IEC 61097-4:2024
(Main)Global maritime distress and safety system (GMDSS) - Part 4: Inmarsat-C ship earth station and Inmarsat enhanced group call (EGC) equipment - Operational and performance requirements, methods of testing and required test results
Global maritime distress and safety system (GMDSS) - Part 4: Inmarsat-C ship earth station and Inmarsat enhanced group call (EGC) equipment - Operational and performance requirements, methods of testing and required test results
IEC 61097-4:2024 specifies the performance requirements and methods of testing for Inmarsat-C ship earth stations (SES) capable of transmitting and receiving direct-printing communications, and for enhanced group call (EGC) receivers, for use in the GMDSS and for use for long-range identification and tracking (LRIT). The available variants are:
Class 0: An EGC receiver, either stand-alone or an element of a GMDSS installation in accordance with the Inmarsat design and installation guidelines (DIGs) for GMDSS installations.
Class 1: A basic SES providing shore-to-ship and ship-to-shore message transfer only.
Class 2: As class 1 but with EGC as an alternative to shore-to-ship transfer using a shared receiver.
Class 3: As class 1 but with EGC using an independent receiver.
NOTE 1 The 34th session of the IMO Sub-Committee on Radiocommunications decided that class 2 equipment would be adequate to provide sufficient availability for the reception of maritime safety information for the GMDSS.
This document complies with IMO performance requirements stated in the normative references, Inmarsat technical characteristics and test procedures, and IEC 60945 general requirements except where modifications are explicitly stated in this document. Technical characteristics essential to GMDSS and LRIT operation as defined by the IMO are identified.
All text of this document, whose wording is identical to that in IMO SOLAS Convention 1974 as amended in 1988 and Resolutions MSC.513(105), MSC.263(84) and MSC.306(87) is printed in italics and reference made to the Resolution/Recommendation and subclause number.
This document covers equipment construction and testing. Matters relating to installation can be found in the Inmarsat Maritime design and installation guidelines (see Bibliography). Those to be found in IMO Resolutions MSC.513(105), MSC.263(84) and MSC.306(87) are reproduced in Annex A.
Responsibility for type approval of Inmarsat-C and Inmarsat-EGC is vested in Inmarsat by IMO Resolutions MSC.513(105) and MSC.306(87) (see 4.2.1). Therefore, this document does not reproduce Inmarsat test procedures in full but refers to where they are given in Inmarsat documentation cited in the normative references to this document (Annex C).
NOTE 2 For the purposes of this document the terms Inmarsat C, Inmarsat-C, Inmarsat Standard-C, Standard-C refer to the same equipment.
General Information
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Standards Content (Sample)
IEC 61097-4 ®
Edition 4.0 2024-02
INTERNATIONAL
STANDARD
Global maritime distress and safety system (GMDSS) –
Part 4: Inmarsat-C ship earth station and Inmarsat enhanced group call (EGC)
equipment – Operational and performance requirements, methods of testing and
required test results
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IEC 61097-4 ®
Edition 4.0 2024-02
INTERNATIONAL
STANDARD
Global maritime distress and safety system (GMDSS) –
Part 4: Inmarsat-C ship earth station and Inmarsat enhanced group call (EGC)
equipment – Operational and performance requirements, methods of testing
and required test results
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 47.020.70 ISBN 978-2-8322-8299-1
– 2 – IEC 61097-4:2024 © IEC 2024
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 7
3 Terms and definitions . 8
4 Performance requirements. 8
4.1 Overview. 8
4.2 Non-operational requirements . 8
4.2.1 General . 8
4.2.2 Warning of radiation hazard . 8
4.2.3 Power supply changeover . 9
4.2.4 Installation . 9
4.3 Operational requirements for ship earth stations . 9
4.3.1 Capabilities. 9
4.3.2 Ship station identity . 9
4.3.3 Distress alerting . 9
4.3.4 Position updating . 10
4.4 Operational requirements for EGC receivers . 10
4.4.1 Capabilities. 10
4.4.2 General . 11
4.4.3 Position and area code updating . 11
4.4.4 Indication of receipt of priority message . 11
4.4.5 Indication of tuning and synchronisation . 12
4.4.6 Printing selection . 12
4.4.7 Printing device . 12
4.5 Performance related requirements from IEC 60945 . 12
4.6 Other requirements . 13
4.7 Long-range identification and tracking . 13
4.7.1 General . 13
4.7.2 Capabilities. 13
4.7.3 Functionality . 15
4.7.4 Communication system . 15
5 Technical characteristics . 15
5.1 Overview. 15
5.2 Environmental and electromagnetic compatibility requirement . 15
5.3 Radiated spurious emissions . 16
5.4 Interfaces . 16
5.5 Interfering signals . 17
6 Methods of testing and required test results . 17
6.1 Overview. 17
6.1.1 General . 17
6.1.2 Performance requirements . 18
6.1.3 Technical characteristics . 18
6.2 Tests of non-operational requirements . 18
6.3 Tests of operational requirements for ship earth stations . 18
6.3.1 Capabilities. 18
6.3.2 Ship station identity . 18
6.3.3 Distress alerting . 18
6.3.4 Position updating . 19
6.4 Tests of operational requirements for EGC receivers . 19
6.4.1 Capabilities. 19
6.4.2 General . 19
6.4.3 Position and area code updating . 19
6.4.4 Indication of receipt of priority message . 20
6.4.5 Indication of tuning and synchronisation . 20
6.4.6 Printing selection . 20
6.4.7 Printing device . 20
6.5 Tests of performance related requirements from IEC 60945 . 20
6.6 Tests of other requirements . 20
6.7 Long-range identification and tracking . 21
6.7.1 General . 21
6.7.2 Capabilities. 21
6.7.3 Functionality . 21
6.7.4 Communication system . 21
6.8 Tests of technical characteristics . 22
6.8.1 Inmarsat tests . 22
6.8.2 Tests for environmental and electromagnetic compatibility . 22
6.8.3 Interfaces . 23
6.8.4 Interfering signals . 23
Annex A (normative) Requirements relating to installation . 24
A.1 General . 24
A.2 Source of electrical energy . 24
A.3 Siting of antennas . 24
A.4 Long-range identification and tracking . 24
A.5 Requirements . 24
Annex B (normative) Radiated unwanted emissions . 25
B.1 Unwanted emissions 30 MHz to 1 000 MHz . 25
B.2 Unwanted emissions above 1 000 MHz . 25
B.3 Unwanted emissions within the bands with carrier-on . 26
B.4 Unwanted emissions within the bands with carrier-off . 27
Annex C (informative) Inmarsat RTP schedule of tests . 28
Bibliography . 32
Table 1 – Data to be transmitted from the shipborne equipment . 15
Table 2 – Environmental conditions . 16
Table B.1 – Limits of unwanted emissions up to 1 000 MHz . 25
Table B.2 – Limits of unwanted emissions above 1 000 MHz . 26
Table B.3 – Limits of unwanted emission within the operating band with carrier-on . 27
Table C.1 – Phase I Inmarsat-C schedule of tests . 28
Table C.2 – Phase I EGC receiver schedule of tests . 30
Table C.3 – Phase II schedule of tests . 31
– 4 – IEC 61097-4:2024 © IEC 2024
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
GLOBAL MARITIME DISTRESS AND SAFETY SYSTEM (GMDSS) –
Part 4: Inmarsat-C ship earth station and
Inmarsat enhanced group call (EGC) equipment –
Operational and performance requirements,
methods of testing and required test results
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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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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IEC 61097-4 has been prepared by IEC technical committee 80: Maritime navigation and
radiocommunication equipment and systems. It is an International Standard.
