The Impact of Power Line Communications, Part 1
Although PLC may seem attractive on the surface, many technical
and interference problems remain for the controversial broadband
deregulation in the EU utility market has led to a new kind of
competition with classical telecom providers. The new players
are using utility-owned power lines in the low-voltage mains grid
to provide broadband Internet access in areas that are mostly
residential. Power line communications (PLC, sometimes called
PLT for power line telecommunications) uses unshielded, 230 V/50
Hz, low-voltage distribution cables inside and outside of buildings
as transmission media up to Mb/second data rates. This requires
mains-injected radio-frequency (RF) levels (e.g., total power
<1 W, spectral power 40d Bm/Hz, 130 MHz) that are EMC
critical, with common-mode (CM) currents on wires (e.g., 20 dBµA
at 1 MHz). Similar signals are normally injected at distribution
international standards have been developed to control radiated
emissions below 30 MHz in the short-wave user spectrum. Most standards
give field strength limitations only above 30 MHz. In Germany,
for example, the applicable regulations are found in RegTP NB
30-07/01. Regulations and standards are supposed to protect, among
others, sensitive monitoring and communications services in both
military and government.
contrast to PLC, other competing broadband services, such as digital
symmetrical subscriber line (xDSL) and cable TV, use well-engineered,
as well as symmetrical, telecom lines with less disturbance potential.
Results from field trials of actual PLC systems throughout Europe
are now available, and some conclusions can be drawn from these
results. Some aspects of the EU mandate M313 regarding telecom
networks are also discussed.
article examines the latest PLC developments. Computer simulations
are discussed and compared with EMC-critical measurement results.
It also reviews the current state of PLC and related wire broadband
technologies, with a focus on European activities.
In the past five years, PLC modem and system developments
have increased throughout Europe. Field trials were started in
the UK, Germany, Spain, Italy, and other EU countries.110
Some utility companies want to use this new technology to provide
value-added services, such as fast Internet access or relatively
fast local bus systems, to clients in private homes or industry.
The technology is designed to work simply by plugging into the
50 Hz, 230 V mains.
is certainly an attractive idea. One should not confuse this technology
with previously existing services that use slow data rates below
149 kHz. It should also not be confused with PLC that operates
over medium-voltage distribution lines in the power grid. However,
unlike xDSL, unshielded low-voltage distribution systems are not
designed primarily for communication purposes.
information technology (IT) equipment, TV and video equipment,
and appliances, a number of obstacles prevent the even distribution
of RF-energy for wire communications within buildings. Impedance
changes, longitudinal signal attenuation, uncontrolled coupling,
radiated emissions, light switches, and time-dependent loads all
present difficulties. EMI filters designed to block high-frequency
PLC signals also cause problems.
Field Trials. Early field trials in the UK, Germany, and Switzerland
showed excessive radiated emissions (some up to 40 dB) above Germany's
NB 30 RegTP limits, which were about 20 dB more relaxed than the
earlier version of 4/2000 RA,UK MPT 1570 in the short-wave spectrum.
The current not-yet-harmonized NB 30 is now viewed as a predominantly
national approach. Germany initially followed a compromise with
statistical EMI disturbance (i.e., not all German coffee mills
are turned on simultaneously). The UK, however, worried mostly
about the man-made noise increase in sensitive receivers, caused
by the always-on phenomenon of this broadband service. Since 9/11,
German agencies have increasingly dealt with sensitive radio communication
issues in addition to medium-wave broadcast service coverage.
Germany, broadcast, military, and commercial interests, as well
as licensed amateur radio services, seriously objected to a nationwide
implementation of PLC. Many theoretical studies by academic institutions
were performed. The studies alluded to potential noise-floor issues.
In parallel, EMC standards slowly but surely began to develop
in consensus groups such as IEC, CENELEC, ETSI, and CEPT. Regulation
authorities, therefore, had to quickly form technology-assessment
advisory boards like ATRT RegTP PLC Working Group. ATRT addresses
all related issues of wire and radio EMI in networks. The remaining
participants in the PLC industry (after the withdrawal of big
players like Norweb, Siemens, EON, and RWE) are fighting for rapid,
widespread installation to fulfill business objectives and investors'
Technology. Generally speaking, the PLC industry appears to be
marketing driven. First-generation PLC modem technology uses mostly
discrete frequencies in two bands (110 MHz outdoors and
1030 MHz indoors).11 Several independent measurement
campaigns in Switzerland, the UK, Germany, and France indicate
40 dBm/Hz injected-signal levels result in radiated emissions
of 2040 dB above NB 30 limits (e.g., at 1 MHz results in
40 dBµV/m, 9 KHz BW, test distance d = 3 m and is equivalent
to 20 dBµA CM current [wire to ground]) on lines in installations.
