T-Mobile
Frequency on UMTS (W-CDMA)/HSPA 3G (not true 4G)
1700 MHz/2100 MHz
Frequency on GSM/GPRS/EDGE 2G
850 MHz and 1900 MHz
http://en.wikipedia.org/wiki/T-Mobile_USA
1700 MHz/2100 MHz
Frequency on GSM/GPRS/EDGE 2G
850 MHz and 1900 MHz
http://en.wikipedia.org/wiki/T-Mobile_USA
AT&T
Frequency on UMTS/HSPA 3G
850 MHz/ 1900 MHz
Frequency on GSM/GPRS/EDGE 2G
850 MHz and 1900 MHz
http://en.wikipedia.org/wiki/AT&T_Mobility