CISPR TR 16-4-4:2007

CISPR TR 16-4-4 ®
Edition 2.1 2017-06
CONSOLIDATED VERSION
TECHNICAL
REPORT
colour
inside
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE

Specification for radio disturbance and immunity measuring apparatus and
methods –
Part 4-4: Uncertainties, statistics and limit modelling – Statistics of complaints
and a model for the calculation of limits for the protection of radio services

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CISPR TR 16-4-4 ®
Edition 2.1 2017-06
CONSOLIDATED VERSION
TECHNICAL
REPORT
colour
inside
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE

Specification for radio disturbance and immunity measuring apparatus and

methods –
Part 4-4: Uncertainties, statistics and limit modelling – Statistics of complaints

and a model for the calculation of limits for the protection of radio services

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.100.10; 33.100.20 ISBN 978-2-8322-4552-1

CISPR TR 16-4-4 ®
Edition 2.1 2017-06
CONSOLIDATED VERSION
REDLINE VERSION
colour
inside
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE
Specification for radio disturbance and immunity measuring apparatus and
methods –
Part 4-4: Uncertainties, statistics and limit modelling – Statistics of complaints
and a model for the calculation of limits for the protection of radio services

– 2 – CISPR TR 16-4-4:2007+AMD1:2017 CSV
 IEC 2017
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Statistics of complaints and sources of interference . 8
4.1 Introduction and history . 8
4.2 Relationship between radio frequency interference and complaints . 8
4.2.1 Radio frequency interference to a fixed radio receiver . 8
4.2.2 Radio frequency interference to a mobile radio receiver . 8
4.2.3 Consequences of the move from analogue to digital radio systems . 8
4.3 Towards the loss of a precious indicator: interference complaints . 9
4.4 CISPR recommendations for collation of statistical data on interference
complaints and classification of interference sources . 9
4.5 Forms for statistics of interference complaints . 10
5 A model for the calculation of limits . 15
5.1 Introduction . 15
5.1.1 Generation of EM disturbances . 15
5.1.2 Immunity from EM disturbances . 15
5.1.3 Planning a radio service . 15
5.2 Probability of interference. 16
5.2.1 Derivation of probability of interference . 16
5.3 Circumstances of interferences . 17
5.3.1 Close coupling and remote coupling . 18
5.3.2 Measuring methods . 19
5.3.3 Disturbance signal waveforms and associated spectra . 21
5.3.4 Characteristics of interfered radio services . 22
5.3.5 Operational aspects . 23
5.3.6 Criteria for the determination of limits . 24
5.4 A mathematical basis for the calculation of CISPR limits . 28
5.4.1 Generation of EM disturbances (source of disturbance) . 28
5.4.2 Immunity from EM disturbances (victim receiver) . 29
5.5 Application of the mathematical basis . 29
5.5.1 Radiation coupling . 29
5.5.2 Wire-line coupling . 31
5.6 Another suitable method for equipment in the frequency range 150 kHz to
1 GHz . 39
5.6.1 Introduction . 39
5.6.2 Derivation of limits . 39
5.6.3 Application of limits . 44
5.6.4 Overview of proposals for determination of disturbance limits for a
given type of equipment. 44
5.6.5 Rationale for determination of CISPR limits in the frequency range
below 30 MHz . 45
5.6.6 Model for limits for the magnetic component of the disturbance field
strength for the protection of radio reception in the range below 30
MHz . 51

 IEC 2017
5.7 Rational for determination of CISPR limits in the frequency range above
1 GHz . 54
5.7.1 Introduction . 54
5.7.2 Consideration and estimated values of µ to µ . 55
P1 P7
5.7.3 Equivalent EMC environment below and above 1 GHz . 61
5.7.4 Overview on parameters of radio communication services operating
in the frequency range above 1 GHz and up to 16 GHz with effect to
electromagnetic compatibility . 62
Annex A Excerpt from CISPR Report No. 31 Values of mains decoupling factor in the
range 0,1 MHz to 200 MHz . 65
Annex B (informative) Conversion of H-field limits below 30 MHz for measurement
distances . 70
Bibliography . 82

Figure 1a – Standard form for statistics on interference complaints recommended for
radio services with analogue modulation and fixed or stationary radio reception . 10
Figure 1b – Standard form for statistics on interference complaints recommended for
radio services with analogue modulation and mobile or portable radio reception . 11
Figure 1c – Standard form for statistics on interference complaints recommended for
radio services with digital modulation and fixed or stationary radio reception . 12
Figure 1d – Standard form for statistics on interference complaints recommended for
radio services with digital modulation and mobile or portable radio reception . 13
Figure 1 – Standard forms for statistics on interference complaints . 13
Figure 2 – Model for remote coupling situation derived disturbance field strength e at
ir
receiving distance r . 25
Figure 3 – Model for close coupling situations . 27
Figure 4 – Example of conversion factors – field strength / common-mode voltage (in
dB) – at feed point, found in practice . 36
Figure 5 – Example of conversion factors – field strength generated by differential-
mode voltage – at feed point, found in practice . 37
Figure 6 – Example of conversion factors – field strength generated by differential-
mode voltage – outside buildings and electrical substations, found in practice . 38
Figure 7 – Example of conversion factors – field strength generated by differential-
mode voltage – inside buildings, found in practice . 39
Figure 8 – horizontal plane radiation pattern on a small purely magnetic antenna . 47
Figure 9 – typical source of magnetic field disturbance . 49
Figure 10 – Model for magnetic field limit at measuring equipment . 52
Figure A.1 – Mains decoupling coefficient as measured by various authors . 67
Figure A.2 – Median and minimum values of mains decoupling factor for the range
0,1 MHz to 200 MHz . 68
Figure A.3 – Typical distributions of deviations from median value of decoupling factor
as indicated in Figure A.2 . 68
Figure A.4 – Measurement of the mains decoupling factor . 69
Figure B.1 – Commercial tool model for H-field conversion . 70
Figure B.2 – Commercial tool model for the application of image theory. 71
Figure B.3 – Photos of OATS measurement setup . 72
Figure B.4 – Comparative simulation result with ground plane and with image theory . 72

