Attachment_3_EAIS_IDD_v5_5_2_(3Apr18).pdf

Distribution Statement A: Approved for Public Release. Distribution is Unlimited.

Encrypted Automatic Identification System (EAIS) Interface Design Description (IDD) v 5.5.2

3 April 2018

Submitted by:

M. V. Kempe, LCDR Date

Navigation Core Technology Branch (CT-N) Engineering Cell Chief

Endorsed by:

M. W. Parsons, GS-13, USCG Date

System Engineer

Approved by:

B. F. Goff, CDR Date

Branch Chief

EAIS Interface Design Description Version 5.5.2 3 Apr 2018

Record of Changes

Change# Date Title or Brief Description Entered By

Original 04 Jun 14 C3CEN EAIS IDD v1.0 LT A.R. Reckley v2 27 Oct 14

Added IEC 61993-2 to references;

clarified para 3.1.6.1; added para 3.3.1.2;

added para 3.3.4.1.1; added para 5.3.1;

added SOTDMA to msg 26 Comm State in Annex 2 para 2.1; deleted “Text” from para 3.23.1.3

M. W. Parsons v3 N/A Version not released v4 N/A Version not released v5 25 Jul 16 Added FIDs 9-37 and complied with revision to USCG EAIS VDL Standard. LCDR M. Kempe

V5.1 7 Mar 17 Removed FID 10, fixed numerous errata with bit widths. Restored ITU1371 conformance for OTAR messages.

LCDR M. Kempe

V5.2 28 Mar 17 Fixed errata for MMSI use on FID 17 & 18.

Added message ack/retry rules. LCDR M. Kempe

V 5.3 20 Apr 17

Added details regarding AES methods.

Increased OTAR ASM’s to AIS slot limits.

Added KMM preamble, made all multi-slot messages structured. Included revised

NMEA 2000 PGN.

LCDR M. Kempe

V 5.4 2 May 17 Added Message 26 variants of SITREP and Static Data ASM, removed Message 25 variants.

LCDR M. Kempe

V 5.4 8 May 17 Corrected table of contents. LCDR M. Kempe

V 5.5 29 Nov 17

Corrected broadcast/addressed error on FID 38, 39. Added additional encryption notes. Corrected typo in PGN description.

Added Plaintext CRC, corrected FID assignment & area notice reference.

Added additional TOI periodicity

LCDR M. Kempe

V 5.5.1 11 Dec 17 Corrected typos. Clarified CRC and encryption boundaries.

LCDR M. Kempe

V 5.5.2 2 Apr 18 Clarified SOTDMA/ITDMA behavior, incorporated revised NMEA 2000 PGN.

LCDR M. Kempe

Table of Contents

1. Scope 1

2. References 2

3. Interface Description 3

Annex 1 – Technical VDL Information 4

Annex 2 – Application Specific Messages 8

Annex 3 – NMEA-0183 Support 99

Annex 4 – NMEA 2000 Support 101

Annex 5 – OTAR Requirements 110

Appendix 1 – Asset Type List 111

Appendix 2 – Search Definitions 114

Appendix 3 – Vessel Target Descriptions 121

Appendix 4 – OTAR Primitive Field Descriptions 123

Appendix 5 – Key Name Codes 124

EAIS IDD v5.5.1 Page 1

1. Scope

1.1. Identification

This Interface Design Description (IDD) specifies the interface characteristics of an Encrypted Automatic Identification System (EAIS) which meets Coast Guard requirements for Sensitive But Unclassified (SBU) Tactical Information Exchange and Display System (STEDS) and Blue Force Tracking (BFT).

1.2. Policy

This IDD meets COMDT (CG-761) operational requirements for STEDS and BFT.

1.3. System Overview

Coast Guard EAIS consists of an EAIS Transponder and an EAIS Presentation Interface (PI).

The EAIS Presentation Interface is typically an Electronic Chart System (ECS) or Electronic Chart Display Information System (ECDIS). In order to comply with the provisions of recommendation 1371-5 from the International Telecommunications Union, the sending PI generates Application Specific Messages (ASMs), which are passed directly without modification to the receiving PI for decryption and interpretation.

EAIS IDD v5.5.1 Page 2

2. References

Name/Number Version Date Title Nav Requirements Mar 2012 eNav Coast Guard Requirements v1.2

COMD (G-OCC-1)

LTR 2000

Jul 2005 Operational Requirements for SBU Tactical Information Exchange and Display System

(STEDS)

IEC 61174 Mar 2010 Specifications for Chart Content and Display Aspects of ECDIS, Edition 6.0

IEC 61993-2 Ed.2 Oct 2012 Class A shipborne equipment of the AIS - Operational and performance requirements

NMEA 0183 Jun 2012 Standard for Interfacing Marine Electronic Devices Version 4.10)

NMEA 2000 Mar 2016 Edition 3.101 Includes the following documents:

Main Document Version 2.000 Appendix A & B Version 2.100 (Parameter Group Definitions) Feb 2015 Appendix C Version 1.201 (Certification Criteria and Test Methods) Appendix D Version 2.100 (Application Notes) Appendix E ISO 11783-3 Data Link Layer Appendix F ISO 11783-5:2001 Network Management Appendix G ISO 11898 Controller Area Network Appendix H Version 1.000 (3rd Party Applications w/ NMEA 2000 Certified 3rd Party Gateway)

ITU-R M. 1371-5 Feb 2014 "Technical Characteristics for a Universal Shipborne Automatic Identification System Using Time Division Multiple Access"

ITU-R M.1084 Mar 2012 Interim solutions for improved efficiency in the use of the band 156-174 MHz by stations in the maritime mobile service

TIA-102.AACA-A Sep 2014 Project25 Digital Radio Over-The-Air-Rekeying (OTAR) Messages and Procedures

FIPS 140-2 May 2001 Security Requirements For Cryptographic Modules

EAIS IDD v5.5.1 Page 3

3. Interface Description

Annex 1 contains a technical description of the EAIS VDL when the AIS messages 8, 25 & 26 are used to transport the Sensitive But Unclassified (SBU) Tactical Information Exchange and Display System (STEDS) Application Specific Messages (ASM).

Annex 1 is based on International Telecommunication Union (lTU) standard ITU-R M.1371-5.

Annex 2 contains the listing of the ASMs used with this IDD.

Annex 3 contains a technical description of NMEA-0183 messages required to integrate an

EAIS capable AIS Transponder with an EAIS capable Presentation Interface (PI) and vice versa. Proprietary NMEA-0183 messages are required for complete integration.

Please see the NMEA-0183 standard for NMEA-0183 messages.

