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Wireless Application Protocol (WAP) is an open international standard for applications that use wireless communication, for example Internet access from a mobile phone. WAP was designed to provide services equivalent to a Web browser with some mobile-specific additions, being specifically designed to address the limitations of very small portable devices. However, during its first years of existence WAP suffered from considerable negative media attention and has been criticised heavily for its design choices and limitations.
Technical specificationsThe primary language of the WAP specification is WML, the Wireless Markup Language, which has been designed from scratch for handheld devices with phone-specific features following the XML guidelines. The official body developing WAP used to be the WAP Forum. The WAP Forum has consolidated (along with many other forums of the industry) into OMA (Open Mobile Alliance), which covers virtually everything in future development of wireless data services. WAP 2.0The new version of WAP, WAP 2.0, is a re-engineering of WAP using XML. Some observers predict that this next-generation WAP will converge with, and be replaced by, true Web access to pocket devices. Whether this next generation (Wireless Internet Protocol to mobile) will still be referred to as WAP is yet to be decided. XHTML Basic, a subset of XHTML, is made to work in mobile devices. WAP PushWAP Push, available since WAP 1.2, has been incorporated into the specification to allow WAP content to be pushed to the mobile handset with minimum user intervention. A WAP Push is basically a specially encoded message which includes a link to a WAP address. A WAP Push can be delivered over WAP bear or SMS bearer. On receiving a WAP Push, a WAP 1.2 or later enabled handset will automatically give the user the option to access the WAP content. In this way, the WAP Push directs the end user to a WAP address where particular content may be stored ready for viewing or downloading to the handset. The address could be a simple page or multimedia content (e.g. polyphonic ring tone) or a Java application. Using WAP Push, one can make it easier for end users to discover and access new mobile services. Commercial statusFailure?WAP was intended as a mobile replacement for the World Wide Web. However, its idiosyncratic protocols cut users off from the true HTML / HTTP Web, leaving only native WAP content and Web-to-WAP proxy content available to WAP users. WAP's charging model, where users have to pay by the minute regardless of the amount of data received, has also been criticized. WAP was hyped at the time of its introduction, leading users to expect WAP to have the performance of the Web. One telco's advertising showed a cartoon WAP user "surfing" through a Neuromancer-like "information space". In terms of speed, ease of use, appearance and interoperability, the reality fell far short of expectations. This led to the unkind, but widely used phrases: "WAP is crap", "Worthless Application Protocol", "Wait And Pay". The main reasons for the failure of WAP were price and closedness. Even though GPRS made WAP cheap, and cell phone operators opened their gateways to access all of the Internet, WAP did not quite take off. Success?However, WAP has seen huge success in Japan. While the largest operator NTT DoCoMo has famously disdained WAP in favor of its in-house system i-mode, rival operators KDDI (au) and Vodafone Japan have both been successful with the WAP technology. In particular, J-Phone's Sha-Mail picture mail and Java (JSCL) services, as well as au's chakuuta/chakumovie (ringtone song/ringtone movie) services are based on WAP. After being shadowed by the initial success of i-mode, the two smaller Japanese operators have been gaining market share from DoCoMo since spring 2001. Korea is also leading the world in providing advanced WAP services. WAP on top of the cdma2000 network has been proven to be the state of the art wireless data infrastructure. According to the Mobile Data Association, June 2004 has seen a considerable increase of 42% in its recorded number of WAP pages viewed compared with the same period in 2003. This takes the total for the second quarter of 2004 to 4 billion. From 2003/2004, WAP has made a stronger resurgence with the introduction of Wireless services (such as Vodafone Live!, T-Mobile T-Zones and other easily-accessible services). Operator revenues are generated by transfer of GPRS and UMTS data which is a different model to the Web, and usage is up. People are starting to use WAP and the early failures have been masked, as the real point of the system – access to wireless services and applications – has come to the forefront. Spin off technologies, such as MMS (picture messaging), a combination of WAP and SMS, have further driven the protocol. Along with an appreciation of device diversity and the changes to underlying pages, to be more device-specific rather than being aimed at lowest common denomintator, has allowed for the content presented to be more compelling and usable. Finally it looks like WAP is having its day. Protocol design lessons from WAPThere has been considerable discussion about whether the WAP protocol design was appropriate. The initial design of WAP was specifically aimed at protocol independence across a range of different protocols (SMS, IP over PPP over a circuit switched bearer, IP over GPRS etc). This has led to a protocol considerably more complex than an approach directly over IP might have caused. Most controversial, especially for many from the IP side was the design of WAP over IP. WAP's transmission layer protocol, WTP, uses its own retransmission mechanisms over UDP/IP to attempt to solve the problem of TCP's inadequacy for high packet loss networks. Related articlesExternal links
WAP URLsWAP URLs currently active for use in WAP research and information access.
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