You don’t call another cell phone, you call a controller which calls the cell phone. It’s quite possible this controller would provide feedback to the user in the form of ringing sounds before the cell phone is actually reached and it’s also likely that some of the cell phones on the plane were still registered on the system so the system would think it likely that the cell phone could be reached.
http://www.ibtimes.co.uk/missing-malaysia-airlines-flight-mh370-passengers-mobile-phones-ring-not-answered-1439560
To this, Dunleavy replied that MAS was calling the mobile phones of the crew members as well, which were ringing, and that he had given the numbers to Chinese investigators.
Relatives of the passengers are urging the authorities to search for the location of phones that rang using the Global Positioning System.
However, at a press conference in Beijing, MAS spokesman Ignatius Ong said one of the numbers that had been passed on to the airline’s command office in Kuala Lumpur failed to get through.