Find "Network mode"
Press the menu icon.
Press Settings.
Press Mobile network.
Press Network mode.
Select network mode
Press WCDMA only or GSM / WCDMA auto.
3G enables you to achieve higher data speeds than when using GSM.
If you select WCDMA only, your phone can only connect to 3G networks.
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 WCDMA only, your phone can only connect to 3G networks.
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.
Exit
Press the Home key to return to standby mode.