Delivering Wireless and Voice Services with XML
IN THIS CHAPTER
• The Vision of Ubiquitous Computing
• Key Technologies
• Wireless Applications with WAP and WML
Voice Applications with VoiceXML
Of all the applications of XML discussed in this book, wireless and voice services are two of the most complex and problematic, and yet they are also the most promising. Both technologies play critical roles in many vendors’ multiple touchpoint visions, from IBM’s Pervasive Computing to AOL Time Warner’s AOL Anywhere. Such vendors envi-sion the Internet as a global enabler of communication among both business and con-sumer users anywhere, at any time. Such visions require that users are able to access Internet-based applications via multiple devices, including traditional telephones, mobile telephones, wireless PDAs, pagers, and whatever other devices are over the horizon.
The technology required to bring this vision of the ubiquitous Internet to life, however, has been unexpectedly challenging. Voice-recognition software, the key to voice services, is only just now maturing. The wireless world has also been struggling with its immatu-rity; wireless technology is characterized by competing communications protocols, inconsistent user interfaces, and confused, disillusioned users.
Unfortunately, the advantages of XML only apply to a relatively small portion of the issues surrounding wireless and voice services. XML can provide a simple way to format and translate data between the various interfaces and the back-office applications that talk to them. In addition, the XML-based technologies of XSL and XSLT are well suited to translating interface-neutral content for the wide variety of user interfaces. However, XML cannot improve voice recognition or solve the problem of incompatible wireless communication protocols. Therefore, it is important to read this chapter with a wary eye. Using the technologies described here is easier said than done.
In this chapter, you will learn
What wireless and voice services are and how to incorporate them into a Web application architecture
The application architecture for wireless services based on the Wireless Application Protocol (WAP) and how it fits into a multiclient Web application architecture
How to develop applications using the Wireless Markup Language (WML), includ-ing an overview of the WML language and a development primer
The application architecture for a VoiceXML service and how it fits into the multiclient Web application architecture, including an overview of the VoiceXML language.