The Windows Phone platform has struggled to find the same success as its Android and iOS rivals. Microsoft is attempting to change this with Windows 10 Mobile, a new smartphone operating system designed to synchronise with the well-received Windows 10 desktop and tablet OS.
Windows 10 Mobile has already launched in the US, via the Microsoft Lumia 950 and Lumia 950 XL smartphones, and is due to arrive in the UK the same way. Read on for more details on the new OS, and don't forget to check our Windows 10 Mobile hands-on review - using the Lumia 950 XL - to see what we think.
Microsoft has now confirmed that Windows 10 Mobile will be available as an update to existing Windows Lumia Phone devices alongside the two new Lumia handsets - the Lumia 950 and Lumia 950 XL - which shipped on 3 December 2015. It also runs on the Lumia 550, which released in Januray 2016.
On its official blog Microsoft has listed the devices that should now be able to upgrade to Windows 10 Mobile as follows: Lumia 1520, 930, 640, 640XL, 730, 735, 830, 532, 535, 540, 635 1GB, 636 1GB, 638 1GB, 430, 435, BLU Win HD w510u, BLU Win HD LTE x150q, and the MCJ Madosma Q501.
Like Windows 10 prior to its launch, test builds of Windows 10 Mobile were available to members of the Windows Insider programme. However, as we found in our Windows 10 Mobile Insider Preview hands-on, these preview builds weren't quite ready for everyday use; features were missing, certain apps wouldn't open and performance was generally sluggish. We've found the launch build to be much more stable and feature-rich, although it still feels like a work-in progress compared with the most recent iOS and Android versions.
Windows 10 Mobile will be a free upgrade to certain Windows Phone 8.1 handsets, so like its predecessor, as well as Android and iOS, it won't be a paid-for product. The only requirement, besides owning a suitable phone, is to install the Lumia Denim software update beforehand.
The downside is that control over when each phone will receive the upgrade lies entirely with Microsoft. Furthermore, not all eligible users will see their phones upgraded on launch day. It could be released in waves, with some handsets receiving the update days or even weeks before others.
Microsoft announced at the 2015 Mobile World Congress in March that devices currently running Windows Phone 8.1 will be upgradeable to Windows 10 Mobile.
However, the company has confirmed only a limited list of Microsoft/Nokia Windows Phones due to upgrade to Windows 10 Mobile: the Lumia 430, 435, 532, 535, 540, 640, 640 XL, 735, 830 and 930.
This excludes the Lumia 520, 530, 625, 630, 635, 925, 1020, 1320 and 1520, all of which are still being sold on Microsoft's website. That isn't to say these devices will never be upgradeable to Windows 10 Mobile - indeed, all of them are compatible with the Windows 10 Mobile Insider Preview - but Microsoft may stagger the rollout by temporarily limiting it to certain devices.
In any case, hope remains even for non-Nokia smartphones. The HTC One M8 For Windows isn't included on Microsoft's list, but received its first compatible Windows 10 Mobile Insider build earlier this year.
Indeed, the 'Recommended components' listed on Microsoft's own site do not specify the need for a Lumia handset. These recommended specs suggest that at least 1GB of RAM, a 3.5in display or larger and at least a 1,400mAh battery should be included on all Windows 10 Mobile devices. Even though these aren't the absolute minimum specs, they're still quite low by modern smartphone standards, so the range of compatible models should be quite broad.
Microsoft has, of course, released two phones for Windows 10 Mobile, the Lumia 950 and Lumia 950 XL.
Even prior to launch, Windows 10 Mobile was equipped with a range of interesting features.
For instance, data and settings, as well as things like alarms and notifications, will automatically sync between a Windows 10 Mobile handset and a Windows 10 machine logged in under the same Microsoft account.
This is part of an attempt by Microsoft to ensure that Windows 10 Mobile mirrors the full Windows 10 as closely as possible. Windows 10 Mobile also includes OneDrive, so documents and photos can be synced with Windows 10 desktops, laptops and tablets via the cloud.
Universal Apps are another key tool in Microsoft's plan to homogenise the mobile and desktop experiences. Comprising first-party and third-party apps vetted by Microsoft, Universal Apps will work on Windows 10 and Windows 10 Mobile, and share feature parity across the two platforms, right down to similar or identical UIs.
Currently confirmed Universal Apps include Microsoft Office Mobile and Microsoft Edge, a new and much-improved replacement browser for Internet Explorer. Third-party Universal Apps from The Guardian and Audible have also since been added.
Universal Apps play a key role in Continuum, a feature which allows Windows 10 Mobile-powered smartphones to act as a pseudo-PC by connecting to a display, mouse and keyboatd via a separate Microsoft Display Dock. This produces a desktop-style UI on the screen, and allows Universal Apps to run on the display while the handset can continue to be used for other things.
Cortana, Microsoft's digital assistant, reappears in Windows 10 Mobile after being introduced in Windows Phone 8.1. Cortana can still be used to set up reminders and search the web, but has received a few upgrades.
It's possible to send emails via voice commands in Windows 10 Mobile, for instance, and Cortana will tailor search results according to the user's tastes and preferences.
These preferences - for certain music, films, food and the like - can be added directly, or Cortana can 'learn' them over time. The digital assistant is also integrated into the Edge browser, and can search for highlighted words, names and locations without navigating away from the page.
A redesigned Action Centre is also present. Similar to its excellent Windows 10 counterpart, the Windows 10 Mobile Action Centre is a highly versatile menu that, in addition to listing notifications, provides quick access to and/or toggle buttons for the Camera app, Airplane Mode, WiFi settings, brightness settings, Bluetooth, torch, VPN setup tool, rotation lock, general Settings menu and more.
The Windows 10 Mobile interface isn't too far off that of Windows Phone 8.1, although it has been updated to look a bit more modern. Live Tiles are translucent, so they don't completely block out custom backgrounds, and a new list of recently installed apps is now instantly accessible by swiping to the right on the home screen.
One of the most attractive features of Windows 10 Mobile is its new-found compatibility with Android and iOS apps. Microsoft has announced various toolkits aimed at getting app developers to port their creations to the new Windows OS.
These include one that will enable Android Java and C++ code to run on Windows 10 Mobile, and one that allows developers to compile iOS objective C, used for iPhone and iPad apps, in Visual Studio to create a Windows version.
In theory, this should result in a much greater selection of Windows 10 Mobile apps compared with Windows Phone 8.1.
New features continue to be added in the ongoing preview builds. Windows 10 Mobile Insider Preview Build 10572, for instance, enabled missed call notifications to be sent to a PC running Windows 10, allowing users to respond with text messages sent straight from this PC instead of their smartphone. Universal apps for Skype calls, messaging and video were also been added in this build, as was the ability to book Uber cabs through Cortana and save offline maps to an SD card.
Security and privacy
Universal Apps sees Microsoft taking the Apple-like position of requiring the app to run in its own sandbox. In the event that the app is infected with malware, this should stop the infection spreading, as the app's processes are run separately from the rest of the system.
Developers needn't worry too much about Windows 10 Mobile becoming a closed-off ecosystem entirely under Microsoft's control, as only apps with Universal App functionality will need to meet the sandbox requirement.
A recent Windows Insider build update also added a Device Encryption function for securing the handset's internal storage, similar to a feature offered in Android. It's entirely optional, but should be a welcome layer of additional protection.
Lastly, Windows 10 Mobile will add the ability to set individual app permissions for location, something that was missing in Windows Phone 8 and 8.1.
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