As of February 22, 2022, AT&T will begin phasing out its 3G/HSPA wireless network service in the U.S. Throughout the year, other U.S. wireless carriers will follow suit. If you're using a mobile device that does not support 4G LTE data and Voice over Long-Term Evolution (VoLTE) roaming, you will not be able to make or receive calls (including 911), send/receive text messages or use data while roaming in the U.S.