Annex 4 contains a technical description of proprietary NMEA-2000/NMEA OneNet PGN messages required to integrate an EAIS capable AIS transponder with an EAIS capable Presentation Interface (PI) and vice versa. Standard NMEA-2000/NMEA OneNet PGN messages are used in the integration, but are not defined by this document. Please see the NMEA-2000/NMEA OneNet PGN standard for NMEA- 2000/NMEA OneNet PGN messages.

Annex 5 contains OTAR requirements for the PI.

Appendix 1 contains a listing of the asset types used with this IDD.

Appendix 2 contains an explanation of Search Pattern Definitions, along with nomenclature and designations.

Appendix 3 contains a listing of vessel, aircraft and submarine Target Descriptions for use with

Target of Interest ASMs.

Appendix 4 contains an explanation of the OTAR Primitive Field Descriptions Appendix 5 contains a listing of Key Name Codes used with OTAR Key names.

EAIS IDD v5.5.1 Page 4

ANNEX 1

1. EAIS Transponder Modes of Operation

Receive-Only

When in this mode of operation the AIS transponder does not transmit any AIS messages, regardless of any commands received from base stations or interrogations from other vessels. The transponder operates exclusively on normal AIS frequencies and does not respond to base station or digital selective calling commands to change frequencies. The transponder receives AIS messages per ITU-R 1371-5, including ASMs and sends them without modification to the Presentation Interface using standard NMEA messages, but transmits nothing (maintaining radio silence). As part of the transition to this mode, the transponder must release all existing VDL reservations.

Normal Transmit

When in this mode of operation, the AIS transponder defaults to operate in Autonomous & Continuous mode, unless switched to Assigned or Polled mode. The transponder transmits and receives AIS messages per ITU-R 1371-5, including all Application Specific Messages from the Presentation Interface or other STEDS entities. The transponder shall conform to the EAIS VHF Data Link Slot Reservation Behavior described below.

Restricted Transmit

When in this mode of operation, the AIS transponder only transmits ASMs of message type 8, 25 or 26, and transmits no other AIS messages. Regardless of the requests to send from the PI or other connected systems, the transponder only transmits ASMs of message type 8, 25 or 26 on the VDL. The transponder shall place no ASMs of message type 6 on the VDL. The transponder shall neither generate nor transmit on the VDL any AIS messages that normally originate within the transponder. The transponder shall operate exclusively on normal AIS frequencies and shall not respond to base station or digital selective calling commands to change frequencies. The transponder shall disregard interrogation (polled) messages. The transponder continues to receive AIS messages per ITU-R 1371, including ASMs and sends them without modification to the Presentation Interface using standard NMEA messages. The transponder shall conform to the EAIS VHF Data Link Slot Reservation Behavior described below.

2. EAIS VHF Data Link Slot Reservation Behavior

The DAC 366 ASMs with FID 4 (TOI - 15s), FID 5 (TOI – 60s), FID 6 (TOI – 180s), FID 10 (SITREP) and FID 11 (Static Data Report) are periodic messages that require scheduled transmission, and are all “Scheduled ASMs”. The PI shall generate the message data and communicate the NMEA requests to send to the transponder for all Scheduled ASMs at triple the VDL transmit rate. The transponder shall retain and transmit only the most recent PI request to send for each Scheduled ASM. Vessel PI’s shall permit the designation of one Scheduled TOI at each periodicity: DAC 366 with FID 4 (TOI - 15s), FID 5 (TOI – 60s), or FID 6 (TOI – 180s).

Upon receipt of a request to send a DAC 366 ASM with FID 4 (TOI - 15s) and/or FID 10 (SITREP) from the PI, the transponder shall conform to ITU-R 1371-5 by using SOTDMA for slot reservations. The transponder shall only maintain a single VDL SOTDMA reservation, and shall conform to the VDL transmit rate(s) articulated in the usage notes in Annex 2 of this IDD. The transponder shall consider the STEDS SOTDMA reservation requirement for a particular FID released after the PI fails to deliver two anticipated requests to send during the VDL transmit period preceding the reserved slot. The transponder shall transmit the most recent PI request to send for a particular FID with the appropriate communications state data to alter or release the VDL reservation.

EAIS IDD v5.5.1 Page 5

Upon receipt of a PI request to send a DAC 366 ASM with FID 5 (TOI – 60s), FID 6 (TOI – 180s) or FID 11 (Static Data Report), the transponder shall conform to ITU-R 1371-5 by using ITDMA for slot reservation. The transponder shall manage the ITDMA reservation for each FID independently of other reservations, and will conform to the VDL transmit rate articulated in the associated usage notes in Annex 2 of this IDD. The transponder shall consider the STEDS ITDMA reservation requirement for a particular FID released after the PI fails to deliver two anticipated requests to send during the VDL transmit period preceding the reserved slot. The transponder shall transmit the most recent PI request to send during the reserved slot, but will not schedule the next slot for that FID.

The transponder shall conform to ITU-R 1371-5 by using RATDMA for all other STEDS requests to send.

EAIS IDD v5.5.1 Page 6

3. CRC Checksum Computation

When computing the 16-bit CRC checksum for the encrypted ASMs, this VDL utilizes the “reflected table driven” implementation, as described in RFC 1662 (Std 51), found at http://www.armware.dk/RFC/rfc/rfc1662.html. RFC 1662 describes the standards for High-level Data Control Link (HDCL). Appendix C.2 of that document lists the code to implement the “reflected table driven” algorithm.

The RFC 1662 code implements the 16-bit CRC as specified below.

• Width: 16 bits

• Polynomial: 1021

• Initial CRC value (seed): FFFF

• Input bytes (8 bits) are processed with bit 0 being treated as the most significant bit (MOB) and bit 7 being treated as the least significant bit

• Final CRC is XORed with: FFFF

• Output CRC (16 bits) is reflected.

• The lower eight bits of the CRC are swapped with the higher eight bits of the CRC

FID 9: Plaintext CRC is applied to payload prior to encryption using all bits from the [Function Identifier] field to [Encryption Bit Padding] field, inclusive. This will be a multiple of 128-bits minus 16 bits.

FID 4, 5, 6, 7, 8, 10, 11, 14, 15, 23, 25, 28: Plaintext CRC is applied to payload prior to encryption using all bits from the [Version] field to [Encryption Bit Padding] field, inclusive. This will be a multiple of 128-bits minus 16 bits.

FID 4, 5, 6, 7, 8, 10, 11, 14, 15, 23, 25, 28: Transmission CRC is applied using all the bits from the DAC field to [Plaintext CRC], inclusive, after the payload has been encrypted. This will be a multiple of 128 plus 16 bits. FID 9 does not use a Transmission CRC.

