage around it just in case some RF might interfer with something.

      There is a saying that when in a deep hole, stop digging. You exhibit a good ignorance of facts with that statement. Firstly, not everything sold in the USA has a metal case - they get a lot of plastic cased "wall warts" just like we do. A lot of the power supplies sold there are **exactly** the same as those sold here, and nearly identical except for the pins sticking in the case of units with integral plug.

      Secondly, and more importantly, their EMC regulations are quite different to ours and it is my understanding that you can very easily built kit that meets the US specs with room to spare, but fails dismally when compared with EU specs. That's not a commentary on whether one system is better or worse than the other - just an observation that they are different.

    4. hplasm

      Nobody cares

      What you 'think' or 'believe' as you have aready demonstrated that you don't have a clue.

  24. oldredlion

    Scrap Ofcom

    because they are useless.

    Wasn't it Ofcom that was supposed to protect the consumer from BT and Phorm? They actually protected BT and they are doing the same in this case.

    Are Ofcom in the pocket of BT? Is it one of those situations were big business offers directorships or special jobs to regulators, because to offer a briefcase of money is illegal?

    And when are Wikileaks going to release the M$ OOXML ISO information? That should prove interesting.

  25. Cameron Colley

    Who the fuck do OFCom think they are?

    We paid for that fucking report so give us it now! You are our fucking servants you ungrateful, lying, corrupt, pathetic little fucks! I really cannot express my anger enough at these fucking parasitic criminals who take our money and refuse to work for us. Hanging would be too good for this bunch of pricks.

    The whole fucking lot should go to jail for theft of public money -- since they're not working for us, but BT.

  26. Anonymous Coward

    These jokers should be ashamed to call themselves radio amateurs

    Eliminating noise has always been a large part of the hobby. Any decent radio amateur knows how to minimise local interference if necessary. These devices have deep notches to prevent ingress and egress to and from the amateur bands - it's part of the specification - so there isn't much noise produced in the HF amateur bands to start with and if you switch in a decent narrow filter on your receiver and it just disappears.

    The guys complaining listen to wide band AM broadcasts in between the amateur bands on crappy domestic receivers with rf and af stages as wide as barn doors.

    There were104 complaints received by OfCom last year the vast majority were eliminated by co-operation with BT who simply ran some UTP in customer premises. Presumably that's 104 radio amateurs who don't have the nounce or manners to knock on their neigbours' doors to do the same

    Incidentally, the guy who set up the "PLT fighting fund" at the Radio Society of Great Britain has just been sacked for financial irregularities, for fiddling 40 grand out of the society apparantly.

    1. Gnomalarta

      AC is about right!

      AC is about right! Dickhead will do though judging by the poster's ignorance of the problem. As someone who suffered wipe out of all SSB signals (not just AM) on all shortwave frequencies up to 18MHz I can assure the poster that a filter is of no use in these circumstances. When the typical background noise level rises more than 30db in a 2.7KHx bandwidth due to three PLT devices within 50 metres Mr Dickhead's filter is about as much use as a liquorice allsort!

      As to the last paragraph and his dig at the RSGB, the mis-use of funds by the General Manager relates to a credit card and has nothing to do with the Spectrum Defence Fund.

    2. Steve X

      Missing the point

      "These devices have deep notches to prevent ingress and egress to and from the amateur bands - it's part of the specification"

      True. The trouble is that the devices as defined DON'T MEET the specification, which is what the whole complaint to Ofcom is about. Ofcom is allowing non-compliant devices to be sold without taking action against the suppliers who are flouting the very rules that Ofcom is mandated to uphold. If the devices actually met the spec there would be much less of a problem.

      The guy sacked from the RSGB was the general manager, so not specifically dedicated to the spectrum defence fund. Not good for them, though, in any event.

  27. Andy3

    More ignorance

    Anonymous Coward says:

    "The guys complaining listen to wide band AM broadcasts in between the amateur bands on crappy domestic receivers with rf and af stages as wide as barn doors."

