Google's Android is currently rolling out a new software build, Android 5.1 Lollipop (LMY471), to smartphones starting with the brand's own, Nexus 4, 5, and 6.

According to the official Android Blog, the new build features numerous capabilities such as support for smartphones with multiple SIM cards, Device Protection and High Definition (HD) voice on compatible phones under the following mobile networks: T-Mobile and Verizon.

The update also provides enhancement for Wi-Fi and Bluetooth connectivity control through Quick Settings.

Moreover, "On-Body Detection", an interesting security feature can be observed when the mobile phones are updated to Android 5.1. This feature works when the phone won't unlock until it is idly set apart from any part of the user's body. This is unlike the security feature on Android 5.0 with the Smart Lock detecting the user's face prior to unlocking the device.

There have been minor bug fixes regarding the multiple SIM handling as well and cleaning up previous mistakes from the Android 5.0. However, according to AndroidPolice, concerns with process killing, battery drain and memory leak haven't been addressed thoroughly with the update.

Only users with Nexus 4, Nexus, 5, Nexus 6, Motorola smartphones and Google Play Edition will be given update priority as it rolls out throughout the month. An alternative using a manual update has been set for handlers with AT&T subscriptions, for Nexus 6, but reports say users are experiencing minor issues, writes Phonearena. On a side note, Nexus 9 will also be part of the update as well as the newly released Moto E.

Android 5.1 Lollipop had surfaced in December for multiple soak tests on many Android One devices. After which, rumors of a February or March release were eminent including the changelog which was provided to Androidpit in December.

There has been no information set by the developers of Android as to when will the new build update on other devices such as Samsung, HTC, ASUS and etc.