Wireless Application Protocol

Wireless Application Protocol: A communications protocol that formats Web data for transmission over wireless Internet connections, letting you surf with a mobile phone or other wireless device.

If access to e-mail and the Web is critical to your mental and fiscal well-being, you need to know about the Wireless Application Protocol. Using a wireless Web service and a mobile phone, pager, or other wireless device that supports WAP, you can tap into the Web from almost anywhere, vendors claim. The wireless Web currently is more hype than reality, but that's changing. Faster wireless Internet access and an increasing number of Web sites that support WAP mean that wireless Web surfing could be the wave of the future.

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.

The Web, Wirelessly

The promise and the practice of WAP are far apart. WAP mobile phones haven't been hot sellers. Jim Cummiskey, director of consulting for Mobile Insights, estimates that only about 5 percent of the approximately 350 million mobile phones in use worldwide support WAP. None of the analysts we spoke to would guess how many of those WAP phones are actually used for Web access.

And because designers have to create Web pages that adhere to strict guidelines in order for them to work with WAP, you can access only a fraction of Web sites with a WAP phone. Mobile Insight's Cummiskey says that of the approximately one billion Web sites, only about 1.5 million are WAP-enabled.

WAP phones are widely available from all major mobile-phone makers including Motorola and Nokia, and usually retail for between $150 and $250 (when purchased along with a wireless service contract). A WAP phone may have a few extra keys to help you navigate a page, but the numeric keypad is still the main means of sending requests.

To get onto the Net, you'll need a Wireless Web service such as Sprint PCS Wireless Web. At press time, services and coverage are spotty, mainly limited to major U.S. metropolitan areas. And not all carriers offer WAP services in all areas.

Additionally, wireless Web services fetch a premium over voice-only mobile plans, although that's expected to change. For example, Sprint PCS Wireless Web costs $49.99 a month for 300 minutes of use, $10 more than voice-only service.

Sites to See

The list of things you can do with a WAP phone is slowly increasing as WAP sites and services roll out. E-mail is standard with most services, and you can get some basic information such as news (from CNN.com), weather (from Weather.com), and financial information ( from Bloomberg.com), to name a few.

In addition, Yahoo! offers a portal specifically for wireless users. E-commerce applications, not surprisingly, are also starting to become available. Amazon was one of the first Web retailers to offer WAP services, and this summer, Charles Schwab will launch its PocketBroker investing service for WAP-enabled phones.

Trends in wireless devices are likely to encourage the use of WAP. Upcoming mobile phones with built-in GPS receivers that pinpoint your location will allow you to automatically receive, for example, restaurant information or travel directions.

But for the longer term, the future of WAP is a bit hazy. Higher-speed wireless networks (up to 1 mbps) will start to become available in the next two to three years, as will better WAP devices with larger screens (some with color). When it comes to wireless, analysts agree that it's not likely to be a one-size-fits-all world. Carl Zetie, an analyst for Giga Information Group, says it's just not clear what wireless services people will use. The future of WAP is still up in the air.

This story, "Wireless Application Protocol" was originally published by PCWorld.

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