Installation-specific parameters determine coupling factors and
antenna gain in wide ranges.
cables (110 MHz) are typically less critical than home installations
(1030 MHz). This was clearly observed in Swiss 200300-m
long cable systems buried in a residential area. Natural wiring
resonance phenomena (stubs to light switches form /L
length) in homes with indoor frequency bands may increase radiation
easily by 10 dB or more. The higher the frequency the higher the
radiation is from these systems.
large system measurements in Germany and elsewhere indicate additional
measurement problems with present metrology of NB 30/MV05 (3 m
distance, 60-cm BB magnetic loop) using a near-field test procedure.
Technicians have difficulty isolating PLC system signals from
background or equipment noise at 3 m. Consequently, this argument
is often used by PLC promoters to question the wisdom of setting
current limits in standards. Man-made noise has increased over
the past two decades (e.g., due to progress in microprocessor
speeds). The 3-m test distance scenario originates from portable
broadcast band receivers with built-in antennas used in apartments.
At a 1-m test distance, however, it is less difficult to find
the EMI source. Moreover, the instrument-noise floor in nonselective
preamplifiers using the CISPR 16 loop antenna is also less difficult
at 1 m.
measurements can be strongly affected by small location changes,
frequencies, natural ambient noise, and emissions of other nearby
electronic devices. Secondary radiators, such as water pipes,
also affect measurements. RF current tests are more direct, but
suffer from standing waves along the lines.
effects and underestimated PLC system antenna factors may also
lead to short-wave signal mirroring at the ionosphere.10
This effect is just beginning to be taken into account by the
Ministry of Economy in Berlin, which supervises the RegTP agency.
The EC has had some discussions on this matter in its EMC WP Group.
These short-wave (sky-wave) propagation effects might lead to
an increase in background noise even far outside Europe.6,
on initial simulations, it appears that sensitive receiving sites
in Germany may experience degradations of 1040 dB at hundreds
of kilometers away from the PLC-polluted area. This, of course,
is unacceptable for security agencies, especially in light of
the present unstable political scenario. Simple sky-wave experiments
seem to confirm degradation shown in simulations. More R&D
is needed to cope with aviation-radio band issues and with long-distance
PLC network effects.
digital technologies came the introduction of power reduction
in broadcasting. Reducing transmit power lowered electromagnetic
pollution and potential health hazards. Unfortunately, these improvements
become useless if, at the same time, the signal-to-noise ratio
(SNR) turns out to be degraded by PLC.
automotive industry is also looking into PLC usage in cars. High-speed
communication buses, however, produce excessive emissions. These
emissions leak into the environment, causing failed control limits
in international CISPR standards.
April, FCC issued a Notice of Inquiry seeking public comment on
the use of power lines to provide Internet and broadband services
(see the sidebar on page 57). Like the United States, Japan is
densely populated and uses many overhead transmission lines in
the low-voltage distribution system. Japan, however, decided in
2002 to prohibit PLC, except in limited R&D field trials.
of High-Frequency PLC
transmission media mains (230 V/50 Hz) with Kb-per-second mains
signaling (similar to EN 50065 3-148.5 kHz at several volts amplitude)
dates back to around 1920. Using frequencies from 1 to 30 MHz
(Mb/second) and injected-RF power levels, from megawatts to watts
total spectrum power, started in the UK in 1996.
lines in homes exhibit bad symmetry, changing impedance, unfavorable
coupling and resonances, and susceptibility to external EMI. So
network internal emissions by CM currents are inevitable. Power
levels of 40dBm/Hz lead to 2040 dB above German NB
have difficulty meeting current conducted disturbance limits of
EN 55022 at the mains port. Moreover, it is extremely difficult
to simulate real PLC traffic in a representative network EMC test-lab
setup. Geometry, size, and, in particular, the ever-changing and
adapting network data parameters make simulation difficult. For
the purpose of broadband access to the Internet, for example,
two bands are normally used: <10 MHz outdoors and >10 MHz
industry now faces a major problem. Established radio-wireless
technologies must peacefully coexist with new, unshielded PLC
systems. If brute force on the transmit-level side is not an option,
smart algorithms and system design from military spread-spectrum
communications technologies might offer a solution.
channel capacity, sophisticated modulations, SNR, and time-domain
procedures, including signal processing and optimized multichannel
path probing, are modern technical challenges. The old slow-speed
applications and simple remote meter reading are far less critical.
