IIRC there's LTE/CDMA, Global and GSM/UMTS. The default setting seems to be "Global." I thought GSM and "global" were basically synonymous but apparently not. And here in the US, why would Verizon have the default setting be "Global" rather than LTE?CDMA? And what is UMTS? Never even heard of that one. And why is it linked with GSM?