An Introduction to WAP/WML

What is WAP?

• WAP stands for Wireless Application Protocol.• WAP is for handheld devices such as mobile

phones.• WAP is designed for micro browsers.• WAP is based on the Internet standards (HTML,

XML and TCP/IP).• WAP consists of WML (Wireless Markup

Language), WMLScript and WTAI (Wireless Telephone Application Interface) .

WAP Forum

• WAP is being developed under the guidance of the WAP Forum, founded in 1997 by Ericsson, Motorola, Nokia, and Unwired Planet.

• WAP Forum website: http://www.wapforum.org

Wireless Environment

• Small screen size

• Limited processing power

• Lack of a full keyboard

• Slow connection speed

• Costly access

A Different Design

• For the above reasons, WAP applications are typically made up of screenfuls of minimal text and lists of options, no graphic design.

• Success is measured by how quickly the user can find information or make a transaction and get out, not how long a user will hang on the site.

Micro Browser, WML, WMLScript

• WAP uses a Micro Browser (eg. Openwave Mobile Browser) that makes minimal demands on hardware, memory and CPU.

• Micro Browser displays info written in a restricted markup language, called WML.

• Micro Browser also uses a reduced version of JavaScript, called WMLScript.

How WAP Works

• WAP-enabled devices communicate with web server through a WAP gateway.

• The gateway converts WAP requests into HTTP requests to the web server.

• The gateway compiles the documents from the server into WAP Binary XML (WBXML) and send it to the phone.

What is WML?

• WML stands for Wireless Markup Language.• WML is an application of XML, thus needs to be

both valid (using WML elements according to the DTD) and well-formed (abiding by the stringent XML syntax rules).

• WML documents have extension .wml

WML Decks and Cards

• A WML application has one or more decks.

• A WML document is a deck.

• The max compiled deck size is 1.4 KB.

• A deck contains some cards (pages).

• A card contains a few screens.

• A screen holds three to six lines of text.

WML tags

• WML is mostly about text.• WML’s tags are similar to HTML’s, but

tags that slow down communication with handheld devices are not a part of the WML standard.

• The use of tables and images is strongly restricted.

• See textbook for a summary of WML tags.

A Simple WML Document

<?xml version="1.0"?><!--XML document<!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 1.1//EN""http://www.wapforum.org/DTD/wml_1.1.xml"><!--DTD<wml>

<card id="no1" title="Card 1"><p>Hello World!</p><!--always placed in <p> tag</card>

</wml>

<?xml version="1.0"?><!--XML document<!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 1.1//EN""http://www.wapforum.org/DTD/wml_1.1.xml"><!--DTD<wml>

<card id="no1" title="Card 1"><p>Hello World!</p><!--always placed in <p> tag</card>

</wml>

Result Mobile Phone Display

------ Card 1 ------

Hello World!

Validate WML Documents

• You may download an emulator program such as Openwave Simulator onto your computer. (http://developer.phone.com/download/)

• Or you can view WML pages using web-based emulators. (http://www.wapemulator.com)