This fourth edition cancels and replaces the third edition published in 2012, Amendment 1:2016
and Amendment 2:2019. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) the addition of a technical requirement in 5.5 for operation in the presence of an interfering
signal, with associated test, resulting from new IMO performance standards given in
resolution MSC.513(105).
The text of this International Standard is based on the following documents:
Draft Report on voting
80/1102/FDIS 80/1113/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.
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 61097 series, published under the general title Global maritime
distress and safety system (GMDSS), 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, or
• revised.
– 6 – IEC 61097-4:2024 © IEC 2024
GLOBAL MARITIME DISTRESS AND SAFETY SYSTEM (GMDSS) –
Part 4: Inmarsat-C ship earth station and
Inmarsat enhanced group call (EGC) equipment –
Operational and performance requirements,
methods of testing and required test results
1 Scope
This part of IEC 61097 specifies the performance requirements and methods of testing for
Inmarsat-C ship earth stations (SES) capable of transmitting and receiving direct-printing
communications, and for enhanced group call (EGC) receivers, for use in the GMDSS and for
use for long-range identification and tracking (LRIT). The available variants are:
Class 0: An EGC receiver, either stand-alone or an element of a GMDSS installation in
accordance with the Inmarsat design and installation guidelines (DIGs) for
GMDSS installations.
Class 1: A basic SES providing shore-to-ship and ship-to-shore message transfer only.
Class 2: As class 1 but with EGC as an alternative to shore-to-ship transfer using a shared
receiver.
Class 3: As class 1 but with EGC using an independent receiver.
th
NOTE 1 The 34 session of the IMO Sub-Committee on Radiocommunications decided that class 2 equipment
would be adequate to provide sufficient availability for the reception of maritime safety information for the GMDSS.
This document complies with IMO performance requirements stated in the normative
references, Inmarsat technical characteristics and test procedures, and IEC 60945 general
requirements except where modifications are explicitly stated in this document. Technical
characteristics essential to GMDSS and LRIT operation as defined by the IMO are identified.
All text of this document, whose wording is identical to that in IMO SOLAS Convention 1974 as
amended in 1988 and Resolutions MSC.513(105), MSC.263(84) and MSC.306(87) is printed in
italics and reference made to the Resolution/Recommendation and subclause number.
This document covers equipment construction and testing. Matters relating to installation can
be found in the Inmarsat Maritime design and installation guidelines (see Bibliography). Those
to be found in IMO Resolutions MSC.513(105), MSC.263(84) and MSC.306(87) are reproduced
in Annex A.
Responsibility for type approval of Inmarsat-C and Inmarsat-EGC is vested in Inmarsat by IMO
Resolutions MSC.513(105) and MSC.306(87) (see 4.2.1). Therefore, this document does not
reproduce Inmarsat test procedures in full but refers to where they are given in Inmarsat
documentation cited in the normative references to this document (Annex C).
NOTE 2 For the purposes of this document the terms Inmarsat C, Inmarsat-C, Inmarsat Standard-C, Standard-C
refer to the same equipment.
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 60945:2002, Maritime navigation and radiocommunication equipment and systems –
General requirements – Methods of testing and required test results
IEC 61108 (all parts), Maritime navigation and radiocommunication equipment and systems –
Global navigation satellite systems (GNSS)
IEC 61162-1, Maritime navigation and radiocommunication equipment and systems – Digital
interfaces – Part 1: Single talker and multiple listeners
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, International Convention for the safety of life at sea (SOLAS),1974 as amended
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 MSC.263(84):2008, Revised performance standards and functional
requirements for the long-range identification and tracking of ships.
IMO Resolution MSC.302(87):2010, Performance standards for bridge alert management
IMO Resolution MSC.306(87):2010, Revised performance standards for enhanced group call
(EGC) equipment as amended by resolution MSC.431(98):2017
IMO Resolution MSC.513(105), Performance standards for INMARSAT-C ship earth stations
capable of transmitting and receiving direct-printing communications
Inmarsat, Inmarsat C System definition manual (SDM) Volume 2 – Part 2, Application Note 2,
Position reporting service
Inmarsat, Inmarsat C System definition manual (SDM) Volume 2 – Part 2, Application Note 3,
Application developers guide to data reporting and polling
Inmarsat, Inmarsat C System definition manual (SDM) Volume 3 – Part 2, Chapter 2, Mobile
earth station technical requirements
Inmarsat, Inmarsat C System definition manual (SDM) Volume 3 – Part 2, Chapter 5, Ship earth
station technical requirements
Inmarsat, Inmarsat C System definition manual (SDM) Volume 3 – Part 2, Chapter 8, Technical
requirements for an EGC receiver
– 8 – IEC 61097-4:2024 © IEC 2024
Inmarsat, Inmarsat C System definition manual (SDM) Change Notice CN150, ATCt signals and
other adjacent interferers
3 Terms and definitions
No terms and definitions are listed in this document.
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
4 Performance requirements
4.1 Overview
Subclauses 4.2 through 4.4 of this document describe performance requirements directly
attributable to IMO Resolutions MSC.306(87) as amended by MSC.431(98) and MSC.513(105)
as listed in the normative references. Subclause 4.5 is provided to highlight those requirements
of IMO Resolution A.694(17) which are not included in the normal Inmarsat requirements for
Inmarsat-C SES type approval. Subclause 4.6 describes other requirements which are required
to make the equipment suitable for GMDSS applications. Subclause 4.7 describes performance
requirements attributable to IMO Resolution MSC.263(84) for long-range identification and
tracking.
4.2 Non-operational requirements
4.2.1 General
(MSC.306(87) A1.1) The enhanced group call equipment to be used in the GMDSS shall comply
with the general requirements set out in Assembly resolution A.694(17) as detailed in IEC 60945
and this document.
(MSC.513(105) A1.1) The Inmarsat-C ship earth station installation provided to meet a
requirement for a ship earth station in SOLAS regulations IV/8.1.4, 9.1.3.3, 9.4.2, 10.1.1 or
10.1.4.3 shall comply with the general requirements set out in resolutions A.694(17). It should
be capable of transmitting and receiving automated telegraphy communications in compliance
with the relevant ITU-R recommendation on direct-printing telegraphy. In addition, the
Inmarsat-C ship earth station shall conform to the following minimum requirements.
