The Samsung Galaxy Alpha on AT&T started receiving the Android 5.0.2 update a few weeks ago. Now it seems that Galaxy Alpha users in South Korea are also receiving the same update. All of the three major carriers in South Korea (SKTelecom, Korea Telecom Freetel, and LG Telecom), are updating their variants of the Galaxy Alpha, and the software updates are also available for download through Samsung Kies.
The models receiving the Android 5.0.2 update include the SM-G850K, SM-G850S, and the SM-G850L. Once Samsung completes updating these models, we expect the Lollipop update will reach Galaxy Alpha owners in other regions. While you should receive an OTA (over-the-air) notification to update your handset, you can try manually checking by heading to Menu > Settings > About Phone > Software Version > Check for updates.
Once you have installed the Android 5.0.2 update, your Galaxy Alpha will receive a new version of the TouchWiz user interface which has been inspired by Google's Material Design language. You also get the updated Lockscreen notifications, a new "recent Apps" multitasking menu, enhanced battery life courtesy of Project Volta, performance improvements courtesy of the new 64-bit ART compiler along with other bug fixes and security enhancements.
source - SamMobile