– 4 – CISPR TR 16-4-4:2007+AMD1:2017 CSV
 IEC 2017
Figure B.5 – Comparison between the simulated conversion factors and the
measurement results . 73
Figure B.6 – Conversion factor C . 74
3_min
Figure B.7 – Conversion factor C . 75
10_min
Figure B.8 – Conversion factor C . 77
10-3_min
Figure B.9 – Recommended conversion factor CF . 79
30m to 3m
Figure B.10 – Recommended conversion factor CF . 80
30m to 10m
Figure B.11 – Recommended conversion factor CF . 81
10m to 3m
Table 1 – Classification of sources of radio frequency interference and other causes of
complaint . 14
Table 2 – Guidance survey of RFI measuring methods . 21
Table 3 – Tabulation of the method of determining limits for equipment in the frequency
range 0,150 MHz to 960 MHz . 41
Table 4 – Calculation of permissible limits for disturbances at about 1 800 MHz from
existing CISPR limits in the frequency range of 900 MHz . 62
Table 5 – List of radio services, typical parameters, and influence factors . 63
Table B.1 – Conversion factor C . 74
3_min
Table B.2 – Conversion factor C . 76
10_min
Table B.3 – Conversion factor C . 78
10-3_min
Table B.4 – Recommended conversion factor CF . 79
30m to 3m
Table B.5 – Recommended conversion factor CF . 80
30m to 10m
Table B.6 – Recommended conversion factor CF . 81
10m to 3m
 IEC 2017
INTERNATIONAL ELECTROTECHNICAL COMMISSION
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE
____________
SPECIFICATION FOR RADIO DISTURBANCE AND IMMUNITY
MEASURING APPARATUS AND METHODS –
Part 4-4: Uncertainties, statistics and limit modelling –
Statistics of complaints and a model for the calculation of limits
for the protection of radio services
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
This consolidated version of the official IEC Standard and its amendment has been prepared
for user convenience.
CISPR 16-4-4 edition 2.1 contains the second edition (2007-070) [documents CISPR/H/147/DTR
and CISPR/H/153/RVC] and its amendment 1 (2017-06) [documents CIS/H/313/DTR and CIS/
H/319/RVC].
In this Redline version, a vertical line in the margin shows where the technical content is
modified by amendment 1. Additions are in green text, deletions are in strikethrough red text. A
separate Final version with all changes accepted is available in this publication.

– 6 – CISPR TR 16-4-4:2007+AMD1:2017 CSV
 IEC 2017
The main task of IEC technical committees is to prepare International Standards. However, a
technical committee may propose the publication of a technical report when it has collected
data of a different kind from that which is normally published as an International Standard, for
example "state of the art".
This second edition of CISPR 16-4-4, which is a technical report, has been prepared by
CISPR subcommittee H: Limits for the protection of radio services.
This second edition of CISPR 16-4-4 contains two thoroughly updated Clauses 4 and 5,
compared with its first edition. It also contains, in its new Annex A, values of the classical
CISPR mains decoupling factor which were determined by measurements in real LV AC mains
grids in the 1960s. It is deemed that these mains decoupling factors are still valid and
representative also for modern and well maintained LV AC mains grids around the world.
The information in Clause 4 – Statistics of complaints and sources of interference – was
accomplished by the history and evolution of the CISPR statistics on complaints about
radio frequency interference (RFI) and by background information on evolution in radio-
based communication technologies. Furthermore, the forms for collation of actual RFI cases
were detailed and structured in a way allowing for more qualified assessment and
evaluation of compiled annual data in regard to the interference situation, as e.g. fixed or
mobile radio reception, or analogue or digital modulation of the interfered with radio service
or application concerned.
The information in Clause 5 – A model for the calculation of limits – was accomplished in
several ways. The model itself was accomplished in respect of the remote coupling situation
as well as the close coupling one. Further supplements of this model were incorporated
regarding certain aspects of the coupling path via induction and wave propagation (radiation)
of classical telecommunication networks. Furthermore, the calculation model on statistics and
probability underwent revision and was brought in line with a more modern mathematical
approach. Eventually the present model was extended for a possible determination of CISPR
limits in the frequency range above 1 GHz.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of the base publication and its amendment will
remain unchanged until the stability date indicated on the IEC web site under
"http://webstore.iec.ch" in the data related to the specific publication. At this date, the
publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
 IEC 2017
SPECIFICATION FOR RADIO DISTURBANCE AND IMMUNITY
MEASURING APPARATUS AND METHODS –

Part 4-4: Uncertainties, statistics and limit modelling –
Statistics of complaints and a model for the calculation of limits
for the protection of radio services

1 Scope
This part of CISPR 16 contains a recommendation on how to deal with statistics of radio
interference complaints. Furthermore it describes the calculation of limits for disturbance field
strength and voltage for the measurement on a test site based on models for the distribution
of disturbances by radiated and conducted coupling, respectively.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60050(161), International Electrotechnical Vocabulary – Chapter 161: Electromagnetic
compatibility
CISPR 11, Industrial, scientific and medical (ISM) radio-frequency equipment –
Electromagnetic disturbance characteristics – Limits and methods of measurement
CISPR 16-4-3, Specification for radio disturbance and immunity measuring apparatus and
methods – Part 4-3: Uncertainties, statistics and limit modelling – Statistical considerations in
the determination of EMC compliance of mass-produced products
3 Terms and definitions
For the purposes of this document, the terms and definitions in IEC 60050(161) as well as the
following apply.
3.1
complaint
a request for assistance made to the RFI investigation service by the user of a radio receiving
equipment who complains that reception is degraded by radio frequency interference (RFI)
3.2
RFI investigation service
institution having the task of investigating reported cases of radio frequency interference and
which operates at the national basis
NOTE Examples include a radio service provider, a CATV network provider, an administration, or a regulatory
authority.
3.3
source
any type of electric or electronic equipment, system, or (part of) installation emanating
disturbances in the radio frequency (RF) range which can cause radio frequency interference
to a certain kind of radio receiving equipment

