INMARSAT ping received, as apparently Boeing's AHM report attempted to automatically transmit (thru Satellite)
The Boeing AHM system did not generate the pings as it was not activated. The hourly pings were generated by Inmarsat (initial ping from satellite and subsequent pings from the plane) for satcom service channel access (in case data was transmitted).
Here's a superbly informative post from yesterday with details. Many missed it apparently due to moderator approval time lag.