    No we don't, and your comments display a worrying ignorance. Many of us use top-flight receivers and have adopted the use of loop antennas and phase-out devices to minimise noise. This is nothing to do with receiver front-ends or filters. You have obviously never suffered with s9++ of whining data-noise which is obliterating not only international utility comms, but strong SW broadcast signals as well. No amount of dynamic range, filtering or indeed prayers to God Almighty will make any difference.

    There's only so much noise reduction can do. The fact is that these PLT devices are radiating high levels of noise from the local mains wiring and breaking the EMC laws by up to 39dB. That's a huge amount by anyone's reckoning. It is illegal and our UK regulator OFCOM tried to cover it up. Now we need action.

    1. Anonymous Coward
      Anonymous Coward

      39dB - wow that's 8,000 time the permitted limit

      Agreed Andy it is worrying that someone like that tries to sound knowledgeable but makes himself sound ill-informed- a' little knowledge is a dangerous thing' is all that poster has just proved

      btw I thought the notches were only on the transmit side and not the receive side - I may be mistaken tho'. In any event I find that notching has little or no effect on diminshing the increasing level of the noise floor on the frequencies notched .

  28. Anonymous Coward


    Considering the vehemence of some of the comments here, I hope you'll forgive me for posting as AC, but I think there's a missing "voice" in this debate...

    Some may find this hard to believe, but not all users of powerline networking products are Dr Evil clones, cackling maniacally at the thought of their home network wreaking mayhem on poor innocent radio hams within hundreds of metres.

    I bought some 200Mbps HomePlug adapters for our home LAN, as (a) the alternatives were unreliable wireless, or spending inordinate time/money/effort threading metres of CAT5e cable through walls and floors (and if you think the latter's no big deal, you don't know my wife ;-)); and (b) at no point did any sellers of HomePlug kit that I encountered, make it clear that using these products will make merry mayhem on radio, TV, etc. for hundreds of metres around.

    Serious question, then: what would you suggest to all those like me, who were using powerline products in good faith (especially if they paid for them, instead of receiving them as freebies from BT), and who don't want trouble with radio hams (or worse, OFCOM), but can't easily switch quickly to an alternative?

    And no, "tough t*ts, you bought it" isn't quite the answer I'm looking for ;-)

    1. Monsieurmarc


      I haven't met your wife but mine is no fan of cable or antenna so I feel your pain.

      These devices could be built to minimise interference however as with all things they are built down to a price with the obvious consequences. Your non free ones maybe well behave well in comparison to the give away device. But unless the test results are published it would be very difficult for you to make an informed decision.

      That is another problem caused by ofcoms obfuscation of the facts.

      If wifi doesnt work for you and cat5 = divorce there are no easy alternatives at this point.

      Unless any of your surrounding neigbours have large antenna that might indicate they are Radio HAMS I would do nothing and see how it comes out in the wash.

      If you think a neighbor might be have a chat with him it would be easy to determine if you are causing a problem and discuss a solution. (like turning them off during certain time windows perhaps so he can do his thing).

      Hams tend to be reasonable guys and don't blame the consumers.

    2. Anonymous Coward
      Anonymous Coward

      Users not to blame

      I don't think anyone can blame the users who accepted (or bought) equipment in good faith.

      The problem lies with the manufacturer or supplier that provided equipment that was not compliant.

      In an ideal world they would have to replace it all with compliant kit, so the end-user was not put into a worse position that was not their fault and take the old kit back so it was out of circulation.

      I suspect we will all be old and grey before that happens.

      If the user did import dodgy stuff from the Far East however then the answer you don't want to hear still applies.

    3. Cameron Colley

      The alternative may be adaptors which do pass certification.

      Or, it may be that BT should be forced to wire your house with CAT6 and pay you for a hotel room while they do it.

      I'm of the opinion that the only real way to network a house is to wire it up -- and unless your wife doesn't want internet connections anywhere but next to the wall socket it comes from I'm sure she could live with it.

    4. McVouty

      Get Your Money Back

      Serious question, then: what would you suggest to all those like me, who were using powerline products in good faith (especially if they paid for them, instead of receiving them as freebies from BT), and who don't want trouble with radio hams (or worse, OFCOM), but can't easily switch quickly to an alternative?

