Short data message (with ACK)

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msg_ID: 
92
Extended description: 
Short data message. ACK is required
Priority: 
not applicable
Access scheme: 
RATDMA
Communication state: 
N/A
Transmitted by: 
Mobile station
Base station

Table 38

Short data message (with acknowledgement)

Field
no.

Value
(dec)

Size
(bytes)

Function

Content

1

92

1

Type

 

2

0 to 216-1

2

Length

Total size in bytes, variable.

3

0 to 232-1

4

Source ID

The unique identifier of the transmitting station, as described in ยง 2.4, Annex 1.

4(1)

0

1

Session ID

Session ID of data session.

5

0 to 232-1

4

Destination ID

Destination MMSI may not be set to zero (broadcast address).

6

0 to 255

1

Retransmission no

Starts with value 0 and increments with every retransmission. Handles lost ACKs

Value of 255 indicates no ACK is requested.

7

 

Variable

Payload

 

Notes:

Should always be transmitted on the RAC by ship and ASC by shore station. The short data message ACK message should be transmitted on the RAC by ship and ASC by shore.

(1)  Session ID is reserved for future use.