WAP/WML Introduction and Resources
The rise in popularity of internet in the late 1990s largely excluded users on mobile devices. Limited hardware resources, small low-resolution screens, and lack of bandwidth could not process and display internet content optimized for viewing on personal computers.
The solution was introduced with the appearance of the Wireless Application Protocol (WAP) and the Wireless Markup Language (WML). WAP is a technical standard for transmitting information over a mobile wireless network, while WML is a markup language for devices that implement WAP, providing most of the functionality of HTML for underpowered mobile devices.
The WAP standard was introduced by the WAP Forum, created in 1989 by the leading players in the mobile industry, with the main goal of creating a standardized protocol for data transmission using various wireless technologies. The first WAP site was launched in October 1999 by the Dutch mobile operator Telfort BV.
In 1998, the WAP Forum also published the WML 1.1 standard, based on Openwave's HDML, Nokia's Tagged Text Markup Language (TTML) and Ericsson's proprietary markup language for mobile content. WML 2.0 was specified in 2001, but was never widely accepted, as it was taken over by more advanced technologies.
The WAP Forum was consolidated into Open Mobile Alliance (OMA) in 2002, along with many other mobile industry forums.
In the time of its introduction, WAP was marketed very aggressively, which led users to expect WAP performance to be on par with non-mobile, fixed internet access. When the first WAP-enabled mobile devices appeared in 1999, they fell short of users' expectations, which was to be expected given their limited hardware resources.
By 2003, WAP made a stronger appearance in Europe, thanks to the introduction of additional wireless services like T-Mobile or Vodafone Live! Operators generated revenue on the GPRS and UMTS data transfer, and WAP traffic in the UK doubled from 2003 to 2004.
WAP was widely adopted in Japan, while in the USA, WAP never really took off. WAP was never fully embraced by major markets such as the US, China, and a lot of other nations, particularly in Asia.
Since then, WAP has largely gone out of use in Europe, as modern mobile devices enabled full support for HTML and CSS. Multimedia Messaging Service (MMS) still remains in use, as a combination of WAP and SMS technologies.
WAP/WML features and design
At the time of its appearance, WAP made it possible for mobile service providers to offer interactive data services, ranging from email, sports results, basic news services, and ringtone downloads to the public.
The WAP standard describes a protocol suite allowing for interoperability of devices and software using different network technologies like CSD, GPRS, CDMA or UMTS. WAP defines five protocol layers: Wireless Datagram Protocol (WDP), Wireless Transport Layer Security (WTLS), Wireless Transaction Protocol (WTP), Wireless Session Protocol (WSP) and Wireless Application Environment (WAE). The WAE defines the Wireless Markup Language (WML) as the primary markup language in WAP versions 1.x. The primary markup language in WAP 2.0 is XHTML Mobile Profile.
WML documents are in fact XML documents that conform to the WML Document Type Definition (DTD). WML documents can be validated using the W3C Markup Validation Service.
A single WML document is also known as a "deck." All data in a deck is structured into one or more "cards" which are in fact pages, and each of them represents a single user interaction.
With the increase of processing power in modern mobile devices, newer devices adopted XHTML and standard HTML instead of WAP/WML.
Learning WAP/WML development should not be too complicated if you have a basic understanding of XML and web programming. All you need is a text editor and a WAP/WML emulator. Setting up your web server to support WAP is also easy to do, and detailed instructions are available online.
However, most major companies and websites have discontinued the use of WAP in the last years, and in fact, most modern mobile internet browsers cannot render and display WAP/WML web pages at all.
Today, WAP/WML is a legacy technology at best. It is no longer widely used, although there are still some niche applications that may require knowledge of WAP/WML. The technology is being phased out of these small niches as well.
There are many resources for WAP/WML available online, since it was very popular during its heyday, so finding you way in WAP/WML should not be a problem:
- Open Mobile Alliance Wireless Application Protocol Downloads lists the latest WAP Forum conformance releases, along with the specifications.
