14 DAY TRIAL // Sony said it would deliver Android 5.1 Lollipop for Xperia Z series back in July and kept its promise. Even though there might be some Xperia Z smartphones that have yet to receive the update at some carriers, the unlocked versions should be up to date by now.
But there's even better news for those who haven't upgraded to a newer Xperia smartphone, since Sony has just started the rollout of Android 5.1.1 Lollipop for the older Xperia Z series.
According to XperiaBlog, a new Android 5.1.1 Lollipop firmware 10.7.A.0.222 is now available for download to those who own Xperia Z series handsets.
In fact, the following devices are now eligible for the said upgrade: Xperia Z (C6602, C6603 variants), Xperia ZL (C6503, C6506 variants), Xperia ZR (C5503), Xperia Tablet Z Wi-Fi (SGP311, SGP312) and Xperia Tablet Z LTE models (SGP321).
Unfortunately, we don't have any information on which countries have received the update first, but we can safely assume that it will be made available worldwide pretty soon.
The update is mostly about bug fixes
It's also worth mentioning that the Stagefright exploit patch has been included in Android 5.1.1 Lollipop as well, which means that Sony won't be releasing it as a separate update.
The update doesn't come with an official changelog, but we already know that Android 5.1.1 Lollipop update is all about bug fixes. So, expect the upgrade to squash some of the bugs that were present in the previous version of Android.
Some under-the-hood improvements might have been added too, which should provide a smoother user experience with the Xperia Z series devices.
Those who qualify for the upgrade should check for its availability. Also, make sure your phone's battery is at least 50% charged prior to the upgrade, and that you are connected to a stable Wi-Fi network.