According to the update notification, the Android 5.1.1 Lollipop brings performance improvements apart from stability and bug fixes. Some users report that they have started receiving the Android 5.1.1 update notification on theLG Nexus 4 with build number LMY47V; LG Nexus 5 with LMY48B, and HTC Nexus 9 LTE with LRX22L.
Considering that Google has just started pushing the OTA (over-the-air) update to the Nexus 4 and Nexus 5 smartphone alongside Nexus 9 LTE tablet, users should expect the rollout to take a few weeks to be completed globally.
Once the Android 5.1.1 Lollipop update is available for your Google Nexus 4, Nexus 5, or Nexus 9 LTE tablet, it will be seen as a system notification. Users can also manually check for it by going into Settings > About Phone > System Updates or download the zipped and Google-signed OTA update file (via Android Police) that has been made available online by users who have already received the update. David Michie has posted a screenshot of the Android 5.1.1 update notification.
As of now, there is no detailed changelog of the new incremental update; though Android 5.1.1 is primarily anticipated to bring a fix for the memory leak issue, a bug that plagued Android 5.0 Lollipop users and even haunted some users on Android 5.1 Lollipop.
Last month, a developer changelog for Android 5.1.1 source code was spotted with a total of 34 commits. The majority of the commits were either changes to core OS functions, or for media decoding/ handling and telephony. The biggest appeared to be a fix for a camera timeout issue on the Nexus 5 and Nexus 6, a fix/ improvement for a remote pass through feature on Chromecast, apart from fixes for security issues.
Google last month initially published the factory images for the Nexus Player, the firm's streaming set-top box. In the same period, the Android Open Source Project (AOSP) was also updated with the Android 5.1.1 source code (build LMY47V).