IEC 62320-2:2008

IEC 62320-2
Edition 1.0 2008-03
INTERNATIONAL
STANDARD
Maritime navigation and radiocommunication equipment and systems –
Automatic identification system (AIS) –
Part 2: AIS AtoN Stations – Operational and performance requirements,
methods of testing and required test results

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IEC 62320-2
Edition 1.0 2008-03
INTERNATIONAL
STANDARD
Maritime navigation and radiocommunication equipment and systems –
Automatic identification system (AIS) –
Part 2: AIS AtoN Stations – Operational and performance requirements,
methods of testing and required test results

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XD
ICS 47.020.70 ISBN 2-8318-9620-7

– 2 – 62320-2 © IEC:2008(E)
CONTENTS
FOREWORD.6

1 Scope.8
2 Normative references .8
3 Terms, definitions and abbreviations .9
3.1 Definitions .9
3.2 Abbreviations .9
4 Description .10
4.1 Types of AIS AtoN Stations .10
4.2 Type 1 AIS AtoN Station.11
4.2.1 Type 1 AIS AtoN Station characteristics .12
4.2.2 Capability .12
4.2.3 Type 1 AIS AtoN Station – Alternatives.12
4.3 Type 2 AIS AtoN Station.13
4.3.1 Type 2 AIS AtoN Station characteristics .14
4.3.2 Capability .14
4.3.3 Control receiver.14
4.3.4 Type 2 AIS AtoN Station – alternatives .14
4.4 Type 3 AIS AtoN Station.14
4.4.1 Type 3 AIS AtoN Station characteristics .15
4.4.2 Type 3 AIS AtoN Station capability .15
4.4.3 AIS receiver (AIS Rx) .15
4.4.4 Type 3 AIS AtoN Station – alternatives .15
4.5 Optional chaining of AIS AtoN Stations (Types 2 and 3) .16
5 Requirements for AIS AtoN Stations .17
5.1 Physical layer requirement .17
5.1.1 Transmitter requirements.17
5.1.2 Receiver requirements.19
5.1.3 Power consumption .20
5.1.4 Environmental requirements .20
5.2 Link layer requirements .20
5.2.1 AIS Messages .21
5.2.2 Synchronisation.21
5.2.3 VDL access schemes .22
5.2.4 Autonomous mode.24
5.2.5 Electronic position fix system.25
5.2.6 Built-in integrity test.26
5.3 Requirements for the configuration method .27
5.3.1 Alternative for Types 1, 2 and 3.27
5.4 Other requirements .28
5.4.1 Additional features.28
5.4.2 Manufacturer’s information .28
5.4.3 Marking and identification.29
6 Tests of AIS AtoN Stations – Method of measurement and required results.29
6.1 General .29
6.2 Test conditions.29