      And no, "tough t*ts, you bought it" isn't quite the answer I'm looking for ;-)

      Complain to Trading Standards. Not fit for purpose. Sale of Goods Act and demand a refund. I ordered Belkins from BT Shop and Devolos from Maplin to test and got full refunds. These are nasty pieces of kit.

    5. Anonymous Coward
      Anonymous Coward


      Thread the cat 5 though holes drilled through your window frames and route it neatly on the outside of the house? That's all BT or Sky would do for a new installation, but I guess it depends how many points you need. Actually I think cat 6, being a bit stiffer, would probably hold its shape and allow you to better lose it in the pointing. It's only very marginally dearer last time I looked too.

    6. This post has been deleted by its author

  29. Andy3


    AC - I know it can be difficult getting data from one place to another in your home. But PLT is not the alternative. It doesn't exist, not in any legal form, anyway. Just imagine that OFCOM did its job and stopped these devices from being imported, manufactured and sold in the UK. What would you have done?

    Persevered? Run the CAT5 as best you could?

    1. Tim Parker


      "I know it can be difficult getting data from one place to another in your home. But PLT is not the alternative. It doesn't exist, not in any legal form"

      I'm no apologist for Ofcom or manufacturers of illegal adaptors, but I thought part of the issue was the we don't actually know at the moment which bits of kit are ok, if any... we certainly know some which are patently breaking the law, but the available data is rather thin on the ground. Even tests of a couple of typical chipsets (e.g. the Intellon HomePlug AV driver) would be better than nothing, as presumably most of the dynamic filtering, notching etc is independent of a given vendors plastic box and power supply - if it's there at all.

      Does anybody have any links to any HomePlug adaptor certification data ?

      1. Anonymous Coward

        . the quest for 'harmonised standard' appears to have been going on for 10 years. . .

        Hi Tim - yes it is difficult. The truth is Manufacturers self-certify not by actually physically testing the device 'live' but by using what is called the TCF (Technical Construction File) as the manufacturers are well aware they cannot meet the required standard EN55022 any other way - "Safety, immunity and harmonics are correct but almost all PLC devices pass over the CISPR 22 class A, B limits so failed the test and we could not generate (directly) the DoC (Declaration of Conformity) needed for Europe"

        The Homeplug Powerline Alliance have also investigated with the ITU-R the possibility of obtaining a dedicated band for the PLT. It will take, if accepted, around 10 to 15 years (as at 2006) and HPA admit that during this interim period the TCF will be always the best compromise but could be subject to discussion…

        It is my understanding that this method (TCF) should or was intended only be used for prototypes, short-runs and one-offs where the cost of the test is a critical factor and not large-scale production – it is an outright abuse of the TCF option. That is why along with Ofcom's failure, pressure of an EU directive this chaotic situation has arisen. The long-suffering consumer is caught in the middle.

        If you search the web you will find the Ofcom (when they were the RA) were warned of the problems that these devices were likely to cause as far back as 2002. The EU committees responsible for producing a 'harmonised standard'. for these device have singularly failed to do so. On checking this appears to have been going on for 10 years not just 5 years I had thought it had - That says it all - can there be compatability between radio and PLT?

        In 2004 Jonathan Stott, BBC Research & Development, had an article published in an EMC journal "PLT and broadcasting – can they co-exist?". This is not too technical Some of his conclusions are:

        - Radio services are entitled to protection from interference under the terms of the International Radio Regulations and the European EMC Directive.

        - The radio spectrum below 30 MHz is a unique resource of special value to radio users because of its long-distance propagation properties which, in the case of broadcasting, are

        essential to international broadcasters and are also of very great value for national broadcasting where countries are large, poor, have scattered populations or are in the Tropics.

        - Broadcasting below 30 MHz is in the process of being transformed by the introduction of DRM to replace AM, bringing greater audio quality and ease of use — an all-round improvement of the listening experience.

        - Mains wiring acts as an antenna at HF and therefore has the potential to radiate and receive electromagnetic fields.