FID 36, 37, 38, 39, 40, 41, 42, 43, 44, 46, 47, 48, 49, 50, 51, 52: Transmission CRC is applied using all the bits from the DAC field to [Encryption Bit Padding], inclusive, after the payload has been encrypted.

This will be a multiple of 128 bits.

FID 45: Does not use a Plaintext or Transmission CRC.

http://www.armware.dk/RFC/rfc/rfc1662.html

EAIS IDD v5.5.1 Page 7

4. AES Encryption

All encryption modules used to encrypt and decrypt STEDS ASM’s must be FIPS 140-2 certified.

STEDS operational ASMs are encrypted using the AES Electronic Code Book (ECB) mode with a key length of 128 bits for compactness. STEDS Payload encryption always uses a null initialization vector and does not use a salt. The boundaries of the encrypted payload vary by FID:

FID 9: All bits from the [Function Identifier] field through the [Plaintext Checksum] field inclusive are encrypted using ECB mode. This will be 128 bits.

FID 4, 5, 6, 7, 8, 10, 11, 14, 15, 23, 25, 28: All bits from the [Version] field through the [Plaintext Checksum] field, inclusive are encrypted using ECB mode. This will be multiples of 128-bits.

OTAR Payload ASMs are encrypted using the AES Output Feed Back (OFB) mode with a key length of 128 bits to comply with less compact, but more stringent TIA Project 25 OTAR requirements.

FID 36, 37, 38, 39, 40, 41, 42, 43, 44, 46, 47, 48, 49, 50, 51, 52: All bits from the [OTAR Message ID] field through the [Encryption Bit Padding] field inclusive are encrypted using the OFB mode. This will be multiples of 128-bits.

The 112-bit KMM preamble governs the preparation for the OFB decryption operation. For example, the KMM preamble for FID 45 specifies that it is unencrypted.

Per TIA Project 25 OTAR requirements, the key wrap algorithm separately encrypts keys using the AES- ECB mode, prior to encryption for transport.

For clarity – In addition to the above, the AES Cipher Block Chaining (CBC) mode is used to add an additional level of protection against "reflection" attacks by separately encrypting the Message Authentication Code (MAC) data field of OTAR messages FID 36, 37, 38, 39, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51 and 52 prior to encryption of the entire payload. This OTAR Message authentication code, is of key length/2, and is calculated per paragraph 13.5.2 of TIA 102.AACA-A, September 2014. FID 40 has no MAC.

In order to conform to ITU-R 1371-5 and NMEA standards, only applications define the binary data of AIS application specific messages. This removes the AIS transponder from any data definition for binary messages 8, 25, or 26. Consequently, the PI shall do all STEDS ASM message creation, encryption, decryption and interpretation. For additional situational awareness, all PIs on operational platforms with non-STEDS capable radars (standalone IMO navigation or C2 tactical radars) shall have an option to share decrypted STEDS target data. In these cases, the PI shall decrypt all received FID 10 (SITREP) and FID 11 (Static Vessel Data) messages, convert to standard VDM-style messages and output using NMEA or other transport methods. This allows the non-STEDS capable radars to display blue force tracks as normal AIS targets.

EAIS IDD v5.5.1 Page 8

ANNEX 2

Legend: In the message format tables in this chapter, red shading indicates the encrypted portions of the ASM, olive indicates message data governed by the Project25 OTAR guidance, and lavender shading indicates optional message data for various OTAR fields.

2.1 Target of Interest – 15s

DAC: 366 FI: 4 (Encrypted)

Published: 14 Jul 2017 Version: 1

Summary of changes:

Version 1:

This is an RTCM compliant update of the FID 1 message listed in the Oct 2014 EAIS IDD. It also replaces the DAC 366 FID 58 message from the same document.

2.1.1 Introduction

The Target of Interest message reports vessel or aircraft contacts with 15 sec VDL periodicity.

2.1.2 Usage Notes

• The Message 26 TOI Message format provides for both a broadcast and addressed TOI message variation. Addressing, when required, shall be performed using the Destination Indicator and Destination ID fields inherent to the Message 26 structure.

• The transponder shall transmit this report on the VDL every 15 seconds. The PI generates and communicates the NMEA request to send at triple the VDL transmit rate - every 5 sec.

The PI shall not retransmit if a FID 9 (Ack) is not received. Vessel PIs shall designate at most one TOI using this FID, and shall only permit designation of Automatic Radar Plotting Aid (ARPA), Mini ARPA (MARPA) or AIS targets. See Annex 1 for more details.

• Cancelling a TOI locally results in the PI setting the “Status” field to zero for the next nine messages, and then halting message generation. This will result in the transmission of three cancellation messages on the VDL, 15 seconds apart. Remote units receiving a TOI will apply Lost Target/Auto Drop processing rules to remove the TOI designation from a target.

2.1.3 Addressed Encrypted Message Format

Target of Interest (Message 26, Addressed)

Parameter # of Bits Description

St an da rd

M es sa ge

H ea de r Message ID 6 Identifier for Message 26; always 26.

Repeat Indicator 2 Indicates how many times a message has been repeated. 0 – 3; 0 = default; 3 = do not repeat any more. Set to zero (default).

Source MMSI 30 MMSI number of source station. Varies according to the transmitter ID.

Destination Indicator 1 0 = broadcast (no Destination ID field) 1 = Addressed (30 bit Destination ID field). Set to 1 (addressed).

Binary Data Flag 1 0 = unstructured binary data (no Application Identifier bits used) 1 = binary data coded as defined by the 16-bit AI. Set to 1 (structured).

Destination ID 30 MMSI number of destination station.

Spare 2 Not used, Set to zero.

EAIS IDD v5.5.1 Page 9

Designated Area Code 10 Designated area code (DAC). Set to 366.

Function Identifier 6 Function identifier. Set to 4.

En cr yp te d

Pa ylo ad

Version 3 Sequential number used to indicate the message version in steps of 1.

0 = test message = default; 1 – 7 = message version. Set to one.

Message Linkage ID 10 A source-specific random number, unique across recent binary messages with Message Linkage ID. Used to connect additional information regarding this TOI with another ASM. The Message Linkage ID and source MMSI uniquely identify the TOI. 1 – 1023; 0 = not available.

Target Acquisition Source 3

Type of Target.

0 = unknown = default; 1 = AIS, 2 = Radar, 3 = visual sighting; 4 = reported; 5 = other electronic surveillance, i.e. DSC, ECDIS, etc.; 6 -7 = reserved.