(MSC.513(105) A1.2) The performance of any enhanced group call facility provided by the ship
earth station shall be in accordance with the performance standards for enhanced group call
equipment set out in resolution MSC.306(87) as amended by resolution MSC.431(98) and with
the following minimum performance requirements.
(MSC.513(105) A2.1)/MSC.306(87) 2) The ship earth station and the EGC equipment shall be
type-approved by Inmarsat and shall comply with the environmental conditions and
electromagnetic compatibility requirements specified in IEC 60945.
4.2.2 Warning of radiation hazard
(MSC.513(105) A4) In order to permit a warning of potential radiation hazards to be displayed
in appropriate locations, a label shall be attached to the radome indicating the distances
2 2 2
external to the radome at which radiation levels of 100 W/m , 25 W/m and 10 W/m exist.
However, the distances which are within the radome need not be indicated.
NOTE Owing to the low transmitted power of Inmarsat-C transmitters (less than 16 dBW) and the omnidirectional
antenna used, this label is not normally required.
4.2.3 Power supply changeover
(See 6.2)
(MSC.513(105) A5.2/MSC.306(87) A4.2) Changing from one source of supply to another or any
interruption of up to 60 s duration of the supply of electrical energy shall not require the
equipment to be manually re-initialized and shall not result in loss of received messages stored
in the memory.
4.2.4 Installation
Requirements for installation of the equipment are given in Annex A.
4.3 Operational requirements for ship earth stations
4.3.1 Capabilities
(See 6.3.1)
The equipment shall comply with regulations IV/8 through IV/10 of SOLAS 1974, as amended,
which prescribe the capabilities of Inmarsat ship earth stations to meet the GMDSS
requirements for ships in the various sea areas. The four capabilities are:
– (SOLAS IV/8.1.4, IV/9.1.3.3 and IV/10.1.4.3) means of initiating the transmission of
ship-to-shore distress alerts.
– (SOLAS IV/10.1.1) transmitting and receiving distress urgency and safety communications.
– (SOLAS IV/10.1.2) initiating and receiving distress priority calls.
– (SOLAS IV/9.4.2, IV/10.4.1) transmitting and receiving general radiocommunications.
4.3.2 Ship station identity
(See 6.3.2)
(MSC.513(105) A3.1) No control external to the equipment shall be available for alteration of
the ship station identity.
4.3.3 Distress alerting
(See 6.3.3)
(MSC.513(105) A3.2) It shall be possible to initiate and make distress calls from the position
from which the ship is normally navigated and from at least one other position designated for
distress alerting.
(MSC.513(105) A3.3) A distress alert shall be activated only by means of a dedicated distress
button. This button shall not be any key of an ITU-T digital input panel or an ISO keyboard
associated with the equipment and shall be physically separated from functional buttons/keys
used for normal operation. This button shall be a single button for no other purpose than to
initiate a distress alert.
(MSC.513(105) A3.4) The dedicated distress button shall:
.1 be clearly identified, red in colour and marked "DISTRESS". Where a non-transparent
protective lid or cover is used, it shall also be marked "DISTRESS; and
.2 be protected against inadvertent operation. The required protection of the distress button
shall consist of a spring-loaded lid or cover permanently attached to the equipment by, for
– 10 – IEC 61097-4:2024 © IEC 2024
example, hinges. It shall not be necessary for the user to remove additional seals or to break
the lid or cover in order to operate the distress button. The operation of the distress button
shall generate a visible and audible indication. The distress button shall be kept pressed for
at least three seconds. A flashing light and an intermittent acoustic signal shall start
immediately. After the three seconds, the transmission of the distress alert is initiated and
the indication shall become steady and the acoustic signal shall stop.
(MSC.513(105) A3.5) The distress alert initiation shall require at least two independent actions.
Lifting of the protective lid or cover is considered as the first action. Pressing the distress button
as specified above is considered as the second independent action.
(MSC.513(105) A3.6) The equipment shall indicate the status of the distress alert transmission.
(MSC.513(105) A3.7) It shall be possible to interrupt and initiate distress messages at any time.
It shall be possible to interrupt repetitive transmissions of distress messages. Such operation
shall not interrupt the transmission of a distress alert or distress message in progress but shall
prevent repetitive transmissions of a distress message.
It shall be possible to select the content of, but not initiate a distress alert using the equipment
keyboard or other means, before depressing one of the dedicated buttons to initiate the distress
alert. It shall also be possible to activate an undesignated (see Note) distress alert by
depressing one of the buttons, at any time.
NOTE Undesignated – unspecified distress alert, i.e. the default setting. All other selectable alerts are "designated".
4.3.4 Position updating
(See 6.3.4)
(MSC.513(105) A3.8) To enable updating of the position:
.1 the status of the position update shall be visible to the operator (e.g. offline, manual or
automatic);
.2 if position data is being updated automatically, a caution shall be raised if no update has
been performed for a period of 10 minutes. The caution shall be removed by receiving new
position data;
.3 if an integral electronic position-fixing aid is not provided, the equipment shall have an
interface conforming to the appropriate international standard;
.4 the equipment shall have facilities for manually entering the ship's position and the time of
the position fix;
.5 if the ship's manually-set position is older than four hours, a caution shall be raised. The
caution shall be removed by inputting or receiving new position data; and
.6 if the ship's position is older than 24 hours, the position is clearly identified with date and
time of the fix in UTC for distress alerting purposes.
The integral electronic position-fixing aid shall comply with the applicable requirements of the
IEC 61108 series.
As a minimum, the interface shall support the sentences GNS, RMC and ZDA described in
IEC 61162-1.
NOTE Subclause 3.3.7, which is referenced in the Inmarsat-C SDM, is 4.3.3 in this edition of this document.
4.4 Operational requirements for EGC receivers
4.4.1 Capabilities
(See 6.4.1)
The equipment shall comply with regulations IV/7 and IV/10 of SOLAS 1974, as amended, which
prescribe the capabilities of EGC receivers to meet the GMDSS requirements for ships in the
various sea areas. The two capabilities are:
– (SOLAS IV/7.1.4) a radio facility for reception of maritime safety information by the Inmarsat
enhanced group calling system.
– (SOLAS IV/10.1.1.3) an Inmarsat ship earth station capable of maintaining watch for
shore-to-ship distress alerts, including those directed to specifically defined geographical
areas.
