The proliferation of wireless consumer devices, such as personal digital assistants (PDAs), digital cell phones and two-way pagers is increasing the demand for m-business and m-commerce. Wireless devices enabled with Internet access allow users to manage their per-sonal and professional lives while away from their desktop computers. By using PDAs, such as the Palm™ handheld computer and the Pocket PC, as well as digital cell phones and laptop computers, users can buy airline tickets and groceries, trade stocks and check their e-mail from remote locations.
Wireless communications technologies are categorized and identified by generation. These include first generation (1G), second generation (2G), two-and-a half generation (2.5G), third generation (3G) and even fourth generation (4G). The analog cell phone is an example of a first-generation technology. As wireless communications evolved from analog to digital transmission, first-generation technologies gave way to second-generation technologies. Second-generation technology, which offers transmission speeds of up to 9.6Kbps, is the current standard for the United States. Today, service providers are devel-oping the next generation—third generation (3G)—of transmission technologies, which promises speeds far greater than those of standard dial-up connections.
The 2.5-generation technologies represent an intermediate step between second-genera-tion and third-generation technologies. These technologies rely on networks that use packet-switching technologies (information is divided into packets when it is sent and then reassem-bled at the receiving end). Many countries, with the exception of Japan and parts of Europe, do not have the spectrum available or the networks to support 3G technologies. Even in Japan and Europe, 3G technologies are not expected to be widely available until 2003 or even 2005. The services are not expected to be released in the United States until 2006.
3G technology enables increased data speeds, larger network capacity and transmis-sion support of multiple data types, including streaming audio, video, multimedia, voice and data. Japan’s NTT DoCoMo leads the world in the development of third-generation technologies with the anticipated release of Wideband Code Division Multiple Access (W-CDMA). NTT DoCoMo is also the developer of i-mode, the most popular wireless Internet service, which boasts over 25 million subscribers. Using a compact version of HTML called cHTML, i-mode offers voice services combined with text messaging, animated graphics and Web browsing.
In the wireless world, there are many programming platforms and technologies. The Wireless Application Protocol (WAP) and Wireless Markup Language (WML) are the most commonly used technologies for wireless communications in the United States; they also are popular in parts of Europe and Asia. In the following sections, we demonstrate how to build wireless applications that use WAP/WML.
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