However, as for a tablet which does not support voice connection there is no dialer app installed
which could be used to send such USSD.
On the another hand it is possible to enter service mode by telling the device a special (really long USSD)
in a special place.
I wonder if it was possible to send the *100# ussd to operator in same way as the service mode is invoked.
Sony Xperia Tablet Z LTE.