Automotive PLC applications are in the early R&D stages.
and Future PLC Technology
Europe, there are basically two technologies (ASCOM [discrete
frequencies] and main.net [spread spectrum]) in PLC over the mains.
The current technology used by ASCOM (Switzerland) and by the
former Norweb (UK) employs several RF carriers about 12
MHz wide (50%) on the mains. Main.net (Israel) uses a wideband
6. Telecom port asymmetrical (tested with T-network) directly
relevant to CM-current, EMI emission limits of EN 55022,
technology tries to lower injected PLC levels, but potentially
at the cost of the SNR. In later nets, there is sometimes a problem
at night, when more people are home and the EMI of home appliances
rises. The surge in use triggers serious signal-to-noise problems
that cause data rates to drop below those of integrated services
digital network (ISDN). To meet current EMC requirements, future
PLC technologies need to decrease emissions by 40 dB. They could
also apply smarter software channeling algorithms.
5. Mains port (tested with V-network), conducted emission
limits (EN 55022, 1998, for class B, QP-detector) combining
both differential and common mode.
(typically 15 dB) is EMI relevant. PLC signal levels, modulation,
and existing line noise are important to bridge the distance without
costly repeaters. The PLC community, therefore, is fighting for
less-stringent regulations and is demanding new EMC standards.
This is addressed in NB 30 in Germany (see Figure 1). It could
also affect these standards: the EU EMC Directive, ITU-R SG1,
CISPR/I/WG3 (TF xDSL), CEPT SE35, CENELEC SC205A, CENECEL/ETSI
(Networks), German DKE UK 767.17.3, and RegTP ATRT UAGr.3.
PLC, problems include statistical limit model changes with always-on
mode and questionable EMC metrology (near- and far-field, line
impedance stabilization network [LISN], CM and differential mode
(DM), longitudinal conversion loss [LCL]transverse conversion
loss [TCL]-coupling). PLC has become controversial concerning
both EMC and general telecom issues.
PLC modulation, such as orthogonal frequency-division multiplexing
(OFDM) and, in particular, spread-spectrum or time-domain options
(similar to ultrawideband), are potentially more EMC suitable.
Modulation is better than high-power individual multifrequency
carriers, for which the only option is the hope that at least
one out of three channels will successfully transmit the desired
information to the end-user. MVV Mannheim (South Germany), which
uses spread spectrum, sometimes has conducted EMI network problems
with data-rate drops below ISDN speed.
for PLC in EMC and telecom standards will certainly affect all
EMC standards developments. Many issues would need to be addressed,
and metrology issues (e.g., V-LISN CISPR versus T-Network).
versus CM (radiation-critical) issues.
55022 multifunction port.
to allow PLC to use the mains port (presently at lower conducted
EMI limits) like a telecom user (with symmetrical lines).
and better-suited test procedures. This includes LCL, network
antenna factors (installation coupling), and updates of currently
used, 20-year-old, man-made noise statistics.
port versus telecom port limits. This topic is so hot, it was
discussed in CISPR 22 and put out for national committee comments
worldwide. Equal rights and fair treatment for all parties involved
is to be achieved.
should be a safety margin between equipment and network emissions
requirements. Equipment is easier to test compared with complete
nets. Net status emission changes in time and location need consideration.
This is typically a computer simulation effort. Tighter specs
will most definitely affect the PLC industry. R&D is costly
and risky. Time to market is essential. The other point of view,
however, is whether it is reasonable to require earlier players
in sensitive radio services to accept major disadvantages.
PLC Standards and Regulations
consensus is required from international technical experts, standards
typically take 24 years to get established. Similar to existing
technologies, PLC needs to be integrated into established harmonized
standards. Fair and equal treatment is a must. Consequently, there
should be no new PLC-only regulations with conflicting limits
to those in EMC and telecom and wireless standards.
