Find out from your carrier what type of signal is available in your area; or use an online coverage checker for your network.
You can set the phone's network preference in Settings, Wireless & Networks, Mobile Networks. The phone will automatically connect to the strongest signal however, so there is normally no need to adjust those settings from their default, but if you live in an area of weak 4G signal, it may be wise to set the phone to 3G-only to prevent it trying to connect and thus wasting battery.
The type of signal to which the phone is connected is displayed in the status bar.
Posted via the Android Central App