– 8 – CISPR TR 16-4-4:2007+AMD1:2017 CSV
 IEC 2017
4 Statistics of complaints and sources of interference
4.1 Introduction and history
The previous edition of CISPR 16-4-4 contained, in its Clause 4, a complete reprint of CISPR
Recommendation 2/3 on statistics of complaints and sources of interference. However, due to
modern technological evolution in radio systems directed towards introduction of digital radio
services, and due to increasing use of mobile and portable radio appliances by the public, the
traditional CISPR statistics of complaints on radio frequency interference are experiencing a
decreasing significance as an indicator of the quality of standardisation work for the protection
of radio services and applications. That is why related information in this edition of
CISPR 16-4-4 is reduced to the necessary minimum allowing interested parties to continue
their complaint-based collation of data on an annual basis.
In order to accommodate the evolution in modern radio technology and mobile and portable
use of radio receiving equipment, it may be necessary to replace or to gather the complaints-
based CISPR statistics by other more modern statistics or means. These new statistics should
be based on a systematic annual collation of data about degradation of quality of radio
services and reception due to electromagnetic disturbances occurring in the environment.
These data will have to be collected and processed, however, primarily by the radio service
providers themselves.
4.2 Relationship between radio frequency interference and complaints
Whatever the radio system involved, official complaints usually represent only a small subset
of all occurring interference situations. Occasional interference generally does not lead to an
official complaint if its duration is brief or if it happens only once in a while. It is only when the
same interference situation occurs repetitively that an official complaint is reported. This
situation also greatly depends on the conditions of use (fixed or mobile) of the victim radio
system.
4.2.1 Radio frequency interference to a fixed radio receiver
Before the wide development of portable radio devices, radio systems that suffered from
interference were generally used in fixed locations. This is the case, for example for a TV set
in a flat or home: if this TV set is regularly interfered with by radiation or conduction from
other equipment located inside or just outside the house, then it is probable that a complaint
will be issued. The same applies if a satellite antenna, a fixed radio link, or a cellular phone
base station suffers from radio frequency interference.
4.2.2 Radio frequency interference to a mobile radio receiver
The multiplication of portable radio systems such as cellular phones and short range radio
systems has changed the conditions regarding interference situations and interference
complaints. The ability for the user to move makes it easier to resolve a particular interference
case, but makes it more difficult to recognise that an interference case has actually occurred.
4.2.3 Consequences of the move from analogue to digital radio systems
In addition to the conditions of use of the victim radio system, technological evolution in radio
services with successive phasing out of analogue and exponential growth of digital
applications also has consequences on the number of reported interference cases.
If a digital mobile phone or a wireless LAN receiver cannot receive the signal from the nearest
base station or access point because of an unwanted emission from a nearby equipment, the
user will never suspect this equipment and will not even consider the possibility of an
interference occurring. He will assume that the coverage of the network is poor and will move
to another place to make his call or to get his connection. Furthermore, as these systems are
generally frequency agile, if one channel is interfered with, the system will choose another
channel, but if all other channels are occupied, then the phone will indicate that the network is

 IEC 2017
busy, and once again, the user will think the network capacity is not large enough to
accommodate his call, but he will never suspect an EMC problem.
Generally for analogue systems, one can hear the interference. With digital and mobile
systems, interference is much less noticeable (muting in audio reception, or frozen images on
the TV set for DVB). In addition, modern digital modulations implement complex escape
mechanisms (data error correction, frequency agile systems, etc.) so that the system can
already be permanently affected from an EMC point of view before an interference case is
actually detected.
4.3 Towards the loss of a precious indicator: interference complaints
The evolutions detailed above – generalisation of mobile use of radio receivers and the move
from analogue to digital radio services – will not reduce the number of interference situations,
but continues to decrease the probability of getting significant numbers of interference
complaints indicating an existing EMC problem. So, along with the growing development of
portable digital radio devices, the usefulness of traditional interference complaints statistics to
support the CISPR work will continue to diminish in importance.
4.4 CISPR recommendations for collation of statistical data on interference
complaints and classification of interference sources
Considering
a) that RFI investigation services may whish to continue publication of statistics on
interference complaints;
b) that it would be useful to be able to compare the figures for certain categories of sources;
c) that varied and ambiguous presentation of these statistics often renders this comparison
difficult,
CISPR recommends
(1) that the statistics provided to National Committees should be in such a form that the
following information may be readily extracted:
(1.1) the number of complaints as a percentage of the total number of sound broadcast
receivers or television broadcast receivers or other radio communication receivers in
operation in a certain country, or region;
(1.2) the relative aggressivity of the various sources of interference in the different frequency
bands;
(1.3) the comparison of the interference caused by the same source in different frequency
bands;
(1.4) the effectiveness of limits (CISPR or national) and other counter-measures on items
(1.1), (1.2), and (1.3);
(1.5) the number of sources of the same type involved in a certain interference case.
Interference may be caused by a group of devices, for example, a number of fluorescent
lamps on one circuit. In such cases, the number to be entered into the statistics is
determined by the RFI investigation service.
NOTE To facilitate comparison of statistics, the method used to determine the number of sources should
be stated.
One source may cause many complaints and one complaint may be caused by more
than one source. Therefore it is clear that the number of sources and the number of
complaints against any classification code may not be related.
For the purpose of these statistics, active generators of electrical energy and apparatus
and installations which cause interference by secondary effects (secondary modulation)
are included. See also appliances of category B in Table 1;

– 10 – CISPR TR 16-4-4:2007+AMD1:2017 CSV
 IEC 2017
(1.6) causes of complaints not related to a source, as e.g. unsatisfactory radio reception due
to a lack of immunity of the radio receiving installation or a lack of coverage with wanted
radio signals, see also appliances of category K in Table 1;
(2) that statistics should cover a complete calendar year; they should whenever possible be
presented in the following form, see standard forms in Figures 1a to 1d, without
necessarily employing more detailed categories than listed in Table 1. It is however not
intended to exclude further subdivisions; these may be desirable, but they should fit into
the scheme of the standard forms set out below; the code numbers refer to the items
listed in Table 1.
4.5 Forms for statistics of interference complaints
1 Radio services with analogue modulation
1.1 Fixed or stationary radio reception
Source of interference Number of complaints per radio service
or other cause of complaint from each source
Classification Description Total number a Other
Broadcasting
code in each b
services
identification
c c
Sound Television
LF/ II I III IV/V
MF/
HF
A 1 1
2 1
etc. as indicated in Table 1
1.1 Fixed or stationary radio reception, analogue Totals
modulation
a LF = low radio frequency (long waves);
MF = medium radio frequency (medium waves);
HF = high radio frequency (short waves).
These three bands may either be grouped together, as shown, or dealt with separately.
II = Band II (VHF/sound broadcasting);
I = Band I (VHF/television broadcasting);
III = Band III (VHF/television broadcasting);
IV/V = Band IV/V (UHF/television broadcasting).
b The service and band affected should be stated.
c At the time of receipt of complaints of interference, i.e. before they have been investigated fully, it may not be
possible to apportion the complaints accurately to the various broadcasting services. If this is so, then the
number of complaints should be stated separately for sound broadcasting and television broadcasting.
IEC  1182/07
Figure 1a – Standard form for statistics on interference complaints recommended for
radio services with analogue modulation and fixed or stationary radio reception

