Preface

Numerous industry leaders in the mobile communications and content industries have announced in March 2001, that they will support XHTML (Extensible Hyper Text Markup Language) for the future evolution of mobile services. They also have declared to develop products, content and services using XHTML as content format. Mobile operators like the Vodafone Group, T-Mobil, Orange, Sonera, Telecom Italia Mobile have also announced to offer XHTML based services.

XHTML shall be the common language for content, regardless of whether it is for the traditional World Wide Web (WWW) services over the high-speed fixed Internet or the evolving mobile devices world.

One might assume, that an evolution from the well known HyperText Markup Language (HTML) to XHTML is a minor step, because both languages have a lot of commonalities. If we remember, how the design of the most web sites looks like and for which web browsers and graphics capabilities they have been optimised, we may expect some difficulties in this evolution process. In addition to that, if we compare the capabilities of some browsers for mobile devices like for Palm organizers or WAP cellular phones, we could imagine, that a revolution must take place.

Due to the very different capabilities of desktop computers and mobile devices and their communication links to the Internet, the consideration of the content language is insufficient. A complete redesign might be necessary, to support both devices' worlds.

It is not very difficult to design a web site for mobile browsers, but we should first know all requirements, capabilities and circumstances to satisfy all needs of a mobile web surfer and his mobile device. Therefore, the first chapter introduces the wireless networks', mobile devices', mobile web browsers' and the application protocol's capabilities. The second chapter gives an overview about other guidelines, especially those of the World Wide Web Consortium (W3C). The third chapter gives guidelines on the layout design and technical solutions like HTML and graphics. The forth chapter discusses the appropriate content formats, i.e. HTML or XHTML. The fifth chapter presents web authoring solutions including content negotiation and static and dynamic content creation techniques. The sixth chapter describes web testing and validation tools. The seventh chapter points out which tools the authors of this book have used to publish this book. The eighth chapter summarises the conclusions. The ninth chapter contains the list of abbreviations used in this book. The tenth chapter lists the references. The eleventh chapter gives some hints where you can find additional information. In order to show some examples of mobile-aware web sites, the authors have collected some addresses of these web sites in Chapter 12. It is only a short list, because of the world-wide lack of support for mobile browsers. The appendix shows examples of mobile web browsers' user-agent identification codes, lists a lot of XML editors and XSLT processors and summarises the most often used document type definitions for mobile web publishing.

Copyright © 2001-2003 by Rainer Hillebrand and Thomas Wierlemann