Flow management suggestion
Transmitter
Coordination centers (for controlled flow management).
Transmission prerequisites
The message is only transmitted if the receiving vessel has previously broadcast a tactical voyage plan which is still considered valid by the control center (e.g. ETA of active waypoint is in the future).
This message can only be sent in response to a "Tactical voyageplan broadcast" or a "Tactical voyageplan broadcast, extended".
The latitude and longitude of suggested active and planned waypoints must match exactly those received in the latest "Tactical voyageplan broadcast" or a "Tactical voyageplan broadcast, extended". If this is not the case, the vessel, to which the flow management suggestion is addressed, must disregard it, and broadcast a new tactical voyageplan message.
Transmission triggering events
The following events must trigger a transmission of this message:
1. On coordination center determining that speed-based changes to tactical voyageplan of vessel will lead to a better overall flow.
Retransmission
Retransmission is not applicable.
Message format
Waypoints are denoted WP0, WP1, WPi,…, WPn and are navigated in sequence. WP0 is the suggested active waypoint currently to be steered towards. WPi, where i ≥ 1, is called the following suggested waypoints.
|
Parameter |
No. of bits |
Description |
|
Message ID |
6 |
Identifier for Message 6; always 6. |
|
Repeat Indicator |
2 |
Used by the repeater to indicate how many times a message has been repeated.
0 - 3
0 = default
3 = do not repeat anymore |
|
Source ID |
30 |
MMSI number of source station. |
|
Sequence number |
2 |
0-3; refer to [AISSPEC5] §5.3.1, Annex 2 |
|
Destination ID |
30 |
MMSI number of destination station. |
|
Retransmit Flag |
1 |
Retransmit Flag should be set upon retransmission: 0 = no retransmission = default 1 = retransmitted. |
|
Spare |
1 |
Not used. Set to zero. |
|
IAI |
16 |
DAC = 219; FI = 6 |
|
WP0, position |
28 |
Longitude in 1/10,000 min,
±180 degrees as per 2’s complement (East = positive, West = negative). |
|
27 |
Latitude in 1/10,000 min,
±90 degrees as per 2’s complement (North = positive, South = negative). |
|
|
WP0, ETA |
5 |
UTC hour Integer value Values outside the range 0-23 are illegal and must not be used.
Values are current or future. |
|
6 |
UTC minute Integer value Values outside the range 0-59 are illegal and must not be used. |
|
|
Suggested following waypoints with relative ETA |
n × 63 |
Variable no. of planned waypoints and ETA’s. n {0..12} See table "Suggested following waypoints." below. |
|
Total |
154-1006 |
|
Table 13. Suggested following waypoints.
|
Parameter |
No. of bits |
Description |
|
WPi, longitude |
28 |
Longitude in 1/10,000 min, ±180 degrees as per 2’s complement (East = positive, West = negative). |
|
WPi, latitude |
27 |
Latitude in 1/10,000 min, ±90 degrees as per 2’s complement (North = positive, South = negative). |
|
WPi, relative ETA |
8 |
Relative ETA from previous waypoint; measured in minutes. Integer value; [0-255]. 0 = Not used. Illegal value.
1 - 255 = Relative ETA measured in number of minutes from previous waypoint. |
|
Total |
63 |
|
Table 14. No. of transmission slots.
|
Payload |
Bits |
Slots |
|
Suggested active waypoint, no following suggested waypoints |
154 |
2 |
|
Suggested active waypoint, 1 following suggested waypoint |
217 |
2 |
|
Suggested active waypoint, 2 following suggested waypoints |
280 |
2 |
|
Suggested active waypoint, 3 following suggested waypoints |
343 |
2 |
|
Suggested active waypoint, 4 following suggested waypoints |
406 |
3 |
|
Suggested active waypoint, 5 following suggested waypoints |
469 |
3 |
|
Suggested active waypoint, 6 following suggested waypoints |
532 |
3 |
|
Transmitting more than 3 slots is not recommended |
||
|
Suggested active waypoint, 7 following suggested waypoints |
595 |
4 |
|
Suggested active waypoint, 8 following suggested waypoints |
658 |
4 |
|
Suggested active waypoint, 9 following suggested waypoints |
721 |
4 |
|
Suggested active waypoint, 10 following suggested waypoints |
784 |
4 |
|
Suggested active waypoint, 11 following suggested waypoints |
847 |
5 |
|
Suggested active waypoint, 12 following suggested waypoints |
910 |
5 |