- WML Tutorial by Tutorials Point will give you a thorough enough understanding of WML to develop WAP applications. This site also has links to other useful WAP/WML resources.
- Learning WML/WAP by Steve Schafer is a series of articles describing how to provide web content to mobile devices using WML. It is very detailed, covering everything you need to know about WAP/WML, from basic examples to advanced uses.
- Introduction to WAP from Academic Tutorials also has a nice and useful WAP/WML tutorial section.
- WinWAP is a WML browser that works on any Windows computer. You can browse WML files locally from your hard drive or the Internet with HTTP (as with your normal Web browser).
Unfortunately, some very useful tools, like the official WAP emulators from Nokia and Ericsson are no longer available for download, as the development of WAP/WML sites has been dropped by most users.
WAP/WML books were also popular at the turn of the century, and some are still available for purchase. Some of them are very comprehensive, but we suggest going through the online resources first, as they are really good. If you still prefer the feel of a book, we chose a few:
- WAP Development with WML and WMLScript (2000) by Forta et al: introduces WML and WAP as wireless application development tools and teaches you how to develop WML applications. It also covers mainstream topics such as security over wireless networks, working with image files for handheld displays, and interacting with wireless users.
- Getting Started with WAP and WML (2001) by Huw Evans and Paul Ashworth: provides information on building WAP services such as: creating your first WML page, handling user input from a cell phone, using images efficiently, and sending information to the user from a WAP server. It also includes information on security considerations when designing WAP application, plus a bonus WML reference.
- WAP and WML: Designing Usable Mobile Sites (2011) by Ryan Sean Younger: gives you an insight into this exciting technology, covering what it is, how to go about designing and building a WAP site and most importantly WAP usability considerations and best practices. This book includes real world case studies and the development of an example WAP site to get you up to speed on all aspects of building a useful and usable WAP site.
- Understanding Wap: Wireless Applications, Devices, and Services (2000) by Marcus Taylor: examines all aspects of Wireless Application Protocol (WAP), particularly the hands-on development of WAP applications. This book explains both the technical details behind WAP as well as the critical business issues related to its implementation.
Most of the WAP/WML books were published in early 2000s, so be aware that many resources mentioned in those books, like useful website examples, simply do not exist anymore.
Today, WAP/WML technology is a thing of the past, as the last WAP 2.0 standard was released in 2002.
But in its time, WAP/WML was a very important step in the evolution of mobile internet technology. Thanks to WAP/WML, information from the internet started to trickle down to mobile devices. Users could finally check news headlines, stock market quotes, sports results, weather, or email on their mobile, anytime, anywhere.
WAP/WML was troubled by the very limited hardware capabilities of mobile devices of that era. For example, the first mobile phone with integrated WAP support was the Nokia 7110, with a monochrome screen and a 96x65 pixel resolution, capable of displaying 6 lines of text.
Reading any content on such devices was difficult and uncomfortable, but getting the content to the device itself was a great accomplishment, and it was made possible by WAP/WML. Users found it easier to check the headlines on their mobile, and read the full content on their PC later. Today though, even inexpensive smartphones feature high resolution displays and the hardware to display all sorts of content; from plain text to HD video. WAP simply could not keep up with the evolution of mobile hardware, and it didn't need to. As mobile processors evolved, they became powerful enough to render desktop-grade content, with full HTML/CSS support, and much more.
While it's an outdated technology, thanks to the development and the implementation of WAP/WML, manufacturers of mobile devices were pushed hard to create faster, more powerful devices with bigger, high-resolution screens. Over time, these devices evolved into the smartphones as we know them today.
Further Reading and Resources
We have more guides, tutorials, and infographics related to web development:
- HTML for Beginners — Ultimate Guide: if you want to learn how to hand-code HTML, this really is the ultimate guide.
- CSS3 — Intro, Guides & Resources: learn the details of webpage layout with this introduction and detailed list of resources.
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