As Samsung has not announced any information on release of Android 5.1 Lollipop for Galaxy S4 LTE, here's an alternate options for users to update their Samsung S4 to latest Android version 5.1 Lollipop via Android 5.1 based CyanogenMod 12.1 (CM 12.1) ROM, it's an Android custom ROM to experience the material design on your Samsung Galaxy S4 LTE.

Lollipop 5.1

So, those who wish to have a experience of Android 5.1 Lollipop on Galaxy S4 LTE, here are the steps you need to follow.

Preparing Your Phone

  • This instructions are for Samsung Galaxy S4 (GT-I9505) only.
  • Phone should be fully charged to prevent interruption during process.
  • Back up the useful data using recovery tools like TWRP.
  • Install the USB drivers for phone on computer if not installed already.
  • Enable USB debugging mode though setting-developer options.USB debugging
  • Device should be rooted with CWM recovery and bootloader unlocked.

Galaxy S4 LTE Android 5.1 Update

Follow the process mentioned below -

  1. Download the Android 5.1 CyanogenMod 12.1 ROM file from the link.
  2. Download Google App's for Android 5.1 file.
  3. Copy the files to phones internal storage memory through USB cable.
  4. Switch off the phone and Reboot into recovery mode(Press and hold Home button, Power button and Volume Up key till logo appears).
  5. Backup the data in recovery mode by selecting Backup/Restore option.How to reboot from recovery mode
  6. After finishing Data backup perform WipeData/Factory Reset function from the menu (Use volume keys to navigate between options and home button to select the option) .factory reset
  7. In the main recovery menu select Install Zip from SD card.
  8. Select Choose Zip from SD card (Use volume keys to navigate and home button to select the file).
  9. Repeat the Step 8 for Installing Google app's.
  10. Return to the recovery menu and click on Reboot system Now.
  11. Wait till the process completes.

NOTE:First reboot may take several minutes to complete, please do not panic and let the process complete.

Congrats your Samsung Galaxy S4 LTE is now running Android 5.1 Lollipop, check the status in Settings > About phone.