For many years the open MHEG standard has been the mainstay of interactivity for digital terrestrial television in the United Kingdom. It was originally developed in the mid-nineties, with little reference to emerging web standards. With the adoption of HbbTV, or hybrid broadcast broadband television, which embraces modern web standards, there is a compelling case to move on. The Digital Television Group has established a cross-industry task group to consider the issues involved.
MHEG-5 is part of a set of international standards developed by the Multimedia and Hypermedia Experts Group. It is a simple declarative language based on scenes that can contain primitive text, graphics and limited actions.
Over 90 million Freeview televisions and boxes have been sold in the United Kingdom since the service was launched in 2002. They all support MHEG-5.
The challenge is how to manage the migration of services from the legacy of MHEG to the world of web standards.
There are common features of the ways in which both MHEG and HbbTV are delivered that should allow an element of parallel operation.
The key question is how long will it be necessary to maintain support for MHEG, which is now mainly used by the BBC for its red button and digital text services and also to support some virtual channels delivered over broadband.
The DTG task group aims to identify use current and future use cases for interactive services.
It will consider migration strategies for introducing HbbTV 2.0 based interactive services to the digital terrestrial television network in the United Kingdom and how to manage the receiver legacy, including the requirements that must be met for the potential removal of MHEG services in the future.