62320-2 © IEC:2008(E) – 3 –
6.2.1 Normal test conditions .29
6.2.2 Extreme test conditions .29
6.2.3 Standard test environment.29
6.2.4 Test signals .30
6.2.5 Arrangements for test signals applied to the receiver input .31
6.2.6 Encoder for receiver measurements .32
6.2.7 Waiver for receivers .32
6.2.8 Impedance.32
6.2.9 Artificial antenna (dummy load) .32
6.2.10 Facilities for access .32
6.2.11 Modes of operation of the transmitter .32
6.2.12 Measurement uncertainties.32
7 AIS AtoN Station tests .33
7.1 RF tests (transmitter and receiver) .33
7.1.1 TDMA transmitter .33
7.1.2 TDMA receivers (Types 2 and 3) .38
7.1.3 Conducted spurious emissions at the antenna .47
8 Functional tests .47
8.1 Tests for configuration method .47
8.1.1 Configure test Message 21 .48
8.1.2 Schedule mode A FATDMA Message 21 (single report, alternating
channel operation).48
8.1.3 Schedule mode B FATDMA Message 21 (dual report, dual channel
operation).49
8.1.4 Schedule mode C FATDMA Message 21 (Single report, single
channel operation).50
8.1.5 Schedule mode A RATDMA Message 21 (Type 3) (single report,
alternating channel operation) .50
8.1.6 Schedule mode B RATDMA Message 21 (Type 3) (dual report, dual
channel operation).51
8.1.7 Schedule mode C RATDMA Message 21 (Type 3) (single channel
operation).52
8.1.8 Addressed binary data Message 6 .52
8.1.9 Unscheduled transmission.53
8.1.10 Test Message 8 .53
8.1.11 AIS AtoN configuration Messages 12.54
8.1.12 AIS AtoN configuration Messages 14.54
8.2 Tests for synchronisation accuracy.54
8.2.1 Implemented synchronisation modes and synchronisation error.54
8.2.2 Synchronisation test without UTC (Types 2 and 3).55
8.3 Tests for EPFS.55
8.3.1 Position source.55
8.3.2 Invalid position .56
8.3.3 Off-position monitor .56
8.4 Additional messages .57
8.4.1 Receive addressed message (Types 2 and 3).57
8.5 Additional functionality .57
8.5.1 Test for configuration of the receiver turn-on times (Types 2 and 3).57
8.5.2 Test for configure proprietary AtoN control .58
8.5.3 Test for configuration of payload re-broadcast .59

– 4 – 62320-2 © IEC:2008(E)
8.5.4 Test for forced broadcast.59
8.5.5 Test for version information .60
8.5.6 Test for AFC – AtoN function ID capability.60
8.5.7 Test for VDL configuration using chaining (Types 2 and 3) .61
8.6 Test for BIIT .62
8.6.1 Purpose.62
8.6.2 Method of measurement .62
8.6.3 Required results .62
8.7 Transmitter shutdown procedure .62
8.7.1 Purpose.62
8.7.2 Method of measurement .62
8.7.3 Required results .62
8.8 Tests for power supply .63
8.8.1 Average power consumption.63
8.9 Environmental tests.63
8.10 Other tests .63
8.10.1 Quality assurance.63
8.10.2 Additional features.63
8.10.3 Manual .63
8.10.4 Marking and identification.64

Annex A (informative) Proposed additional IEC 61162 AIS AtoN Station sentences .65
Annex B (informative) AIS AtoN Station configuration structures.75
Annex C (normative) Message 21 – AtoN status bits.97

Bibliography.98

Figure 1 – Functional block diagram of a Type 1 AIS AtoN Station.11
Figure 2 – Functional block diagram of a Type 2 AIS AtoN Station.14
Figure 3 – Functional block diagram of a Type 3 AIS AtoN Station.15
Figure 4 – Power versus time mask .23
Figure 5 – Reporting modes for Message 21.25
Figure 6 – Block diagram of AIS AtoN test setup.30
Figure 7 – Format for repeating four-packet cluster.31
Figure 8 – Measurement arrangement .33
Figure 9 – Measurement arrangement .34
Figure 10 – Emission mask .35
Figure 11 – Measurement arrangement for modulation accuracy.36
Figure 12 – Power versus time mask .37
Figure 13 – Measurement arrangement.39
Figure 14 – Measurement arrangement.40
Figure 15 – Measurement arrangement.40
Figure 16 – Measurement arrangement with messages.41
Figure 17 – PER/BER or SINAD measuring equipment .43
Figure 18 – Measurement arrangement for inter-modulation .45
Figure 19 – Measurement arrangement for blocking or desensitisation .46