4.4.2 General
(See 6.4.2)
(MSC.306(87) A1.3 as amended by resolution MSC.431(98)) Alternatively to the requirement in
paragraph MSC.306(87) A1.2, the equipment need not provide means to produce a printed copy
of received information if it is installed in combination with an interface connecting it to
navigation equipment that is compliant with resolution MSC 252(83), as amended, on Revised
Performance standards for integrated navigation systems (INS). Provisions for interconnection
to a shipborne integrated radiocommunication system (IRCS) when used in the GMDSS
(resolution A.811(19)) shall also be included.
If no means are provided by the equipment to produce a printed copy of received information
then the manufacturer's documentation shall clearly describe that the equipment can only be
used when connected to equipment enabled for the display of enhanced group calls as
described in IEC 61924-2.
(MSC.306(87) A1.4) The enhanced group call installation may be either separate or combined
with other installations. Elements of other installations, e.g. the antenna, low noise amplifier
and down converter of the ship earth system, may be shared for the reception of enhanced
group call messages.
4.4.3 Position and area code updating
(See 6.4.3)
(MSC.306(87) A3.1) The equipment shall provide a visual indication that the ship's position has
not been updated during the last 12 hours. It shall only be possible to reset this indication by
revalidating the ship's position. See also 4.3.4.
(MSC.306(87) A3.2) Means shall be provided to enter the ship's position and current and
planned NAVAREA/METAREA codes manually so that area group calls can be received. Means
shall also be provided to enter current and planned coastal warning service coverage areas and
different classes of messages. Optionally, the ship's position, as determined by the navigational
equipment may be entered automatically and the NAVAREA/METAREA code automatically
derived therefrom.
NOTE NAVAREAs and METAREAs are geographical sea areas established for the purpose of co-ordinating the
broadcast of navigational and meteorological safety information. The world is currently divided into 21 areas (I to
XXI). The boundaries are shown in the IMO International SafetyNET Manual.
4.4.4 Indication of receipt of priority message
(See 6.4.4)
(MSC.306(87) A3.3) Provision shall be made for a specific aural alarm and visual indication at
the position from which the ship is normally navigated to indicate receipt of a distress or urgency
priority EGC message. It shall not be possible to disable this alarm and it shall only be possible
to reset it manually and only from the position where the message is displayed or printed.
– 12 – IEC 61097-4:2024 © IEC 2024
4.4.5 Indication of tuning and synchronisation
(See 6.4.5)
(MSC.306(87) A3.4) The equipment shall indicate when it is not correctly tuned or synchronized
to the enhanced group call carrier.
4.4.6 Printing selection
(See 6.4.6)
(MSC.306(87) A3.5) Any message shall be printed regardless of the character error rate of its
reception. The equipment shall print a low-line mark if a character is received corrupted.
(MSC.306(87) A3.6) Acceptance or rejection of service codes shall be under the operator's
control except that equipment shall always receive navigational and meteorological warnings
and forecasts, search and rescue information, and shore-to-ship distress alerts, which are
directed to a fixed or absolute geographical area in which the ship is operating.
NOTE The service codes (C ) are described in the IMO International SafetyNET Manual. They have similar
meanings as the subject indicator characters (B ) in the NAVTEX system described in the IMO NAVTEX Manual and
Recommendation ITU-R M.540.
(MSC.306(87) A3.7) Means shall be provided to prevent the reprinting of a message once it has
been received without error.
4.4.7 Printing device
(See 6.4.7)
(MSC.306(87) A3.8) The printing device shall be capable of printing at least the standard
International Alphabet Number 5 (IA5) character set. Other character sets are optionally used
according to ISO 2022 standards.
(MSC.306(87) A3.9) The printing device shall be able to print at least 40 characters per line.
(MSC.306(87) A3.10) The signal processor and printing device shall ensure that if a word
cannot be accommodated in full on one line, it shall be transferred to the next line. The printing
device shall automatically feed five lines after completing the printed messages.
(MSC.306(87) A3.11) A local audible alarm shall be sounded to give advanced warning of the
printing device "paper low" condition. It shall not be possible to confuse the sound of the "paper
low" alarm with that of the distress or urgency alarm caused by the reception of a distress or
urgency priority message.
4.5 Performance related requirements from IEC 60945
(See 6.5)
The equipment shall comply with those subclauses of IEC 60945 appropriate to its equipment
class. The subclauses of IEC 60945:2002 referenced below, amend or augment the
corresponding requirements of the Inmarsat-C SDM.
– 4.1 General
– 4.2 Design and operation
– 4.3 Power supply
– 4.4 Durability and resistance to environmental conditions (see 4.2)
– 4.5 Interference (see 4.2)
– 4.6 Safety precautions
– 4.7 Maintenance
– 4.8 Equipment manuals
– 4.9 Marking and identification
4.6 Other requirements
(See 6.6)
Message display facilities shall be suitable for displaying received distress-related messages.
It is recommended that the display facilities should comply with the corresponding requirements
for EGC receivers in 4.4.6 and 4.4.7.
Any programming material or software that forms part of the equipment and which is necessary
for meeting the GMDSS requirements shall be permanently installed in the equipment. Any
software needed to fulfil any distress and safety requirements of the GMDSS shall not be stored
on any medium which can be accessed, modified or corrupted.
Any ancillaries associated with Inmarsat-C equipment, such as visual display units, keyboards
and printers, shall be available immediately on demand to service GMDSS functional
requirements. These ancillaries shall also be provided with fixing arrangements to prevent
unauthorized removal or disconnection.
4.7 Long-range identification and tracking
4.7.1 General
(See 6.7.1)
Long-range identification and tracking of ships (LRIT) is a requirement of regulation V/19-1 of
SOLAS 1974 as amended.
NOTE 1 IEC 62729 contains general information on LRIT.
For the purposes of LRIT the Inmarsat-C SES shall support the Inmarsat enhanced
pre-assigned data reporting service (reserved access), the enhanced data reporting service
(unreserved access), and the polling service.
NOTE 2 Enhanced and enhanced pre-assigned data reporting offers additional capabilities and features over the
Inmarsat data reporting service particularly; use of an internal data reporting checksum, inclusion of the ship earth
station identification to ensure unambiguous identification of stations, an acknowledgement mechanism managing
multiple assignments inside the Ocean Region and across Ocean Regions, changing reporting intervals, controlling
and querying assignments and status request facility to ensure reliable transfer.
4.7.2 Capabilities
4.7.2.1 Transmission of information
(See 6.7.2)
(MSC.263(84) A4.1.1) Shipborne equipment shall be capable of automatically and without
human intervention on board the ship transmitting the ship's LRIT information at 6-hour intervals
to an LRIT Data Centre.
(MSC.263(84) A4.4.1) When a ship is undergoing repairs, modifications or conversions in dry-
dock or in port or is laid up for a long period, the master or the Administration may reduce the
frequency of the transmission LRIT information to one transmission every 24-hour period or
may temporarily stop the transmission of such information.
– 14 – IEC 61097-4:2024 © IEC 2024
NOTE LRIT data centres are set up by governments, either individually or in cooperation with other governments.
