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RATDMA Schedule configuration
Using the RATDMA (Random Access TDMA) access scheme the time for each transmission
made by the transceiver is specified. The transceiver will determine the actual slots used
for transmission based on internal knowledge of the AIS environment gained from the AIS
receivers.
The parameters required for an RATDMA schedule are as follows.
Channel 1 start UTC
This is the hour and minute of the frame in which transmission will occur on channel 1. The
slot used within this frame will be determined by the transceiver.
Channel 1 interval
This is the interval in minutes between transmissions on channel 1. A typical value is 6
minutes.
Channel 2 start UTC
This is the hour and minute of the frame in which transmission will occur on channel 2. The
slot used within this frame will be determined by the transceiver.
Channel 2 interval
This is the interval in minutes between transmissions on channel 1. A typical value is 6
minutes.
The transceiver is now configured to report message #21 on channel 1 every 6th minute,
and on channel 2 every 6th minute, but offset by three minutes from channel 1. This results
in a transmission of message #21 every three minutes on alternating channels. The actual
start slot selected for each channel will depend on the FATDMA allocations in the area of
operation.