IEC 61108-6:2023

IEC 61108-6
®

Edition 1.0 2023-02
INTERNATIONAL
STANDARD



Maritime navigation and radiocommunication equipment and systems – Global
navigation satellite systems (GNSS) –
Part 6: Navigation with Indian constellation (NavIC)/Indian regional navigation
satellite system (IRNSS) – Receiver equipment – Performance requirements,
methods of testing and required test results

IEC 61108-6:2023-02(en)

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IEC 61108-6

®


Edition 1.0 2023-02




INTERNATIONAL



STANDARD



















Maritime navigation and radiocommunication equipment and systems – Global

navigation satellite systems (GNSS) –

Part 6: Navigation with Indian constellation (NavIC)/Indian regional navigation

satellite system (IRNSS) – Receiver equipment – Performance requirements,

methods of testing and required test results























INTERNATIONAL

ELECTROTECHNICAL


COMMISSION





ICS 33.060; 47.040; 47.060 ISBN 978-2-8322-6363-1




  Warning! Make sure that you obtained this publication from an authorized distributor.


® Registered trademark of the International Electrotechnical Commission

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– 2 – IEC 61108-6:2023 © IEC 2023
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and abbreviated terms . 8
3.1 Terms and definitions . 8
3.2 Abbreviated terms . 8
4 Minimum performance requirements . 9
4.1 Object . 9
4.2 IRNSS/NavIC receiver equipment . 10
4.2.1 Minimum facilities . 10
4.2.2 Configuration . 10
4.2.3 Quality assurance . 10
4.3 Performance of IRNSS/NavIC receiver equipment . 10
4.3.1 General . 10
4.3.2 Equipment interfaces . 11
4.3.3 Accuracy . 12
4.3.4 Acquisition . 12
4.3.5 Protection . 13
4.3.6 Antenna design . 13
4.3.7 Sensitivity and dynamic range . 14
4.3.8 Effects of specific interfering signals . 14
4.3.9 Position update . 14
4.3.10 Differential IRNSS/NavIC input . 15
4.3.11 Navigation warnings and status indications . 15
4.3.12 Output of COG, SOG and UTC . 17
4.3.13 Typical interference conditions . 18
5 Methods of testing and required test results . 18
5.1 Test sites . 18
5.2 Test sequence . 19
5.3 Standard test signals . 19
5.4 Determination of accuracy . 20
5.5 General requirements and presentation requirements . 20
5.5.1 Normal environmental conditions for tests . 20
5.5.2 General requirements . 20
5.5.3 Presentation requirements . 20
5.6 Receiver performance tests . 20
5.6.1 IRNSS/NavIC receiver equipment . 20
5.6.2 Position output. 20
5.6.3 Equipment interfaces . 21
5.6.4 Accuracy . 21
5.6.5 Acquisition . 22
5.6.6 Protection . 23
5.6.7 Antenna design . 23
5.6.8 Sensitivity and dynamic range . 23
5.6.9 Protection from other shipborne transmitters . 24
5.6.10 Position update . 25
5.6.11 Differential IRNSS/NavIC input . 25

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IEC 61108-6:2023 © IEC 2023 – 3 –
5.6.12 Navigational warnings and status indications . 26
5.6.13 Accuracy of COG and SOG. 28
5.6.14 Validity of COG and SOG information . 29
5.6.15 Output of UTC . 29
5.7 Tests for typical RF interference conditions. 29
5.7.1 Simulator conditions . 29
5.7.2 Navigation solution accuracy test . 29
5.7.3 Re-acquisition test . 30
Annex A (normative) Typical IRNSS/NavIC interference environment. 32
A.1 IRNSS/NavIC CW in-band and near-band interference environment . 32
A.2 Band-limited noise-like interference . 33
A.3 Pulsed interference . 34
A.4 IRNSS/NavIC minimum antenna gain . 35
Annex B (normative) Alert management . 36
Bibliography . 37

