The term “mobile computing” includes mobile users, devices, applications, and networks. All of these components differ from their stationary correspondents. They imply such issues as location awareness, network quality of service, drastically limited device capabilities, and limited power supply. Perhaps more dramatic is another issue, platform proliferation. This heightens the importance of application design and development independent of the platform. The platform proliferation issue can be addressed effectively by using nonproprietary methodologies and tools, such as unified modeling language (UML) and Extensible Markup Language (XML), as much as possible. That is the topic of this book.

The author is an executive consultant who works with a variety of companies as an architect or chief technology officer. He has had a variety of engagements in the mobile arena with startups as well as with Fortune 500 companies.

The book is structured into 19 chapters, grouped into four sections. The first section (four chapters) provides an introduction to mobile computing. Chapter 1 emphasizes the dimensions of mobile computing versus the conditions of a mobile user. These considerations lead to a high-level plan of the mobile software architecture. Chapter 2 looks at some commercial and open source frameworks and tools for mobile software development. There are two approaches: using a unifying language (for instance, Java or wireless application protocol) or a unifying operating system (for instance, Windows CE or EPOC). A new and different approach is Qualcomm’s BREW. The designers of BREW have approached the problem of building development platforms for software applications from a more hardware-oriented perspective. Chapter 3 is devoted to XML. The author presents document object model (DOM) and simple application programming interface (API) for XML (SAX) parsing of XML Web servic!es, followed by some key XML technologies for mobile computing, including: XML schema, Wireless Markup Language (WML) and XForms, call controlXML and XML Pipeline, Speech Synthesis Markup Language (SSML), and resource description framework (RDF). Chapter 4 looks at UML; though not all mobile platforms use object-oriented programming (OOP) technologies, most do. UML provides an industry-accepted way to document requirements, design, and implementation.

The second section (four chapters) looks at user interface problems. Chapter 5 shows how to separate concerns regarding particular user interfaces (such as graphical ones) from the concerns shared by all types of user interfaces. Chapter 6 describes how to complement generic user interfaces, and render graphical user interfaces for a variety of visual text-driven devices, such as personal digital assistants (PDAs) and data-enabled cellular phones. Chapter 7 deals with voice user interface (VUI) technologies, such as voice recognition, text-to-speech technologies, voice transcription, and VoiceXML. Chapter 8 combines the information from the previous chapters, and shows how to design interfaces that use multiple media types and multiple channels.

The third section (six chapters) covers a disparate set of topics, each relating to a specific dimension of mobility, or addressing a specific aspect of the mobile condition. Chapter 9 focuses on mobile agents and peer-to-peer architectures for mobile applications. Chapter 10 looks at various wireless technologies and their effect on architecture, protocols, and other aspects of design and implementation. Disconnected users need to access data on their devices, even when they are not connected to the network. Chapter 11 addresses this issue, and discusses mobile data synchronization and replication. Chapter 12 covers two key dimensions of mobility--location sensitivity and active transactions--and shows how to incorporate such functionality into the design, and how to implement it for some of the frameworks and tools discussed in the first section. Chapter 14 discusses mobile security issues.

The last section (five chapters) pulls everything together. Chapter 15 goes back to the dimensions of mobility, to explain how to apply a wise methodology to mobile development. It relates the specifics of a UML-based development cycle to mobile applications. Chapter 16 discusses architecture, design, and technology selection for mobile applications. It stresses practical concerns with architectures for mobile devices, and concludes with some architectural patterns. Chapter 17 is about hurdles--voice user interface hurdles, multimodal applications hurdles, and hurdles with building location-based applications. Chapter 18 discusses testing issues: how to validate mobile use cases before development; the effect of mobility dimensions on software testing, stress testing, and scalability; and how to test location-based functionality. Chapter 19 is a case study, which covers the gathering of requirements, the detailed design, and the implementation.

This book discusses engineering issues related to various facets of mobile computing. It speaks about concerns that mobile developers face, regardless of the platform used.