A:AnswerYes, Nokia devices are fully compatible with AT&T. You can also activate with other carriers that are compatible with these bands: GSM: 850/900/1800/1900
WCDMA: Band 1, 2, 4, 5, 8
LTE: Band 2, 3, 4, 5, 7, 12, 17, 28, 38
A:AnswerIt's not even a LTE but Volte device. You can get solid voice calls over LTE but data speeds are 4g+. 5 g phones won't be common starting 2021.