A Technical Background on Mobile Web Protocols
Studying mobile web development should be started with a clear understanding of its roots.
When the idea of browsing the Internet through the mobile phone started, standards bodies decided to use a markup language that addresses the constraints of the mobile web (as discussed two posts before). This markup was then called WML or Wireless Markup Language. WML was created in the attempt to make web browsing experience possible in limited mobile devices. WML is based in XML.
WML content is served by ordinary HTTP servers like Apache. They are accessed via a WAP gateway, which sits (on the server side) between the mobile phone browser and the Internet. WAP stands for Wireless Application Protocol which defines the delivery mechanism of mobile web content. The very first version of Wap (version 1.0) used binary encoding before WML is sent to the mobile phone.
WML will soon be competed by another mobile web standard but this time, something that is better and is something that is not built upon the limitations of the mobile web device. XHTML MP (mobile profile) gave more powers and flexibility to web developers and designers developing for the mobile platform. Along with the introduction of this new, and more advanced markup language is the evolution of the protocol that delivers it: WAP 2.0 improved on many things that version 1 had, the most notable being the direct delivery of mobile web content to the phone without the need for binary encoding.