62320-2 © IEC:2008(E) – 5 –
Table 1 – Description of AIS AtoN Stations .10
Table 2 – Summary of optional Type 1 AIS AtoN Station messages .13
Table 3 – Summary of optional Type 3 AIS AtoN Station messages .16
Table 4 – Chaining of AIS AtoN Stations.17
Table 5 – Required parameter settings for an AIS AtoN Station .18
Table 6 – Required settings of physical layer constants .18
Table 7 – Modulation parameters of the physical layer of the AIS AtoN Station.18
Table 8 – Minimum required TDMA transmitter characteristics .19
Table 9 – Required receiver characteristics .19
Table 10 – Maximum allowed time error.22
Table 11 – Definitions of timing for Figure 4.23
Table 12 – AIS AtoN Station reaction to BIIT conditions.27
Table 13 – Standard sentences.28
Table 14 – Content of first two packets .31
Table 15 – Fixed PRS data derived from ITU-T O.153 .31
Table 16 – Maximum values of absolute measurement uncertainties.33
Table 17 – Peak frequency deviation versus time .37
Table 18 – Definition of timings for Figure 12.38
Table 19 – Frequencies for inter-modulation test .45
Table B.1 – Parameter setting in Message 25 for AIS AtoN Station applications .75
Table B.2 – Parameter setting in Message 6 for AIS AtoN Station applications .75
Table B.3 – Message 25 or 6 function identifier used for configuration and query via
the VDL .76

– 6 – 62320-2 © IEC:2008(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MARITIME NAVIGATION AND RADIOCOMMUNICATION
EQUIPMENT AND SYSTEMS –
AUTOMATIC IDENTIFICATION SYSTEM (AIS) –

Part 2: AIS AtoN Stations –
Operational and performance requirements,
methods of testing and required test results

FOREWORD
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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.
International Standard IEC 62320-2 has been prepared by IEC Technical Committee 80:
Maritime navigation and radiocommunication equipment and systems.
The text of this standard is based on the following documents:
FDIS Report on voting
80/507/FDIS 80/518/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

62320-2 © IEC:2008(E) – 7 –
A list of all parts of IEC 62320 series, under the general title: Maritime navigation and
radiocommunication equipment and systems – Automatic Identification System (AIS) can be
found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

– 8 – 62320-2 © IEC:2008(E)
MARITIME NAVIGATION AND RADIOCOMMUNICATION
EQUIPMENT AND SYSTEMS –
AUTOMATIC IDENTIFICATION SYSTEM (AIS) –

Part 2: AIS AtoN Stations –
Operational and performance requirements,
methods of testing and required test results

1 Scope
This part of IEC 62320 specifies the operational and performance requirements, methods of
testing and required test results for AIS AtoN Stations compatible with the performance
standards adopted by IMO Res. MSC.74(69), annex 3, Universal AIS. It incorporates the
technical characteristics of non-shipborne AIS AtoN equipment, included in Recommendation
ITU-R M.1371 and IALA Recommendation A-126. Where applicable, it also takes into account
the ITU Radio Regulations. This standard takes into account other associated IEC
International Standards and existing National Standards, as applicable.
This standard is applicable for Automatic Identification System (AIS) installations on Aids to
Navigation (AtoN).
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60945, Maritime navigation and radiocommunication equipment and systems – General
requirements – Methods of testing and required test results
IEC 61108-1, Maritime navigation and radiocommunication equipment and systems – Global
navigation satellite systems (GNSS) – Part 1: Global positioning system (GPS) – Receiver
equipment – Performance standards, methods of testing and required test results
IEC 61108-2, Maritime navigation and radiocommunication equipment and systems – Global
navigation satellite systems (GNSS) – Part 2: Global navigation satellite system (GLONASS)
– Receiver equipment – Performance standards, 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 results
IEC 61162-1, Maritime navigation and radiocommunication equipment and systems – Digital
interfaces – Part 1: Single talker and multiple listeners
IEC 62287-1, Maritime navigation and radiocommunication equipment and systems – Class B
shipborne equipment of the automatic identification system (AIS) – Part 1: Carrier-sense time
division multiple access (CSTDMA) techniques
ITU Radio Regulations, Appendix 18, Table of transmitting frequencies in the VHF maritime
mobile band
62320-2 © IEC:2008(E) – 9 –
ITU-R Recommendation M.1371, Technical characteristics for an automatic identification
system using time division multiple access in the VHF maritime mobile band
ITU-T Recommendation O.153, Basic parameters for the measurement of error performance
at bit rates below the primary rate
IALA Recommendation A-126, The Use of Automatic Identification System (AIS) in Marine
Aids to Navigation
3 Terms, definitions and abbreviations
For the purposes of this document, the following terms, definitions and abbreviations apply.
3.1 Definitions
3.1.1
Aids to Navigation
(AtoN)
device or system external to vessels that is designed and operated to enhance the safe and
efficient navigation of vessels and/or vessel traffic
3.1.2
Message 21
AtoN report transmitted on the VHF data link by an AIS station
3.1.3
Real AIS AtoN
AIS AtoN station which is physically located on the AtoN
3.1.4
Synthetic AIS AtoN
Message 21 transmitted from an AIS station located remotely from the AtoN
3.1.5
Virtual AIS AtoN
Message 21 transmitted from an AIS station for an AtoN which does not physically exist
3.2 Abbreviations
AES Advanced Encryption Standard
AIS Automatic Identification System
BIIT Built-in Integrity Tests
BT  Bandwidth Time Product
CSTDMA Carrier Sense Time Division Multiple Access
DGNSS Differential Global Navigation Satellite System
EPFS Electronic Position Fixing System
EUT Equipment Under Test
FATDMA Fixed Access Time Division Multiple Access
GNSS Global Navigation Satellite System
IMO International Maritime Organisation
MAC Medium Access Control
MMSI Maritime Mobile Service Identity
NRZI Non-Return to Zero Inverted

