Cellular service operates from two types of technologies. One is CDMA which is what Verizon, Sprint, and US Cellular uses, in the USA. The other is GSM which is the service AT&T, T-Mobile and other cellular providers use. It is also the prominent technology used in Europe. CDMA technology is upgrading and getting rid of 3G service over the next 2 to three years. However we have done extensive research and GSM 3G networks will be around for a long time.