I dont know about australia but in europe should you try to use
your mobile phone in flight over land you will find it has no
service... in flight it will be "in line of sight" of many cells and
I think this causes the phone company computer to " turn you
off".... do not fear however back on the ground it will work fine again.. 15 years ago I used to use my old analogue phone
from the flight deck all the time!!!