Windows Phone 101

,Personalized Windows Phone Start Screens

Windows Phone 8, Fair Use

Windows Phone is Microsoft's current series of mobile operating systems. It is the succesor to the Windows Mobile series. However the visual and underlying differences between the two operating systems are numerous. The two operating systems are not compatible. Applications designed for Windows Mobile will not run on Windows Phone. The good news is Windows Phone will be able to receive available updates automatically through Microsoft Update. Gone are the horrors of device ROM updates associated with earlier version of Windows mobile operating systems. There are also restore points available for Windows Phone. However there can still be hardware restrictions that prevent earlier WP devices from upgrading to a newer WP versions.

Windows Phone version history contains details about each version of WP. The first delivery of Windows Phone was operating system version 7 (OS 7.0) and was called release 7 (WP 7). WP 7 was delivered in October 2010. Code name Mango was then shipped the last quarter of 2011 as operating system version 7.1 (OS7.1) and was called release 7.5 (WP 7.5). The core of the WP 7.X operating systems was Windows Embedded Compact, with a layer of customized Windows Phone technology on top.

WP 8 (Apollo) is the latest WP release and was delivered in October 2012 as operating system version 8 (OS 8.0). In WP 8 Microsoft switched to a Windows NT core. This means WP 8 has many of the same elements as NT (NTFS file system, same networking stack, DirectX). This improves the amount of code reusability between WP 8 and Windows 8. However, WP 7.x devices can not be updated to WP 8. Also new applications compiled specifically for WP 8 will not run on WP 7.x. However Microsoft did release a free WP 7.8 update for legacy devices which included some features present in WP 8. Additional changes in WP 8 include:

  • Enhanced processor interaction with multi-core support
  • Support for multiple screen resolutions. In addition to WP 7's 800x400, added 1280x720 and 1280x768.
  • Multitasking enhancements. Location-based apps like exercise trackers and navigations aids can now run in the background.
  • Graphic API XNA is deprecated, being replaced with DirectX. See Nokia Developer article Windows Phone 8 Games - Migrating from XNA to DirectX
  • IE 10 which has a better engine for JavaScript
  • A new start screen with the availablitity of different size tiles
  • Built in technology to encrypt the entire device (operating system and data files)
  • Support fo the UEFI secure boot protocol to better protect against malware
  • Full support fo microSD cards

Windows Phone Releases and OS Versions

WP 7 and WP 8 releases directly correspond to WP operating system (OS) versions 7.0 and 8.0. However the WP 7.5 release uses OS version 7.1.

Windows Phone (WP) Release Operating System (OS) Version
Windows Phone 8 Windows Phone OS 8.0
Windows Phone 7.5 Windows Phone OS 7.1
Windows Phone 7 Windows Phone OS 7.0

OS Versions Compatability(OS 7.1/OS 8.0).

  • Apps that target OS 8.0 will not run on OS 7.1
  • Apps that target OS 7.1 will run on both OS 7.1 and OS 8.0

Microsoft's support page indicates mainstream support for WP 7.8 will end on 9/9/2014 and mainstream support for WP 8 will end on 1/2/2016. There is a lot of speculation and rumors about the next major version of WP. It is referred to as the "WP Blue" update and is expected to bridge the gaps between WP 8 and Windows 8. There are rumors of a centralized Notification Center and a new way to manage multitasking. Some also speculate about improvements in the area of speech recognition, especially when used with the WP Bing search app. The estimated release date is around the end of 2013 or the first months of 2014.

The Nokia Developer website contains an article called Co-development for Windows Phone 7/8 and Windows 8 guide which explains how to target multiple platforms including Windows Phone7/8, and beyond. The article compares various WP 7 and WP 8 components and discusses Cross Platform Code Reusability Best Practices and Portable Class Libraries.

Windows Phone Consumer Based Focus

Microsoft's previous mobile operating system (Windows Mobile) was focused more on enterprises, while it's latest mobile operating system (Window Phone) is more focused on the individual consumer. In WP you can still tie into Share Point and Exchange and create enterprise applications, but the primary focus of the newer WP platform is now the individual consumer. To help convey their new focus, Microsoft created the following video called "Meet the new Windows Phone: Reinvented Around You".

