Thanks Avish
I changed the name of the WiFi to a continuous 8 character word without space or special characters.
Security to WPA2PSK.
As I read somewhere it is a WiFi bug.
Did the same when got a freezing issue on my friends s4.
Posted via Android Central Pro
I had this issue and my phone was freezing for every 15-20 minutes.
What I did to recover from this issue is configure the wifi tethering.
I am on baseband I9300DDEMG2
I have not experienced the freezing for over a month now.:)