CISPR TR 31:2024

Description of the radio services database

CISPR TR 31: 2024, which is a Technical Report, covers the rationale behind the database containing the characteristics of radio services. The database is a "living document " in the format of a spreadsheet file in the EMC Zone of the IEC web site: https://www.iec.ch/emc/radio-services-database . As new input for the IEC Radio Services Database arrives, this Technical Report provides guidance and support for the systematic collation of data on those radio services which are relevant for determination of CISPR limits according to CISPR TR 16-4-4. All interested parties are invited to contribute with relevant data to the database, e.g., via the National Committees represented in CISPR/H. The objective of the database is to register those characteristics which are relevant for derivation and specification of limits for disturbances from electric and/or electronic equipment, systems and installations. Committees responsible for generic and/or product emission EMC standards use this information together with CISPR TR 16-4-4.
This third edition cancels and replaces the second edition published in 2012. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) A new Clause 3 covers a line of essential definitions of radio parameters, the knowledge of which is necessary to get qualified input data for inclusion of essential requirements in the present radio services database (RSD) maintained by CISPR and IEC.
b) The radio parameters and conditions of use of radio receivers listed in Table 1 of this edition of CISPR TR 31 are provided now with instructive advice in its new Subclauses 5.1 and 5.2, on selection of data for input to the RSD and retrieval of that data for consideration and use with the limits setting model as in CISPR TR 16-4-4 which was missing in the previous edition of CISPR TR 31.
c) Finally, another new informative Annex B informs, to the extent necessary, on the principles of ITU-R on determination of data for the minimum usable field strength (to be inserted in Column (E) of the RSD) and of the associated tolerable disturbance at the antenna of the radio reception system or other self-contained radio receiver (also to be used as input with the limits-setting model in CISPR TR 16-4-4), which concerns only parties who are concerned with designing and projecting of radio-communication/broadcast networks and with coverage planning of related radio services. Knowledge of these fundamental principles also by CISPR experts will ensure that only valid data will get future input to the RSD maintained by CISPR and IEC.

DESCRIPTION DE LA BASE DE DONNEES DES SERVICES RADIO

General Information

• Status: Published
• Publication Date: 24-Nov-2024
• ICS: 33.100.10 - Emission
• Technical Committee: CIS/H - Limits for the protection of radio services
• Current Stage: PPUB - Publication issued
• Start Date: 25-Nov-2024
• Completion Date: 20-Dec-2024

Relations

• Revises: CISPR TR 31:2012 - Database on the characteristics of radio services
• Effective Date: 05-Sep-2023

Overview

CISPR TR 31:2024 (IEC) is a Technical Report that describes the IEC/CISPR Radio Services Database (RSD) - a “living” spreadsheet hosted in the IEC EMC Zone (https://www.iec.ch/emc/radio-services-database). The report explains the rationale, structure and acceptable input for the database that records radio‑service characteristics used when deriving CISPR emission limits in conjunction with CISPR TR 16‑4‑4. This third edition (2024) replaces the 2012 edition and introduces technical revisions to improve data quality and usability.

Key topics

• Purpose and scope: Systematic collation of radio‑service parameters relevant to electromagnetic compatibility (EMC) limits for electrical/electronic equipment, systems and installations.
• Living database format: The RSD is maintained as a spreadsheet on the IEC website and updated as new contributions arrive.
• Definitions and parameters: New Clause 3 supplies essential definitions (e.g., RF protection ratio, minimum usable field strength, minimum usable signal strength, necessary bandwidth) to ensure consistent, qualified input.
• Data selection and retrieval guidance: New Subclauses 5.1 and 5.2 give practical advice on what radio parameters to enter and how to retrieve/use them with the CISPR limits‑setting model.
• ITU‑R principles: Informative Annex B summarizes ITU‑R principles for determining minimum usable field strength and the associated tolerable disturbance at the antenna - important for coverage planning and interference assessments.
• Contribution process: All interested parties are invited to submit data (typically via National Committees in CISPR/H) to keep the RSD current and reliable.