 IEC 2017
1 Radio services with analogue modulation
1.2 Mobile or portable radio reception
Source of interference Number of complaints per radio service
or other cause of complaint from each source
Classification Description Total number a Other
Broadcasting
code in each b
services
identification
c c
Sound Television
LF/ II I III IV/V
MF/
HF
A 1 1
2 1
etc. as indicated in Table 1
1.2 Mobile or portable radio reception, analogue Totals
modulation
a LF = low radio frequency (long waves);
MF = medium radio frequency (medium waves);
HF = high radio frequency (short waves).
These three bands may either be grouped together, as shown, or dealt with separately.
II = Band II (VHF/sound broadcasting);
I = Band I (VHF/television broadcasting);
III = Band III (VHF/television broadcasting);
IV/V = Band IV/V (UHF/television broadcasting).
b The service and band affected should be stated.
c At the time of receipt of complaints of interference, i.e. before they have been investigated fully, it may not be
possible to apportion the complaints accurately to the various broadcasting services. If this is so, then the
number of complaints should be stated separately for sound broadcasting and television broadcasting.
IEC  1183/07
Figure 1b – Standard form for statistics on interference complaints recommended for
radio services with analogue modulation and mobile or portable radio reception

– 12 – CISPR TR 16-4-4:2007+AMD1:2017 CSV
 IEC 2017
2 Radio services with digital modulation
2.1 Fixed or stationary radio reception
Source of interference Number of complaints per radio service
or other cause of complaint from each source
Classification Description Total number a Other
Broadcasting
code in each b
services
identification
c c
Sound Television
LF/ II I III IV/V
MF/
HF
A 1 1
2 1
etc. as indicated in Table 1
2.1 Fixed or stationary radio reception, digital Totals
modulation
a LF = low radio frequency (long waves);
MF = medium radio frequency (medium waves);
HF = high radio frequency (short waves).
These three bands may either be grouped together, as shown, or dealt with separately.
II = Band II (VHF/sound broadcasting);
I = Band I (VHF/television broadcasting);
III = Band III (VHF/television broadcasting);
IV/V = Band IV/V (UHF/television broadcasting).
b The service and band affected should be stated.
c At the time of receipt of complaints of interference, i.e. before they have been investigated fully, it may not be
possible to apportion the complaints accurately to the various broadcasting services. If this is so, then the
number of complaints should be stated separately for sound broadcasting and television broadcasting.

IEC  1184/07
Figure 1c – Standard form for statistics on interference complaints recommended for
radio services with digital modulation and fixed or stationary radio reception

 IEC 2017
2 Radio services with digital modulation
2.2 Mobile or portable radio reception
Source of interference Number of complaints per radio service
or other cause of complaint from each source
Classification Description Total number a Other
Broadcasting
code in each b
services
identification
c c
Sound Television
LF/ II I III IV/V
MF/
HF
A 1 1
2 1
etc. as indicated in Table 1
2.2 Mobile or portable radio reception, digital Totals
modulation
a LF = low radio frequency (long waves);
MF = medium radio frequency (medium waves);
HF = high radio frequency (short waves).
These three bands may either be grouped together, as shown, or dealt with separately.
II = Band II (VHF/sound broadcasting);
I = Band I (VHF/television broadcasting);
III = Band III (VHF/television broadcasting);
IV/V = Band IV/V (UHF/television broadcasting).
b The service and band affected should be stated.
c At the time of receipt of complaints of interference, i.e. before they have been investigated fully, it may not be
possible to apportion the complaints accurately to the various broadcasting services. If this is so, then the
number of complaints should be stated separately for sound broadcasting and television broadcasting.
IEC  1185/07
Figure 1d – Standard form for statistics on interference complaints recommended for
radio services with digital modulation and mobile or portable radio reception
Figure 1 – Standard forms for statistics on interference complaints
For RFI investigation services which would like to issue reports on statistics of interference
complaints it is recommended to use the classification of interference sources set out in
Table 1. Use of this classification will facilitate comparison of RFI situations observed in
different countries.
– 14 – CISPR TR 16-4-4:2007+AMD1:2017 CSV
 IEC 2017
Table 1 – Classification of sources of radio frequency interference
and other causes of complaint
Classification code Description of the source
A Industrial, scientific, and medical (ISM) RF apparatus (CISPR 11)
A.1 Industrial, scientific, and medical (ISM) RF apparatus (group 2) inclusive microwave
ovens and RF lighting appliances
A.2 Other industrial or similar apparatus (group 2) as e.g. arc welding equipment or
spark generating apparatus (EDM), etc.
A.3 Other industrial or similar apparatus (group 1) as e.g. generators, motors,
convertors, semiconductor controlled devices, etc.
B Electric power supply, distribution and electric traction (CISPR 11, CISPR 18)
B.1 Power supply installations (AC or DC voltages exceeding 100 kV) as e.g. overhead
power lines, generating and switching stations, converting stations, etc.
B.2 Power supply installations (AC or DC voltages 1 kV to 100 kV) as e.g. overhead
power lines, generating and switching stations, converting stations, etc.
B.3 Low voltage (LV) power supply and distribution (AC or DC voltages up to 1 kV)
B.4 Electric traction as e.g. for railways, tramways, or trolley buses
C Low power appliances as normally used in households, offices
and small workshops (CISPR 14)
C.1 Motors in household appliances e.g. in electric tools, vacuum cleaners, etc.
C.2 Contact devices, thermostats, etc.
C.3 Semiconductor controlled appliances (less than 1 kW load)
D Gaseous discharge and other lamps and luminaries (CISPR 15)
Fluorescent lamps and luminaries, neon advertising signs, self-ballasted lamps, etc.
a
Radio broadcast receiving installations (CISPR 13, CISPR 25)
E
E.1 Sound broadcast receivers for fixed or mobile use
E.2 Television broadcast receivers for fixed or mobile use
E.3 Cable television installations (CATV)
a
Radio communication systems (ITU Recommendations)
F
F.1 Radio broadcast or communication transmitters for fixed or mobile use
F.2 Radio communication receivers for fixed or mobile use
G Ignition systems of internal combustion engines (CISPR 12)
Cars, motor bikes, boats, trucks, etc. if propelled by electrical means or internal
combustion engines or both, exclusive electric traction vehicles
H Information and communication technology (ICT) appliances (CISPR 22)
H.1 Wire-bound telecommunication terminal equipment (TTE) and telecommunication
equipment (TE) in the infrastructure of networks as e.g. in telecommunication
centres, wire-bound LAN, etc.
H.2 Data processing equipment (DPE) such as e.g. computers and ancillary equipment
H.3 Radiation from wire-bound telecommunication networks
I Identified sources other than those specified (IEC 61000-6-3 and IEC 61000-6-4)
K Other causes of complaint
K.1 Lack of immunity of radio receiving installations or other appliances
K.2 Lack of coverage of wanted radio service (weak or faulty wanted signals)
a
Only those complaints belong to the statistics where a radio broadcast receiving installation (E) or a component
of a radio communication system (F) was identified as causing the interference.

