This should help:
iPhone 4S and Verizon iPhone 4 use the MDM6600 (in other words, support ALL the frequencies!)
The specs aren't going to advertise it because apple has no intention of running on those frequencies.
https://forums.macrumors.com/threads/1092599/
AWS is UMTS 1700
iPhone 4S and Verizon iPhone 4 use the MDM6600 (in other words, support ALL the frequencies!)