I believe it is LTE only. Now you may find some areas that your phone drops to 4G that the watch still gets LTE since there is nothing to drop down to and it’ll still try to connect to LTE and work. You have 14 days to test it out to see how it works where you live.
Apple says the AW is LTE and UMTS "capable" as listed on their tech spec page for US models. The ATT network frequency information I can find seems to indicate they still use LTE and UMTS. I just wonder if anyone has experience actually using it outside of LTE coverage since on paper it looks like it will work. I'm outside of my return period now and I have a plan with a sim that doesn't support an added device at the moment, so before jumping through hoops to get a new sim, and paying activation fees and service on the watch, I wanted to hear from others on it.
The UMTS frequencies Apple states on their website are-
- UMTS
- 850 MHz
- 1700 MHz
- 1900 MHz
The ATT frequencies I found are-
Frequencies used on the AT&T Network Frequency range Band number Protocol Class Status Notes
850 MHz
GSM/
GPRS/
EDGE 2G Decommissioning by 2017[30] Plans to sunset 2G network by approximately January 1, 2017
[31]
1900 MHz PCS II
GSM/
GPRS/
EDGE 2G Decommissioning by 2017[30] Plans to sunset 2G network by approximately January 1, 2017
[31]
850 MHz CLR V
UMTS/
HSPA+ 21Mbit/s 3G/"4G" Active
[32]
1900 MHz PCS 2
UMTS/
HSPA+ 21Mbit/s 3G/"4G" Active
[32]
700 MHz Lower B/C 17
LTE 4G Active
[33] Main LTE band providing complete coverage
850 MHz CLR 5
LTE 4G Active
[34] Main LTE band providing coverage in areas lacking 700 Lower B and/or C blocks.
1700 MHz AWS 4
LTE 4G Active
[35][36] Additional LTE band for more bandwidth in many markets
1900 MHz PCS 2
LTE 4G Active
[37] Additional LTE band for more bandwidth in many markets
700 MHz Lower D/E 29
LTE 4G Active
[38] LTE band providing supplemental downlink bandwidth.
2300 MHz WCS 30
LTE 4G Active
[39] Additional LTE band for more bandwidth in select markets
