Google rolls out Android 5.1 update of its mobile operating system with its general availability.

Android 5.1 Lollipop was already a reality for entry-level smartphones of Android One initiative with availability in some Asian markets. Google now formalizes a general availability of the update to its mobile operating system.

As usual, the deployment will be gradual and will be long depending on the reactivity of various manufacturers partnered. To date, adoption rates of Android 5.0 Lollipop is 3.3% . First served will be the Nexus 6 smartphone and Nexus 9 tablet.

Note, however, that the factory images for the Nexus 5, the Nexus 10 and Nexus 7 (2012, Wi-Fi) are available online on this address. Remember that it is wiser for ordinary users to wait for an OTA broadcast. With a factory image, you have to manually flash the device. It is a reset of the configuration and removing settings and data.

A new Android 5.1 feature precisely Device protection for lost or stolen devices that will remain unusable even if restoring the factory settings. The reason is that after reset, the operation will require entering the user name and the Google password associated with the device.

This is one of the few new features announced by Google to Android 5.1, but they are not numerous. It is therefore also question of official support for multiple SIM cards (on a device with multiple ports for SIM cards) for HD voice calls on compatible smartphones (and if it is proposed by the operator).

With Android 5.1 Lollipop, Google also mentioned improvements like to join faster Wi-Fi networks, Bluetooth devices associated to control for quick settings.