– 10 – 62320-2 © IEC:2008(E)
PER Packet Error Rate
PI Presentation Interface
RAIM Receiver Autonomous Integrity Monitoring
RATDMA Random Access Time Division Multiple Access
RF Radio Frequency
Rx Receive
SBAS Satellite-Based Augmentation System
SOTDMA Self Organizing Time Division Multiple Access
TDMA Time Division Multiple Access
Tx Transmit
UTC Universal Time Co-ordinated
VDL VHF Data Link
VSWR Voltage Standing Wave Ratio
NOTE Abbreviations related to IEC 61162 series are not included in the above list. For their meaning refer to that
International Standard.
4 Description
4.1 Types of AIS AtoN Stations
There are three types of AIS AtoN Stations as defined in Table 1. The AIS AtoN Stations may
optionally include additional capabilities as defined in the “Alternatives” column.
Table 1 – Description of AIS AtoN Stations
Type 1 AIS Type 2 AIS Type 3 AIS
Requirements Alternatives
AtoN Station AtoN Station AtoN Station
Two receiving
Receiver for
processes for
VDL receiver No receiver control
autonomous
functions only
mode
21 plus one or more of 6, 8,
12, 14, 25 and other
Transmitted
appropriate messages (Types
messages
1, 2 and 3)
plus 7, 13 (Type 3 only)
Access mode FATDMA and RATDMA (Type
FATDMA
for Message 21 3 only)
FATDMA (Types 1 and 2)
Access Mode
for messages
One or more of FATDMA,
other than 21,
RATDMA or CSTDMA (Type
if implemented
3)
Configuration /
Defined by the manufacturer
communication
with standard sentences
Defined by manufacturer
method
(Types 1, 2 and 3)
62320-2 © IEC:2008(E) – 11 –
Table 1 (continued)
Type 1 AIS Type 2 AIS Type 3 AIS
Requirements Alternatives
AtoN Station AtoN Station AtoN Station
The electrical and physical
characteristics shall be
Physical
defined by the manufacturer.
communication None
(Types 1, 2 and 3)
interface
As defined by the
Transmit power 12,5 W manufacturer (Types 1, 2 and
3)
Transmitter Single channel (Types 1, 2
Dual channel
capability and 3)
Synthetic and
No Yes (Types 1, 2 and 3)
Virtual AtoN
Positioning Surveyed position only (no
EPFS and surveyed position
device EPFS) (Types 1, 2 and 3)
UTC Direct, indirect or semaphore
Direct only
synchronisation (Type 3)
Shall not respond to assignment Messages 16
Assignment
and 23
Interrogation Shall not respond to interrogation Message 15

4.2 Type 1 AIS AtoN Station
Type 1 AIS AtoN Station has no receiver. It transmits on FATDMA slots given in its
configuration. Figure 1 shows the functional block diagram of a Type 1 AIS AtoN Station.