Administrations decide to which LRIT data centre ships entitled to fly their flag are required to transmit the LRIT
information. The LRIT information is described in Table 1.
This requirement is achieved by the reserved data reporting service using a data network
identity (DNID) and a member number to associate the LRIT information with an LRIT data
centre. Information about the DNID and member number is downloaded by polling commands
(see 4.7.2.2) under the control of an Administration.
There shall be no control external to the equipment to set up or remove DNIDs. However,
facilities shall be provided to stop the transmission of LRIT information and to increase the
intervals between transmissions to 24 h, by controls external to the equipment. Facilities shall
also be provided to re-enable the transmissions at 6 h intervals. These facilities shall be security
protected so that access can be restricted to the master only.
4.7.2.2 Remote configuration
(MSC.263(84) A4.1.2) Shipborne equipment shall be capable of being configured remotely to
transmit LRIT information at variable intervals (Pre-scheduled position reports).
The equipment shall be capable of being remotely configured to transmit LRIT information at
intervals ranging from a minimum of 15 min to periods of 6 h to the LRIT data centre,
irrespective of where the ship is located and without human interaction on board the ship.
The equipment shall also be capable of being remotely configured to stop the transmission of
LRI
...
IEC 61097-4 ®
Edition 4.0 2024-02
COMMENTED VERSION
INTERNATIONAL
STANDARD
colour
inside
Global maritime distress and safety system (GMDSS) –
Part 4: Inmarsat-C ship earth station and Inmarsat enhanced group call (EGC)
equipment – Operational and performance requirements, methods of testing and
required test results
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IEC 61097-4 ®
Edition 4.0 2024-02
COMMENTED VERSION
INTERNATIONAL
STANDARD
colour
inside
Global maritime distress and safety system (GMDSS) –
Part 4: Inmarsat-C ship earth station and Inmarsat enhanced group call (EGC)
equipment – Operational and performance requirements, methods of testing
and required test results
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 47.020.70 ISBN 978-2-8322-8342-4
– 2 – IEC 61097-4:2024 CMV © IEC 2024
CONTENTS
FOREWORD .4
INTRODUCTION to Amendment 2 .
1 Scope .7
2 Normative references .8
3 Terms and definitions .9
4 Performance requirements .9
4.1 Overview .9
4.2 Non-operational requirements .9
4.2.1 General .9
4.2.2 Warning of radiation hazard . 10
4.2.3 Power supply changeover . 10
4.2.4 Installation . 10
4.3 Operational requirements for ship earth stations . 10
4.3.1 Capabilities . 10
4.3.2 Ship station identity . 10
4.3.3 Distress alerting . 10
4.3.4 Position updating . 11
4.4 Operational requirements for EGC receivers . 12
4.4.1 Capabilities . 12
4.4.2 General . 12
4.4.3 Position and area code updating . 13
4.4.4 Indication of receipt of priority message . 13
4.4.5 Indication of tuning and synchronisation . 13
4.4.6 Printing selection . 13
4.4.7 Printing device . 14
4.5 Performance related requirements from IEC 60945 . 14
4.6 Other requirements . 14
4.7 Long-range identification and tracking . 15
4.7.1 General . 15
4.7.2 Capabilities . 15
4.7.3 Functionality . 16
4.7.4 Communication system . 17
5 Technical characteristics . 17
5.1 Overview . 17
5.2 Environmental and electromagnetic compatibility requirement . 17
5.3 Radiated spurious emissions . 18
5.4 Interfaces . 18
5.5 Interfering signals . 19
6 Methods of testing and required test results . 19
6.1 Overview . 19
6.1.1 General . 19
6.1.2 Performance requirements . 19
6.1.3 Technical characteristics . 19
6.2 Tests of non-operational requirements . 19
6.3 Tests of operational requirements for ship earth stations . 19
6.3.1 Capabilities . 19
6.3.2 Ship station identity . 20
6.3.3 Distress alerting . 20
6.3.4 Position updating . 20
6.4 Tests of operational requirements for EGC receivers . 21
6.4.1 Capabilities . 21
6.4.2 General . 21
6.4.3 Position and area code updating . 21
6.4.4 Indication of receipt of priority message . 21
6.4.5 Indication of tuning and synchronisation . 21
6.4.6 Printing selection . 21
6.4.7 Printing device . 22
6.5 Tests of performance related requirements from IEC 60945 . 22
6.6 Tests of other requirements . 22
6.7 Long-range identification and tracking . 22
6.7.1 General . 22
6.7.2 Capabilities . 22
6.7.3 Functionality . 23
6.7.4 Communication system . 23
6.8 Tests of technical characteristics. 24
6.8.1 Inmarsat tests . 24
6.8.2 Tests for environmental and electromagnetic compatibility . 24
6.8.3 Interfaces . 24
6.8.4 Interfering signals . 24
Annex A (normative) Requirements relating to installation . 26
A.1 General . 26
A.2 Source of electrical energy. 26
A.3 Siting of antennas . 26
A.4 Long-range identification and tracking . 26
A.5 Requirements . 26
Annex B (normative) Radiated unwanted emissions. 27
B.1 Unwanted emissions 30 MHz to 1 000 MHz . 27
B.2 Unwanted emissions above 1 000 MHz . 27
B.3 Unwanted emissions within the bands with carrier-on . 28
B.4 Unwanted emissions within the bands with carrier-off . 29
Annex C (informative) Inmarsat RTP schedule of tests . 30
Bibliography . 34
List of comments . 35
Table 1 – Data to be transmitted from the shipborne equipment . 16
Table 2 – Environmental conditions . 17
Table B.1 – Limits of unwanted emissions up to 1 000 MHz . 27
Table B.2 – Limits of unwanted emissions above 1 000 MHz . 28
Table B.3 – Limits of unwanted emission within the operating band with carrier-on . 29
Table C.1 – Phase I Inmarsat-C schedule of tests . 30
Table C.2 – Phase I EGC receiver schedule of tests . 32
Table C.3 – Phase II schedule of tests . 33
– 4 – IEC 61097-4:2024 CMV © IEC 2024
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
GLOBAL MARITIME DISTRESS AND SAFETY SYSTEM (GMDSS) –
Part 4: Inmarsat-C ship earth station and
Inmarsat enhanced group call (EGC) equipment –
Operational and performance requirements,
methods of testing and required test results
FOREWORD
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This commented version (CMV) of the official standard IEC 61097-4:2024 edition
4.0 allows the user to identify the changes made to the previous IEC
61097-4:2012+AMD1:2016+AMD2:2019 CSV edition 3.2. Furthermore, comments from
IEC TC 80 experts are provided to explain the reasons of the most relevant changes,
or to clarify any part of the content.
A vertical bar appears in the margin wherever a change has been made. Additions are in
green text, deletions are in strikethrough red text. Experts' comments are identified by a
blue-background number. Mouse over a number to display a pop-up note with the
comment.