Target ID 30 MMSI if type is Target Acquisition source=1 (AIS), Sender generated ID otherwise

TOI Status 3 Designator for TOI Status. 0 = cancel; 1 = active; 2 = being followed; 3 = being boarded; 4 = request to cancel, 5 = request to update, 6 = reserved, 7 = reserved.

Target Type 3 Type of Target 0 = vessel = default; 1 = aircraft; 2 = submersible; 3-7 = reserved.

Target Description and Cargo 8 Description of target type and cargo, see Appendix 3.

Interest 8 Code to indicate what interest in vessel is. To be defined. Could be used as an 8-bit binary matrix, similar to ATON Status bits. TBD.

Ti m e o f T

OI

R ep or t

UTC Hour 5 UTC Hour of TOI report.

0 – 23; 24 = UTC hour not available = default; 25 - 31 = reserved.

UTC Min 6 UTC Minute of TOI report.

0 – 59; 60 = UTC minute not available = default; 61 - 63 (reserved for future use).

UTC Sec 6 UTC Second of TOI report.

0 – 59; 60 = UTC second not available = default; 61 - 63 (reserved).

Longitude 28 Longitude in 1/10,000 min (+/-180 degrees, East = positive, West = negative - 2’s complement). 181 degrees = not available = default.

Latitude 27 Latitude in 1/10,000 min (+/-180 degrees, East = positive, West = negative - 2’s complement). 91 degrees = not available = default.

SOG 10

Speed over ground. Scale dependent on value of Target Type flag.

Aircraft: 0 – 1000 kts (1 kt increments); 1001 = 1001 kts or higher; 1002 = not available = default; 1003 – 1023 = reserved.

Vessel or submersible: 0 – 100.0 kts (0.1 kt increments); 1001 = 100.1 kts or higher; 1002 = not available = default; 1003 – 1023 = reserved.

COG 12 Course over ground in 1/10 degree steps.

0 - 359.9 degrees; 3600 = not available = default; 3601 - 4095 = reserved.

Encryption Bit Padding 78 Sufficient spare bits to ensure that the binary data is a multiple of 128 bits for block encryption (256). Set to zero.

Plaintext Checksum 16 16-bit CRC calculated as per EAIS Specification

Transmission Checksum 16 16-bit CRC calculated as per EAIS Specification

EAIS IDD v5.5.1 Page 10

Fo ot er

Spare 4 Four extra bits to ensure the message ends on a byte boundary. Set to zero.

Communications State

Selector 1 0 = SOTDMA communication state follows 1 = ITDMA communication state follows

Communications State 19 SOTDMA communication state (see ITU 1371-5 § 3.3.7.2.2, Annex 2), if communication state selector flag is set to 0, or ITDMA communication state (§ 3.3.7.3.2, Annex 2), if communication state selector flag is set to 1.

Total bits 384 2 Slot Binary Message

2.1.4 Broadcast Encrypted Message Format

Target of Interest (Message 26, Broadcast)

Parameter # of Bits Description

St an da rd

M es sa ge

H ea de r

Message ID 6 Identifier for Message 26; always 26.

Repeat Indicator 2 Indicates how many times a message has been repeated. 0 – 3; 0 = default; 3 = do not repeat any more. Set to zero (default).

Source MMSI 30 MMSI number of source station. Varies according to the transmitter ID.

Destination Indicator 1 0 = broadcast (no Destination ID field) 1 = Addressed (30 bit Destination ID field). Set to zero (broadcast).

Binary Data Flag 1 0 = unstructured binary data (no Application Identifier bits used) 1 = binary data coded as defined by the 16-bit AI. Set to 1 (structured).

Destination ID 0 MMSI number of destination station. Not used.

Spare 0 Not used.

Bi na ry D at a

Designated Area Code 10 Designated area code (DAC). Set to 366.

Function Identifier 6 Function identifier. Set to 4.

En cr yp te d Pa

Message Linkage ID 10 A source-specific random number, unique across recent binary messages with Message Linkage ID. Used to connect additional information regarding this TOI with another ASM. The Message Linkage ID and source MMSI uniquely identify the TOI. 1 – 1023; 0 = not available.

Target Acquisition Source 3

Type of Target.

0 = unknown = default; 1 = AIS, 2 = Radar, 3 = visual sighting; 4 = reported; 5 = other electronic surveillance, i.e. DSC, ECDIS, etc.; 6 -7 = reserved.

Target ID 30 MMSI if type is Target Acquisition source=1 (AIS), Sender generated ID otherwise

TOI Status 3 Designator for TOI Status. 0 = cancel; 1 = active; 2 = being followed; 3 = being boarded; 4 = request to cancel, 5 = request to update, 6 = reserved, 7 = reserved.

Target Type 3 Type of Target 0 = vessel = default; 1 = aircraft; 2 = submersible; 3-7 = reserved.

Target Description and Cargo 8 Description of target type and cargo, see Appendix 3.

Interest 8 Code to indicate what interest in vessel is. To be defined. Could be used as an 8-bit binary matrix, similar to ATON Status bits. TBD.

EAIS IDD v5.5.1 Page 11

Bi na ry D at a

En cr yp te d Pa

Ti m e o f T

OI

R ep or t

UTC Hour 5 UTC Hour of TOI report.

0 – 23; 24 = UTC hour not available = default; 25 - 31 = reserved.

UTC Min 6 UTC Minute of TOI report.

0 – 59; 60 = UTC minute not available = default; 61 - 63 (reserved for future use).

UTC Sec 6 UTC Second of TOI report.

0 – 59; 60 = UTC second not available = default; 61 - 63 (reserved).

Longitude 28 Longitude in 1/10,000 min (+/-180 degrees, East = positive, West = negative - 2’s complement). 181 degrees = not available = default.

Latitude 27 Latitude in 1/10,000 min (+/-180 degrees, East = positive, West = negative - 2’s complement). 91 degrees = not available = default.

SOG 10

Speed over ground. Scale dependent on value of Target Type flag.

Aircraft: 0 – 1000 kts (1 kt increments); 1001 = 1001 kts or higher; 1002 = not available = default; 1003 – 1023 = reserved.

Vessel or submersible: 0 – 100.0 kts (0.1 kt increments); 1001 = 100.1 kts or higher; 1002 = not available = default; 1003 – 1023 = reserved.

COG 12 Course over ground in 1/10 degree steps.

0 - 359.9 degrees; 3600 = not available = default; 3601 - 4095 = reserved.

Encryption Bit Padding 78 Sufficient spare bits to ensure that the binary data is a multiple of 128 bits for block encryption (256). Set to zero.

