Even if we don't know exactly what phone it is yet.
Slated for release sometime in the spring of 2019, this mystery phone will be the second 5G-capable device on AT&T's network, alongside the mmWave Netgear Nighthawk 5G Mobile Hotspot, which should be coming out later this month. Both devices will feature Qualcomm's Snapdragon X50 5G modem.
Of course, a 5G device won't do you much good without proper 5G coverage, and while most markets might not see 5G until well into 2020, AT&T is already making its 5G network available in Atlanta, Charlotte, Dallas, Houston, Indianapolis, Jacksonville, Louisville, Oklahoma City, New Orleans, Raleigh, San Antonio, and Waco by the end of 2018.
The company also has plans of expanding its new network in the first half of 2019 — when Samsung's mystery 5G phone comes out — in Las Vegas, Los Angeles, Nashville, Orlando, San Diego, San Francisco, and San Jose.