1. Field limits below 30 MHz (EdBµV/m
= H+51.5 dB) FCC (>2 MHz still debated) NB 30 (1M Hz
= 40 dBµVm),
MPT UK, Norway, BBC.
is no such thing as creating national standards anymore in the
EU.12 NB 30, with its MV05 test procedure, therefore,
has triggered EU discussions about RegTP. NB 30 excludes several
national-security frequency bands from PLC use. Even if NB 30
limits do not remain accepted in international norms as a compromise,
peaceful coexistence in the spectrum with radio systems is mandatory.
It was discovered recently that PLC signals interfere with some
short-range devices (SRD) operating in the short-wave spectrum.
Such SRDs include antishoplifting devices used in department stores.
2. NB 30 E-field limits and corresponding common-mode current.
is important to review the requirements of a standard such as
ETSI EN 300 330-1 V1.3.1 (2001). The scope states, "The present
document applies to SRD transmitters and receivers: a) transmitters
operating in the range from 9 kHz to 25 MHz, and inductive loop
TX operating from 9 kHz to 30 MHz; b) receivers operating from
9 kHz to 30 MHz. The present document applies to generic SRDs:
inductive loop systems; with an antenna connection and/or with
an integral antenna; for alarms, identification systems, telecommand,
telemetry, etc.; applications with or without speech."
to EN 300 330-1, when selecting parameters for new SRDs that may
have inherent human safety implications, manufacturers and users
should pay particular attention to the potential for interference
from other systems, such as PLC, operating in the same or adjacent
present document covers fixed stations, mobile stations, and portable
stations. The issue here is emissions received, rather than transmitted
(low-power, spurious emissions). To reach the limit set in NB
30, it takes 50100 m in residential areas. There is no control
of SRD interference from PLC installations, which worries groups
such as the Low Power Radio Association (http://www.lpra.org).
For a 3-m receiving distance (and including secondary radiation
effects of nearby conductors), CEPT has determined that a reasonable
limit is 18 dBµVm for 8 MHz (QP-CISPR) and 15 dBµVm
for 13.56 MHz. Consequently, this industry favors limits lower
than those in NB 30. Reports from the UK have indicated that modern
electronic fault, current-detection devices are being unintentionally
tripped by PLC RF. This is a potential safety problem for the
speaking, there are issues arising from requirements in both the
EMC Directive and the R&TTE Directive. Unique national frequency
allocations still exist and must be considered. For example, German
regulations, as well as CISPR 11, define many safety- and security-critical
frequencies in the short-wave ISM band. Among these are aeronautical
and maritime distress channels. Moreover, ITU defines primary
and secondary allocation status for user groups in general. It
is estimated about one million SRD units, including electronic
article surveillance, are installed throughout the EU.
technical issues surrounding PLC are noise floor and SNR, especially
when compared with existing technologies such as local-area networks
(LANs) and xDSL and their interference potential. In the past,
little attention had been paid to commercial system EMC; box testing
was the dominant concern.
the introduction of PLC, the commercial EMC community has now
been forced into system thinking. Addressing system issues is
also part of the new EU Mandate, M313. This mandate resulted from
commercial interference. Leakage from worn-out coax cable caused
cable TV systems to interfere with air-traffic-control systems
over major German cities. For the military, aviation, and automotive
industries, this system is mission critical. The box-test procedures
must be made with system aspects in mind. In particular, procedures
must address cables, which can propagate CM currents.
1 gives an overview of currently applicable and proposed magnetic-field
strength limits below 30 MHz. Following conventions, the corresponding
E field is calculated using 377 W (51.5
dB W), based on free space impedance
(E/H = Z). Naturally, this calculation does not reflect physics,
because at 10 MHz (L = 30 m) far field,
using oversimplified L/6, the far field
begins at roughly 5 m. A comparison of NB 30 field limits and
CM currents in installations is shown in Figure 2. Depending on
the equipment used, as defined in CISPR 16-1, these limits are
already difficult to meet with 60-cm broadband loop antennas.
The noise margin is below 6 dB in some areas (see Figure
3). Using 3-m limits below 10 MHz, the instrument noise introduces
large measurement uncertainty SNR. Detector choice from peak-to-quasipeak
or average may give about 10 dB better SNR. Tuned loop antennas
can improve this further by 20 dB.
is interesting to look at other limits as well. IT equipment under
EN 55022 Class B is significant. At 30 MHz (30 dBµVm) at
10 m converted to 3 m (10 dB) distance (assuming far field) and
converted from 120 to 9 kHz BW (11 dB, assuming PLC noise signals),
the result is about 51 dBµVm results in H = 0 dBµA/m.
