My smart phone is Sony Experia E D2105.
Sometimes it reboots suddenly.

This morning It rebooted again.
I waited until the reboot was completed.

But Again it happened over and over again!
My smart phone kept rebooting!

I had to think of the solution,
Then, The only way I could do was turn off all connection!

I turned off WIFI and bluetooth connection, immidiately after rebooting!
It seemed working well again!