Updated September 2009
What does PLT equipment do?
Power line telecommunications (PLT) apparatus uses a technology that can carry data on mains wiring around the house and is used to connect computers or other digital devices.
It reduces the need for additional wiring in the home, offers high data rates and is easy to install. As a result it is proving useful and popular, with around 750,000 Pairs of equipment estimated to be in use in the UK today.
Is PLT equipment new to market?
Yes. Although PLT technology has been in existence for some years, its proliferation as a mass market product is a relatively recent development.
How many brands of PLT apparatus are there on the UK market?
There are about 25 brands of PLT apparatus on the market in the UK. The largest supplier is British Telecommunications plc (BT). BT includes Comtrend UK Limiteds PLT apparatus as part of its BT Vision package. This apparatus is required to comply with the EMC regulations.
What is electromagnetic compatibility (EMC)?
Electromagnetic compatibility is the engineering process which limits the natural electromagnetic fields produced by electrical appliances. This ensures that household products (for example, television, video or kettle) can all work within the home without disrupting each other.
Most electrical equipment produces an electromagnetic field as a natural by-product of its operation; an electromagnetic disturbance. That disturbance can in turn affect the operation of other nearby equipment. For that reason, manufacturers aim to keep this disturbance to an acceptable level so that different products, particularly household products, can all operate in the home.
There are legal requirements about acceptable levels of electromagnetic disturbance.
What are the EMC legal requirements?
In common with other electronic products sold in the UK, PLT apparatus is required to comply with the Electromagnetic Compatibility Regulations 2006 (the EMC Regulations) which are based on a European Directive.
These regulations aim to ensure that the electromagnetic disturbance generated by electronic equipment does not exceed a level above which other equipment (including radio and telecoms equipment) cannot operate as intended (and that the equipment itself has an adequate level of immunity to electromagnetic disturbance).
These requirements are described in the legislation, and are referred to as the essential requirements.
In short therefore, the EMC regime provides a set of rules across the EU to ensure the levels of electromagnetic disturbance are regulated.
Who does the law on EMC apply to?
The person who places products on the market (usually the manufacturer or the importer) is responsible for compliance and must ensure that equipment meets the essential requirements and does not produce an excessive level of electromagnetic disturbance.
Failure to meet this core obligation can result in a criminal offence.
How does a manufacturer demonstrate compliance?
Evaluation of electromagnetic disturbance is carried out by conducting engineering tests. Compliance can be demonstrated through self assessment or by involving an accredited organisation known as a notified body.
As an alternative to carrying out an assessment, the equipment can be manufactured and tested against reference standards (called harmonised standards because they are harmonised across the European Union). If that is done, then there is a legal presumption of compliance.
What is Ofcoms role under the EMC legislation?
The UK Government department for Business Innovation and Skill (BIS) is responsible for overseeing the EMC Regulations.
Enforcement powers are delegated to Ofcom where there is a radio spectrum protection or management issue. Ofcom can bring criminal prosecutions and can suspend sales if it believes an offence is taking place.
In connection with our functions we engage with BIS, the EU Commission DG Enterprise and other Member States through Administration and Cooperation Groups (ADCO).
What enquiries and complaints has Ofcom received about PLT?
Over the past 12 months Ofcom has received 143 individual PLT interference complaints; all from radio enthusiasts. Of these 121 have been investigated and referred to the apparatus supplier who has resolved 104. The solutions employed include replacing the apparatus, hard wiring and conventional wireless alternatives.
All of the complaints relate to the inability to receive radio transmissions in the High Frequency (HF) band (3 to 30MHz).
There are many other users of the HF Band including long range aeronautical and oceanic communications, the Ministry of Defence and international broadcasters. Ofcom has not received complaints of interference to these services.
Has Ofcom investigated PLT equipment?
Yes. Ofcom has exercised its enforcement functions under the EMC Regulations. Ofcom has investigated alleged breaches of the EMC regulations resulting from the supply of Comtrend PLT apparatus by BT.
What has Ofcom found?
On the evidence, Ofcom has not so far found that there is a breach of the EMC essential requirements. Ofcom has therefore decided against taking further enforcement action at this time. Ofcom is working together with Comtrend and BT to reduce any negative effects in individual cases and we support them in doing so.
It is recognised that EMC compliant equipment may still, in certain circumstances, have the capacity to cause interference to other radio communications equipment. This may happen due to the manner in which it is installed or operated.
Evaluating the complaints received and the evidence so far obtained, Ofcom has concluded that there does not at present appear to be significant public harm arising from this situation.
Is there an EU harmonised standard for PLT?
No. The EU has not yet published a suitable harmonised standard for this type of apparatus. The mass marketing of PLT equipment is a recent development.
Are existing EU harmonised standards for other products helpful?
Existing harmonised standards are helpful only to a limited extent because they are not specifically intended for this type of equipment. Ofcom believes the electromagnetic disturbance produced by this technology is an inevitable by-product of its operation and not attributed to poor design or manufacturing.
Would the development of an EU standard for PLT help?
Yes. At present, testing and assessment takes place against a backdrop of wider technical uncertainty than is normally the case and there is an increase in the take-up of this apparatus across Europe.
The development of such a standard would be an important step. The standard could be used by manufacturers and Notified Bodies to assess performance against recognised benchmarked values.
If the apparatus complied with the harmonised standard under the Regulations, there would be a legal presumption that the apparatus met the essential requirements.
It is clear that the public interest (and the interests of manufacturers and suppliers) across Europe would be best served by the publication of a suitable standard. This is an aspiration of the EU Commission which Ofcom supports.
Is the EU taking action?
Yes. The EU Commission is aware of concerns resulting from the proliferation of PLT in the EU and in response, issued a mandate (M/313) to the European Committee for Electrotechnical Standardisation (CENELEC) to produce a PLT harmonised standard. Work on this is currently taking place.
(Also, in 2005 the EU Commission issued a recommendation 2005/292/EC giving guidance to Member States on enforcement issues related to PLT.)
Is Ofcom studying the issue further?
In view of the concern expressed by stakeholders Ofcom commissioned an independent study into the likelihood and extent of interference caused by PLT apparatus. This study is due to be completed in November 2009 and will involve consultation with the Radio Society of Great Britain and other stakeholders. We will be publishing the results. It is hoped that the results will increase knowledge about the effects of PLT equipment and contribute to the development of manufacturing techniques and product design.
What else can Ofcom do?
Ofcom can provide advice and assistance to those who complain of interference with radiocommunications equipment. Any individuals who wish to report specific cases that may be caused by PLT apparatus, or any other source, should contact Ofcoms advisory team on 0300 123 3333 for further assistance.
We continue to liaise with BIS and other interested stakeholders in respect of PLT interference and will provide further updates on any significant developments.