Figure 1 – Logical interfaces of IRNSS/NavIC receiver . 11
Figure A.1 – CW interference thresholds for IRNSS/NavIC L5 band receivers in steady
state navigation . 33
Figure A.2 – CW interference thresholds for IRNSS/NavIC S band receivers in steady
state navigation . 33
Figure A.3 – Effect of interference bandwidth on interference thresholds for
IRNSS/NavIC receivers (for noise like interference) . 34

Table 1 – Acquisition time limits . 13
Table 2 – RAIM integrity status . 17
Table 3 – Accuracy of COG . 18
Table 4 – RF interference value . 30
Table A.1 – CW interference thresholds for IRNSS/NavIC L5 band receivers in steady-
state navigation . 32
Table A.2 – CW interference thresholds for IRNSS/NavIC S band receivers in
steady‑state navigation . 32
Table A.3 – Interference threshold for band-limited noise-like interference to
IRNSS/NavIC receivers in steady-state navigation . 34
Table A.4 – Interference thresholds for pulsed interference . 35
Table A.5 – IRNSS/NavIC minimum antenna gain . 35
Table B.1 – Required alerts and their classification . 36

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– 4 – IEC 61108-6:2023 © IEC 2023
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

MARITIME NAVIGATION AND RADIOCOMMUNICATION EQUIPMENT
AND SYSTEMS – GLOBAL NAVIGATION SATELLITE SYSTEMS (GNSS) –

Part 6: Navigation with Indian constellation (NavIC)/Indian regional
navigation satellite system (IRNSS) – Receiver equipment – Performance
requirements, methods of testing and required test results

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
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interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
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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.
IEC 61108-6 has been prepared by IEC technical committee 80: Maritime navigation and
radiocommunication equipment and systems. It is an International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
80/1055/FDIS 80/1058/RVD

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 International Standard is English.

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IEC 61108-6:2023 © IEC 2023 – 5 –
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.
A list of all parts in the IEC 61108 series, published under the general title Maritime navigation
and radiocommunication equipment and systems – Global navigation satellite systems (GNSS),
can be found on the IEC website.
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,
• replaced by a revised edition, or
• amended.

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– 6 – IEC 61108-6:2023 © IEC 2023
MARITIME NAVIGATION AND RADIOCOMMUNICATION EQUIPMENT
AND SYSTEMS – GLOBAL NAVIGATION SATELLITE SYSTEMS (GNSS) –

Part 6: Navigation with Indian constellation (NavIC)/Indian regional
navigation satellite system (IRNSS) – Receiver equipment – Performance
requirements, methods of testing and required test results



1 Scope
This part of IEC 61108 specifies the minimum performance requirements, methods of testing
and required test results for the Indian regional navigation satellite system (IRNSS), also known
as Navigation with Indian Constellation (NavIC), shipborne receiver equipment, based on IMO
resolution MSC.449(99), which uses the signals from NavIC/IRNSS in order to determine
position.
This document takes account of the general requirements given in IMO resolution A.694(17)
and is associated with IEC 60945. When a requirement in this document is different from
IEC 60945, the requirement in this document takes precedence. This document also takes into
account, as appropriate, requirements for the presentation of navigation-related information on
shipborne navigational displays given in IMO resolution MSC.191(79) and is associated with
IEC 62288. This document further takes into account, as appropriate, requirements for bridge
alert management given in IMO resolution MSC.302(87) and is associated with IEC 62923-1.
This document applies to navigation in ocean waters for the standard positioning service and
harbour entrances, harbour approaches and coastal waters, as defined in IMO resolution
A.1046(27) within IRNSS/NavIC coverage area as given in IMO resolution MSC 449(99).
All text of this document whose meaning is identical to that in IMO resolution MSC. 449(99) is
printed in italics and the resolution and paragraph number indicated between brackets, i.e.
"(M.449(99)/A1.2)".
The requirements in Clause 4 are cross-referenced to the tests in Clause 5 and vice versa.
NOTE 1 A description of the IRNSS standard positioning service can be found in the interface control documents
which were officially released in 2017 in the public domain (see ISRO-IRNSS-ICD-SPS-1.1).
NOTE 2 The IRNSS constellation was renamed as "NavIC" (navigation with Indian constellation) in 2016.
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 60945, Maritime navigation and radiocommunication equipment and systems – General
requirements – Methods of testing and required test results
IEC 61108-4, Maritime navigation and radiocommunication equipment and systems – Global
navigation satellite systems (GNSS) – Part 4: Shipborne DGPS and DGLONASS maritime radio
beacon receiver equipment – Performance requirements, methods of testing and required test
results

