Technical Terms and Definitions

HDML - Protocol

Handheld Device Markup Language is used to format content for Web-enabled mobile phones. HDML is's (formerly known as Unwired Planet) proprietary language, which can only be viewed on mobile phones that use browsers. HDML came before the WAP standard was created. It uses's Handheld Device Transport Protocol (HDTP), instead of WAP. Phones access HDML sites the following way: Once the URL is typed into the phone, the phone sends the request to's UP.Link gateway. The gateway sends a HTTP request to the Web server. The Web servers returns the page via HTTP back to the UP.Link gateway. The gateway sends the data via HDTP to the wireless carrier's network and down to the phone.