        - Power-Line Transmission has the potential to cause substantial interference to reception of broadcasting in listener’s homes.

        - This potential has been confirmed by the recording and measurement of actual interference from all the PLT systems examined.

        - A limit that did protect broadcasting and other radio services would have the effect of outlawing PLT and other similar broadband services. This is probably politically untenable, however, it may not be necessary.

        - What is needed is for interference to be prevented. It appears that this can only be achieved if PLT does not operate at the same time, at the same frequency and in the same place as broadcast reception is taking place. ‘Notching’ of the PLT system is proposed as the way to achieve this.

        - Notching alone is not enough. It has to be verified that sufficiently deep notches can be achieved. They have to be flexibly allocated whenever and wherever needed. A human

        system for doing this would be costly, slow to respond to need and would raise difficult ethical questions over censorship.

        - A possible method has been suggested whereby the PLT system might itself determine automatically which parts of the spectrum are occupied by radio signals and avoid them. An experiment suggests that this should be feasible. (Poster's note to the last suggestion - it is only theoretical and has not been shown to be practical)

        The article is one of many that can be found on - this is a site for EMC professionals.

  30. James Pickett


    Sounds like Phorm all over again. How's that going, BTW?

  31. kain preacher

    PLC and America

    Sure PLC are sold in America, but most DSL providers do not support them . When I was at ATT we told the customer the must unplug them before we will give support. PLC were shown to slow down DSL under certain conditions . You get enough PLC in an apartment and you can destroy DSL and radio .

  32. This post has been deleted by its author

  33. Mage Silver badge

    Not just "HAM"s

    Also interferes with SW Broadcast, Maritime & Aeronautical HF, NFC tags, CB, Community Radio and low band VHF, cable broadband uplink.

    The newer units also interfere with higher VHF Mobile, FM Radio, Airband and marine band.

    The more there are the worse the background noise level.

    If PSUs and CFLs allowed the same interference level they would be cheaper. The Comtrend / PLT / Homeplugs etc then of course would have to use higher power levels.

    It's reasonable that these should be tested in pairs, with realistic data on realistic house wiring. It's unreasonable that they get FCC and CE by testing singly or without data.

  34. Anonymous Coward
    Anonymous Coward

    Amateurs are rare?

    There's 30,000 active amateurs in the UK.

    As for knocking on your neighbours door, that would be great if only it was the odd neighbour. If you live in a row of terraces and every single one of them is knocking out the HF bands, that becomes a little more than a "slight annoyance".

    The more we allow this, the more BT will install them in people's homes (why do people use BT as an ISP anyway?) Ofcom's job is to police the spectrum - as they did with a repeater recently where someone went to jail for 18 months for misusing a repeater that directly affected less than 100 people!

    As for clubbing together, isn't that what it's about? if a couple of dozen individuals phone up, they'll be given a short thrift. If people get together and donate thousands of pounds to a "fighting fund" then the cause is given a chance

    1. Anonymous Coward
      Anonymous Coward

      "why do people use BT as an ISP anyway?"

      old people. They've been scammed so many times by door to door utility salesmen that all other telecoms companies are suspect. Can't really blame them, you get a lot of the same sales scumbags working for the more well known broadband companies. They don't seem to bother going door to door anymore but they do drop their scummy lie-filled leaflets through the letterbox. If you're not clued up you'd be forgiven for thinking that your only broadband alternative is to buy a bloody Sky TV package. Not an appealing prospect for those of us who don't pour special brew on our cornflakes in the morning.

  35. Andy 2E0VKG


    I don't think it's perhaps been made clear enough in this debate, but speaking as a radio amateur, I don't know of any other radio amateur who blames the consumers who have bought and are using these devices. In fact, they should be as pissed off as we are, because they've been sold something that isn't fit for purpose and could potentially cause them a lot of problems.

    The thing that annoys me the most about all of this, though, is that one of the requirements of my licence - and a point that is repeatedly drilled into you whilst working through the exams - is that as a radio amateur I must not cause interference to other radio users. If I'm suspected as being the source of interference - even quite innocently - Ofcom have to power to inspect my equipment at any time of the day or night. Yet companies can sell devices to consumers - who by and large aren't versed in the intricacies of RF - which can effectively crap all over large amounts of spectrum.