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IEC 61108-6:2023 © IEC 2023 – 7 –
IEC 61108-5:2020, Maritime navigation and radiocommunication equipment and systems –
Global navigation satellite systems (GNSS) – Part 5: BeiDou navigation satellite system (BDS)
– Receiver equipment – Performance requirements, methods of testing and required test results
IEC 61162-1, Maritime navigation and radiocommunication equipment and systems – Digital
interfaces – Part 1: Single talker and multiple listeners
IEC 61162-2, Maritime navigation and radiocommunication equipment and systems – Digital
interfaces – Part 2: Single talker and multiple listeners, high-speed transmission
IEC 61162-450, Maritime navigation and radiocommunication equipment and systems – Digital
interfaces – Part 450: Multiple talkers and multiple listeners – Ethernet interconnection
IEC 62288, Maritime navigation and radiocommunication equipment and systems –
Presentation of navigation-related information on shipborne navigational displays – General
requirements, methods of testing and required test results
IEC 62923-1, Maritime navigation and radiocommunication equipment and systems – Bridge
alert management – Part 1: Operational and performance requirements, methods of testing and
required test results
IEC 62923-2, Maritime navigation and radiocommunication equipment and systems – Bridge
alert management – Part 2: Alert and cluster identifiers and other additional features
IMO resolution A.694(17):1991, General requirements for shipborne radio equipment forming
part of the Global maritime distress and safety system (GMDSS) and for electronic navigational
aids
IMO resolution A.915(22), Revised maritime policy and requirements for a future Global
Navigation Satellite System (GNSS)
IMO resolution A.1046(27), Worldwide radio navigation system
IMO resolution MSC.302(87), Performance standards for bridge alert management
IMO resolution MSC.449(99), Performance Standards for Shipborne IRNSS Receiver
Equipment
ITU-R Recommendation M.823-3, Technical characteristics of differential transmissions for
global navigation satellite systems from maritime radio beacons in the frequency band
283.5-315 kHz in Region 1 and 285-325 kHz in Regions 2 and 3
ISRO-IRNSS-ICD-SPS-1.1, Navigation with Indian Constellation System – Signal in Space
Interface Control Document for Standard Positioning Service V 1.1, Aug 2017 [viewed
2022-11-11]. Available at
https://www.isro.gov.in/media_isro/pdf/Publications/Vispdf/Pdf2017/irnss_sps_icd_version1.1-
2017.pdf
RTCM 10402, RTCM Recommended Standards for Differential GNSS (Global Navigation
Satellite Systems) Service

