Parameter

# of Bits

Description

Standard Message Header

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.

Binary Data

Designated Area Code

10

Designated area code (DAC). Set to 366.

Function Identifier

6

Function identifier. Set to (decimal) 36.

Encrypted Payload

Version

3

Sequential number used to indicate the message version in steps of 1. 0 = test message = default; 1 – 7 = message version. Set to zero.

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 11.11.

Set to 0-127 according to description. If = 127 there must be associated text (reference Table 11.10 & Table 11.11 of IALA ASM DAC=001, FI=23)

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 – 9

Sub- areas

Max 783

From 1 to 9 sub-areas, each structured as in Tables 11.4 - 11.9 of IALA ASM DAC=001, FI=22. A short text description may be associated with the areas using Sub-area 5: Associated text (see Table 11.10). Each sub-area is 87 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.

Checksum

16

16-bit CRC calculated as per EAIS Specification

Footer

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 § 3.3.7.2.1, 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 –

1024

2 - 5 Slot Binary Message

Parameter

# of Bits

Description

Standard Message Header

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.

Binary Data

Designated Area Code

10

Designated area code (DAC). Set to 366.

Function Identifier

6

Function identifier. Set to 36.

Encrypted Payload

Version

3

Sequential number used to indicate the message version in steps of 1. 0 = test message = default; 1 – 7 = message version. Set to zero.

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 11.11.

Set to 0-127 according to description. If = 127 there must be associated text (reference Table 11.10 and 11.11 of IALA ASM DAC=001, FI=23)

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 – 9

Sub- areas

Max 783

From 1 to 9 sub-areas, each structured as in Tables 11.4 - 11.9 of IALA ASM DAC=001, FI=22. A short text description may be associated with the areas using Sub-area 5: Associated text (see Table 11.10). Each sub-area is 87 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.