Rumors are swirling that Apple will announce the iPad 3 in early March. The Wall Street Journal reported that both AT&T and Verizon will stock 4G LTE-enabled editions. Both carriers sell the iPad 2 with 3G connectivity as well as a Wi-Fi-only edition. According to the Journal, it's unclear if Sprint or T-Mobile will also vend the 4G LTE model. Sprint's 4G LTE network is more limited in the U.S. than that of Verizon and AT&T.
4G connectivity reportedly delivers mobile broadband speeds up to ten times as fast as 3G. When 4G LTE is not available, the iPad will switch to a slower mobile broadband network. On AT&T, that means 4G HSPA+ and 3G mobile broadband. Verizon's would require at least 3G EVDO for back-up support.