    On the subject of filters - they're not going to sort everything, or even most things. Most of my time on HF is spent working with digital modes, where the bandwidth required can range from 31Hz to 2 or 3kHz. One of my neighbours has a rather noisy (RF-wise) plasma TV, and that makes things extremely difficult at times, I can tell you.

  36. Anonymous Coward

    FTTC aka VDSL

    BT Openreach are starting to deploy VDSL in various parts of the UK. Others refer to it as FTTC, but it is actually still a copper based technology largely reliant on a clean RF spectrum and limited background noise.

    Are there any analyses of the impact of PLT/PLC on VDSL (independent or otherwise)?

    I suspect the folks in BT Martlesham know, but are not permitted to say what they know, because it would make life difficult for BT Retail.

    1. This post has been deleted by its author

  37. Anonymous Coward

    Just the one?

    Ofcom tells us it's just a single lobby group.

    I wonder why this (these, in reality) were formed.

    1. Anonymous Coward

      WHO IS US

      You can see why - when Ofcom tells the 'porkie pies' - I am circumspect at their responses, statistics etc., and so should you be!

      . . . . . . . . or is the coffee not strong enough yet!?

      We are all individuals and most can still use the old grey matter and do not need to be told what to think - I do hope you can too - all I ask of anyone is 'treat other people as you would like to be treated yourself' and 'do no harm', because that is my philosophy and it has served me well.

  38. Andy3

    Lies and Greed.

    I'm currently not suffering from PLT noise (just SMPS etc), but a while ago I found the entire spectrum from about 4 MHz to 20 Mhz was unusable due to some very strong whining-type noises which I recognised as PLT.

    It was strong enough to knock out all but the strongest BC stations, so the utilities and such-like stood no chance - they were completely buried.

    Once I had found out where the noise was coming from, I realised I vaguely knew the guy who lived there and I gave him a knock.

    He confirmed that he had recently bought a pair of PLA's (not Comtrend), so I asked him if he would come to my house (about 50 yards away) to see the problem.

    Once he saw (and heard) the amount of noise on my radios, he was horrified and told me he would wire the system as soon as possible. He turned off his PLA's the same afternoon.

    He was a reasonable bloke but sadly many are not and dig in their heels, often seeming to take delight in the trouble they are causing. Such is modern society.

    If these things - which breach every rule in the EMC book - were not on the market, none of this trouble would be happening. Comtrend, the other makers and OFCOM have brought this about through their lies and greed.

  39. Blofeld's Cat
    Black Helicopters

    If these things are broadcasting data...

    How difficult is it to make a transmitter/receiver to tap into the signals?

    Maybe it suits THEM to let these things continue squarking away. I mean who needs a search warrant or a wiretap when you can just park your van a couple of streets away?

    We need an evil genius icon.

  40. Anonymous Coward

    double standards . . . . .

    There is also a strong argument that these devices are actually RF devices which would classify a PLT device as a Wireless Telegraphy Apparatus in terms of the Wireless Telegraphy Act 2006. That would mean that they should be appropriately certifed as licence exempt or the user would require a licence to use them.

    It all come into focus under s116 of the WTA, which is part of the interpretation section of the Act, when looked at in conjuntion with sections 8, 115 and 117 of the Act:

    "“wireless telegraphy” means the emitting or receiving, over paths that are not provided by any material substance constructed or arranged for the purpose, of energy to which subsection (2) applies."

    Mains wiring is NOT a “material substance constructed or arranged for the purpose, of energy to which subsection (2) applies” – i.e. it has been specifically manufactured for the distribution of mains electricity at ~50Hz and not like that designed and manufactured for RF e.g. Coaxial cable or balanced line/feeder. The result is that mains wiring acts as a radiator or aerial.

    To be certified as licence exempt then “The condition is that the use of stations or apparatus of that description is not likely to involve undue interference with wireless telegraphy” would need to be met along with any other condition that Ofcom may devise.

