How to enable 4G in Samsung Galaxy S4 SPH-L720 I have a Samsung Galaxy S4 SPH-L720 I want to use 4G. How can I enable 4G in Samsung Galaxy S4 SPH-L720.
Go in settings and then mobile network,
If u  want to use only 4G then change the network mode to LTE only and then just right next to it is network operator, click that option and go for automatic search and register. Your cell will be registered to the 4G bands of your career and then simply turn the Mobile Data on.
There You Go!