This publication contains the CMV and the official standard. The full list of comments is
available at the end of the CMV.
IEC 61097-4 has been prepared by IEC technical committee 80: Maritime navigation and
radiocommunication equipment and systems. It is an International Standard.
This fourth edition cancels and replaces the third edition published in 2012, Amendment 1:2016
and Amendment 2:2019. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) the addition of a technical requirement in 5.5 for operation in the presence of an interfering
signal, with associated test, resulting from new IMO performance standards given in
resolution MSC.513(105). 1
The text of this International Standard is based on the following documents:
Draft Report on voting
80/1102/FDIS 80/1113/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.
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 61097 series, published under the general title Global maritime
distress and safety system (GMDSS), 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, 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.
– 6 – IEC 61097-4:2024 CMV © IEC 2024
INTRODUCTION to Amendment 2
NOTE This amendment adds a requirement for an interface for alert management and removes the requirement to
produce a printed copy of received safety information providing there is an interface to other navigation display
equipment. This results from amendments to the performance standards for enhanced group call equipment agreed
by the International Maritime Organization in resolution MSC.431(98) in 2017. It can be noted that the technical
provisions for the interface for the transfer of received data to other navigation display equipment were included in
IEC 61097-4:2012/AMD1:2016.
GLOBAL MARITIME DISTRESS AND SAFETY SYSTEM (GMDSS) –
Part 4: Inmarsat-C ship earth station and
Inmarsat enhanced group call (EGC) equipment –
Operational and performance requirements,
methods of testing and required test results
1 Scope
This part of IEC 61097 specifies the performance requirements and methods of testing for
Inmarsat-C ship earth stations (SES) capable of transmitting and receiving direct-printing
communications, and for enhanced group call (EGC) receivers, for use in the GMDSS and for
use for long-range identification and tracking (LRIT). The available variants are:
Class 0: An EGC receiver, either stand-alone or an element of a GMDSS installation in
accordance with the Inmarsat design and installation guidelines (DIGs) for
GMDSS installations.
Class 1: A basic SES providing shore-to-ship and ship-to-shore message transfer only.
Class 2: As class 1 but with EGC as an alternative to shore-to-ship transfer using a shared
receiver.
Class 3: As class 1 but with EGC using an independent receiver.
th
NOTE 1 The 34 session of the IMO Sub-Committee on Radiocommunications decided that class 2 equipment
would be adequate to provide sufficient availability for the reception of maritime safety information for the GMDSS.
This document complies with IMO performance requirements stated in the normative
references, Inmarsat technical characteristics and test procedures, and IEC 60945 general
requirements except where modifications are explicitly stated in this document. Technical
characteristics essential to GMDSS and LRIT operation as defined by the IMO are identified.
All text of this document, whose wording is identical to that in IMO SOLAS Convention 1974 as
amended in 1988 and Resolutions A.807(19) MSC.513(105), MSC.263(84) and MSC.306(87) is
printed in italics and reference made to the Resolution/Recommendation and subclause
number.
This document covers equipment construction and testing. Matters relating to installation may
also can be found in the Inmarsat Maritime design and installation guidelines (see Bibliography).
Those to be found in IMO Resolutions A.807(19) MSC.513(105), MSC.263(84) and
MSC.306(87) are reproduced in Annex A.
Responsibility for type approval of Inmarsat-C and Inmarsat-EGC is vested in Inmarsat by IMO
Resolutions A.807(19) MSC.513(105) and MSC.306(87) (see 4.2.1). Therefore, this document
does not reproduce Inmarsat test procedures in full but refers to where they are given in
Inmarsat documentation cited in the normative references to this document (Annex C).
NOTE 2 For the purposes of this document the terms Inmarsat C, Inmarsat-C, Inmarsat Standard-C, Standard-C
refer to the same equipment.
– 8 – IEC 61097-4:2024 CMV © IEC 2024
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 60945:2002, Maritime navigation and radiocommunication equipment and systems –
General requirements – Methods of testing and required test results
IEC 61108 (all parts), Maritime navigation and radiocommunication equipment and systems –
Global navigation satellite systems (GNSS)
IEC 61162-1, Maritime navigation and radiocommunication equipment and systems – Digital
interfaces – Part 1: Single talker and multiple listeners
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, International Convention for the safety of life at sea (SOLAS),1974 as amended
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.807(19):1995, Performance Standards for INMARSAT-C ship earth stations
capable of transmitting and receiving direct-printing communications as amended by Resolution
MSC.68(68) Annex 4
IMO Resolution MSC.263(84):2008, Revised performance standards and functional
requirements for the long-range identification and tracking of ships.
IMO Resolution MSC.302(87):2010, Performance standards for bridge alert management
IMO Resolution MSC.306(87):2010, Revised performance standards for enhanced group call
(EGC) equipment as amended by resolution MSC.431(98):2017
IMO Resolution MSC.513(105), Performance standards for INMARSAT-C ship earth stations
capable of transmitting and receiving direct-printing communications
Inmarsat, Inmarsat C System definition manual (SDM) Volume 2 – Part 2, Application Note 2,
Position reporting service
Inmarsat, Inmarsat C System definition manual (SDM) Volume 2 – Part 2, Application Note 3,
Application developers guide to data reporting and polling
Inmarsat, Inmarsat C System definition manual (SDM) Volume 3 – Part 2, Chapter 2, Mobile
earth station technical requirements
Inmarsat, Inmarsat C System definition manual (SDM) Volume 3 – Part 2, Chapter 5, Ship earth
station technical requirements
Inmarsat, Inmarsat C System definition manual (SDM) Volume 3 – Part 2, Chapter 8, Technical
requirements for an EGC receiver
Inmarsat, Recommended test procedures (RTP) for the type approval of Inmarsat -C mobile
earth stations
Inmarsat, Inmarsat C System definition manual (SDM) Change Notice CN150, ATCt signals and
other adjacent interferers
3 Terms and definitions 2
No terms and definitions are listed in this document.
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
4 Performance requirements
4.1 Overview
Subclauses 4.2 through 4.4 of this document describe performance requirements directly
attributable to IMO Resolutions A.807(19) and MSC.306(87) as amended by MSC.431(98) and
MSC.513(105) as listed in the normative references. Subclause 4.5 is provided to highlight
those requirements of IMO Resolution A.694(17) which are not included in the normal Inmarsat
requirements for Inmarsat-C SES type approval. Subclause 4.6 describes other requirements
which are required to make the equipment suitable for GMDSS applications. Subclause 4.7
describes performance requirements attributable to IMO Resolution MSC.263(84) for long-
range identification and tracking.