Plaintext Checksum 16 16-bit CRC calculated as per EAIS Specification

Transmission Checksum 16 16-bit CRC calculated as per EAIS Specification

Fo

Selector 1 0 = SOTDMA communication state follows 1 = ITDMA communication state follows

Communications State 19 SOTDMA communication state (see ITU 1371-5 § 3.3.7.2.2, Annex 2), if communication state selector flag is set to 0, or ITDMA communication state (§ 3.3.7.3.2, Annex 2), if communication state selector flag is set to 1.

Total bits 352 2 Slot Binary Message

2.2 Target of Interest – 60s

DAC: 366 FI: 5 (Encrypted)

Published: 9 Nov 2017 Version: 1

Summary of changes:

Version 1:

This is a variant of the TOI that uses a 60 second VDL transmit interval.

2.2.1 Introduction

The Target of Interest message reports vessel or aircraft contacts with 60 sec VDL periodicity.

2.2.2 Usage Notes

EAIS IDD v5.5.1 Page 12 message variation. Addressing, when required, shall be performed using the Destination Indicator and Destination ID fields inherent to the Message 26 structure.

• The transponder shall transmit this report on the VDL every 60 seconds. The PI generates and communicates the NMEA request to send at triple the VDL transmit rate - every 20 sec.

The PI shall not retransmit if a FID 9 (Ack) is not received. Vessel PIs shall designate at most one TOI using this FID, and shall only permit designation of Automatic Radar Plotting Aid (ARPA), Mini ARPA (MARPA) or AIS targets. See Annex 1 for more details.

• Cancelling a TOI locally results in the PI setting the “Status” field to zero for the next nine messages, and then halting message generation. This will result in the transmission of three cancellation messages on the VDL, 60 seconds apart. Remote units receiving a TOI will apply Lost Target/Auto Drop processing rules to remove the TOI designation from a target.

2.3 Target of Interest – 180s

DAC: 366 FI: 6 (Encrypted)

Published: 9 Nov 2017 Version: 1

Summary of changes:

Version 0:

This is a variant of the TOI that uses a 180 second VDL transmit rate.

2.3.1 Introduction

The Target of Interest message reports vessel or aircraft contacts with 180 sec VDL periodicity.

2.3.2 Usage Notes

message variation. Addressing, when required, shall be performed using the Destination Indicator and Destination ID fields inherent to the Message 26 structure.

• The transponder shall transmit this report on the VDL every 180 seconds. The PI generates and communicates the NMEA request to send at triple the VDL transmit rate - every 60 sec.

The PI shall not retransmit if a FID 9 (Ack) is not received. Vessel PIs shall designate at most one TOI using this FID, and shall only permit designation of Automatic Radar Plotting Aid (ARPA), Mini ARPA (MARPA) or AIS targets. See Annex 1 for more information.

• Cancelling a TOI locally results in the PI setting the “Status” field to zero for the next nine messages, and then halting message generation. This will result in the transmission of three cancellation messages on the VDL, 180 seconds apart. Remote units receiving a TOI will apply Lost Target/Auto Drop processing rules to remove the TOI designation from a target.

EAIS IDD v5.5.1 Page 13

2.4 Target of Interest – 600s

DAC: 366 FI: 7 (Encrypted)

Published: 9 Nov 2017 Version: 1

Summary of changes:

Version 0:

This is a variant of the TOI that uses a 600 second VDL transmit rate.

2.4.1 Introduction

The Target of Interest message reports vessel or aircraft contacts with 600 sec VDL periodicity.

2.4.2 Usage Notes

message variation. Addressing, when required, shall be performed using the Destination Indicator and Destination ID fields inherent to the Message 26 structure.

• The transponder shall transmit this report on the VDL whenever received from the PI. The PI generates and communicates the NMEA request to send every 600 sec. The PI shall not retransmit if a FID 9 (Ack) is not received. Vessel PIs shall designate at most one target as a TOI using this FID, and shall only permit designation of Automatic Radar Plotting Aid (ARPA), Mini ARPA (MARPA) or AIS targets. See Annex 1 for more information.

• Cancelling a TOI locally results in the PI setting the “Status” field to zero for the next three messages, and then halting message generation. This will result in the transmission of three cancellation messages on the VDL, 600 seconds apart. Remote units receiving a TOI will apply Lost Target/Auto Drop processing rules to remove the TOI designation from a target.

2.5 Target of Interest – Single

DAC: 366 FI: 8 (Encrypted)

Published: 9 Nov 2017 Version: 1

Summary of changes:

Version 0:

This is a variant of the TOI that is not periodic (uses reporting interval = inf).

2.5.1 Introduction

The Target of Interest message report contacts with no VDL periodicity.

2.5.2 Usage Notes

message variation. Addressing, when required, shall be performed using the Destination Indicator and Destination ID fields inherent to the Message 26 structure.

• The PI shall not retransmit if a FID 9 (Ack) is not received. The PI does not repeat this report on a periodic basis. The PI transmits an updated TOI message with the same Linkage ID when PI user interaction results in TOI property changes. Cancelling a TOI locally results in the PI generating three messages, six minutes apart, with the “Status” field set to zero.

EAIS IDD v5.5.1 Page 14

2.6 Message Acknowledgement

DAC: 366 FI: 9 (Encrypted)

Published: 14 July 2017 Version: 1 Summary of changes:

Version 1:

This is an RTCM compliant update of the FID 2 message listed in the Oct 2014 EAIS IDD.

2.6.1 Introduction

This Message 25 payload is used to acknowledge PI reception of an addressed, encrypted STEDS message.

2.6.2 Usage Notes

• Acknowledgement linkage back to the original message is based upon source MMSI, source FI, and source Message Linkage ID.

• If the received FID 28 (Encrypted Text Message), has its “ACK flag” field set to zero, then this acknowledgement shall not be sent. Otherwise, all encrypted, addressed STEDS messages receive this acknowledgement from the recipient PI.

• For all non-TOI ASMs: If the sending PI does not receive a STEDS ACK after 150 seconds, the sending PI shall retry transmission. The sending PI shall retry a maximum of three times, waiting 150 seconds each time for an STEDS ACK. This indicates a maximum of four transmitted messages: one initial and three retries.

EAIS IDD v5.5.1 Page 15

2.6.3 Broadcast Encrypted Message Format

Message Acknowledgement (Message 25, Broadcast)

St an da rd

M es sa ge

H ea de r

Message ID 6 Identifier for Message 25; always 25.

Repeat Indicator 2 Indicates how many times a message has been repeated. 0 – 3; 0 = default; 3 = do not repeat any more. Set to zero (default).