    Additionally there would have to be some spectrum space allocated for the devices. This is a problem as there is no such allocation for the devices, which are wideband in nature, and the amount of spectrum used with the latest devices can be up to around 300MHz.

    But wait, do not such devices or similar already have “Recognised Spectrum Access” (spectrum space)? Yes, such does exist for PLC which is a narrowband version of PLT/PLA in the LF part of the spectrum.

    So why is Ofcom applying double standards here?

    What is really going on?

    Are these devices actually Radio Transmitters?

  41. Martin Usher

    So I take it that its OK to open my own radio station?

    Yes, I know that running a small FM transmitter will cause planes to fall out of the sky, ambulances to crash and the world as we know it to end but given the indifference to a genuine interference source you'd think they'd not be interested in going after a harmless low bandwidth user.

    There must be a missing link somewhere......let me see......ah, money! Of course! Damning powerline kit will alienate Ofcom's sponsors.

  42. Anonymous Coward

    Who regulates the captive regulators?

    Ah, I forgot, the Conservative party.

  43. David 45

    OFCOM gums hundreds to death

    OFCOM never did have any teeth.

  44. Anonymous Coward
    Thumb Up

    "Are these devices actually Radio Transmitters?"

    Yes, that's what they are.

    There's at least one video floating around that shows this. It shows two bits of PLT kit on entirely separate pieces of mains cabling (not grid-connected, out in a field with two separate generators or something like that) talking to each other with nothing except the ether to connect them together - but the electrically isolated networks still manage to transfer data.

    The video therefore shows quite clearly that these devices are radio transmitters/receivers, unlicenced and indeed unlicenceable, but don't expect facts like that to be considered relevant when BT Vision is in the frame.

    Hopefully someone with a better memory than me will be able to provide a link.

    1. This post has been deleted by its author

  45. Andy3

    Regulating the regulators?

    "Ah, I forgot, the Conservative party." - AC.

    Actually Ofcom was set up under Labour, and this whole thing (the reports commission and their suppression) all happened under Labour.

    At least some Coalition MP's and Ministers are showing *some* interest.

  46. Anonymous Coward
    Anonymous Coward

    do new build houses come wired up with cat6?

    I think that they should be. That's not going to help the majority of us but really a house built in this day and age needs to be suitable for running a basic home network.

    I don't think anyone would really want to mess around with wireless or powerline networking if they could plug in a cable that would be 10 times as fast with no security considerations or radio interference to worry about.

    Obviously we would still want wifi for the smartphone or the tablet but the modest data requirements of those devices would mean that we won't be caning the airwaves like we are now.

    1. SImon Hobson Silver badge

      RE: do new build houses come wired up with cat6?

      You avvin a larf mate ?

      Finally, only a century or so after it's invention, man (but not all) new builds have been routinely wired with the bare minimum for phone service. Many are even wires for this new fangled TV thingy. A few are even wired for something called satellite - whatever that is ;-)

      Expecting the average "electric plumber" to understand the concept of data networking is pushing expectations a bit.

      An end user asked what he was supposed to do other than PLT. The answer is :

      what would you do if there weren't already power and lighting circuits in the house ?

      what would you do if there weren't already TV antenna cables in the house ?

      what would you do if there weren't already phone cables in the house ?

      The answer in all those cases is you either got a house with them already installed, you had them installed, your use some sort of radio (eg set top antenna for TV, DECT phone), or you go without. Walk down pretty well any street and you'll see TV and sat cables tossed over roofs, strung every which way on walls, and cover plates to hide the big lump of brick/rendering broken out by the installer when he drilled the holes.

      The things is there are very, very, very few situations where data cabling **cannot** be installed or wireless used. If it's not been installed as a "built in" facility then it's probably going to be messy to install and/or messy in having cable strung around, but in most cases cable is possible. It's a matter of how much you want to use the service that cabled network allows.

      Finally, I'll echo what others have said. It's not the end users fault. They've been sold a solution that is claimed to be legal - it's not the end users fault that these units are anything but.

      1. This post has been deleted by its author

  47. Anonymous Coward

    So how many PLT devices can we get around Ofcom's offices?

