Memorandum submitted by Electromagnetic
Compatibility Industry Association (EMCIA)
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 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.
(c) 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.
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 (eg 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).
n 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
[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://www.ofcom.org.uk/radiocomms/ifi/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.
5 October 2009
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