Originally Posted by
Pontius Navigator
That was the assumption by the INMARSAT guy who thought the aircraft was trying to handshake.
The aircraft systems logon to the satellite(s) by calling them first then they are polled at intervals to check that their receiver is still ready and the low level link is still good. If the aircraft system thinks it has lost the signal - say due to a power down then back up - it might try to restart the lost link. As this last ping was from the aircraft and out of time, it is possibly another log on attempt from the aircraft system that was interrupted.