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3 Terms, definitions and abbreviated terms
For the purposes of this document, the following terms and definitions 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
NOTE All definitions and abbreviations used are the same as those used in ISRO-IRNSS-ICD-SPS-1.1.
3.1 Terms and definitions
3.1.1
integrity
ability of the system to provide users with warnings within a specified time when the system
should not be used for navigation
3.1.2
Indian regional navigation satellite system
IRNSS
independent satellite navigation system developed and operated by India
Note 1 to entry: IRNSS can provide 3D position, velocity and time information for users within 1 500 km from the
Indian geopolitical boundary.
Note 2 to entry: IRNSS is known as NavIC and the words are used interchangeably in this document.
3.1.3
IRNSS/NavIC time
time reference built and kept by IRNSS
nd
Note 1 to entry: The IRNSS system time start epoch is 00:00 UT on Sunday August 22 1999 (midnight between
st nd
August 21 and 22 ). At the start epoch, IRNSS system time is ahead of UTC by 13 leap seconds (i.e. IRNSS time,
nd st
August 22 1999, 00:00:00 corresponds to UTC time August 21 1999, 23:59:47).
3.2 Abbreviated terms
BAM bridge alert management
CAM central alert management
COG course over ground
CW continuous wave
DNavIC differential navigation with Indian constellation
EUT equipment under test
GNSS global navigation satellite system
GPS global positioning system
HAL horizontal alert limit
HDOP horizontal dilution of precision
HPL horizontal protection limit
ICD interface control document
MKD minimum keyboard and display
NavIC navigation with Indian constellation
NB narrow band
NPLI national physical laboratory of India

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IEC 61108-6:2023 © IEC 2023 – 9 –
PDOP position dilution of precision
PNT position navigation and timing
RAIM receiver autonomous integrity monitor
RF radio frequency
RFCS radio frequency constellation simulator
RFI radio frequency interference
SOG speed over ground
SPS standard positioning service
UTC universal time coordinated
WB wide band
4 Minimum performance requirements
4.1 Object
(M.449(99)/A1.2) The IRNSS Standard Positioning Service (SPS) provides positioning,
navigation and timing services, free of direct user charges. The IRNSS SPS receiver equipment
should be capable of receiving and processing the IRNSS SPS signal. It should be capable of
tracking all IRNSS satellites.
(M.449(99)/A1.3) Receiver equipment for the Indian Regional Satellite System (IRNSS)
intended for navigational purposes on ships with maximum speeds not exceeding 70 knots shall,
in addition to the general requirements contained in resolution A.694(17), comply with the
following minimum performance requirements.
(M.449(99)/A1.4) This standard covers the basic requirements of position fixing, determination
of course over ground (COG), speed over ground (SOG) and timing either for navigation
purposes or as input to other functions. The standards do not cover other computational
facilities which may be in the equipment nor cover the requirements for other systems that may
take input from the IRNSS receiver.
This document contains the basic minimum performance requirements for use of IRNSS/NavIC
standard positioning service (SPS) signals for navigational position fixing, including differential
corrections, and, in addition, for the determination of speed and direction of the movement of
the antenna over the ground.
Other computational activity, input/output activity or extra display functions which may be
provided shall not degrade the performance of the equipment below the minimum performance
requirements set out in this document.
The IRNSS/NavIC receiver equipment shall comply with:
– the provisions of IMO resolutions A.1046(27), MSC. 449(99), MSC.302(87) and A.694(17);
– the accuracy requirements of the SPS interface control document;
– tests in accordance with IEC 60945.

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4.2 IRNSS/NavIC receiver equipment
4.2.1 Minimum facilities
(M.449(99)/A2.1) The term "IRNSS receiver equipment" as used in these performance
standards includes all the components and units necessary for the system to properly perform
its intended functions. The equipment shall include the following minimum facilities:
a) antenna capable of receiving IRNSS signals;
b) IRNSS receiver and processor;
c) means of accessing the computed latitude/longitude position;
d) data control and interface; and
e) position display and, if required, other forms of output.
If the IRNSS/NavIC receiver forms part of an approved integrated navigation system (INS),
requirements of c), d) and e) may be provided within the INS.
If the IRNSS/NavIC receiver forms part of an approved multi-system PNT, requirements of c),
d) and e) may be provided within the multi-system PNT.
4.2.2 Configuration
The IRNSS/NavIC receiver equipment may be supplied in one of several configurations to
provide the necessary position information. Examples are as follows:
– stand-alone receiver with means of accessing computed position via a keyboard with the
positional information suitably displayed and with means to display alert
...