 IEC 2017
5 A model for the calculation of limits
5.1 Introduction
A harmonized method of calculation is an important precondition for the efficient discussion of
CISPR li
...

CISPR TR 16-4-4 ®
Edition 2.2 2020-04
CONSOLIDATED VERSION
TECHNICAL
REPORT
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INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE

Specification for radio disturbance and immunity measuring apparatus and
methods –
Part 4-4: Uncertainties, statistics and limit modelling – Statistics of complaints
and a model for the calculation of limits for the protection of radio services

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CISPR TR 16-4-4 ®
Edition 2.2 2020-04
CONSOLIDATED VERSION
TECHNICAL
REPORT
colour
inside
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE

Specification for radio disturbance and immunity measuring apparatus and

methods –
Part 4-4: Uncertainties, statistics and limit modelling – Statistics of complaints

and a model for the calculation of limits for the protection of radio services

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.100.10; 33.100.20 ISBN 978-2-8322-8261-8

CISPR TR 16-4-4 ®
Edition 2.2 2020-04
CONSOLIDATED VERSION
REDLINE VERSION
colour
inside
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE

Specification for radio disturbance and immunity measuring apparatus and
methods –
Part 4-4: Uncertainties, statistics and limit modelling – Statistics of complaints
and a model for the calculation of limits for the protection of radio services

– 2 – CISPR TR 16-4-4:2007+AMD1:2017
+AMD2:2020 CSV  IEC 2020
CONTENTS
FOREWORD . 7
1 Scope . 9
2 Normative references . 9
3 Terms and definitions . 9
3.1 Terms and definitions . 9
3.2 Symbols and abbreviated terms. 10
4 Statistics of complaints and sources of interference . 11
4.1 Introduction and history . 11
4.2 Relationship between radio frequency interference and complaints . 11
4.2.1 Radio frequency interference to a fixed radio receiver . 11
4.2.2 Radio frequency interference to a mobile radio receiver . 11
4.2.3 Consequences of the move from analogue to digital radio systems . 11
4.3 Towards the loss of a precious indicator: interference complaints . 12
4.4 CISPR recommendations for collation of statistical data on interference
complaints and classification of interference sources . 12
4.5 Forms for statistics of interference complaints . 13
5 A model for the calculation of limits . 18
5.1 Introduction . 18
5.1.1 Generation of EM disturbances . 18
5.1.2 Immunity from EM disturbances . 18
5.1.3 Planning a radio service . 18
5.2 Probability of interference. 19
5.2.1 Derivation of probability of interference . 19
5.3 Circumstances of interferences . 20
5.3.1 Close coupling and remote coupling . 21
5.3.2 Measuring methods . 22
5.3.3 Disturbance signal waveforms and associated spectra . 24
5.3.4 Characteristics of interfered radio services . 25
5.3.5 Operational aspects . 26
5.3.6 Criteria for the determination of limits . 27
5.4 A mathematical basis for the calculation of CISPR limits . 31
5.4.1 Generation of EM disturbances (source of disturbance) . 31
5.4.2 Immunity from EM disturbances (victim receiver) . 32
5.5 Application of the mathematical basis . 32
5.5.1 Radiation coupling . 32
5.5.2 Wire-line coupling . 34
5.6 Another suitable method for equipment in the frequency range 150 kHz to
1 GHz . 42
5.6.1 Introduction . 42
5.6.2 Derivation of limits . 42
5.6.3 Application of limits . 47
5.6.4 Overview of proposals for determination of disturbance limits for a
given type of equipment. 47
5.6.5 Rationale for determination of CISPR limits in the frequency range
below 30 MHz . 48

+AMD2:2020 CSV  IEC 2020
5.6.6 Model for limits for the magnetic component of the disturbance field
strength for the protection of radio reception in the range below 30
MHz . 54
5.7 Rational for determination of CISPR limits in the frequency range above
1 GHz . 57
5.7.1 Introduction . 57
5.7.2 Consideration and estimated values of µ to µ . 59
P1 P7
5.7.3 Equivalent EMC environment below and above 1 GHz . 64
5.7.4 Overview on parameters of radio communication services operating
in the frequency range above 1 GHz and up to 16 GHz with effect to
electromagnetic compatibility . 65
Annex A Excerpt from CISPR Report No. 31 Values of mains decoupling factor in the
range 0,1 MHz to 200 MHz . 69
Annex B (informative) Conversion of H-field limits below 30 MHz for measurement
distances . 74
Annex C (informative) Model for estimation of radiation from photovoltaic (PV) power
generating systems . 86
Annex D (informative) Model for the estimation of radiation from in-house extra low
voltage (ELV) lighting installations . 119
Bibliography . 133

Figure 1a – Standard form for statistics on interference complaints recommended for
radio services with analogue modulation and fixed or stationary radio reception . 13
Figure 1b – Standard form for statistics on interference complaints recommended for
radio services with analogue modulation and mobile or portable radio reception . 14
Figure 1c – Standard form for statistics on interference complaints recommended for
radio services with digital modulation and fixed or stationary radio reception . 15
Figure 1d – Standard form for statistics on interference complaints recommended for
radio services with digital modulation and mobile or portable radio reception . 16
Figure 1 – Standard forms for statistics on interference complaints . 16
Figure 2 – Model for remote coupling situation derived disturbance field strength e at
ir
receiving distance r . 28
Figure 3 – Model for close coupling situations . 30
Figure 4 – Example of conversion factors – field strength / common-mode voltage (in
dB) – at feed point, found in practice . 39
Figure 5 – Example of conversion factors – field strength generated by differential-

mode voltage – at feed point, found in practice . 40
Figure 6 – Example of conversion factors – field strength generated by differential-
mode voltage – outside buildings and electrical substations, found in practice . 41
Figure 7 – Example of conversion factors – field strength generated by differential-
mode voltage – inside buildings, found in practice . 42
Figure 8 – horizontal plane radiation pattern on a small purely magnetic antenna . 50
Figure 9 – typical source of magnetic field disturbance . 52
Figure 10 – Model for magnetic field limit at measuring equipment . 55
Figure A.1 – Mains decoupling coefficient as measured by various authors . 71
Figure A.2 – Median and minimum values of mains decoupling factor for the range