Type 1 AIS AtoN Station
EPFS
Controller
Configuration
AIS Tx
External interface
Timing and
sync device
Power
BIIT
supply
IEC  285/08
Figure 1 – Functional block diagram of a Type 1 AIS AtoN Station

– 12 – 62320-2 © IEC:2008(E)
4.2.1 Type 1 AIS AtoN Station characteristics
The characteristics of the Type 1 AIS AtoN Station are:
• transmits using FATDMA;
• no receive capability, therefore:
– cannot be configured via the VDL,
– cannot synchronise to other stations;
• configuration interface as defined by the manufacturer;
• 12,5 W transmitter power;
• dual channel transmission.
4.2.1.1 Controller
The controller composes Message 21 and ensures the correct operation of the AIS AtoN
Station on the VDL.
4.2.1.2 Timing and synchronisation device
This device provides the time and synchronisation for the controller.
4.2.1.3 Power supply
The power supply generates the internal voltages.
4.2.1.4 BIIT
The Built-in Integrity Tests (BIIT) shall provide integrity monitoring.
4.2.1.5 EPFS
Electronic Position Fixing System (EPFS) provides the current position of the AtoN.
4.2.1.6 Configuration
The interface used to configure the AIS AtoN Station.
4.2.2 Capability
Type 1 AIS AtoN Station is capable of transmitting Message 21 using FATDMA.
4.2.3 Type 1 AIS AtoN Station – Alternatives
4.2.3.1 Additional controller capability
In addition to Message 21, the controller shall compose optional output messages to the VDL
using FATDMA as described in Table 2.

