Wireless Application Protocol (WAP)

WAP Forum

• WAP is the wireless application protocol devised by the WAP Forum for mobile devices
• The WAP Forum is not part of the WWW Consortium
• The early WAP specs ignored W3C work
• Belatedly, the WAP Forum is trying to integrate its work with the W3C, and is trying to make their markup language XML compliant

Handhelds

• Handheld devices are the target market, such as mobile phones and PDAs such as the Palm Handheld
• Characterised by
  • less powerful CPUs
  • Less memory (ROM and RAM)
  • Restricted power consumption
  • Smaller displays
  • Different input devices e.g. keypad

Wireless networks

• Less bandwidth e.g. 9.6 kbps
• More latency (1/3 second per satellite hop)
• Less connection stability
• Less predictable availability

Web model

WAP model

Example WAP Network

WML

• WML is Wireless Markup Language
• It is based on the idea that a document is a deck of cards
• It supports responses to user actions
• WML is (now) specified by an XML DTD

WAP Tutorial

iMode

• WAP and WML are being promoted in Europe and the US
• The number of WAP servers is currently very small
• The charges for WAP connections are time-based
• There is a small number of WAP phones available
• iMode is the Japanese equivalent
• iMode has over 10 million users in Japan
• iMode users pay on data volumes downloaded rather than on a time basis

cHTML

• iMode uses a subset of HTML called cHTML (Compact HTML)
• cHTML is a W3C proposal
• It simplifies HTML by leaving out computationally heavy markup such as
  • JPEG images
  • Tables
  • Image maps
  • Multiple character fonts and styles
  • Background colour and image frame stylesheets
• iMode adds a bunch of additional characters to cHTML to reduce text
  • joy
  • kisses
  • sadness
  • hot spring baths..

iMode and Web Browsers

• WML markup will not show in current Web browsers as it is not HTML
• cHTML markup will show in browsers as it is a subset of HTML
• Additional iMode tags will be ignored
• Additional iMode characters will be ignored
• So, iMode documents will convey most of their meaning in ordinary Web browsers
• Most current iMode content is in Japanese, though...