Applications

• For committees writing CISPR product or generic emission standards, the RSD supplies radio‑service characteristics needed with CISPR TR 16‑4‑4 to derive protective emission limits.
• For EMC engineers, test laboratories and standards developers, the report clarifies which radio parameters are relevant and how to use them in limit‑setting and compliance assessments.
• For radio network planners and broadcasters, Annex B provides the fundamentals to relate minimum usable field strength and tolerable disturbance to coverage and interference planning.
• For national regulators and technical committees, the RSD supports harmonized decisions on protection requirements for radio services.

Related standards

• CISPR TR 16‑4‑4 (limits‑setting model for disturbance limits)
• ITU‑R recommendations (principles referenced in Annex B, e.g., minimum usable field strength methodologies)
• IEC 60050‑151 / Electropedia (terminology)

Contributing validated radio‑service data helps ensure robust, transparent EMC limit setting and consistent protection of radio services.

Standards Content (Sample)

CISPR TR 31 ®
Edition 3.0 2024-11
TECHNICAL
REPORT
colour
inside
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE
Description of the radio services database

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CISPR TR 31 ®
Edition 3.0 2024-11
TECHNICAL
REPORT
colour
inside
INTERNATIONAL SPECIAL COMMITTEE ON RADIO INTERFERENCE

Description of the radio services database

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.100.10  ISBN 978-2-8327-0034-1

– 2 – CISPR TR 31:2024 © IEC 2024
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms, definitions and abbreviated terms . 5
3.1 Terms and definitions. 5
3.2 Abbreviated terms . 7
4 Global advice on usage of the database . 8
4.1 General . 8
4.2 Input to the database . 8
4.3 Use of data from the database for limits determination . 8
5 Outline of the database and explanations to its content . 8
5.1 Outline of the database . 8
5.2 Additional information on the characteristics used in the radio service
database . 10
Annex A (informative) Reporting Form . 13
Annex B (informative) Determination of the minimum usable field strength and
associated tolerable disturbance field strength from sources other than radio
equipment, at the antenna of radio stations according to the radio standards and
recommendations of ITU-R . 15
B.1 Determination of the minimum usable field strength . 15
B.2 Determination of the maximum value (limit) for unwanted emanations of EMI
sources other than radio equipment . 16
Bibliography . 17

Figure A.1 – Example for entries of data in the Radio Services Database based on the
principles defined in Clause 5 . 14

Table 1 – Terms used in the headers of the database and explanations on their
purpose . 9
Table A.1 – Reporting form . 13

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
DESCRIPTION OF THE RADIO SERVICES DATABASE

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
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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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shall not be held responsible for identifying any or all such patent rights.
CISPR 31 has been prepared by CISPR subcommittee H: Limits for the protection of radio
services, of IEC technical committee CISPR: International special committee on radio
interference. It is a Technical Report.
This third edition cancels and replaces the second edition published in 2012. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) A new Clause 3 covers a line of essential definitions of radio parameters, the knowledge of
which is necessary to get qualified input data for inclusion of essential requirements in the
present radio services database (RSD) maintained by CISPR and IEC.

– 4 – CISPR TR 31:2024 © IEC 2024
b) The radio parameters and conditions of use of radio receivers listed in Table 1 of this edition
of CISPR TR 31 are provided now with instructive advice in its new Subclauses 5.1 and 5.2,
on selection of data for input to the RSD and retrieval of that data for consideration and use
with the limits setting model as in CISPR TR 16-4-4 which was missing in the previous
edition of CISPR TR 31.
c) Finally, another new informative Annex B informs, to the extent necessary, on the principles
of ITU-R on determination of data for the minimum usable field strength (to be inserted in
Column (E) of the RSD) and of the associated tolerable disturbance at the antenna of the
radio reception system or other self-contained radio receiver (also to be used as input with
the limits-setting model in CISPR TR 16-4-4), which concerns only parties who are
concerned with designing and projecting of radio-communication/broadcast networks and
with coverage planning of related radio services. Knowledge of these fundamental principles
also by CISPR experts will ensure that only valid data will get future input to the RSD
maintained by CISPR and IEC.
The text of this Technical Report is based on the following documents:
Draft Report on voting
CIS/H/509/DTR CIS/H/520/RVDTR
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this Technical Report is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
IMPORTANT – The "colour inside" logo on the cover page of this document 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.

