The word "mobility," meaning the "capacity for motion," has been in English usage since at least 1425 (derived from the Middle French and ultimately from the Latin mobilitatem). However, the word has taken on new meaning in recent years as the interest in equipping both consumers and business users with "information anywhere, anytime, and on any device" has gained momentum. In fact, this mantra is in part lifted from Microsoft's vision statement that changed from Bill Gates and Paul Allen's original 1975 vision of "a computer on every desk and in every home." The new statement, "empower people through great software anytime, any place and on any device," was created in mid-1999 as Microsoft caught hold of this trend in mobility, and that ultimately resulted in you reading this book today. The Compact Framework is one part of Microsoft's vision for mobility. Microsoft likes to call this new and exciting period the PC-plus era.
This trend can be traced from the initial adoption and subsequent spread of cellular technology in the 1980s to the personal digital assistant (PDA), wireless Web phones, and smartphones of today. This technology has in turn helped transform not only business culture, but also our entire society into one that values and depends on mobility.
In 2001, an estimated 300 million wireless phones were used worldwide. This number is expected to grow to one billion by 2005.
At a societal level this capacity for motion has allowed people to integrate their work and home lives to a greater degree than ever before by managing the ever increasing flow of information through the use of these electronic tools. A recent study indicated that today, 19% of workers describe themselves as mobile workers. Clearly, the culture of mobility is now ingrained in today's workers, a fact that is clearly of interest to software developers and architects as they contemplate serving business users in the coming years.
And in fact, if industry forecasts are any indication, the adoption of mobile technologies and mobile life and work styles will only increase in the years ahead. For example, the research firm IDC in July of 2002 estimated that the number of mobile workers in the United States will increase from 92 to 105 million from 2001 to 2006, that segment growing twice as fast as the general workforce, while they estimate that 60% of Fortune 1000 companies will deploy a mobile application server by the end of 2003. However, this trend isn't confined to the largest organizations. In fact, a recent survey indicates that nearly half of small and medium-sized businesses are making wireless devices a spending priority. The end result is that by 2006, two-thirds of all workers will be mobile in some capacity, which includes everything from traditional "road warriors" to workers roaming with a wireless device on a corporate campus.
 VAR Business.com, "IT Strategies in SMB," August 2002.
As you might imagine, the combination of the acceptance of mobile work styles and more advanced technology has created a positive reinforcement pattern. As the demand for mobile technologies increases, the market responds with technological advances, and it is those very advances that drive demand for yet more sophisticated and integrated technologies. Several recent technologies that have participated in this feedback loop to fuel more productive applications include XML Web Services; wireless LAN (WLAN) technology, including the Institute of Electrical and Electronics Engineers (IEEE) 802.11 specifications; Wireless Application Protocol (WAP) for wireless Web phones; Virtual Private Networks (VPNs); wireless personal area network (WPAN) technologies, such as BlueTooth; the anticipated rollout of 2.5G and 3G networks by major carriers; and more sophisticated devices like the Pocket PC 2002 and 2003 with built-in support for streaming media, the Tablet PC, and smartphones; and, of course, robust development and runtime environments like the Compact Framework.
Further, in many cases, the technologies themselves are entangled within the loop. For example, as the number of business workers with wireless Internet capability (estimated by the IDC in November 2001 to increase from 2.6 million in 2000 to 49 million by 2005) increases, there will be a corresponding increase in the investment in public WLAN technology, where high-speed wireless networks are available in public spaces such as airports and malls for use by business workers and the public at large.
 Estimated by Cahners In-Stat/MDR in January 2002 to grow almost 60-fold by 2005.
This positive feedback loop will likely continue into the future as new technologies, such as Mobile IP and the Multimedia Messaging Service (MMS), are developed that enable multimodal communications to take advantage of 3G networks allowing users to exchange photos, sounds, video clips, and text messages. For a good overview of the technological landscape for wireless computing now and into the future see the book by Alesso and Smith in the "Related Reading" section at the end of the chapter.
Of course, there is more behind the need to create mobile applications than simply a chase-your-tail mentality where businesses adopt technology for technology's sake. By providing anytime, anywhere access to information, a business can immediately realize two primary benefits that have cascading implications.
Making faster and more informed decisions: If business users are able to access corporate information (e-mail, corporate documents, line-of-business data) on mobile devices and not only when they are officially in the office, they make decisions in a timely fashion. This often results in heading off problems, leading to increased revenue and greater customer satisfaction. The motivation behind faster decision making and more empowered employees has been proven many times over in the implementation of corporate Intranet portals where a cross section of job-specific information is accessible to business users, thereby enabling them to collate all the relevant data.
Improved data accuracy: Many of the first mobile applications businesses implement automate processes involving data collection. Using a mobile device, business users can capture electronically information that in the past involved handwritten forms, followed by faxing and data entry. This leads not only to information that is accurate, but also to reduced cycle times and a significant labor and cost reduction.
There is now a synergy of business rationale, culture, and technology that will enable business to create robust and exciting mobile applications. In the next section we'll unpack the concept of information anywhere, anytime, and on any device to look at several of the common mobile scenarios, along with the types of devices that are used.