It is not clear which end initiates the communication. There are conflicting statements by experts.
The Inmarsat Exec said the statement "the satellite wants to see if you still want service." That indicates to me that the satellite, not the SATCOM, initates the ping. It sounds like, after 60 minutes of silence, the Satellite wants to confirm that you are still on it's network. If you don't respond, it takes you off of its active device registry until you come back online and initiate contact.