The worldwide mobile wireless industry is quickly moving from traditional, voice-based cellular phone services to combined voice and data services, as a result of increasing demand for mobile data access and the deployment of high-speed wireless data services utilizing a variety of wireless technologies. For example, 2.5G/3G wireless services are being rolled out and used by a rapidly growing number of subscribers, and the number of WiFi hotspots and residential wireless LANs continues to grow substantially. The trend is clear: Cell phones, PDAs, and portable consumer electronic devices will likely merge into a single, handheld device as a universal personal communicator and computing platform (generally called a smartphone). Indeed, the market has seen a dramatic increase in smartphone sales when compared to the fairly slow growth of PDA sales worldwide.

Generally, a smartphone is a powerful, multi-function cell phone that incorporates a number of PDA functionality, such as a personal scheduler, calendar, and address book, as well as the ability to access Internet services and applications using either a keypad or a stylus. In addition to making a call from a smartphone, users can surf the web, check e-mail, create documents, play online games, update schedules, or access an enterprise network via a virtual private network (VPN). Wireless Internet access is enabled by means of cellular wireless networks - such as GSM/GPRS, CDMA, CDMA2000, or WCDMA, among others.

Bill Gates, Chairman and then Chief Software Architect of Microsoft, introduced his vision for the smartphone at the 2004 Mobile Developer Conference:

An increasing number of high-end cell phones and smartphones are equipped with powerful mobile processors (such as ARM processors), 64–128MB memory, 256–512MB flash storage, and even 2–4GB hard drives. Examples include the Motorola Q, SPV C600, and O2 XDA II. Some smartphones are PDA-based with handwritten recognition or a tiny keyboard, and phone functions as add-on features, such as Palm Xplore and Palm Treo. In fact, cell phone manufacturers and PDA manufacturers have different views regarding the future of smartphone devices. Unsurprisingly, each camp believes their device will prevail, with add-on functionality of devices from the other side. As wireless technologies and the mobile market continue to evolve, it is still too early to tell which approach will finally win. Nevertheless, one thing is certain: They both need reliable, high-performance, low-power consumption operating systems and software to leverage the wireless services.

Microsoft Smartphone refers to Microsoft's platform for next-generation cell phones - basically a software architecture with Windows CE as the operating system, plus a rich set of applications such as Pocket Internet Explorer and Pocket Outlook and powerful software development tools such as .NET Compact Framework and Visual Studio 2005. (We use Smartphone to refer to Microsoft Smartphone throughout this book and smartphone to refer to general multifunction cell phones.)

This book focuses on software development issues and practices on smartphones running Microsoft Windows Mobile software. There are, of course, other software development solutions. For example, Palm Inc., also provides a software development kit (SDK) for Palm OS smartphones, and you can find an SDK and supporting tools for Symbian OS, another popular cell phone operating system.