    So if we got a nice large number of PLT devices together plugged in to a mocked up ring main just outside Riverside House, 2a Southwark Bridge Road, London such that it wiped out the FM and DAB bands, do you think they might pay a bit more attention?

    "But they're perfectly legal devices, guv. Look your own reports say they are. Sorry, do they interfere with your radio reception. What a shame."

  48. Anonymous Coward
    Black Helicopters

    tin foil hats on folks

    they want consumers to run out and buy this kit, knocking out radio comms.

    That way when the government is ready to turn the whole country into a powerline network for surveillance smart meters, they can say "well it won't effect comms anymore than they already are effected by consumer electronics"

  49. Anonymous Coward
    Thumb Up

    "do new build houses come wired up with cat6?"

    It's ridiculous that they don't.

    Obviously you could use it for data.

    Less obviously the more adventurous could use it for "wall wart replacements" using power over Ethernet technology. Things are starting to be USB powered, but PoE gives you a greater wattage from the socket, and the PoE chips are cheap as, er well, chips.

    Given that it's low power low(ish) voltage DC there's probably a photovoltaic angle in there somewhere too.

  50. Anonymous Coward

    Corrupt or just lazy?

    Disclosure: I am a professional installer and user of HF, VHF, UHF, L-band and SHF communications equipment. I hold an amateur radio license but have not had a radio installation for 3 years. I also am temporarily operating an 85Mbit PLT system in my new home until I get round to pulling the carpets and floor up so I can cable from my modem to my home office. Posting AC because I really don't want Ofcom to recognise my name.

    PLT will always emit radio into the environment. If you put radio frequency signals into an unscreened, untwisted-pair cable the cable will act as an antenna and that radio will leak out. There is nothing that can be done to stop it. To anyone saying that filters are the answer I would point out that 1mW of RF 100m away is about the same to a receiver as 60W at 25km or 1kW at 100km. The math is a gross approximation but it should give a rough idea. Since a radio link needs a signal greater than the noise by a decent margin the figures in practice will be worse.

    A number of the posters above are alleging corruption within Ofcom. I wouldn't go that far. I 'd be far more inclined to put their behaviour down to laziness than corruption or malice. They are great at having consultations then doing what they were going to do anyway but I've found them to be sorely lacking when it comes to doing things to benefit radio users.

    As examples of Ofcom's laziness I would cite an experience a friend of mine (who is generally pretty law abiding and pays for his licenses) had when testing a radio indoors on the bench on an unoccupied hire channel (without a license). About 15 minutes into the test Ofcom showed up at the door (they said they were in the next street and had detected it - I believe them as they couldn't have got there from their base in that time.) They got really heavy and threatened to confiscate not only the radio concerned but tens of thousands of pounds of other radio gear unrelated to the offence. A few weeks later I was at an event and found a channel I was paying for occupied by a 100% duty cycle audio link. I called Ofcom and asked for assistance but it was Saturday and they said there was nothing they could do and I should go back to the frequency hire people and request another channel then reprogram all my radios. It kind of looks to me like they're happy to do their job when it's easy but not when it involves getting off their backsides. It's much easier to put on "pirate radio is evil FM" than to go and chase down illegal users...

    If Ofcom were to ban PLT I can't imagine the number of times they would be asked to get off their backsides to try and remove installations. They don't have enough people to do it but is saying "we let this get out of control and we can't put a stop to it" a valid reason for not enforcing the law? I'd at least like them to stop further sales. I don't know the spec of smart meter modems but as another poster observed, this could well have bearing on the deployability of that technology too.

    I see their handling of amateur radio licensing as further evidence of reluctance to do work. The users views at consultation were pretty-much ignored and the solution adopted was the one with the least work for Ofcom (with the exception of one idea which they could never have got away with).

    Ofcom seem unable to see that their reluctance to actually do anything may well end up being their undoing. One day, I believe someone in government will turn round and use their inaction as the basis for a decision to abolish them.

    I can't think of any radio professional I know that thinks Ofcom is doing a good job for users of the spectrum.

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