For the record, Cricket Wireless is not simply an AT&T MVNO, but rather a wholly owned subsidiary of AT&T that operates on the same network. AT&T LTE operates on bands 1, 2, 4, 5, and 17. (This means it operates in the 700 MHz B band, the 1700/2100 AWS-I band, and areas where AT&T has refarmed old GSM 850 and 1900 MHz network spectrum to LTE.) On Cricket Wireless, LTE speeds top out around 10 Mbps (though AT&T's network is not capped, Cricket is). This is comparable to 4G HSPA+ speeds in many areas. Any AT&T phone will work with 4G LTE on Cricket. Any international smartphone that supports HSPA+ in the 850/1900 MHz and 1700/2100 MHz bands will work with full 4G HSPA+ support.