Source MMSI 30 MMSI number of source station. Varies according to the transmitter ID.

Destination Indicator 1 0 = broadcast (no Destination ID field) 1 = Addressed (30 bit Destination ID field). Set to 0 (broadcast).

Binary Data Flag 1 0 = unstructured binary data (no Application Identifier bits used) 1 = binary data coded as defined by the 16-bit AI. Set to zero (unstructured).

Destination ID 0 MMSI number of destination station. Not used.

Spare 0 Not used.

B in ar y A pp lic at io n Da ta (e nc ry pt ed

Function Identifier 6 Function identifier. Set to 9.

Version 3 Sequential number used to indicate the message version in steps of 1.

0 = test message = default; 1 – 7 = message version.

Set to one.

Original Message Source 30 MMSI of the source of the message being acknowledged.

Original Message DAC 10 DAC of the message to be acknowledged. Set to 0 if no DAC (AIS message 25/26 messages).

Original Message FI 6 Functional Identifier of message being acknowledged. 0 – 63.

Original Message MLID 10 MLID of the source message to be acknowledged.

Original Message Checksum 16 16-bit plaintext CRC of the source message to be acknowledged.

UTC Hour 5 UTC Hour of ACK.

0 – 23; 24 = UTC hour not available = default; 25 - 31 = reserved.

UTC Min 6 UTC Minute of ACK.

0 – 59; 60 = UTC minute not available = default; 61 - 63 (reserved for future use).

UTC Sec 6 UTC Second of ACK.

0 – 59; 60 = UTC second not available = default; 61-63 (reserved for future use).

Encryption Bit Padding 14 Sufficient spare bits to ensure that the binary data is a multiple of 128 bits for block encryption (128). Set to 0.

Total bits 168 1 Slot Binary Message

EAIS IDD v5.5.1 Page 16

2.7 Situation Report (SITREP) for Vessels and Aircraft

DAC: 366 FI: 10 (Encrypted)

Published: 14 Jul 2017 Version: 1

Summary of changes:

Version 1:

This is an RTCM compliant update of the FID 0 Message 25 listed in the Oct 2014 EAIS IDD. It also replaces the DAC 366, FI 56 Position Report from the same document.

2.7.1 Introduction

The Situation Report Message is used to send the equivalent information to AIS Message 1 but removes less essential data to compress message size.

2.7.2 Usage Notes

• This report can be used for both vessels and aircraft.

Note: Only aircraft engaged in SAR (using SAR transponder) may transmit AIS.

• The position report shall be transmitted on the VDL once every 30 seconds when the unit has registered a speed over ground (SOG) of less than 3 knots for more than 3 minutes and once every 15 seconds when SOG is 3 knots or greater. Aircraft should transmit on the VDL at 10 second intervals.

• The PI generates and communicates the NMEA request to send at triple the maximum VDL transmit rate - every 5 sec for vessels, every 3 sec for aircraft. The PI must automatically generate this report in Restricted Transmit Mode. The PI may be optionally configured to automatically generate this report in Normal Transmit Mode. See Annex 1 for more information.

2.7.3 Broadcast Encrypted Message Format

Situation Report (Message 26, Broadcast)

St an da rd

M es sa ge

H ea de r

Message ID 6 Identifier for Message 26; always 26.

Repeat Indicator 2 Indicates how many times a message has been repeated. 0 – 3; 0 = default; 3 = do not repeat any more. Set to zero (default).

Source MMSI 30 MMSI number of source station. Varies according to the transmitter ID.

Destination Indicator 1 0 = broadcast (no Destination ID field) 1 = Addressed (30 bit Destination ID field). Set to 0 (broadcast).

Binary Data Flag 1 0 = unstructured binary data (no Application Identifier bits used) 1 = binary data coded as defined by the 16-bit AI. Set to 1 (structured).

Destination ID 0 MMSI number of destination station. Not Used.

Spare 0 Not used.

EAIS IDD v5.5.1 Page 17

Bi na ry

D at a Designated Area Code 10 Designated area code (DAC). Set to 366.

Function Identifier 6 Function identifier. Set to (decimal) 10.

En cr yp te d

Pa

Time of Position - UTC Min 6 UTC Minute of the position.

0 – 59; 60 = UTC minute not available = default; 61 - 63 (reserved for future use).

Time of Position - UTC Sec 3

UTC Seconds of the position; 10-second resolution.

0 = 0 sec; 1 =10 sec; 2 = 20 sec; 3 = 30 sec; 4 = 40 sec; 5 = 50 sec; 6 = unknown = default; 7 = (reserved for future use).

Craft Flag 1 Indicates whether report is from a vessel or aircraft.

0 = vessel = default; 1 = aircraft.

Longitude 28 Longitude in 1/10,000 min (±180 degrees, East = positive, West = negative.

181 degrees = not available = default). Negative in 2’s complement.

Latitude 27 Latitude in 1/10,000 min (±90 degrees, North = positive, South = negative, 91 degrees = not available = default). Negative in 2’s complement.

Altitude 12 Altitude above sea level in 1m increments. Set to 0 for vessels.

0-4,000 m; 4001 = 4,001 m or higher; 4,002 = unknown = default.

COG 12 Course over ground in 1/10° increments.

0-359.9 degrees; 3,600 = not available = default; 3,601 – 4095 = reserved.

SOG 10

Speed over ground. Scale dependent on value of craft flag.

Aircraft: 0 – 1000 kts (1 kt increments); 1001 = 1001 kts or higher; 1002 = not available = default; 1003 – 1023 = reserved.

Operational Status 4

Operational status of the craft reporting.

0 = unknown = default 1 = ops normal 2 = on scene as directed 3 = returning to port/land 4 = awaiting instructions 5 = Bravo at home port 6 = Bravo at port other than home 7 = Charlie, homeport 8 = Charlie, in repair 9-15 reserved.

Encryption Bit Padding 6 Sufficient spare bits to ensure that the binary data is a multiple of 128 bits for block encryption. Set to 0.

Plaintext Checksum 16 16-bit CRC calculated as per EAIS Specification

Transmission Checksum 16 16-bit CRC calculated as per EAIS Specification

Fo

Selector 1 0 = SOTDMA communication state follows

1 = ITDMA communication state follows

Communications State 19 SOTDMA communication state (see ITU 1371-5 § 3.3.7.2.2, Annex 2), if communication state selector flag is set to 0, or ITDMA communication state (§

Total bits 224 2 Slot Binary Message

EAIS IDD v5.5.1 Page 18

2.8 Static Data Report

DAC: 366 FI: 11 (Encrypted)

Published: 14 Jul 2017 Version: 1

Summary of changes:

Version 1:

This is an RTCM compliant update of the FID 1 message listed in the Oct 2014 EAIS IDD. It also replaces the DAC 366, FI 57 Static Data Report from the same document.

