PLT; PowerLine Telecommunications
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Latest NewsLab Tests Reveal Truth!
The EMC legislation relies upon the quality of the tests undertaken by laboratories and to this end, labs with the authorisation to test to the harmonised standards are called Notified Bodies. The personnel responsible are highly trained and the results definitive. We have just published a set of results for a Comtrend PLT adapter from one such Notified Body. The result speaks for itself.
<< Test Results Here >>
The EMC legislation relies upon the quality of the tests undertaken by laboratories and to this end, labs with the authorisation to test to the harmonised standards are called Notified Bodies. The personnel responsible are highly trained and the results definitive. We have just published a set of results for a Comtrend PLT adapter from one such Notified Body. The result speaks for itself.
<< Test Results Here >>
Ofcom Commissions Report
Due to criticism from many fronts including the RSGB and from the Industry Association the EMCIA and Summit Group, Ofcom have commissioned yet another report into PLT. .
Originally scheduled to be published at the end of November 2009 it was to cover the existing PLT 'standard' of 2 - 28 MHz but was adjusted to include VHF in light of the new gigabit PLT standard which will pollute up to 300 MHz. A freedom of information request has determined it is scheduled for publication in April.
300 MHz in the FOIA >>
Urgent - 300 MHz is live!
We recently purchased a Belkin "Gigabit Powerline HD Starter Kit" model F5D4076uk.
The units were installed per the manual and the emissions inside the house effectively wiped out most radio reception from:-
0.1 MHz to 370 MHz.
The units have been sent away for examination and testing to the current harmonised standards for Conducted Emissions. A report will be published in due course.
Belkin Field Test Results
Due to criticism from many fronts including the RSGB and from the Industry Association the EMCIA and Summit Group, Ofcom have commissioned yet another report into PLT. .
Originally scheduled to be published at the end of November 2009 it was to cover the existing PLT 'standard' of 2 - 28 MHz but was adjusted to include VHF in light of the new gigabit PLT standard which will pollute up to 300 MHz. A freedom of information request has determined it is scheduled for publication in April.
300 MHz in the FOIA >>
Urgent - 300 MHz is live!
We recently purchased a Belkin "Gigabit Powerline HD Starter Kit" model F5D4076uk.
The units were installed per the manual and the emissions inside the house effectively wiped out most radio reception from:-
0.1 MHz to 370 MHz.
The units have been sent away for examination and testing to the current harmonised standards for Conducted Emissions. A report will be published in due course.
Belkin Field Test Results
FAQ
- What is PLT?
- PLT is an umbrella term for devices which transport computer data over the mains electrical system.
- Is PLT the same as BPL?
- Broadly speaking they are the same kind of technology; BPL refers to a system which transports data over the local electricity network (Regional Electricity Company), rather than on the mains circuits of a single dwelling.
- What data rates are there?
- The original HomePlug was 14Mbps, later other versions became available with 50, 85, 200 Mbps. A new version currently being pushed through 'Standards' is a Gigabit version.
- What frequencies do they operate on?
- Broadly speaking, 2 MHz to 28 MHz. The new G.hn version (Gigabit) is set to operate right up to 300 MHz.
- How do I know if I am suffering interference from an installation?
- It is quite likely that if there is an installation near you, you won't have any doubt! For those who are curious, UKQRM has a small 'sound database' with audio samples of the most common.
- If they are not legal, why hasn't the government taken enforcement action and had them recalled?
- There is no clear answer to this. Compliance testing to EN55022 has proven that these devices are simply unable to meet the emissions levels laid down in European and UK law. It is commonly believed that pressure from political corners to meet the "Digital Britain" targets and powerful corporate lobby have a part to play.
- Why haven't you, UKQRM, RSGB or anyone else taken legal action?
- Fighting a regulator is no simple matter. The RSGB has consulted its lawyers and pressing for a Judicial Review looks the most likely to succeed. An initial price tag of £75,000 has been set. You offering to pay???
- Is there a way I can contribute to the fight against this invisible menace?
