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Glossary

WTVML

Worldwide TV Mark-up Language used for interactive services delivered to televisions and similar devices.

WTVML is a markup language that provides a content authoring format for interactive television service applications based on internet standards.

WTVML is an application of XML or eXtensible Markup Language and is reverse compatible with the WML Wireless Mark-up Language used on mobile phones.

It enables interactive television interfaces to be described in a declarative manner, including support for explicit layout and focus behaviour without the need for CSS or JavaScript.

Designed to deal with the constraints of a television screen display when used with a remote control, it provides support for limited input facilities. It is designed to be efficient in its use of device resources, requiring modest memory and processing power.

As with WML, content can be organised into cards and decks, where a card is unit of user interaction and a deck is a unit of transmitted content.

Content can be transmitted to a set-top box either as broadcast data or via the return path and it is common for services to employ both methods although a return path is not required.

In order to address the requirements of interactive television, WTVML adds television related functions and layout control through extensions to provide precise control over televisual presentation.

Much of the technology required for delivering WTVML services is based on existing Internet standards and it is possible to employ shared infrastructure and back-end business processes to provide services across the web and interactive television.

WTVML is currently deployed on over 8 million devices on the BSkyB platform in the UK. Network and device licences are available from Sky spin-off Miniweb Interactive.

WTVML forms the basis of an open standard ETSI TS 102 322 Specification for a Lightweight Microbrowser for Interactive TV Applications, based on and compatible with WML, published by ETSI the European Telecommunications Standards Institute.