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Latest NewsThe 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 >>
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
Memorandum submitted by Electromagnetic Compatibility Industry Association (EMCIA)
Contents Page No.
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
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
(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.
(c) All service organisations that employ electronic equipment.
(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, who may be contacted at keith.armstrong@cherryclough.com, telephone & fax: 01785 660 247.
The EMCIA Secretariat is Nutwood UK Limited,
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
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
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
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
In order to satisfy Item b) by permitting PLT to exist,
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.
3.4 PLT cannot comply with the EMC Directive
Within
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
[2] Why broadband PLT is bad for EMC, Tim Williams, EMC Journal January 2009, Issue 80, pp 25-34, www.theemcjournal.com
[3]
[4] VDSL2 and in-door PLT Coexistence, E
[5] The Wireless
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
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
The original document can be viewed at www.parliament.uk