2.8.1 Introduction

The Static Data Message is used to send the equivalent information to AIS Message 5 but removes less essential data to compress message size.

2.8.2 Usage Notes

• The FID 11 static data report shall be transmitted on the VDL once every 6 minutes.

• The data is matched by MMSI to the corresponding FID 10 message to provide additional information.

• The PI generates and communicates the NMEA request to send at triple the maximum

VDL transmit rate - every 120 sec. The PI must automatically generate this report in Restricted Transmit Mode. The PI may be optionally configured to automatically generate this report in Normal Transmit Mode. See Annex 1 for more information.

2.8.3 Broadcast Encrypted Message Format

Static Data Report (Message 26, Broadcast)

St an da rd

M es sa ge

H ea de r

Message ID 6 Identifier for Message 26; always 26.

Repeat Indicator 2 Indicates how many times a message has been repeated. 0 – 3; 0 = default; 3 = do not repeat any more. Set to zero (default).

Source MMSI 30 MMSI number of source station. Varies according to the transmitter ID.

Destination Indicator 1 0 = broadcast (no Destination ID field) 1 = Addressed (30 bit Destination ID field). Set to 0 (broadcast).

Binary Data Flag 1 0 = unstructured binary data (no Application Identifier bits used) 1 = binary data coded as defined by the 16-bit AI. Set to 1 (structured).

Destination ID 0 MMSI number of destination station. Not Used.

Spare 0 Not used.

EAIS IDD v5.5.1 Page 19 ry

D at a Designated Area Code 10 Designated area code (DAC). Set to 366.

Function Identifier 6 Function identifier. Set to (decimal) 11.

En cr yp te d

Pa

Asset Name 90 Maximum 15 characters 6-bit ASCII as per ITU 1371.

"@@@@@@@@@@@@@@@@" = not available = default.

The Name should be as shown on the station radio license.

Asset Type 10 Asset Type as per Appendix 1 of this VDL.

DTE 1 Data terminal equipment (DTE) ready.

0 = available, 1 = not available = default.

Encryption Bit Padding 8 Sufficient spare bits to ensure that the binary data is a multiple of 128 bits for block encryption. Set to 0.

Plaintext Checksum 16 16-bit CRC calculated as per EAIS Specification

Transmission Checksum 16 16-bit CRC calculated as per EAIS Specification

Fo

Selector 1 0 = SOTDMA communication state follows

1 = ITDMA communication state follows

Communications State 19 SOTDMA communication state (see ITU 1371-5 § 3.3.7.2.2, Annex 2), if communication state selector flag is set to 0, or ITDMA communication state (§

Total bits 224 2 Slot Binary Message

EAIS IDD v5.5.1 Page 20

2.9 Area Notice

DAC: 366 FI: 14 (Encrypted)

Published: 14 Jul 2017 Version: 1

Summary of changes:

Version 1:

This is an encrypted version of DAC:367 FI: 22, version 2 listed on IALA ASM collection.

This ASM only has a Message 26 variant.

2.9.1 Introduction

This message provides encrypted dynamic information concerning a specified geographic area, polyline or positions.

2.9.2 Usage Notes

• This Message 26 Area Notice provides for both a broadcast and addressed messages.

Message addressing, when required, shall be performed using the Destination Indicator and Destination ID fields inherent to the Message 26 structure.

• There can be up to 8 sub-areas associated with each notice.

• This message can be used to convey advisory lines or tracks, but Route Information should be used recommended or directed route.

• The PI shall expect a FID 9 (Ack) for the addressed form of the message, and shall retransmit according to the Usage Notes of FID 9 if it does not receive one.

2.9.3 Addressed Encrypted Message Format

Encrypted Area Notice Message (Message 26, Addressed)

St an da rd

M es sa ge

H ea de r

Message ID 6 Identifier for Message 26; always 26.

Repeat Indicator 2 Indicates how many times a message has been repeated. 0 – 3; 0 = default; 3 = do not repeat any more. Set to zero (default).

Source MMSI 30 MMSI number of source station. Varies according to the transmitter ID.

Destination Indicator 1 0 = broadcast (no Destination ID field) 1 = Addressed (30 bit Destination ID field). Set to 1 (addressed).

Binary Data Flag 1 0 = unstructured binary data (no Application Identifier bits used) 1 = binary data coded as defined by the 16-bit AI. Set to 1 (structured).

EAIS IDD v5.5.1 Page 21 ry

D at a Designated Area Code 10 Designated area code (DAC). Set to 366.

Function Identifier 6 Function identifier. Set to (decimal) 14.

En cr yp te d

Pa

Message Linkage ID 10 A source-specific random number, unique across recent binary messages with Message Linkage ID. Used to connect the additional information in this Area Notice Message with another ASM. The Message Linkage ID and the source MMSI uniquely identify the sent message. 1 – 1,023; 0 = not available.

Notice Description 7 Notice Description as defined in Table 11.

Set to 0-127 according to description. If = 127 or = 125 there must be associated text (reference Table 10 & Table 11 of IALA ASM DAC=367, FI=22)

Start date and time of Area

UTC Month 4 Start UTC month of the Area notice. 1 -12; 0 = not available = default;

13 -15 = reserved for future use

UTC Day 5 Start UTC day of the Area notice.

1 -31 0 = not available = default

UTC Hour 5 Start UTC hour of the Area notice.

0 – 23 24 = not available = default 25- 31 = reserved for future use

UTC Minute 6 Start UTC Minute of the Area notice. 0 – 59; 60 = not available = default 61-63 reserved for future use

Duration 18 Minutes until end of Area notice. Measured from start date and time of Area Notice. 0 = cancel Area Notice; 262,143 = undefined = default Maximum duration is 262,142 minutes (182.04 days).

Number of Sub-areas 4 1 – 8

Action 1 Action Parameter: 0 = Advisement; 1 = Directive.

Spare 1 Set to zero for byte alignment.

Sub- areas Max 768 From 1 to 8 sub-areas, each structured as in Tables 5 – 10 of IALA ASM DAC=367, FI=22. A short text description may be associated with the areas using Sub-area 5: Associated text (see Table 10). Each sub-area is 96 bits.

Encryption Bit Padding Variable Sufficient spare bits to ensure that the binary data is a multiple of 128 bits for block encryption (128, 256, 384, 512, 640, 768, or 896). Set to 0.