4.2 Non-operational requirements
4.2.1 General
(A.807(19) A1.1/MSC.306(87) A1.1) The Inmarsat Standard-C ship earth station installation
capable of transmitting and receiving direct-printing communications, and (MSC.306(87) A1.1)
The enhanced group call equipment to be used in the GMDSS shall comply with the general
requirements set out in Assembly resolution A.694(17) as detailed in IEC 60945 and this
document. 3
(MSC.513(105) A1.1) The Inmarsat-C ship earth station installation provided to meet a
requirement for a ship earth station in SOLAS regulations IV/8.1.4, 9.1.3.3, 9.4.2, 10.1.1 or
10.1.4.3 shall comply with the general requirements set out in resolutions A.694(17). It should
be capable of transmitting and receiving automated telegraphy communications in compliance
with the relevant ITU-R recommendation on direct-printing telegraphy. In addition, the
Inmarsat-C ship earth station shall conform to the following minimum requirements.
(MSC.513(105) A1.2) The performance of any enhanced group call facility provided by the ship
earth station shall be in accordance with the performance standards for enhanced group call
equipment set out in resolution MSC.306(87) as amended by resolution MSC.431(98) and with
the following minimum performance requirements.
(A.807(19) A2/(MSC.513(105) A2.1)/MSC.306(87) 2) The ship earth station and the EGC
equipment shall be type-approved by Inmarsat and shall comply with the environmental
conditions and electromagnetic compatibility requirements specified in IEC 60945.
– 10 – IEC 61097-4:2024 CMV © IEC 2024
4.2.2 Warning of radiation hazard
.513(105) A4) In order to permit a warning of potential radiation hazards to be
(A.807(19)(MSC
displayed in appropriate locations, a label shall be attached to the radome indicating
2 2
the distances external to the radome at which radiation levels of 100 W/m , 25 W/m and
10 W/m exist. However, the distances which are within the radome need not be indicated.
NOTE Owing to the low transmitted power of Inmarsat-C transmitters (less than 16 dBW) and the omnidirectional
antenna used, this label is not normally required.
4.2.3 Power supply changeover
(See 6.2)
(A.807(19)(MSC.513(105) A5.2/MSC.306(87) A4.2) Changing from one source of supply to
another or any interruption of up to 60 s duration of the supply of electrical energy shall not
require the equipment to be manually re-initialized and shall not result in loss of received
messages stored in the memory.
4.2.4 Installation
Requirements for installation of the equipment are given in Annex A. 4
4.3 Operational requirements for ship earth stations
4.3.1 Capabilities
(See 6.3.1)
The equipment shall comply with regulations IV/8 through IV/10 of SOLAS 1974, as amended,
which prescribe the capabilities of Inmarsat ship earth stations to meet the GMDSS
requirements for ships in the various sea areas. The four capabilities are:
– (SOLAS IV/8.1.5.1/4, IV/9.1.3.3 and IV/10.1.4.3) means of initiating the transmission of
ship-to-shore distress alerts.
– (SOLAS IV/10.1.1.1) transmitting and receiving distress urgency and safety communications
using direct-printing telegraphy.
– (SOLAS IV/10.1.1.2) initiating and receiving distress priority calls.
– (SOLAS IV/9.3.2/IV/10.1.1.4 IV/9.4.2, IV/10.4.1) transmitting and receiving general
radiocommunications, using either radiotelephony or direct-printing telegraphy.
NOTE In the case of this equipment only direct-printing telegraphy applies. 5
4.3.2 Ship station identity
(See 6.3.2)
(A.807(19)(MSC.513(105) A3.1) No control external to the equipment shall be available for
alteration of the ship station identity.
4.3.3 Distress alerting
(See 6.3.3)
(A.807(19)(MSC.513(105) A3.2) It shall be possible to initiate and make distress calls from the
position from which the ship is normally navigated and from at least one other position
designated for distress alerting.
(A.807(19)(MSC.513(105) A3.3) A distress alert shall be activated only by means of a dedicated
distress button. This button shall not be any key of an ITU-T digital input panel or an ISO
keyboard provided on the equipment associated with the equipment and shall be physically
separated from functional buttons/keys used for normal operation. This button shall be a single
button for no other purpose than to initiate a distress alert. 6
(A.807(19)(MSC.513(105) A3.4) The dedicated distress button shall:
.1 be clearly identified, red in colour and marked "DISTRESS". Where a non-transparent
protective lid or cover is used, it shall also be marked "DISTRESS; and
.2 be protected against inadvertent operation. The required protection of the distress button
shall consist of a spring-loaded lid or cover permanently attached to the equipment by, for
example, hinges. It shall not be necessary for the user to remove additional seals or to break
the lid or cover in order to operate the distress button. The operation of the distress button
shall generate a visible and audible indication. The distress button shall be kept pressed for
at least three seconds. A flashing light and an intermittent acoustic signal shall start
immediately. After the three seconds, the transmission of the distress alert is initiated and
the indication shall become steady and the acoustic signal shall stop.
(A.807(19) A3.5)(MSC.513(105) A3.5) The distress alert initiation shall require at least two
independent actions. Lifting of the protective lid or cover is considered as the first action.
Pressing the distress button as specified above is considered as the second independent action.
(A.807(19)(MSC.513(105) A3.6) The equipment shall indicate the status of the distress alert
transmission.
(A.807(19)(MSC.513(105) A3.7) It shall be possible to interrupt and initiate distress messages
at any time. It shall be possible to interrupt repetitive transmissions of distress messages. Such
operation shall not interrupt the transmission of a distress alert or distress message in progress
but shall prevent repetitive transmissions of a distress message.
It shall be possible to select the content of, but not initiate a distress alert using the equipment
keyboard or other means, before depressing one of the dedicated buttons to initiate the distress
alert. It shall also be possible to activate an undesignated (see Note) distress alert by
depressing one of the buttons, at any time.
NOTE Undesignated – unspecified distress alert, i.e. the default setting. All other selectable alerts are "designated".
4.3.4 Position updating
(See 6.3.4)
(A.807(19) A3.8): Facilities shall be provided to automatically update the ship’s position and the
time at which the position was determined from a suitable electronic position-fixing aid which
may be an integral part of the equipment. For equipment which does not have an integral
position-fixing aid, such facilities shall include a suitable interface conforming to IEC 61162.
(MSC.513(105) A3.8) To enable updating of the position:
.1 the status of the position update shall be visible to the operator (e.g. offline, manual or
automatic);
.2 if position data is being updated automatically, a caution shall be raised if no update has
been performed for a period of 10 minutes. The caution shall be removed by receiving new
position data;
.3 if an integral electronic position-fixing aid is not provided, the equipment shall have an
interface conforming to the appropriate international standard;
.4 the equipment shall have facilities for manually entering the ship's position and the time of
the position fix;
– 12 – IEC 61097-4:2024 CMV © IEC 2024
.5 if the ship's manually-set position is older than four hours, a caution shall be raised. The
caution shall be removed by inputting or receiving new position data; and
.6 if the ship's position is older than 24 hours, the position is clearly identified with date and
time of the fix in UTC for distress alerting purposes. 7
The integral electronic position-fixing aid shall comply with the applicable requirements of the
IEC 61108 series.
