Sony Japan has officially confirmed that the OTA update of the Android 5.1.1 Lollipop firmware will come to the Sony Xperia Z2 and the Xperia Z3 smartphones and their variants by the end of this month.

The Xperia Blog reports that the update will bring improvements such as new options in the notification menu for Wi-Fi and Bluetooth. The Settings menu will also get refreshed icons along with new animations.

The Xperia Z2 (D6502 and D6503 models) and the Xperia Z3 (D6653) are going to receive the Android 5.1.1 Lollipop OTA update with firmware version 23.4.A.0.546.

The Xperia Z2 Tablet with model number SGP521 and other Xperia Z3 variants such as the Xperia Z3 Dual (D6633) and the Xperia Z3 Compact (D508 and D5833 variants) are confirmed to receive Android 5.1.1,  Android Geeks reported.

The publication further states that the Android 5.1.1 Lollipop for the Xperia Z2 and the Xperia Z3 variants will be rolled out in stages. Only a few handsets will receive the firmware update at the beginning. Once the initial release is successful, remaining owners of the Xperia Z2 and Xperia Z3 smartphones and tablets will receive it.

Users will also automatically see the arrival of the OTA update through a notification. Alternatively, users can look it for it manually by checking for system updates in Settings. Since the firmware update is big, downloading it through a mobile data plan can incur high charges. Hence, it is recommended to use a Wi-Fi connection to download the firmware.

According to another Xperia Blog report, Sony has released Android M Developer Preview build for 12 Xperia devices such as the Xperia Z3, Xperia Z3 Compact, Xperia Z3 Tablet Compact, Xperia Z2, Xperia Z2 Tablet, Xperia Z1, Xperia Z1 Compact, Xperia Z Ultra, Xperia E3, Xperia M2, Xperia T2 Ultra and Xperia T3. When the final version of the Android M is officially released later this year, these devices are likely to receive it first.