DESCRIPTION OF THE RADIO SERVICES DATABASE

1 Scope
This Technical Report covers the rationale behind the database containing the characteristics
of radio services. The database is a "living document " in the format of a spreadsheet file in the
EMC Zone of the IEC web site:
https://www.iec.ch/emc/radio-services-database
As new input for the IEC Radio Services Database arrives, this Technical Report provides
guidance and support for the systematic collation of data on those radio services which are
relevant for determination of CISPR limits according to CISPR TR 16-4-4. All interested parties
are invited to contribute with relevant data to the database, e.g., via the National Committees
represented in CISPR/H.
The objective of the database is to register those characteristics which are relevant for
derivation and specification of limits for disturbances from electric and/or electronic equipment,
systems and installations. Committees responsible for generic and/or product emission EMC
standards use this information together with CISPR TR 16-4-4.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 60050-151:2001, International Electrotechnical Vocabulary (IEV) – Part 151: Electrical and
magnetic devices
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-151 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp

– 6 – CISPR TR 31:2024 © IEC 2024
3.1.1
RF protection ratio
R
p
minimum value of the radio-frequency (RF) signal-to-noise (S/N) ratio required to obtain the
specified radio reception quality under specified conditions and at the specified point (here: RF
protection ratio at the antenna of the radio station or other kind of self-contained radio receiver)
Note 1 to entry: The specified conditions include the field strength of the wanted radio signal according to 3.1.2.
Note 2 to entry: For digital radio services, the RF protection ratio can also be given as minimum value of the required
RF carrier-to-noise (C/N) ratio.
Note 3 to entry: For performance tests on radio receivers at standardised test sites, the specified point will be the
RF antenna port and input of the receiver, see also 3.1.4.
[SOURCE: ITU-R Vocabulary V.573, Term F22, modified (addition of "radio-frequency (RF)",
"radio" and "(here: RF protection ratio at the antenna of the radio station or other kind of self-
contained radio receive)", replacement of "signal-to-interference (S/I)"by "signal-to-noise
(S/N)", replacement of Notes to entry)]
3.1.2
minimum usable field strength
E
min
minimum value of the field-strength or power flux-density at the
antenna of the radio station necessary to permit the specified reception quality, under the
specified receiving conditions, in the presence of natural and man-made noise (see
Recommendation ITU-R P.372 [4]), but in the absence of interference from other transmitters
Note 1 to entry: The specified quality is determined in particular by the RF protection ratio against noise, and for
fluctuating noise, by the percentage of time during which this protection ratio must be ensured.
Note 2 to entry: The receiving conditions include, amongst others:
‒ the type of radio transmission, and frequency band used;
‒ the receiving equipment characteristics (as, e.g. receiving antenna gain, receiver characteristics, siting);
‒ receiver operating conditions, particularly the geographical zone, the time and the season.
Note 3 to entry: Where there is no ambiguity, the term "minimum field strength" can be used.
Note 4 to entry: The term "minimum usable field strength" corresponds to the term "minimum field strength to be
protected" which appears in many ITU texts.
[SOURCE: ITU-R Vocabulary V.573, Term F31, modified (addition of "at the antenna of the
radio station")]
3.1.3
necessary bandwidth
for a given class of emission, the width of the frequency band which is just sufficient to ensure
the transmission of information at the rate and with the quality required under specified
conditions
Note 1 to entry: Emissions in this band are commonly referred to as within the intended emission bandwidth.
[SOURCE: ITU-R Radio Regulations (2020), Article 1.152, modified – Addition of Note 1 to
entry]
3.1.4
minimum usable signal strength
MUS
minimum value of the wanted radio signal's strength at the RF input of the radio station's