62320-2 © IEC:2008(E) – 13 –
Table 2 – Summary of optional Type 1 AIS AtoN Station messages
Msg Message name Message description Application examples
ID
6 Binary addressed message Binary data for addressed Monitoring of AtoN lantern,
communication power supply, etc.
8 Binary broadcast message Binary data for broadcast Meteorological and
communication hydrological data
12 Addressed safety related Safety related data for Warn AtoN malfunctioning
message addressed communication
14 Broadcast safety related Safety related data for Warn AtoN malfunctioning
message broadcast communication
25 Single slot binary message Binary data for addressed or Status report
broadcast communication
NOTE The Type 1 AIS AtoN Station should not retransmit the addressed binary message (Messages 6 and 12).
The number of retries should be set to 0.
4.2.3.2 Configuration method
The Type 1 AIS AtoN Station may be configured using standard configuration sentences.
(IEC 61162-1 and as described in Annex A).
4.2.3.3 No EPFS
When a surveyed position is used, the EPFS may not be required.
4.2.3.4 TDMA transmitter (AIS Tx)
The TDMA transmitter may operate on a single channel.
4.2.3.5 External interface
The external interface(s) may be used for communication with external devices (for example
AtoN lantern, AtoN power supply, hydrological and meteorological instruments, etc.).
4.2.3.6 Synthetic and Virtual AtoN
The AIS AtoN Station may be capable of transmitting Message 21 for Synthetic and Virtual
AIS AtoN.
4.3 Type 2 AIS AtoN Station
Type 2 AIS AtoN Station transmits on FATDMA slots.
Type 2 AIS AtoN Station has a control receiver for messages containing configuration
sentences (see Annex B). Figure 2 shows the functional block diagram of a Type 2 AIS AtoN
Station.
– 14 – 62320-2 © IEC:2008(E)
Type 2 AIS AtoN Station
EPFS
AIS Tx
Controller Control Rx
Configuration
External interface
Timing and
sync device
Power
BIIT
supply
IEC  286/08
Figure 2 – Functional block diagram of a Type 2 AIS AtoN Station
4.3.1 Type 2 AIS AtoN Station characteristics
The characteristics of the Type 2 AIS AtoN Station are:
• transmits using FATDMA;
• limited receiver capability, therefore cannot maintain a slot map and cannot use RATDMA
access scheme;
• configuration interface as defined by the manufacturer;
• 12,5 W transmitter power;
• dual channel transmission.
4.3.2 Capability
A Type 2 AIS AtoN Station has the capabilities of a Type 1 AIS AtoN Station, with the addition
of a control receiver.
4.3.3 Control receiver
The Type 2 AIS AtoN Station shall have a receiver operating on an AIS channel for control
functions only.
4.3.4 Type 2 AIS AtoN Station – alternatives
The Type 2 AIS AtoN Station alternatives include all the Type 1 AIS AtoN Station alternatives.
4.4 Type 3 AIS AtoN Station
Type 3 AIS AtoN Station has AIS receive and transmit capabilities in accordance with
Recommendation ITU-R M.1371. Figure 3 shows the functional block diagram of a Type 3
AIS AtoN Station.
62320-2 © IEC:2008(E) – 15 –
Type 3 AIS AtoN Station
EPFS
AIS Tx
Controller
AIS Rx
Configuration
External interface
AIS Rx
Timing and
sync device
Power
supply
BIIT
IEC  287/08
Figure 3 – Functional block diagram of a Type 3 AIS AtoN Station
4.4.1 Type 3 AIS AtoN Station characteristics
The characteristics of the Type 3 AIS AtoN Station are:
• receiving capability on both AIS channels,
• transmits using FATDMA.
4.4.2 Type 3 AIS AtoN Station capability
A Type 3 AIS AtoN Station has the capability of a Type 1 AIS AtoN Station, with the addition
of AIS receivers.
4.4.3 AIS receiver (AIS Rx)
The Type 3 AIS AtoN Station shall have two AIS (TDMA) receiving processes to produce and
maintain a slot map for autonomous interaction with the VDL.
4.4.4 Type 3 AIS AtoN Station – alternatives
The Type 3 AIS AtoN Station alternatives include all the Type 1 and Type 2 AIS AtoN Station
alternatives, with the additions of 4.4.4.1, 4.4.4.2 and 4.4.4.3.
4.4.4.1 Additional controller capability
In addition to Message 21, the controller composes optional output messages to the VDL as
described in Table 3.
– 16 – 62320-2 © IEC:2008(E)
Table 3 – Summary of optional Type 3 AIS AtoN Station messages
Msg Message name Message description Application examples
ID
6 Binary addressed message Binary data for addressed Monitoring of AtoN
communication equipment
7 Binary acknowledge message Acknowledge of addressed
binary message
8 Binary broadcast message Binary data for broadcast Meteorological and
communication hydrological data
12 Addressed safety related Safety related data for Warn AtoN malfunctioning
message addressed communication
13 Safety related acknowledge Acknowledge of addressed
message safety related message
14 Broadcast safety related Safety related data for Warn AtoN malfunctioning
message broadcast communication
25 Single slot binary message Binary data for addressed or Status report
broadcast communication
4.4.4.2 Access mode
4.4.4.2.1 Message 21
Transmits using FATDMA or RATDMA.
4.4.4.2.2 Messages other than Message 21
For each message other than Message 21, the Type 3 AIS AtoN Station may use FATDMA,
CSTDMA or RATDMA.
4.4.4.3 Indirect and semaphore synchronisation
A Type 3 AIS AtoN Station may optionally synchronise to other AIS Stations using UTC
indirect synchronisation or other AIS Stations acting as semaphore.
4.5 Optional chaining of AIS AtoN Stations (Types 2 and 3)
A chain of AIS AtoN Stations allows for communication from an AIS Base Station to AIS AtoN
Stations that are remotely located and unable to communicate directly with the Base Station.
Messages are passed from station to station until the intended recipient is reached.
The concept requires an AIS AtoN Station to have knowledge of other AIS AtoN Stations in
the chain, namely its parent and all children below it in the chain. A “parent station” is a
station that is in the direction of the Base Station. A “child station” is a station that is directed
away from a Base Station. In order to prevent unnecessary retransmission of the messages,
each AIS AtoN Station in a chain may have only one parent, but may have multiple children
(this includes all Synthetic and Virtual AIS AtoN).
Messages 6 and 25 are used for the transfer of the encrypted binary field. It is assumed that
the whole chain has the same encryption key. The source ID and “MMSI of AtoN” fields of
Message 6 or 25 are used to determine whether the received message is from a parent or
child station. If not, then the received message is ignored.
The encrypted binary data field is decrypted to obtain the function ID and “MMSI of AtoN”. If
the source ID of the message is set to the parent station ID and the function ID is a
configuration, query request or function, and the MMSI of the AIS AtoN Station is in the chain,
then the message shall be retransmitted, with the source ID set to own MMSI. If the source ID

