1

004

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 § 2.4, Annex 1

4

0 to 2³²-1

4

Destination ID

The unique identifier of the ship being assigned a logical channel as described in § 2.4, Annex 1

5

0-255

1

Logical Channel Tx

Logical channel assigned to the session for transmission. Transmission only applies to data slots.(1) LC of 255 indicates no resource

6

0-255

1

Logical Channel Rx

Logical channel assigned to the session for reception. Reception only applies to data signalling slots.(1) LC of 255 indicates no resource

7

0-255

1

Link ID

The link ID that should be used in the TDMA channel. This will apply to Messages 74, 75, 76 and 13

8

1-255

1

TDMA frame delay

The number of TDMA frames to delay before the resource may be used. Resource may only be assigned from the start of the next TDMA frame. Default 1 (2) (3)

9 (4)

0

1

Session ID

Session ID

10

0-255

1

CQI

Received channel quality indicator as defined in § 1.2.8, Annex 2

(1)  The resource allocation message will always be sent on the signalling channel when being sent in response to a resource request (#90) message and will always be sent in the assigned TDMA channel when sent in response to an end fragment (#76). When the resource allocation message is being sent in the assigned TDMA channel, then the message should be transmitted in the same VDE packet as the ACK (#13) message. See fragment continuation for more details.

(2)  When assigning a logical channel, then both the logical channel Tx and the logical channel Rx should have identical TDMA channel numbers. The assigned LCs may have the same physical channels for simplex communication and different physical channels for duplex communication.

(3)  The TDMA frame delay allows for the efficient transferal of LC from one vessel to another with as little as possible wasting of slots.

(4)   The session ID is reserved for future use.