As a minimum, the interface shall support the sentences GNS, RMC and ZDA described in
IEC 61162-1.
(A.807(19) A3.9): Provision shall also be made for manual entry of position information and of
the time at which the position was determined.
(A.807(19) A3.10): An alarm shall be activated when no position data is received from the
electronic position-fixing aid or, in the case of manual input, the position information is over 4
hours old. Any position information not updated for more than 24 hours shall be clearly
identified. See also 3.4.3.
NOTE Subclause 3.3.7, which is referenced in the Inmarsat-C SDM, is 4.3.3 in this edition of this document.
4.4 Operational requirements for EGC receivers
4.4.1 Capabilities
(See 6.4.1)
The equipment shall comply with regulations IV/7 and IV/10 of SOLAS 1974, as amended, which
prescribe the capabilities of EGC receivers to meet the GMDSS requirements for ships in the
various sea areas. The two capabilities are:
– (SOLAS IV/7.1.54) a radio facility for reception of maritime safety information by the
Inmarsat enhanced group calling system.
– (SOLAS IV/10.1.1.3) an Inmarsat ship earth station capable of maintaining watch for
shore-to-ship distress alerts, including those directed to specifically defined geographical
areas.
4.4.2 General
(See 6.4.2)
(MSC.306(87) A1.3 as amended by resolution MSC.431(98)) Alternatively to the requirement in
paragraph MSC.306(87) A1.2, the equipment need not provide means to produce a printed copy
of received information if it is installed in combination with an interface connecting it to
navigation equipment that is compliant with resolution MSC 252(83), as amended, on Revised
Performance standards for integrated navigation systems (INS). Provisions for interconnection
to a shipborne integrated radiocommunication system (IRCS) when used in the GMDSS
(resolution A.811(19)) shall also be included.
If no means are provided by the equipment to produce a printed copy of received information
then the manufacturer's documentation shall clearly describe that the equipment can only be
used when connected to equipment enabled for the display of enhanced group calls in
compliance with the applicable as described in IEC 61924-2 requirements.
NOTE The testing standard for compliance with INS (Resolution MSC 252(83)) is IEC 61924-2. The testing standard
for compliance with IRCS (Resolution A.811(19)) is IEC 62940.
(MSC.306(87) A1.4) The enhanced group call installation may be either separate or combined
with other installations. Elements of other installations, e.g. the antenna, low noise amplifier
and down converter of the ship earth system, may be shared for the reception of enhanced
group call messages.
4.4.3 Position and area code updating
(See 6.4.3)
(MSC.306(87) A3.1) The equipment shall provide a visual indication that the ship's position has
not been updated during the last 12 hours. It shall only be possible to reset this indication by
revalidating the ship's position. See also 4.3.4.
(MSC.306(87) A3.2) Means shall be provided to enter the ship's position and current and
planned NAVAREA/METAREA codes manually so that area group calls can be received. Means
shall also be provided to enter current and planned coastal warning service coverage areas and
different classes of messages. Optionally, the ship's position, as determined by the navigational
equipment may be entered automatically and the NAVAREA/METAREA code automatically
derived therefrom.
NOTE NAVAREAs and METAREAs are geographical sea areas established for the purpose of co-ordinating the
broadcast of navigational and meteorological safety information. The world is currently divided into 21 areas (I to
XXI). The boundaries are shown in the IMO International SafetyNET Manual.
4.4.4 Indication of receipt of priority message
(See 6.4.4)
(MSC.306(87) A3.3) Provision shall be made for a specific aural alarm and visual indication at
the position from which the ship is normally navigated to indicate receipt of a distress or urgency
priority EGC message. It shall not be possible to disable this alarm and it shall only be possible
to reset it manually and only from the position where the message is displayed or printed.
4.4.5 Indication of tuning and synchronisation
(See 6.4.5)
(MSC.306(87) A3.4) The equipment shall indicate when it is not correctly tuned or synchronized
to the enhanced group call carrier.
4.4.6 Printing selection
(See 6.4.6)
(MSC.306(87) A3.5) Any message shall be printed regardless of the character error rate of its
reception. The equipment shall print a low-line mark if a character is received corrupted.
(MSC.306(87) A3.6) Acceptance or rejection of service codes shall be under the operator's
control except that equipment shall always receive navigational and meteorological warnings
and forecasts, search and rescue information, and shore-to-ship distress alerts, which are
directed to a fixed or absolute geographical area in which the ship is operating.
NOTE The service codes (C ) are described in the IMO International SafetyNET Manual. They have similar
meanings as the subject indicator characters (B ) in the NAVTEX system described in the IMO NAVTEX Manual and
Recommendation ITU-R M.540.
(MSC.306(87) A3.7) Means shall be provided to prevent the reprinting of a message once it has
been received without error.
– 14 – IEC 61097-4:2024 CMV © IEC 2024
4.4.7 Printing device
(See 6.4.7)
(MSC.306(87) A3.8) The printing device shall be capable of printing at least the standard
International Alphabet Number 5 (IA5) character set. Other character sets are optionally used
according to ISO 2022 standards.
(MSC.306(87) A3.9) The printing device shall be able to print at least 40 characters per line.
(MSC.306(87) A3.10) The signal processor and printing device shall ensure that if a word
cannot be accommodated in full on one line, it shall be transferred to the next line. The printing
device shall automatically feed five lines after completing the printed messages.
(MSC.306(87) A3.11) A local audible alarm shall be sounded to give advanced warning of the
printing device "paper low" condition. It shall not be possible to confuse the sound of the "paper
low" alarm with that of the distress or urgency alarm caused by the reception of a distress or
urgency priority message.
4.5 Performance related requirements from IEC 60945
(See 6.5)
The equipment shall comply with those subclauses of IEC 60945 appropriate to its equipment
class. The subclauses of IEC 60945:2002 referenced below, amend or augment the
corresponding requirements of the Inmarsat-C SDM.
– 4.1 General
– 4.2 Design and operation
– 4.3 Power supply
– 4.4 Durability and resistance to environmental conditions (see 4.2)
– 4.5 Interference (see 4.2)
– 4.6 Safety precautions
– 4.7 Maintenance
– 4.8 Equipment manuals
– 4.9 Marking and identification
4.6 Other requirements
(See 6.6)
Message display facilities shall be suitable for displaying received distress-related messages.
It is recommended that the display facilities should comply with the corresponding requirements
for EGC receivers in 4.4.6 and 4.4.7.
Any programming material or software that forms part of the equipment and which is necessary
for meeting the GMDSS requirements shall be permanently installed in the equipment. Any
software needed to fulfil any distress and safety requirements of the GMDSS shall not be stored
on any medium which can be accessed, modified or corru
...
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