0,1 MHz to 200 MHz . 72

– 4 – CISPR TR 16-4-4:2007+AMD1:2017
+AMD2:2020 CSV  IEC 2020
Figure A.3 – Typical distributions of deviations from median value of decoupling factor
as indicated in Figure A.2 . 72
Figure A.4 – Measurement of the mains decoupling factor . 73
Figure B.1 – Commercial tool model for H-field conversion . 74
Figure B.2 – Commercial tool model for the application of image theory. 75
Figure B.3 – Photos of OATS measurement setup . 76
Figure B.4 – Comparative simulation result with ground plane and with image theory . 76
Figure B.5 – Comparison between the simulated conversion factors and the
measurement results . 77
Figure B.6 – Conversion factor C . 78
3_min
Figure B.7 – Conversion factor C . 79
10_min
Figure B.8 – Conversion factor C . 81
10-3_min
Figure B.9 – Recommended conversion factor CF . 83
30m to 3m
Figure B.10 – Recommended conversion factor CF . 84
30m to 10m
Figure B.11 – Recommended conversion factor CF . 85
10m to 3m
Figure C.1 – Schematic overview of the considered model influence factors . 87
Figure C.2 – Schematic representation of probability of existence of PV generator
groups in the field . 90
Figure C.3 – Schematic representation of mean value C and variance σ . 90
PV CPV
Figure C.4 – General model for coupling of CM disturbances of a GCPC to an
attached photovoltaic power generating system (PV generator) . 91
Figure C.5 – Geometric representation of a PV generator with 18 modules . 93
Figure C.6 – Field strength determination by maximization (height scan) along a red
line . 94
Figure C.7 – Geometrical representation of Group A PV generators . 101
Figure C 8 – Combined coupling factor C for Group A PV generators (r = 10m) . 101
PV
Group A sim
Figure C.9 – Geometrical representation of Group B PV generators . 102
Figure C.10 – Combined coupling factor C for Group B PV generators
PV
GroupB sim
(r = 10 m) 102
Figure C.11 – Geometrical representation of Group C PV generators . 103
Figure C.12 – Combined coupling factor C for Group C PV generators
PV
Group C sim
(r = 10 m). 103
Figure C.13 – Geometrical representation of Group D PV generators . 104
C
Figure C.14 – Combined coupling factor for Group D PV generators
PV
GroupD sim
(r = 10 m). 104
Figure C.15 – Measurement setup . 106
Figure C.16 – Antenna orientations . 106
Figure C.17 – Coupling factor C for Group A PV generators . 107
PV
Group A meas
Figure C.18 – Coupling factor C for Group C PV generators . 108
PV
Group Cmeas
Figure C.19 – Coupling factor C for Group D PV generators . 108
PV
Group D meas
+AMD2:2020 CSV  IEC 2020
Figure C.20 – Ratio of registered PV power generating systems in Germany . 110
Figure C.21 – Ratio of registered PV power generating systems in Sweden . 111
Figure C.22 – Simulation results m (test case) . 113
TC
Figure C.23 – Simulation results m (use case) . 114
L
Figure C.24 – Overview of the calculated U values for radio services between
TC Limit
150 kHz and 30 MHz at a distance of d = 10 m . 118
Figure D.1 – Application of ELV lamps . 120
Figure D.2 – Typical components and wiring for an ELV lamp connected to a power
source and the associated lumped-circuit model of the ELV part . 121
Figure D.3 – Coupling scenarios . 123
Figure D.4 – Two wire scenario . 123
Figure D.5 – Field strength derived by Biot-Savart-law applied to a differential mode
current in comparison with the values in CISPR 15:2018, Table 9 (3 m) converted to
10 m . 125
Figure D.6 – Principal model used for the simulations . 126
Figure D.7 – Electric field distribution (at 10 MHz) on a vertical plane at a distance of
10 m from the vertical two wire system . 127
Figure D.8 – Coupling factor result for 3 different scenarios . 128
Figure D.9 – Overview of the calculated U values for radio services between
Limit
150 kHz and 30 MHz . 132

Table 1 – Classification of sources of radio frequency interference and other causes of
complaint . 17
Table 2 – Guidance survey of RFI measuring methods . 24
Table 3 – Tabulation of the method of determining limits for equipment in the frequency
range 0,150 MHz to 960 MHz . 44
Table 4 – Calculation of permissible limits for disturbances at about 1 800 MHz from
existing CISPR limits in the frequency range of 900 MHz . 65
Table 5 – List of radio services, typical parameters, and influence factors . 67
Table B.1 – Conversion factor C . 78
3_min
Table B.2 – Conversion factor C . 80
10_min
Table B.3 – Conversion factor C . 82
10-3_min
Table B.4 – Recommended conversion factor CF . 83
30m to 3m
Table B.5 – Recommended conversion factor CF . 84
30m to 10m
Table B.6 – Recommended conversion factor CF . 85
10m to 3m
Table C.1 – Coupling factors C . 105
PV
i sim
Table C.2 – Coupling factors C and calibration factors . 109
PV
i meas
Table C.3 – Overview coupling factors C . 109
PV
i
ρ
Table C.4 – Estimation of . 111
i
Table C.5 – Mismatch loss values m and m determined by measurement and
L TC
simulation . 114

