What is WAP?

Here's what you need to know:

Wireless Markup Language, a distant cousin to HTML, is used to format Web data for the tiny screens used in WAP-enabled devices.
Wireless devices receive and transmit data at a mere 9.6-kbps, which makes for long waits while surfing.
Currently, only a small percentage of mobile phones support WAP and few Web sites serve up WAP content.

For accessing the Internet, handheld wireless devices--such as mobile phones--are poor substitutes for a PC. Low-power processors, miniscule amounts
of RAM, and (most importantly) limited screen sizes mean these devices can't handle the HTML graphics or the amount of content on a typical Web page. In addition, the typical data speed through digital cellular networks is 9600 bits per second, a fraction of the speed of a hard-wired Internet connection.

To compensate for these difficulties, a group of wireless companies developed Wireless Application Protocol. WAP consists of four parts: the Wireless Application Environment, the Wireless Session Protocol, the Wireless Transport Protocol and the Wireless Transport Layer Security. Of these, you'll only come face to face with WAE, which displays Web content on your screen.

WAE includes Wireless Markup Language, a variant of the familiar HTML used to display Web content on your monitor. WML can include text and hyperlinks, but no graphics. WAP mobile phones include a microbrowser--a stripped down version of the browser you're reading this with--that displays WML content.

While you only notice the WAE part of WAP, the other parts play essential roles in the background. The Wireless Session Protocol establishes and closes connections with WAP Web sites. The Wireless Transport Protocol helps make sure data packets get where they're going. Wireless connections are less reliable than wired connections, so it's vital to make sure data that you send and receive are accepted. The Wireless Layer Security, a subset of the Secure Sockets Layer often used for credit-card-based transactions on the Web, compresses and encrypts the data sent from your wireless device.

The Web Via WAP

When you connect to a wireless network and request access to a Web site that supports WAP, your mobile phone sends the request via radio waves to the nearest cell, where it's routed through the Internet to a gateway server. The gateway server translates the request into the Web's standard HTTP format and sends it to the Web site.

When the site responds, it returns HTML documents to the gateway server, where they're converted to WML and routed to the nearest antenna. The antenna sends the data via radio waves to your WAP device and the microbrowser displays the page.

Because of their graphics and other content, however, not all standard HTML Web pages can be translated to WML. In order to make a Web site WAP-ready, Web designers need to limit their content using specific guidelines. Because of these restrictions, only a small percentage of the Web is available to WAP-enabled wireless devices.