AOSP Android 5.1 Lollipop For 2011 Sony Xperia Devices
Your Xperia is old but your Xperia is capable for the Android Lollipop. XDA’s LegacyXperiaAOSP has started working upon your Sony Xperia 2011 phones to get them over Android 5.1 Lollipop. And the team behind this project seem to be successful. The team says that this is an attempt to get stable build of ROM, not just crazy changes to make things working. It is pure AOSP project and offer just AOSP experience. Just a few apps that were not Material were updated to using AOSP and the team will not add any other external feature/app/etc. This project is covering following devices:
Sony Xperia Active
Xperia Arc S
Xperia Neo V
Xperia Neo L
Xperia Mini Pro
As far, the ROM is still in beta stage and you might experience bugs. But we hope all the bad things will be ironed out. In order to try, you need to be on ICS 4.1.B.0.587 full ftf flashed. If you are on LT15i (Arc), flash LT18i (Arc S) ftf and MT15i (Neo) users need to flash MT11i (Neo V) ftf. For complete installation guide and downloading about this AOSP Android 5.1 project, head over to XDA thread.