Samsung had released Android 5.1.1 update to unlocked and carrier models of the Galaxy S6 and the Galaxy S6 edge long back, but Galaxy S6 Active users weren't so lucky. However, AT&T has finally released Android 5.1.1 Lollipop update to the Galaxy S6 Active (SM-G890A) today.
Alongside the latest version of Android Lollipop, the update also brings Samsung Pay to the device. The update with build number G890AUCU3BOJE has been released as an OTA, and will be rolled out in phases, so it may take a few days before you see the update notification on your device.
If you are impatient like us, you can go to Settings » System » About device » Software update to manually check for the update on your Galaxy S6 Active. If you've installed the latest update already, do let us know about the performance of the device through the comments section below.