Find "Network mode"
Press the menu icon.
Press Settings.
Press Mobile network.
Press Network mode.
Select network mode
Press WCDMA only, GSM only, GSM / WCDMA auto or GSM / WCDMA / LTE auto.
3G (UMTS) or 4G (LTE) enables you to achieve higher data speeds than when using 2G (GSM).
If you select WCDMA only, your phone can only connect to 3G networks.
If you select GSM only, you can't achieve high data speeds.
If you select GSM / WCDMA auto, your phone automatically switches between the two network modes provided that you're within range of a 3G network.
If you select GSM / WCDMA / LTE auto, your phone automatically switches between the three network modes provided that you're within range of a 3G or a 4G network.
If you select WCDMA only, your phone can only connect to 3G networks.
If you select GSM only, you can't achieve high data speeds.
If you select GSM / WCDMA auto, your phone automatically switches between the two network modes provided that you're within range of a 3G network.
If you select GSM / WCDMA / LTE auto, your phone automatically switches between the three network modes provided that you're within range of a 3G or a 4G network.
Exit
Press the Home key to return to standby mode.