62320-2 © IEC:2008(E) – 17 –
of the message is set to the station’s MMSI and the function ID is a query response, then the
message shall be retransmitted, with the ”MMSI of AtoN” set to the parent MMSI. Any other
combination of known or unknown MMSI is ignored (see Table 4).
The chaining algorithm may be ignored by setting the source ID field to “@@@@@”. The AIS
AtoN Station shall attempt to decrypt the binary data field, and check that it is the intended
recipient of the message before processing the message any further.
Table 4 – Chaining of AIS AtoN Stations
Source ID Application MMSI of AtoN Action by Own Station
Identifier from Encrypted
Binary Field
Parent Function ID = Responding AIS In all cases, if function ID = query response, then ignore
query response AtoN Station
Parent Function ID = Intended If function ID = configuration or query request or functional,
configuration or recipient then verify intended recipient is in the chain and re-
query request or transmit message with source ID set to own station MMSI
functional
Parent Function ID = Own station If function ID = configuration or query request or functional,
configuration or then verify that the intended recipient is own station and
query request or then process
functional
Responding Function ID = Own station In all cases, if function ID = query response, then re-
child query response transmit the message with ”MMSI of AtoN” set to own
station’s parent MMSI
Child Function ID = Intended In all cases, if Function ID = configuration or query request
configuration or recipient or functional, then ignore
query request or
functional
“@@@@@” Own station Process
“@@@@@” Other Ignore
Other Ignore Ignore
5 Requirements for AIS AtoN Stations
5.1 Physical layer requirement
5.1.1 Transmitter requirements
5.1.1.1 Channel
The AIS AtoN Station shall operate on dual channels, Channel 1 and Channel 2, in the VHF
Maritime Mobile Service band, using 25 kHz bandwidth, according to the ITU Radio
Regulations, Appendix 18.
5.1.1.2 Channel alternatives
The Type 1, Type 2 and Type 3 AIS AtoN Stations may transmit on a single channel only,
either Channel 1 or Channel 2.
5.1.1.3 Parameter settings
Table 5 and Table 7 are derived from Recommendation ITU-R M.1371 and give the
parameters required for an AIS AtoN Station. For the meaning of the symbols and additional
information (footnotes) refer to the appropriate section of Recommendation ITU-R M.1371.

– 18 – 62320-2 © IEC:2008(E)
Table 5 – Required parameter settings for an AIS AtoN Station
Symbol Parameter name Setting (FATDMA, Setting (CSTDMA)
RATDMA)
PH.RFR Regional frequencies Two channels between 156,025 MHz and 162,025 MHz
PH.AIS1 Channel 1 (default Channel 1) 161,975 MHz
PH.AIS2 Channel 2 (default Channel 2) 162,025 MHz
PH.BR Bit ra
...