– 6 – CISPR TR 16-4-4:2007+AMD1:2017
+AMD2:2020 CSV  IEC 2020
Table C.6 – Calculation of U for radio services between 150 kHz and 30 MHz
TC Limit
at a distance of d = 10 m . 116
Table D.1 – Calculation of U for radio services between 150 kHz and 30 MHz . 131
Limit
+AMD2:2020 CSV  IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE
____________
SPECIFICATION FOR RADIO DISTURBANCE AND IMMUNITY
MEASURING APPARATUS AND METHODS –
Part 4-4: Uncertainties, statistics and limit modelling –
Statistics of complaints and a model for the calculation of limits
for the protection of radio services
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
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between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
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5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
This consolidated version of the official IEC Standard and its amendments has been
prepared for user convenience.
CISPR 16-4-4 edition 2.2 contains the second edition (2007-07) [documents CISPR/
H/147/DTR and CISPR/H/153/RVC], its amendment 1 (2017-06) [documents CIS/H/313/
DTR and CIS/H/319/RVC] and its amendment 2 (2020-04) [documents CIS/H/402/DTR and
CIS/H/407A/RVDTR].
In this Redline version, a vertical line in the margin shows where the technical content
is modified by amendments 1 and 2. Additions are in green text, deletions are in
strikethrough red text. A separate Final version with all changes accepted is available in
this publication.
– 8 – CISPR TR 16-4-4:2007+AMD1:2017
+AMD2:2020 CSV  IEC 2020
The main task of IEC technical committees is to prepare International Standards. However, a
technical committee may propose the publication of a technical report when it has
collected data of a different kind from that which is normally published as an International
Standard, for example "state of the art".
This second edition of CISPR 16-4-4, which is a technical report, has been prepared by
CISPR subcommittee H: Limits for the protection of radio services.
This second edition of CISPR 16-4-4 contains two thoroughly updated Clauses 4 and 5,
compared with its first edition. It also contains, in its new Annex A, values of the classical
CISPR mains decoupling factor which were determined by measurements in real LV AC mains
grids in the 1960s. It is deemed that these mains decoupling factors are still valid and
representative also for modern and well maintained LV AC mains grids around the world.
The information in Clause 4 – Statistics of complaints and sources of interference – was
accomplished by the history and evolution of the CISPR statistics on complaints about radio
frequency interference (RFI) and by background information on evolution in radio-based
communication technologies. Furthermore, the forms for collation of actual RFI cases were
detailed and structured in a way allowing for more qualified assessment and evaluation of
compiled annual data in regard to the interference situation, as e.g. fixed or mobile
radio reception, or analogue or digital modulation of the interfered with radio service or
application concerned.
The information in Clause 5 – A model for the calculation of limits – was accomplished in
several ways. The model itself was accomplished in respect of the remote coupling situation
as well as the close coupling one. Further supplements of this model were
incorporated regarding certain aspects of the coupling path via induction and wave
propagation (radiation) of classical telecommunication networks. Furthermore, the calculation
model on statistics and probability underwent revision and was brought in line with a
more modern mathematical approach. Eventually the present model was extended for a
possible determination of CISPR limits in the frequency range above 1 GHz.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of the base publication and its amendments will
remain unchanged until the stability date indicated on the IEC web site under
"http://webstore.iec.ch" in the data related to the specific publication. At this date, the
publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
+AMD2:2020 CSV  IEC 2020
SPECIFICATION FOR RADIO DISTURBANCE AND IMMUNITY
MEASURING APPARATUS AND METHODS –

Part 4-4: Uncertainties, statistics and limit modelling –
Statistics of complaints and a model for the calculation of limits
for the protection of radio services

1 Scope
This part of CISPR 16 contains a recommendation on how to deal with statistics of radio
interference complaints. Furthermore it describes the calculation of limits for disturbance field
strength and voltage for the measurement on a test site based on models for the distribution
of disturbances by radiated and conducted coupling, respectively.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60050-161, International Electrotechnical Vocabulary (IEV) – Part 161: Electromagnetic
compatibility (available at http://www.electropedia.org)
CISPR 11, Industrial, scientific and medical (ISM) radio-frequency equipment –
Electromagnetic Radio-frequency disturbance characteristics – Limits and methods of
measurement
CISPR 16-4-3, Specification for radio disturbance and immunity measuring apparatus and
methods – Part 4-3: Uncertainties, statistics and limit modelling – Statistical considerations in
the determination of EMC compliance of mass-produced products
CISPR 15:2018, Limits and methods of measurement of radio disturbance characteristics of
electrical lighting and similar equipment
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-161 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1 Terms and definitions
3.1.1
complaint
a request for assistance made to the RFI investigation service by the user of a radio receiving
equipment who complains that reception is degraded by radio frequency interference (RFI)

