Electromagnetic Compatibility Industry Association

The EMCIA was formed on 20th March 2002 for the benefit of companies involved in Supplying, Designing, Testing and Manufacturing EMC products.

The EMCIA Secretariat is Nutwood UK Ltd, publishers of The EMC Journal, www.theemcjournal.com

The EMC Information Centre has a very useful and detailed page on PLT. It is well worth a read! Especially the Greedy PLT book

We also recommend downloading and reading the PLT articles in the following EMC Journals:

An interesting read from Tim Williams of Elmac Services: After the EMC Directive

Parliamentary Memo

In October 2009, the EMCIA submitted a Parliamentary Memo on the effects of PLT. It is reproduced here for history and easy reading. The original document can be viewed at www.parliament.uk

The EMCIA Memo to the Parliamentary Working Ctte on Broadband

Memorandum submitted by Electromagnetic Compatibility Industry Association (EMCIA)

Parliament Logo

Contents:

1 Executive Summary. [2]

2 The EMCIA - a brief introduction. [3]

3 Factual information. [4]

3.1 PLT causes unacceptable electromagnetic interference (EMI). [4]

3.2 Ofcom suffers from a conflict of interest over PLT. [4]

3.3 EMC standards experts have failed to find a solution for PLT. [5]

3.4 PLT cannot comply with the EMC Directive. [5]

3.5 References. [6]

3.6 Further information, discussions and demonstrations. [6]

4 What we would like the Committee to consider including in its report [7]

1 Executive Summary

We very strongly recommend that the Committee specifically excludes the use of PowerLine Telecommunication (PLT*) technologies as an option for the delivery of broadband Internet.

One mechanism for providing broadband Internet access might be thought to be PLT, and similar digital communications technologies, that use the electric power lines (the "mains") to, and within, homes to carry the high speed data signals used by broadband Internet.

But mains wiring is unsuitable for carrying such signals, and so PLT results in excessive electromagnetic interference (EMI).

The very high levels of EMI emitted by PLT have serious consequences for radio communications in the "Short-Wave" band (1 - 30MHz), including potentially severe safety consequences.

It can also interfere with the delivery of broadband Internet by xDSL technologies using telephone cables, slowing their data rate.

* PLT also goes by other names, including PowerLine Communications (PLC) and Broadband over PowerLine (BPL)

2 The EMCIA - a brief introduction

The full name of the EMCIA is the Electromagnetic Compatibility Industry Association.

The EMCIA was formed in March 2002 for the benefit of companies involved in the supply, design, test or manufacture of EMC* products, or the provision of EMC Services. The EMCIA is a UKTI Accredited Trade Organisation.

* EMC is short for Electromagnetic Compatibility - the ability of equipment or a system to function satisfactorily in its electromagnetic environment, when used as intended:

- without causing intolerable electromagnetic interference (EMI) into its environment, and,

- without suffering unacceptable degradation of performance due to EMI present in its operating environment.

The achievement of EMC is vital for everything that employs electricity and/or electronics, and is necessary for:

(a) All manufacturers who incorporate electronic devices within their products.

Including: agricultural; consumer; commercial; communications; industrial; education; science; military; transport (road, rail, air, space, marine, etc.); national infrastructures (electricity and gas generation and distribution; telecommunications and Internet; radio and TV broadcasting; water supply and sewage treatment, etc.); medical; security; building automation; etc.

Based on figures from ORGALIME, the total value of these manufactured goods in the UK is in excess of £30 billion per year.

(b) Owners/operators of systems/installations that employ electronic equipment

Including all buildings and vehicles: agricultural; scientific; residential; commercial; industrial; healthcare; national infrastructure; communications; military (land, sea, air, space); educational; governmental; etc.

(d) Employers who provide work equipment incorporating electronic devices

Including: agricultural; retail; commercial; entertainment; industrial; government; military; communications; scientific research; transport; healthcare; education; transport; etc.

The author of this Memorandum is Keith Armstrong, the President of the EMCIA.

The EMCIA Secretariat is Nutwood UK Limited,
Eddystone Court,
De Lank Lane,
St Breward,
Bodmin,
Cornwall.
PL30 4NQ,
telephone: 01208 851 530,
fax: 01208 850 871.

3 Factual information

3.1 PLT causes unacceptable electromagnetic interference (EMI).

The mains power distribution network, both to and within homes, is unsuited to carrying the high frequencies used by high-speed data signals.

Furthermore the mains network already carries high-frequency interference caused by the operation of electrical and electronic products - although its magnitude is regulated by international standards.

For these reasons, for PLT to communicate a data rate that is sufficient for broadband Internet, over adequate distances, it must inject such high levels of signals into the mains network that copious levels of EMI are emitted from the mains wiring.

The emitted levels of EMI are far above those permitted by test standards generally used for ensuring compliance with the EMC Directive [1].

In fact, a single PLT device in a home creates as much EMI as would over 1,000 barely-EMC Directive-compliant products all plugged into the same mains socket.

