How to fix connection problem and invalid MMI code in android

To Fix Connection Problem or Invalid MMI Code
on android.....

this method is simply
entering into device information mode and
activating Radio and Turn on IMS over SMS

To Enter information mode :

>Dial *#*#4636#*#* in the dialer

>Navigate to Device/Phone Information

>Click on "Run Ping Test "
After the Ping test is performed

>Click on "Turn Off Radio"
then

"Click on "Turn on SMS over IMS"

IMS :IP Multimedia Subsystem

IP :Internet Protocol

SIP:Session Initiation Protocol

While this setting is off SMS is sent or received
over a period of 1x(times) the circuit switched
connection
Finally reboot .