CISPR TR 16-4-4:2007

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

This Technical Report 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. 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 low-voltage AC mains grids in the 1960s.respectively.

General Information

• Status: Published
• Publication Date: 15-Jul-2007
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 33.100.10 - Emission
• ICS: 33.100.20 - Immunity
• Technical Committee: H - Limits for the protection of radio services
• Current Stage: PPUB - Publication issued
• Start Date: 16-Jul-2007
• Completion Date: 16-Jul-2007

Standards Content (Sample)

TECHNICAL CISPR
REPORT 16-4-4
Second edition
2007-07
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
Reference number
CISPR 16-4-4/TR:2007(E)
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TECHNICAL CISPR
REPORT 16-4-4
Second edition
2007-07
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
PRICE CODE
Commission Electrotechnique Internationale
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue
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TR CISPR 16-4-4 © IEC:2007(E)
CONTENTS

FOREWORD...........................................................................................................................4

1 Scope...............................................................................................................................6

2 Normative references .......................................................................................................6

3 Terms and definitions .......................................................................................................6

4 Statistics of complaints and sources of interference .........................................................7

4.1 Introduction and history...........................................................................................7

4.2 Relationship between radio frequency interference and complaints .........................7

4.2.1 Radio frequency interference to a fixed radio receiver .................................7

4.2.2 Radio frequency interference to a mobile radio receiver ..............................7

4.2.3 Consequences of the move from analogue to digital radio systems..............7

4.3 Towards the loss of a precious indicator: interference complaints............................8

4.4 CISPR recommendations for collation of statistical data on interference

complaints and classification of interference sources ..............................................8

4.5 Forms for statistics of interference complaints.........................................................9

5 A model for the calculation of limits ................................................................................14

5.1 Introduction ...........................................................................................................14

5.1.1 Generation of EM disturbances..................................................................14

5.1.2 Immunity from EM disturbances.................................................................14

5.1.3 Planning a radio service ............................................................................14

5.2 Probability of interference......................................................................................15

5.2.1 Derivation of probability of interference .....................................................15

5.3 Circumstances of interferences .............................................................................16

5.3.1 Close coupling and remote coupling ..........................................................17

5.3.2 Measuring methods ...................................................................................18

5.3.3 Disturbance signal waveforms and associated spectra ..............................20

5.3.4 Characteristics of interfered radio services ................................................21

5.3.5 Operational aspects...................................................................................22

5.3.6 Criteria for the determination of limits ........................................................23

5.4 A mathematical basis for the calculation of CISPR limits .......................................27

5.4.1 Generation of EM disturbances (source of disturbance) .............................27

5.4.2 Immunity from EM disturbances (victim receiver) .......................................28

5.5 Application of the mathematical basis....................................................................29

5.5.1 Radiation coupling.....................................................................................29

5.5.2 Wire-line coupling......................................................................................30

5.6 Another suitable method for equipment in the frequency range 150 kHz to

1 GHz....................................................................................................................

5.6.1 Introduction ...............................................................................................38

5.6.2 Derivation of limits.....................................................................................38

5.6.3 Application of limits ...................................................................................43

5.6.4 Overview of proposals for determination of disturbance limits for a

given type of equipment.............................................................................43

5.7 Rational for determination of CISPR limits in the frequency range above

1 GHz....................................................................................................................44

5.7.1 Introduction ...............................................................................................44

5.7.2 Consideration and estimated values of μ to μ ....................................45

P1 P7

5.7.3 Equivalent EMC environment below and above 1 GHz...............................51

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TR CISPR 16-4-4 © IEC:2007(E)
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.....................................................................52

Annex A Excerpt from CISPR Report No. 31 Values of mains decoupling factor in the

range 0,1 MHz to 200 MHz ...................................................................................................55

Bibliography..........................................................................................................................60

Figure 1a – Standard form for statistics on interference complaints recommended for

radio services with analogue modulation and fixed or stationary radio reception .....................9

Figure 1b – Standard form for statistics on interference complaints recommended for

radio services with analogue modulation and mobile or portable radio reception...................10

Figure 1c – Standard form for statistics on interference complaints recommended for

radio services with digital modulation and fixed or stationary radio reception ........................11

Figure 1d – Standard form for statistics on interference complaints recommended for

radio services with digital modulation and mobile or portable radio reception........................12

Figure 2 – Model for remote coupling situation derived disturbance field strength e at

receiving distance r...............................................................................................................24

Figure 3 – Model for close coupling situations.......................................................................26

Figure 4 – Example of conversion factors – field strength / common-mode voltage (in

dB) – at feed point, found in practice ....................................................................................35

Figure 5 – Example of conversion factors – field strength generated by differential-

mode voltage – at feed point, found in practice .....................................................................36

Figure 6 – Example of conversion factors – field strength generated by differential-

mode voltage – outside buildings and electrical substations, found in practice ......................37

Figure 7 – Example of conversion factors – field strength generated by differential-

mode voltage – inside buildings, found in practice ................................................................38

Figure A.1 – Mains decoupling coefficient as measured by various authors ..........................57

Figure A.2 – Median and minimum values of mains decoupling factor for the range

0,1 MHz to 200 MHz .............................................................................................................58

Figure A.3 – Typical distributions of deviations from median value of decoupling factor

as indicated in Figure A.2 .....................................................................................................58

Figure A.4 – Measurement of the mains decoupling factor ....................................................59

Table 1 – Classification of sources of radio frequency interference and other causes of

complaint ..............................................................................................................................13

Table 2 – Guidance survey of RFI measuring methods .........................................................20

Table 3 – Tabulation of the method of determining limits for equipment in the frequency

range 0,150 MHz to 960 MHz................................................................................................40

Table 4 – Calculation of permissible limits for disturbances at about 1 800 MHz from

existing CISPR limits in the frequency range of 900 MHz ......................................................52

Table 5 – List of radio services, typical parameters, and influence factors ............................53

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TR CISPR 16-4-4 © IEC:2007(E)
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

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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

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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is

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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.

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.

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TR CISPR 16-4-4 © IEC:2007(E)

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.
The text of this standard is based on the following documents:
Enquiry draft Report on voting
CISPR/H/147/DTR CISPR/H/153/RVC

Full information on the voting for the approval of this standard can be found in the report on

voting indicated in the above table.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

The committee has decided that the contents of this publication will remain unchanged until

the maintenance result 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.
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TR CISPR 16-4-4 © IEC:2007(E)
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
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TR CISPR 16-4-4 © IEC:2007(E)
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

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TR CISPR 16-4-4 © IEC:2007(E)

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;
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TR CISPR 16-4-4 © IEC:2007(E)

(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
...