This EMI has a negative effect on users of radio communications, both nearby and further afield [2], and could have severe safety consequences (e.g. for short-wave radiocommunications with aircraft, or in the case of a national disaster).

It is often implied by proponents of PLT (and by Ofcom, see [3]) that the "Short-Wave" communications that suffer the greatest EMI from PLT are only used by hobbyists, but in the case of Ethnic Minorities they may be the only way they keep in touch with news and events in their home countries.

The EMI from PLT also affects the delivery of broadband signals via telephone wires, for example the new VDSL2 standard, as shown by [4].

3.2 Ofcom suffers from a conflict of interest over PLT

Ofcom have investigated many complaints of EMI from existing PLT in-home installations.

The last publicly available figure is that 143 such complaints were recorded over a period of 12 months, making it by far the largest single cause of interference complaints to Ofcom.

Ofcom could take enforcement action against PLT under the 2006 EMC Regulations [1], or under the Wireless Telegraphy Act 2006 [5], but despite the high rate of interference complaints Ofcom has recently stated that it will not take enforcement action at this time [3].

Ofcom has two statutory duties that, in the case of PLT, are in conflict. As set out in the UK Communications Act 2003, these are to ensure:

a) The radio spectrum (the airwaves used by everyone from taxi firms and boat owners, to mobile-phone companies and broadcasters) is used in the most effective way.

b) The UK has a wide range of electronic communications services, including high-speed information services (for example, broadband).

In order to satisfy Item b) by permitting PLT to exist, Ofcom has abandoned Item a).

3.3 EMC standards experts have failed to find a solution for PLT

Numerous attempts have been made at the international standards level [6] for the last twelve years to attempt to find a way in which PLT apparatus could be made to coexist with radio services, without causing excessive EMI.

UK experts have been actively involved in this work, which has failed so far, due to the unmanageable technical contortions involved.

3.4 PLT cannot comply with the EMC Directive

Within Europe, the EMC Directive [1] (and corresponding UK EMC Regulations) regulates the placing on the market Of apparatus which could cause EMI.

Serious concerns have been raised regarding the compliance of PLT apparatus with this Directive [7].

As already mentioned, a single PLT device in a home creates as much EMI as would more than 1,000 barely-EMC Directive-compliant products - that each just about scraped under the emissions limits in the relevant EMC test standards - all of them plugged into the same mains socket in that house and operating at the same time.

The European Commission, accepting that "PLC manufacturers have the impression that, even if their technical file is convincing, they run a serious risk of a sales ban by market surveillance authorities", have seen fit to neuter the enforcement of the Directive rather than require the PLT manufacturers to make their products comply [8].

3.5 References

We will be pleased to supply any/all of these documents.

[1] The EMC Directive, 2004/108/EC, from: http://eur-lex.europa.eu/LexUriServ/site/en/oj/2004/l_390/l_39020041231en00240037.pdf

Implemented in the UK as The EMC Regulations 2006; Statutory Instrument 2006 No. 3418, from: http://www.opsi.gov.uk/si/si2006/uksi_20063418_en.pdf

[2] Why broadband PLT is bad for EMC, Tim Williams, EMC Journal January 2009, Issue 80, pp 25-34, www.theemcjournal.com

[3] Ofcom statement, 3rd September 09, published at http://stakeholders.ofcom.org.uk/enforcement/spectrum-enforcement/plt/

[4] VDSL2 and in-door PLT Coexistence, ETSI, LAN09AF033 Ed.02, July 16, 2009. ETSI is the European Telecommunications Standardisation Institute, and it makes this report available as: PLT52_TD12_VDSL2-PLT_Plugtest_Report, ETSI, 2009.pdf

[5] The Wireless Telegraphy Act 2006, from: http://www.opsi.gov.uk/acts/acts2006/ukpga_20060036_en_1

[6] The relevant International Electrotechnical Commission (IEC) committee is CISPR/I, which has a Project Team on PLT, www.iec.ch/zone/emc/emc_cis.htm

[7] RF Emissions of Powerline Ethernet adaptors, Tim Williams, EMC Journal, Issue 82, May 2009, pp 15-18, www.theemcjournal.com

[8] In the OJEU C197/3 of 21st August 09, the Commission delayed by two years the implementation date of a standard that PLT manufacturers believe would prevent them marketing their products.

3.6 Further information, discussions and demonstrations

We will be pleased to provide a very great deal more information on this issue, either as documents, discussions, or even practical demonstrations of the generation of EMI from PLT, and its consequences for short-wave radio reception.

We can provide access to a wide range of recognised UK experts in all of the areas mentioned above, including those who are not members of the EMCIA.

4 What we would like the Committee to consider including in its report

For the reasons given in section 3 above - we very strongly recommend that the Committee specifically excludes the use of Power Line Telecommunication (PLT) technologies as an option for the delivery of broadband Internet.

5th October 2009

Page updated: 15th August 2021