Windows Phone and Nokia

In early 2011 a partnership between Windows Phone and Nokia® was announced. Nokia stated they would use WP as their primary smartphone operating-system (replacing Symbian). Nokia also announced the integration of their services (Nokia Maps with Bing Maps, Nokia's Ovi store with the Windows Phone Store). AT & T® currently has two WP Nokia smartphones included with their wireless plans (Nokia Lumia 820, Nokia Lumia 920. Verizon Wireless® also has two WP Nokia smartphones with their wireless plans (Nokia Lumia 822, Nokia Lumia 928). T-Mobile® has the Nokia Lumia 521 WP 8 smartphone for $149.00 with no service contract. It is also available at Walmart for $129.88. This low-cost phone contains a 1GHz dual-core Qualcomm Snapdragon S4 processor. Most other competing WP 8 phones use the 1.5GHz processor. The Lumia 521 benchmarks at about 30% less powerful than the competing devices. Of course they cut back in other areas also, but for the price it is a great phone.

Update (5/28/13): Yesterday I bought a Nokia Lumia 521 at Walmart for $129.88 to use for application testing. View Nokia Lumia 521 Article

Update (9/2/13): Microsoft announced it is acquiring Nokia’s Devices & Services business for a reported 7.2 billion dollars.

The following video for the Lumia 920 Windows Phone is one of Nokia's most popular commercials.

Windows Phone 8.0 Hardware Requirements

Engadget published an article titled Windows Phone 8 Review which listed the minimum hardware requirements for WP8 as:

  • Qualcomm Snapdragon S4 dual-core processor
  • Minimum 512MB RAM for WVGA phones; minimum 1GB RAM for 720p / WXGA
  • Minimum 4GB flash memory
  • GPS and A-GNSS; GLONASS is supported if OEMs decide to include it
  • Support for micro-USB 2.0
  • 3.5mm stereo headphone jack with three-button detection support
  • Rear-facing AF camera with LED or Xenon flash, optional front-facing camera (both need to be VGA or better) and dedicated camera button
  • Accelerometer, proximity and ambient light sensors, as well as vibration motor (magnetometer and gyroscope are optional)
  • 802.11b/g and Bluetooth (802.11n is optional)
  • DirectX graphics hardware support with hardware acceleration for Direct3D using programmable GPU
  • Multi-touch capacitive touch screen with minimum of four simultaneous points
  • All Windows Phone 8 devices must include the same standard set of buttons: each one needs to have Start, back, search, power, camera and volume up / down keys

The requirements for WP 8 devices have increased slightly from the WP 7.5 requirements. For example the minimum RAM has increased from 256MB to 512MB. This could be part of the reason WP 8 will not run on WP 7 devices.

Windows Phone 7.x Hardware Requirements

From the Wayback Machine the WP 7 Hardware requirements are:

Standard Hardware

• At least 256 MB of RAM
• At least 8 GB of flash storage
• Support for both cellular and Wi-Fi connections
• An 800 x 480 WVGA display, capable of rendering most web content in full-page width and displaying movies in widescreen format
• A common set of hardware buttons that include: Start, Search, and Back buttons
• 4-point multi-touch screen
• A-GPS Assisted GPS
• Accelerometer

Optional Hardware

• Compass
• Gyro
• Primary Camera on the back of device
• Front-facing Camera

Metro - Microsoft's Design Language

Metro is a design language created by Microsoft and used with the Windows products. It stresses that a user interface should contain clarity, readablitiy, simplicity, and consistent motions. As a terminology update, Microsoft seems to be getting away from the name Metro, and is instead calling it Microsoft Design Language. While the design language started with the Windows Phone platform, Microsoft is using the design principles in more than just its WP products. They are using the principles to create a familiar experience across all of its product offerings. Microsoft has tutorial videos for the Design Language of Windows Phone which explain the guiding principles of their design language:

  • Light and Simple - focus on primary tasks with whitespace and simplication of interaction.
  • Typography - right balance of weight and position can create a visual hierachy. A specially-made version of Microsoft’s Segoe font family, Segoe WP, is used as the main font family for all typographical elements.
  • Transisitions - consistent set of user motions provides context for usability. Appropriate use of the pivot and panorama transistions.
  • Content, not Chrome - content becomes the main focus. Especially relevant with WP because of smaller screen size and touch interactions.
  • Honesty - design for form factor of hand-held device. Design simplified forms of interaction.