- Yes, two ways.
- a) If you have PLT interference, report it to Ofcom who will come and investigate. Follow these instructions.
- b) Make a donation to the RSGB 'Spectrum Defence Fund'
- How far does PLT cause interference?
- Piece of string question. The interference has been observed to over 1.2km from a single dwelling however there is a complication. Shortwave signals can bounce off the upper atmosphere and come back down to earth. This behaviour peaks every 11 years and a peak has not happened with PLT in widespread use. From 2010 on there is an increasing chance a single PLT installation could interfere half-way around the world.
- I have a set of Powerline adapters, should I stop using them?
- That is a matter for your conscience alone. However should a Stakeholder (radio user) become aware that they are suffering interference from PLT and request Ofcom's help to resolve the issue, there is every chance that Ofcom may come knocking at your door. To date, most instances of PLT interference have only been resolved to the complainant's satisfaction by removal of the devices.
- Will I be fined?
- Unlikely. Until a court rules PLT is illegal or Ofcom changes its mind, this will not happen. However since Ofcom have taken a very 'grey' position, should a PLT user refuse to cooperate with Ofcom to resolve the interference, the complainant may force this into a court and there is no telling where that could lead. What is certain is that radio is protected by international law so you are not likely to come out of this particularly well.
- Why has this taken so long to become public?
- There is a cocktail of reasons. We 'Brits' are not very good at complaining. No one knows for sure when the noise interference was first connected with PLT. Ofcom only started to record PLT interference the month prior to the UKQRM website going live in 2008.
- This is a load of old horse shit from a bunch of wrinkly old radio hams.
- Good job you don't live next door to me.
- I want to continue using my PLT equipment because the Wi-Fi channels are all full in my area. Is there something I can do to stop it interfering?
- Turn it off and run an Ethernet cable, sorry. There is a new gigabit Wi-Fi coming along soon.
- Is there a chance you could be wrong about this?
- None. Please type in PLT interference into YouTube and see the effects for yourself. (Done for you here)
- I read somewhere that 'Adaptive Notching' will stop the interference. Will it?
- No. Unless the PLT device has a radio and aerial system similar to the local radio users AND the PLT device knows which station EACH and every user is listening to at ANY moment, it is not possible.
- Someone told me to stick a load of clip-on ferrite suppressors on the mains cables of household appliances, will this work?
- It is very unlikely since the adapters plug straight into the mains sockets and connect into the ring-main of your house. The electrical wiring itself acts as an antenna. However if you are a neighbour AND still friends with someone suffering, there is no harm in experimentation. Each installation is different and will react differently.
- I've just bought a set of adapters, can I get my money back?
- That's a real tough one. Since the adapters cause interference when they are operating at specification, they are not faulty. Ofcom have made it clear that from a legal standpoint once the devices have been manufactured and imported, it becomes a matter for Trading Standards to enforce compliance legislation. Your best bet is to try and return them as 'bought in error' if they are unopened or "Not fit-for-purpose due to radio interference". Beyond that I am not qualified to comment.
- I want to pursue non-compliance through Trading Standards, how should I do this?
- EMC law is complex and to succeed you need to be back by sympathetic experts. I suggest speaking with the RSGB or the EMCIA who may be able to offer some tips and/or some measure of support.
- I have heard that some PLT interferes with VHF, is this true?
- Yes. The new Gigabit PLT has been directly observed to interfere to above 350 MHz, blocking VHF FM radio broadcast, the new DAB radio system and even the Civil Air band!
- How is this going to end?
- Unknown. There are 65,000 Amateur transmitting licences in the UK. The number of Shortwave Listeners is unknown. Other Stakeholders of Shortwave include Emergency Communications, Aeronautical and maritime communications, military and diplomatic communications, Time signals and radio astronomy. As the ionospheric propagation increases with the 11 year sunspot cycle the distances PLT interference can travel will only increase. In the end it is a numbers game. Some people will carry on using the devices for years to come immaterial of any legal developments so the sum of the interference will be determined by the number of PLT devices left in service.