AT&T has yet to give the official nod for the update, however it seems Galaxy S4 Active users are in the process of getting Android 4.3. The update is on the larger size in terms of MBs, and will have your handset jumping from Android 4.2.2. Along with the bump to Android 4.3, the handset will also be sitting with baseband version I537UCUBML2 once the update has been installed.
We first saw details of the update earlier in the month when several user reports surfaced on the xda-developers forums. A Galaxy S4 Active review unit here in the office has yet to receive the update, however based on the reports, we are seeing the file size measure in at well above the 700MB mark. Simply put, once on your device, this is one you will want to grab using WiFi.
Similar to the other Android 4.3 updates we have been seeing go out from Samsung lately, this one is bringing support for the Galaxy Gear. Some of the other highlights include the ability to drag and drop to uninstall applications. AT&T is also adding a few pre-installed apps with this update. They are billing these are "AT&T Signature Experience preloads" and they will be arriving as Kindle, Lookout, City ID, Password Keeper, Games and AT&T Mobile Protection.
Until we hear something direct from AT&T we will not know the extent of the rollout process. But in the meantime, we suggest AT&T users keep an eye out for an update notification. Once that arrives you will simply need to follow the prompts. Otherwise, those with a Galaxy S4 Active in their hand can navigate to Settings -> More (tab) -> About device -> Software update -> Check for updates to try and get the process started.
[UPDATE] Our previously mentioned review unit has just received the update and is now running Android 4.3.
VIA: Android Central