– 10 – CISPR TR 16-4-4:2007+AMD1:2017
+AMD2:2020 CSV  IEC 2020
3.1.2
RFI investigation service
institution having the task of investigating reported cases of radio frequency interference and
which operates at the national basis
NOTE EXAMPLE Examples include a Radio service provider, a CATV network provider, an administration, or a
regulatory authority.
3.1.3
source
any type of electric or electronic equipment, system, or (part of) installation emanating
disturbances in the radio frequency (RF) range which can cause radio frequency interference
to a certain kind of radio receiving equipment
3.2 Symbols and abbreviated terms
E permissible interference field strength at the point A in space where the antenna
ir
of the victim receiver is located – without consideration of probability factors
E permissible interference field strength at the point A in space where the antenna
Limit
of the victim receiver is located – with consideration of probability factors
R protection ratio
P
C coupling factor describing the proportionality of the field strength E with the
PV
square root of the power P injected as common mode into the radiating structure
by the apparatus (GCPC)
Group A defined PV generator group for single-family detached houses
Group B defined PV generator group for multi-storey buildings with flat roof tops
Group C defined PV generator group for sun tracking supports (“trees”)
Group D defined PV generator group for large barns in the countryside
ρ probability of an individual PV generator being a member of Group i
i
C
group-independent mean value for the coupling factor
PV
P disturbance power emitted by a GCPC with the complex source impedance Z
S S
P power injected into the PV generator eventually radiated via that installation
L
P disturbance power determined at the DC-AN on a standardized test site according
TC
to CISPR 11 with fixed impedance Z = 150 Ω
TC
U permitted disturbance voltage limit
Limit
P probability for time coincidence (µ in dB)
7 P7
P probability for location coincidence (µ in dB)
8 P8
P probability for frequency coincidence inclusive harmonics(µ in dB)
4 P4
m mismatch loss in use case (between the GCPC with complex source impedance
L
Z and the PV generator with complex load impedance Z )
S L
m mismatch loss in test case (between the GCPC with complex source impedance
TC
Z and the DC-AN according to CISPR 11 with measurement impedance fixed to
S
Z = 150 Ω)
TC
AMN artificial mains network
CM common mode
DC-AN DC artificial network
DM differential mode
+AMD2:2020 CSV  IEC 2020
GCPC grid connected power converter
S/N noise power/signal power
4 Statistics of complaints and sources of interference
4.1 Introduction and history
The previous edition of CISPR 16-4-4 contained, in its Clause 4, a complete reprint of CISPR
Recommendation 2/3 on statistics of complaints and sources of interference. However, due to
modern technological evolution in radio systems directed towards introduction of digital radio
services, and due to increasing use of mobile and portable radio appliances by the public, the
traditional CISPR statistics of complaints on radio frequency interference are experiencing a
decreasing significance as an indicator of the quality of standardisation work for the protection
of radio services and applications. That is why related information in this edition of
CISPR 16-4-4 is reduced to the necessary minimum allowing interested parties to continue
their complaint-based collation of data on an annual basis.
In order to accommodate the evolution in modern radio technology and mobile and portable
use of radio receiving equipment, it may be necessary to replace or to gather the complaints-
based CISPR statistics by other more modern statistics or means. These new statistics should
be based on a systematic annual collation of data about degradation of quality of radio
services and reception due to electromagnetic disturbances occurring in the environment.
These data will have to be collected and processed, however, primarily by the radio service
providers themselves.
4.2 Relationship between radio frequency interference and complaints
Whatever the radio system involved, official complaints usually represent only a small subset
of all occurring interference situations. Occasional interference generally does not lead to an
official complaint if its duration is brief or if it happens only once in a while. It is only when the
same interference situation occurs repetitively that an official complaint is reported. This
situation also greatly depends on the conditions of use (fixed or mobile) of the victim radio
system.
4.2.1 Radio frequency interference to a fixed radio receiver
Before the wide development of portable radio devices, radio systems that suffered from
interference were generally used in fixed locations. This is the case, for example for a TV set
in a flat or home: if this TV set is regularly interfered with by radiation or conduction from
other equipment located inside or just outside the house, then it is probable that a complaint
will be issued. The same applies if a satellite antenna, a fixed radio link, or a cellular phone
base station suffers from radio frequency interference.
4.2.2 Radio frequency interference to a mobile radio receiver
The multiplication of portable radio systems such as cellular phones and short range radio
systems has changed the conditions regarding interference situations and interference
complaints. The ability for the user to move makes it easier to resolve a particular interference
case, but makes it more difficult to recognise that an interference case has actually occurred.
4.2.3 Consequences of the move from analogue to digital radio systems
In addition to the conditions of use of the victim radio system, technological evolution in radio
services with successive phasing out of analogue and exponential growth of digital
applications also has consequences on the number of reported interference cases.
If a digital mobile phone or a wireless LAN receiver cannot receive the signal from the nearest
base station or access point because of an unwanted emission from a nearby equipment, the
user will never suspect this equipment and will not even consider the possibility of an

– 12 – CISPR TR 16-4-4:2007+AMD1:2017
+AMD2:2020 CSV  IEC 2020
interference occurring. He will assume that the coverage of the network is poor and will move
to another place to make his call or to get his connection. Furthermore, as these systems are
generally frequency agile, if one channel is interfered with, the system will choose another
channel, but if all other channels are occupied, then the phone will indicate that the network is
busy, and once again, the user will think the network capacity is not large enough to
accommodate his call, but he will never suspect an EMC problem.
Generally for analogue systems, one can hear the interference. With digital and mobile
systems, interference is much less noticeable (muting in audio reception, or frozen images on
the TV set for DVB). In addition, modern digital modulations implement complex escape
mechanisms (data error correction, frequency agile systems, etc.) so that the system can
already be permanently affected from an EMC point of view before an interference case is
actually detected.
4.3 Towards the loss of a precious indicator: interference complaints
The evolutions detailed above – generalisation of mobile use of radio receivers and the move
from analogue to digital radio services – will not reduce the number of interference situations,
but continues to decrease the probability of getting significant numbers of interference
complaints indicating an existing EMC problem. So, along with the growing development of
portable digital radio devices, the usefulness of traditional interference complaints statistics to
support the CISPR work will continue to diminish in importance.
4.4 CISPR recommendations for collation of statistical data on interference complaints
and classification of interference sources
Considering
a) that RFI investigation services may whish to continue publication of statistics on
interference complaints;
b) that it would be useful to be able to compare the figures for certain categories of sources;
c) that varied and ambiguous presentation of these statistics often renders this comparison
difficult,
CISPR recommends
(1) that the statistics provided to National Committees should be in such a form that the
following information may be readily extracted:
(1.1) the number of complaints as a percentage of the total number of sound broadcast
receivers or television broadcast receivers or other radio communication receivers in
operation in a certain country, or region;
(1.2) the relative aggressivity of the various sources of interference in the different frequency
bands;
(1.3) the comparison of the interference caused by the same source in different frequency
bands;
(1.4) the effectiveness of limits (CISPR or national) and other counter-measures on items
(1.1), (1.2), and (1.3);
(1.5) the number of sources of the same type involved in a certain interference case.
Interference may be caused by a group of devices, for example, a number of fluorescent
lamps on one circuit. In such cases, the number to be entered into the statistics is
determined by the RFI investigation service.
NOTE To facilitate comparison of statistics, the method used to determine the number of sources should
be stated.
One source may cause many complaints and one complaint may be caused by more
than one source. Therefore it is clear that the number of sources and the number of
complaints against any classification code may not be related.

+AMD2:2020 CSV  IEC 2020
For the purpose of these statistics, active generators of electrical energy and apparatus
and installations which cause interference by secondary effects (secondary modulation)
are included. See also appliances of category B in Table 1;
(1.6) causes of complaints not related to a source, as e.g. unsatisfactory radio reception due
to a lack of immunity of the radio receiving installation or a lack of coverage with wanted
radio signals, see also appliances of category K in Table 1;
(2) that statistics should cover a complete calendar year; they should whenever possible be
presented in the following form, see standard forms in Figures 1a to 1d, without
necessarily employing more detailed categories than listed in Table 1. It is however not
intended to exclude further subdivisions; these may be desirable, but they should fit into
the scheme of the standard forms set out below; the code numbers refer to the items
listed in Table 1.
4.5 Forms for statistics of interference complaints
1 Radio services with analogue modulation
1.1 Fixed or stationary radio reception
Source of interference Number of complaints per radio service
or other cause of complaint from each source
Classification Description Total number a Other
Broadcasting
code in each b
services
identification
c c
Sound Television
LF/ II I III IV/V
MF/
HF
A 1 1
2 1
etc. as indicated in Table 1
1.1 Fixed or stationary radio reception, analogue Totals
modula
...