receiver necessary to get reasonably discernible discrimination between the content of radio
transmission and receiving-system-internal circuit noise, under specified test conditions, in the
absence of external radio noise and interference from other transmitters
Note 1 to entry: The specified conditions concern performance tests (type tests) on receivers of a given category
intended for use with the service and verification of compliance with the requirements specified in radio standards
and other specifications, as e.g., Recommendations of ITU-R for reference receivers, like e.g., MUS and the required
co-channel RF protection ratio, see 3.1.1. For the latter the "specified point " as in 3.1.1 is the RF antenna port and
input of the receiver.
Note 2 to entry: Verification of compliance with specified requirements concerns the suitability of the receiver for
use with the service in respect of:
‒ the required RF protection ratio (3.1.1) and necessary bandwidth (3.1.3) for the type of radio transmission, and
the frequency band used for the service, and
‒ the receiver's minimum usable signal strength or sensitivity (MUS) in terms of the wanted radio signal's power or
voltage needed at the receiver's antenna port, the former being lower-bounded in the receiver's passband by its
internal (thermal) circuit noise power floor.
Note 3 to entry: For self-contained radio receiver categories and for individual receiving stations in stationary use,
performance tests or checks can also concern verification of compliance with the required minimum usable field
strength or power flux density according to 3.1.2, either on a test site (i.e., in an SAC or FAR) in absence of external
noise and interference, or also in situ, at the installation site of the station concerned in presence of rather negligible
levels of external noise and interference.
3.2 Abbreviated terms
For the purposes of this document, the following abbreviated terms apply.
CW NB Continuous Wave Narrow Band
EM Electromagnetic
EMC Electromagnetic Compatibility
EMI Electromagnetic Interference
FAR Fully Anechoic Room
GBB Gaussian Broad Band
IBB Impulsive Broad Band
IN Impulsive Noise
ITU-R International Telecommunication Union Radiocommunication Sector
MMN Man-Made-Noise
MUS Minimum Usable (signal) Strength
RA Radiocommunication Assembly (ITU-R)
RF Radio-frequency
RFI Radio-frequency Interference
RRC Regional Radiocommunication Conference (of members of ITU-R)
Rx Radio receiver
SAC Semi-Anechoic Chamber
SCN Single-Carrier Noise
S/N Signal-to-Noise (ratio)
S/I Signal-to-Interference (ratio)
WGN White Gaussian Noise
WRC World Radiocommunication Conference (of members of ITU-R)

– 8 – CISPR TR 31:2024 © IEC 2024
4 Global advice on usage of the database
4.1 General
The database contains objective radio system characteristics and subjective information on
typical intended usage.
In order to obtain concise and objective data it is necessary to define which out of the various
data from the many available planning parameters for radio services need be included in the
radio database, together with further information about the conditions in typical use of the radio
services and in particular its radio receivers.
The structure of the database and its data are kept up-to-date and maintained solely by
CISPR/H. In the database, parameters are given on a line-by-line basis. If a radio service
offers/specifies radio parameters for different modes of radio reception, then the respective
data are found in separate lines in the database, which commonly belong then to the same
service. Hence duplication of several data entries can be observed in such cases.
4.2 Input to the database
Input can be made by using the template (Annex A reporting form) and by forwarding the input
to the CISPR H Secretariat. An example for up-to-date input in the spreadsheet forming the
Radio Services Database is found in Annex A.
4.3 Use of data from the database for limits determination
The database is found at the IEC web site https://www.iec.ch/emc/radio-services-database and
is freely accessible. Product committees preparing EMC emission standards need to consider
in which frequency ranges their equipment are likely to generate emissions. The relevant
frequency ranges in this database can be consulted in order to identify which radio
...