Telecommunications

Culture Media and Sport written question – answered on 27th April 2011.

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Photo of David Mowat David Mowat Conservative, Warrington South

To ask the Secretary of State for Culture, Olympics, Media and Sport what recent discussions he has had on the future regulation of power line telecommunications devices; and if he will make a statement.

Photo of Mark Prisk Mark Prisk The Minister of State, Department for Business, Innovation and Skills

I have been asked to reply.

I have had no such discussions, however my officials have responded to a number of inquiries concerning power line telecommunication (PLT) equipment and its compliance with the Electromagnetic Compatibility Regulations. In common with most electronic products sold in the UK, PLT equipment is required to comply with the Electromagnetic Compatibility (EMC) Regulations 2006, which are based on the European Electromagnetic Compatibility Directive, 2004/108/EC.

Enforcement powers are delegated to the Office of Communication (Ofcom) where a radio spectrum protection or management issue occurs. Ofcom has investigated 219 incidents, with one still to resolve, but has not concluded that PLT products fail to comply with the essential requirements of the EMC Regulations. The essential requirements require that equipment shall be designed and manufactured, having regard to the state of the art and good engineering practice, so as to ensure that the electromagnetic disturbance generated does not exceed the level above which radio and telecommunications equipment or other equipment cannot operate as intended.

The technical solution to ensure the essential requirements of the Regulations are met will vary with the state of the art, latest good engineering practice, extent of knowledge and similar variables and no revision of the technical requirement is currently foreseen.

Power line equipment manufacturers are committed to continuous innovation as technology advances, allowing them to comply with the requirements and spirit of the regulations while providing products to better meet general consumer expectations and needs.

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Yes3 people think so

No47 people think not

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Annotations

John Petters
Posted on 4 May 2011 2:51 pm (Report this annotation)

It is a pity Mr Prisk has not discussed the problem of Power line telecommunications (PLT) with the Radio Society of Great Britain (RSGB) or members of UKQRM.

Both organisations would have advised him that in practice these devices do not comply with the Essential Requirements of the EU Directive and the EMC Regulations 2006.

His statement that 219 incidents have been investigated is grossly inaccurate. Ofcom's own website states the figure is 272. It is believed to be many more.

He should also consult GCHQ who stated,
"We are already measuring an increase in the HF noise floor in the vicinity of our HF
receiving stations, with wide variations between day time and night time levels. The
propagation of noise in this band also varies according to seasonal changes and
other natural phenomena.
In the Power Line Technology (PLT) meeting of 8 February 2011 the Civil Aviation
Authority, amongst others, expressed a view that the RFI from these devices was
likely to pose a safety of life risk. We concur and support this view from our own
perspective.
Other interference issues have been raised by MoD, BBC, RSGB, and other players
in the telecommunications industry.
Although not wishing to be product specific, we understand that Comtrend currently
estimates that in excess of 1.5 million units are in circulation within the UK and that
numbers are due to escalate significantly with the release and promotion of Youview..
Additionally, BT Vision service also supplies the Comtrend 9020 product.
Currently there is no agreed harmonised standard to regulate these devices and
therefore, de facto, they should not be available for sale/use within the EU".

Ofcom commissioned a report as far back as 2008 into the BT Vision Comtrend adaptors which stated,
“Ethernet Powerline Adaptors do not satisfy the essential requirements of the EMC Directive”.
Ofcom fought tooth and nail to prevent publication of this report, which proves conclusively that Ofcom had the required evidence that PLT does not comply, yet refuse to take the action they are obliged to take to protect the radio spectrum and the safety of air travel and national security. Ofcom was ordered to publish this report recently or risk being held in contempt of court by the Information Commissioner's office.
See PLT interfering with Instrument Landing System, Airband and ambulance emergency frequencies here:
http://www.youtube.com/watch?v=kyYeTWHUnUk
and DAB radio here:
http://www.youtube.com/watch?v=_wvtBhilvz4
John Petters

A Campbell Dun
Posted on 4 May 2011 5:27 pm (Report this annotation)

Under the Wireless Telegraphy Act 2006 (WTA) (http://www.legislation.gov.uk/ukpga/2006/36/section/116), since PowerLine Technology works by injecting a modulated carrier signal (electromagnetic energy) on the mains wiring/cable and that mains cable is a path that is not provided by any material substance constructed or arranged for the purpose, of energy to which subsection 116(2) applies, it can be deduced that PLT devices are in fact wireless telegraphy transceivers with the mains wiring acting as the aerial.

The paths that are provided by 'any material substance constructed or arranged for the purpose, of energy to which subsection (2) applies' generally fall into coaxial cable, balanced lines/feeders or specific screened cabling not mains cable. This is all fundamental and well known to those technically competent. As a result unscreened mains wiring will result in the mains wiring to radiating RF energy (as well as being conducted by the wiring). This means that EMC regulations should apply. In the absence of a conflict with any EU Law a member state Law surely applies (the 2004 emc regulations).

PLT unlike its narrowband cousin PLC, has no frequency allocation and is neither licensed nor licence exempt but uses spectrum allocation used by licensed users; see Ofcom's own UNITED KINGDOM FREQUENCY ALLOCATION TABLE - 2010. Annex J (http://stakeholders.ofcom.org.uk/binaries/spectrum/spectrum-...).

It is also to be noted that HPA (Homeplug Powerline Alliance) has investigated the matter of spectrum allocation with the ITU (http://www.ban-plt.co.uk/downloads/hpa-fail.pdf). It was found in 2006 that it would take between 10 and 15 years to get an allocation (HPA presentation slide 8 but slide 4 is also informative regarding emissions), presumably a contiguous chunk, sufficient for these greedy devices, would not be available. It looks like even the manufacturers are aware that these devices are Wireless Telegraphy apparatus.

A paper entitled "BRIEF ON THE POTENTIAL INTERFERENCE FROM POWER LINE TELECOMMUNICATION TO AERONAUTICAL SYSTEMS" ("http://www.icao.int/anb/panels/acp/wg/f/wgf23/acp-wgf23-ip20-information paper on plt.doc") by the CAA to the ICAO on 27 September 2010 shows clear concern by the CAA regarding PLT of which Ofcom are well aware I'm sure. Section 2 states "Since main wiring was originally designed for the transmission of AC power modulated at frequencies around 50 Hz their ability to carry higher frequencies is limited" which seems to echo the terms of the WTA s116. However sections 3 and 4 of the documant are perhaps of more public concern.

If Ofcom does accept PLT (PowerLine Technology) is a wireless telegraphy then WHY are they defying statute and allow PLT (PowerLine Technology) devices to be sold and installed in this country?

It surely matters not how many or how few these devices interfere with (always provided members of the public are aware of the cause) but the fact that it does cause interference and the potential given the varying propagation conditions.

Ofcom's continual attempt to sideline or diminish radio amateurs technical awareness of the problem is to detract from the real problem which is the other parts of the spectrum that are not notched (protected) from this interference. Notches still allow the noise floor on amateur bands to increase. I see no criticism of such groups as CAA, NATO, BBC and the EBU (European Broadcasting Union) who all have their concerns about these devices. Now what is that all about?

Instead of showing technical competence in dealing with this matter, Ofcom seeks to trivialise it with such myths as a "clean spectrum" - no-one least of all amateurs have ever mentioned anything like that and even the least technically knowledgeable person knows that such a term is an absurdity. I am sorry to say this but Ofcom is clearly being political about a factual technical matter that, and given recent revelations, they neither appear to address nor fully understand unlike the EMC professionals.

See how the professionlas view PLT: http://www.compliance-club.com/default.aspx?id=17

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