Plaintext Checksum 16 16-bit CRC calculated as per EAIS Specification

Transmission Checksum 16 16-bit CRC calculated as per EAIS Specification

Fo

Selector 1 0 = SOTDMA communication state follows

1 = ITDMA communication state follows

Communications State 19 SOTDMA communication state (see ITU 1371-5 § 3.3.7.2.2, Annex 2), if communication state selector flag is set to 0, or ITDMA communication state (§ 3.3.7.3.2, Annex 2), if communication state selector flag is set to 1.

Total bits 384 –

2 - 5 Slot Binary Message

EAIS IDD v5.5.1 Page 22

2.9.4 Broadcast Encrypted Message Format

Area Notice Message (Message 26, Broadcast)

St an da rd

M es sa ge

H ea de r

Message ID 6 Identifier for Message 26; always 26.

Repeat Indicator 2 Indicates how many times a message has been repeated. 0 – 3; 0 = default; 3 = do not repeat any more. Set to zero (default).

Source MMSI 30 MMSI number of source station. Varies according to the transmitter ID.

Destination Indicator 1 0 = broadcast (no Destination ID field) 1 = Addressed (30 bit Destination ID field). Set to 0 (broadcast).

Binary Data Flag 1 0 = unstructured binary data (no Application Identifier bits used) 1 = binary data coded as defined by the 16-bit AI. Set to 1 (structured).

Destination ID 0 MMSI number of destination station. Not used.

Spare 0 Not used.

Bi na ry D at a

Designated Area Code 10 Designated area code (DAC). Set to 366.

Function Identifier 6 Function identifier. Set to 14.

En cr yp te d Pa

Message Linkage ID 10 A source-specific random number, unique across recent binary messages with Message Linkage ID. Used to connect the additional information in this area notice Message with another ASM. The Message Linkage ID and the source MMSI uniquely identify the sent message. 1 – 1,023; 0 = not available.

Notice Description 7 Notice Description as defined in Table 11.

Set to 0-127 according to description. If = 127 or = 125 there must be associated text (reference Table 10 and 11 of IALA ASM DAC=367, FI=22)

Start date and time of Area

UTC Month 4 Start UTC month of the Area notice. 1 -12 0 = not available = default, 13 -15 = reserved for future use

UTC Day 5 Start UTC day of the Area notice. 1 -31; 0 = not available = default

UTC Hour 5 Start UTC hour of the Area notice. 0 – 23 24 = not available = default, 25- 31 = reserved for future use

UTC Minute 6 Start UTC Minute of the Area notice. 0 – 59 60 = not available = default, 61-63 reserved for future use

Duration 18 Minutes until end of Area notice. Measured from start date and time of Area Notice. 0 = cancel Area Notice, 262,143 = undefined = default Maximum duration is 262,142 minutes (182.04 days).

Number of Sub-areas 4 Total count of sub-areas. 1 – 8 Action 1 Action Parameter: 0 = Advisement; 1 = Directive.

Spare 1 Set to zero for byte alignment.

Sub- areas Max 768 From 1 to 9 sub-areas, each structured as in Tables 5 – 10 of IALA ASM DAC=367, FI=22. A short text description may be associated with the areas using Sub-area 5: Associated text (see Table 10). Each sub-area is 96 bits.

Encryption Bit Padding Variable Sufficient spare bits to ensure that the binary data is a multiple of 128 bits for block encryption (256, 384, 512, 640, 768, or 896). Set to 0.

EAIS IDD v5.5.1 Page 23

Fo

Selector 1

0 = SOTDMA communication state follows 1 = ITDMA communication state follows

Communications State 19 SOTDMA communication state (see ITU 1371-5 § 3.3.7.2.2, Annex 2), if communication state selector flag is set to 0, or ITDMA communication state (§ 3.3.7.3.2, Annex 2), if communication state selector flag is set to 1.

Total bits 352 –

EAIS IDD v5.5.1 Page 24

2.10 Route Information

DAC: 366 FI: 15 (Encrypted)

Published: 14 Jul 2017 Version: 1

Summary of changes:

Version 1:

This is an encrypted version of Route information modified from IMO Circ. 289 DAC:001 FI: 27 and 28 listed in IALA ASM collection.

This ASM only has a Message 26 variant.

2.10.1 Introduction

This message provides encrypted information concerning a route.

2.10.2 Usage Notes

• This Message 26 Route Information provides for both broadcast and addressed messages. Message addressing, when required, shall be performed using the Destination Indicator and Destination ID fields inherent to the Message 26 structure.

• The route may contain up to 14 waypoints, to keep maximum message size parity with other STEDS messages.

• The PI shall expect a FID 9 (Ack) for the addressed form of the message, and shall retransmit according to the Usage Notes of FID 9 if it does not receive one.

2.10.3 Addressed Encrypted Message Format

Route Information Message (Message 26, Addressed)

St an da rd

M es sa ge

H ea de r

Message ID 6 Identifier for Message 26; always 26.

Repeat Indicator 2 Indicates how many times a message has been repeated. 0 – 3; 0 = default; 3 = do not repeat any more. Set to zero (default).

Source MMSI 30 MMSI number of source station. Varies according to the transmitter ID.

Destination Indicator 1 0 = broadcast (no Destination ID field) 1 = Addressed (30 bit Destination ID field). Set to 1 (addressed).

Binary Data Flag 1 0 = unstructured binary data (no Application Identifier bits used) 1 = binary data coded as defined by the 16-bit AI. Set to 1 (structured).

EAIS IDD v5.5.1 Page 25 ry

D at a Designated Area Code 10 Designated area code (DAC). Set to 366.

Function Identifier 6 Function identifier. Set to (decimal) 15.

En cr yp te d

Pa

Message Linkage ID 10 A source-specific random number, unique across recent binary messages with Message Linkage ID. Used to connect the additional information in this Route Message with another ASM. The Message Linkage ID and the source MMSI uniquely identify the sent message. 1 – 1,023; 0 = not available.

Sender Classification 3 0 = ship = default, 1 = authority, 2 - 7 (reserved for future use)

Route Type 5

0 = not available = default 1 = mandatory route 2 = recommended route 3 = alternative route 4 = recommended route through ice 5 = ship route plan 6 - 30 (reserved for future use) 31 = cancellation (cancel route as identified by Message Linkage ID)

Start date and time of route

UTC

Month 4 Start UTC month of the Area notice. 1 -12

0 = not available = default, 13 -15 = reserved for future use

UTC Day 5 Start UTC day of the Area notice. 1 -31; 0 = not available = default

UTC Hour 5 Start UTC hour of the Area notice. 0 – 23 24 = not available = default, 25- 31 = reserved for…