Force 3G or 4G Android Kitkat 4.4 

In the dialer type in *#*#4636#*#*.

Go to Phone information and scroll down to ‘Set preferred network type’ and set it to ‘LTE/CDMA’.
And now your phone will not try to connect to EDGE/2G.

Note this mode completely disables GSM/EDGE/2G so when the phone is out of reach from a 3G tower, you will not be able to make phone calls. In this case just switch back to a GSM mode.