Live Tiles

Live Tiles are rectangular screen areas that can present information and launch applications. Live Tiles can be used to create an individualized user interface. Individuals can pin the tiles in a way that meets their particular needs. In WP 8 the Start Screen was enhanced with the availability of multi-sized tiles. The following Microsoft video is about the use of Live Tiles and the new Start Screen for WP 8.

Windows Phone Hubs

Microsoft design stresses "integrated experiences" that utilize hubs. A hub is more than just a place to store related applications. Each hub has content which may be obtained from different sources. Some content may be from online sources and other on-device sources. Hubs are typically panoramic. They extend across multiple screen widths because they provide more information than can fit into one screen. They are also extensible. Developers can add to the built-in hubs to add new features. The six hubs defined by Microsoft design are:

  1. People Hub - This is where your mobile contacts are stored. Also live feeds from social networks like facebook and photos.
  2. Music & Video Hub - Provides access to MP3s synched from your PC. Also videos, zune online media, and online radio.
  3. Games Hub - Brings integration with Xbox LIVE experience to WP. Games can only be lauched from the Games Hub.
  4. Pictures Hub - Makes it easy to take and share photos/videos to social networks. Integrates with web and PC.
  5. Office Hub - Offers mobile versions of Word, Excel, PowerPoint, and One Note. Also allows integration with Mobile Outlook for corporate users.
  6. Windows Phone Marketplace Hub - Places where WP applications can be downloaded.

Windows Azure - The Microsoft Cloud Platform

You probably have heard how Office 365 runs all the familiar Office Applications from the Azure cloud. This allows the same access to the applications in both the desktop and mobile environments.

And you probably know about SkyDrive, the free Microsoft application that allow users up to 7G of free storage in their Azure cloud. Available on both WP 7, WP 8 and Windows 8.

But did you know that Azure has been opened up to add support for Virtual Machines? An Azure virtual machine is a server in the cloud you can control and manage. You can quickly create a new VM in only a few seconds using the Windows Azure Management Portal. There are numerous VM templates from which to choose, or you can create a custom VM. Now you can potentially access many different applications from both desktop and mobile via Azure.

Azure has also been opened up to developers. Microsoft published the Windows Azure SDK which provides APIs and schema for programming in the Windows Azure environment. Microsoft Patterns and Practices provides a free book titled Developing an Advanced Windows Phone 7.5 App that Connects to the Cloud. The book (PDF format) and code samples can be downloaded. The 185 page book uses a fictitious company named Tailspin who's product is online surveys. The book uses the company through out the chapters to illustrate how to design and develop the mobile client application to run on WP 7.5. The book follows the developer as he determines the best way to design the mobile client application in the cloud.

Software Architecture

The software architecture was changed between WP 7 and WP 8. It moved from a Windows CE core to an NT core. XNA was deprecated, moving to DirectX. Device encryption and more secure boot protocols were added. Further changes include: additional screen resolutions, multitasking enhancements, and full support for microSD cards. The system diagrams below give an indication of how some of the software architecture was changed between WP 7 and WP 8.

In the Microsoft article Chapter 1: Windows Phone 7 Platform introduced to iPhone application developers the WP 7 software architecture was illustrated with the following diagram.

,WP 7 Software Architecture

Windows Phone 7 Architecture, Fair Use

Windows Phone Platform for Android Developers

Microsoft Open Technologies published a white paper called Windows Phone Guide for Android Application Developers. The first chapter of the white paper contains a side-by-side comparison of the Frameworks for Android and Windows Phone 7, as shown below:

,Comparison of Android and WP 7 Frameworks

Stack Comparision of WP vs Android, Fair Use

The white paper compares and contrasts Windows Phone with Android from a developers perspective.The Microsoft Open Technologies web site contains additional articles and videos about the experiences of developers who have ported their applications from Android to WP. They also offer a forum where the "App Guy" will respond to questions regarding porting applications to Windows Phone. There are also hooks into the MSDN documentation where appropriate.


Microsoft is making a strong effort to acquire market share in the mobile device segment. As a result, Windows Phone developers can expect to find free on-line training, low-cost smart phones, and comprehensive documentation of WP8. For more information about Windows Phone, see my Windows Phone Software and Hardware article.