Android 5.1.1 is being pushed out by US Cellular for the Samsung Galaxy S6 and Galaxy S6 edge, bringing a number of fixes along with it.
If you are sporting a Galaxy S6 or Galaxy S6 edge on US Cellular, you will want to check your devices for an update. The carrier is now pushing out Android 5.1.1 to both devices, but unfortunately it has not released a proper change log for the update.
Source: iMore