Verizon and Sprint use CDMA. AT&T and T-Mobile use GSM. The frequencies that T-Mobile uses are non-standard, IIRC.
AT&T => 107.3M Verizon => 116.8M T-Mobile => 44M Sprint => 64.3M
Verizon and Sprint use CDMA. AT&T and T-Mobile use GSM. The frequencies that T-Mobile uses are non-standard, IIRC.
More information: http://en.wikipedia.org/wiki/List_of_United_States_wireless_... (Note: the numbers on that page are different from the numbers on the individual carrier pages in some cases)