This converted EMC limit is more than 20 dB higher than NB 30,
which needs to take network-specific effects into account. To
put the limits into the right perspective, one should compare
limits found in other important industry standards below 30 MHz
(see Figure 4).
11 (industrial, scientific, and medical equipment), CISPR 15 (lighting),
and EN 50121 (railways) all have limits above those in NB 30.
Other standards are also based on fairly old interference statistics
models. Modern telecom and wireless aspects are only partly accounted
for in these standards. Moreover, before deregulation settled
in during the last decade, the various public telephone services
(formerly monopolistic) used their strength more easily to set
spectrum usage rules. Certain industry groups now seem to dominate
this process, and the focus is moving in nontelecom-oriented directions.
Another important consideration is the simple conducted- emissions
limits (see Figures 5 and 6). Taking 60 dBµV (Class B, QP),
30 MHz across 50 W (34 dB W),
gives a 26 dBµA mixed-mode signal (CM + DM). The CISPR 16
V-shaped LISN does not separate the components. The proposed draft
value in NB 30about 12 dBµA (30 MHz)makes sense
for residential areas and is consistent with the need to account
for network effects.
is also worth mentioning that actual mains impedance (P/N/PE)
measurements in the Netherlands revealed, as expected, large variations
from 9 to almost 500 W (1.8 to 29 MHz).13
Such variations have been known in the EMC community for several
decades. The statistical average value, 50 W,
has been used for about 30 years. For the hotly debated PLC telecom
port (see Figure 6), the limit is somewhat relaxed. This limit
is 74 dBµV (Class B, QP), 30 MHz. The corresponding current
is calculated using 150 W (44 dBW)
line (CM) impedance. Consequently, the result is 30 dBµA.
real interest of the PLC community is an interim clause that specifies
a 10-dB relaxation in the CM case between 6 and 30 MHz (40 dBµA).
PLC developers would like to use a multifunction port because
mains is their telecom port. It would certainly be interesting
to check for impedance variations as well. No data are currently
is especially critical to note the technical noise-floor problem
in measurements for real EMI environments in city locations such
as a flat in Paris. In these locations, the appliance noise can
easily mask network-related limits at 3 m (see Figure
at conducted effects as the origin of radiation, under normal
V-LISN conditions, it seems nearly impossible to operate PLC data
transmission in a safe and reliable way.
FCC Docket 03-104: FCC Begins Inquiry
Regarding Broadband Over Power Line
part of its ongoing effort to promote spectrum flexibility
and access to broadband services for all Americans, and
to encourage multiple platforms for broadband, especially
new facilities-based platforms, FCC issued a Notice of Inquiry
seeking public comment on using existing electrical power
lines to provide Internet and broadband services to homes
over power line (BPL) can provide consumers with the freedom
to access broadband services from any room in the house,
without adding or paying for additional connections, by
simply plugging a BPL device into an existing electrical
outlet. BPL may be able to provide an additional means for
"last-mile" delivery of broadband services and may offer
a competitive alternative to digital subscriber line (DSL)
and cable modem services. This will also enable access to
communications services in rural and remote areas of the
country. In addition, BPL systems can be used by electric
utility companies to more effectively manage their electric
inquiry addresses the two types of BPL: access and in-house.
Access BPL uses medium-voltage (1000 to 40,000 V) power
lines to bring Internet and other broadband applications
to homes and offices. In-house BPL uses existing electric
utility wiring to network computers and printers, as well
as smart appliances, within a building. The Commission noted
that existing rules for unlicensed carrier current systems,
which couple radio-frequency (RF) energy to the alternating
current (ac) electrical wiring for the purpose of communications,
have been successful. However, these carrier current systems
have operated with relatively limited communications capability
on frequencies below 2 MHz, over a narrow spectrum bandwidth.
