Microsoft Lumia phone
A man is silhouetted against a video screen as he poses with a Lumia 820 smartphone in this photo illustration taken in the central Bosnian town of ZenicaReuters

Microsoft's much-awaited Lumia Denim OTA (Over-The-Air) update has been reportedly pushed to Windows Phone 8 OS-powered devices in select regions of Europe and Asia including China and India.

Some Nokia Lumia 520 and Lumia 525 phone owners in the subcontinent have started receiving the new Lumia Denim update notifications, reported Windows Central.

To check the OTA update manually on the Lumia phone

Go to Settings >> Phone update >> Check for updates

It has to be noted that the software update is released in phases, so it will take some time to reach all corners across the globe.

Some of the improvements include voice-assistant Cortana, live folder options, enhanced Glance feature and many more.

Brief description of Key features of Lumia Denim update:

Cortana: This is an intuitive personal digital assistant, similar to Siri (in Apple devices) and Google Now (in Android Devices). Its persona is inspired by the popular artificial intelligence character (Master Chief's AI side-kick) seen in the much-loved "Halo" video game series. It is powered by Microsoft's search engine, Bing, and SensorCore technology..

[Note: This feature will be available in the UK and China as a Beta version. Whereas India, Canada and Australia will have access to Cortana as a public Alpha version.]

One of key aspects of Cortana is that it will learn your search and phone operation patterns (with your permission) and in time it gets better with predicting your behaviour. It checks in with you before she assumes you're interested in something and give suggestions/recommend options, such as nearest restaurant and best dishes in the locality. And in the morning, it will dish out real-time traffic and weather condition details to plan your travel route accordingly.

[Note: Microsoft has already released the intuitive voice-assistant feature Cortana with Lumia Cyan update in USA and other select regions, but emerging markets like India and China and other Asian and European regions will now finally get the Cortana feature in Lumia Denim update.

For US residents, Cortana now includes an improved natural language, car kit integration via Bluetooth for contacts, snooze reminders and calendar improvements.]

Glance Screen – Select Lumia devices can now show more at a glance with Bing Weather, or Bing Health & Fitness data, in addition to time and date, notifications and application data.

Live folders – This feature enables user keep the phone more organised. If you prefer to keep your apps or games organised, you can now put them into folders. Simply press, hold and drag an app over another to create a new folder on the Start screen. Each folder can be renamed by tapping on the text field above the open folder.

Apps Corner – This option lets users to create a customised Start screen, where only specific apps or games are accessible. This could be particularly useful in the workplace if you're issuing Windows Phones to employees.

SMS merge and forwarding – Select individual text messages to either delete them out of a messaging thread, or to copy and past them into a new message in order to forward them.

Snooze Times – now user can choose the snooze interval time within the Alarm app.

Consumer VPN – Maintain privacy and security when using data while connected to public Wi-Fi hotspots or even with your home Wi-Fi.

Mobile Web Site improvements in IE – Connect and browse even faster with improved downloading speeds on mobile websites.

Store Live Tile (US only) – The Store Live Tile displays featured apps and games that are the most popular in the Store, or most relevant for you.

Lumia Camera (only Select high-end Lumia series phones) – This app replaces the Nokia Camera as the official photo-editing application tool. Besides improved image processing algorithm (for low-light photography), new features include speed, Moment Capture and Rich Capture [More information, HERE].

Here is the official Microsoft Lumia Support video detailing the Lumia Denim update features:

Microsoft Lumia Denim Windows Phone Update Released in Select Regions Including India [How to Install - Video]Microsoft Lumia Support via YouTube