Now, the availability of faster chip sets and the development
of sophisticated modulation techniques have produced new
digital power line designs that use multiple carriers spread
over a wide frequency range (e.g., 280 MHz) and are
capable of high data rates. The Commission further noted
that providers of broadband over power line equipment are
free to continue to deploy their networks in conformance
with existing Part 15 rules, and potential rule changes
as a result of this proceeding will address prospective
Commission, in this inquiry, seeks information, comment,
and technical data on issues concerning broadband over power
current state of high-speed BPL technology.
potential interference effects, if any, on authorized
results from BPL experimental sites.
appropriate measurement procedure for testing emission
characteristics for all types of carrier current systems.
that may be needed in Part 15 technical rules and the
equipment approval process to foster the development
of BPL and to ensure that interference is not caused
to other services as a result of this technology.
by the Commission April 23, 2003, by Notice of Inquiry (FCC
03-100). For more information, contact Anh T. Wride at 202-418-0577.
a recent proposal from the PLC industry to push the limits via
CISPR/I/44/CD (September 2002), an interesting study was conducted
as a response by the German administration. As shown in Figures
6 and 7, the question remains as to whether an approach of using
the mains port for telecom PLC purposes is acceptable with respect
to the overall consequences to spectrum users.
is clear that there are problems testing PLC modems in transmission
mode at the mains port using telecom networks and telecom limits.
Simplifying this reduces the problem to trying to make use of
some LCL, 36 dB with T-LISN, according to CISPR 22, in order to
push the limits. LCL is a measure for the average RF symmetry
of telecom network lines.
Experimental data presented at a recent CISPR/I/WG3 meeting left
serious doubt about whether near-end LCL measurements can be used
to predict a common network balance performance. Three effects
were proposed for investigation. Each effect is suspected to cause
better LCL measurement results if an additional cable is inserted
in the test setup.
For simulation, relevant common cable parameters were used. By
this simple simulation, the following conclusions can be drawn:
desired injected symmetrical DM, PLC line signal (L to N) is partly
transformed into unwanted, asymmetrical portions (L and/or N to
ground), causing CM currents and, therefore, radiated EMI.
implementing this CISPR/I/44/CD proposalwith the negative
German administration response (PLC chimney transmission
bands about 25 MHz and 1122 MHz) would lead to an
EN 55022 B mains port limit increase by more than 50 dB. This
strongly indicates unsolved technical problems with the present
generation of PLC technology. Peaceful coexistence with established
technologies is currently unlikely. The technical EMI problems
are discussed in Part 2 of this article beginning on page 58.
Communications Literature Overview, University Essen, Germany,
Hansen, "Megabits per Second on 50 Hz Power Lines," (IEEE EMC
Society Newsletter, Practical Papers, Winter 2001) http://www.emcs.org.
Amateur Radio Club, DARC, http://www.darc.de.
and Noise Considerations, RSGB UK EMC Committee, http://www.qsl.net/rsgb_emc/emcslides.html.
of ATRT UAGr.3 WG PLC Advisory Board of RegTp protocols
since 1998Communications in German by e-mail to members,
not classified: "Sky Wave PLC Simulation," Dr. Widmer, ASCOM CH
(Estimates about 10dB noise increase for 40dBm/Hz nationwide
Study: Auswirkungen PLC auf die Fernmeldeaufklärung 9/2001,
"PLC Effects on Listening Posts, Including Sky Waves Result: Demanding
25 dB Decrease of NB 30 Limits 1.530 MHz."
findings from tests and simulations, EMC Wroclaw 6/2000 Symposium,
Poland-PLC WS with Dr. Vick -Dresden, Germany.
Stecher, "EMC Aspects of PLC," page 407 ff, (EMC Europe 2000 Brugge,
Belgium, September, 2000).
Welsh, "Investigation of likely increase in established radio
noise floor due to widespread deployment of PLT, ADSL and VDSL
broadband access technologies," (EMC Zurich 2001 Symposium, March).
Marthe et al., "Outdoor Radiated Emission Associated with PLC
Systems," F.Issa et al. Session paper D3-A2-02; "Indoor Radiated
Emission Associated with PLC Systems," session paper D3-A2-01.
"Compatibility between Radio-Communications Services and PLC Systems"
WS EU DG Enterprise, Brussels, with Mark Bogers, March 5, 2001
(current state of technical work is not that high, including small
Commissie Veron, Koos Fockens Dutch PLC Measurements, June 21,
2002, "The radio amateur and the effects of the use of the 230
Volt power line for broadband data communication (PLC)."
August 7, 2001, the European Commission issued the standardization
mandate M 313 addressed to CEN, CENELEC, and ETSI, asking them
to produce EMC harmonized standards for all (not only PLC) telecommunication
Hansen, Dr.-Ing., is founder and president of EES (1991) Switzerland
and Germany, specializing in international consulting, high-tech
marketing, training, innovative EMC test products, accredited
testing, and R&D. He can be reached at +41 566 337381 or via