The MHEG standard used for providing interactivity on Freeview digital terrestrial television in the United Kingdom is being upgraded to provide additional support for high-definition displays in preparation for Freesat. This latest development of the early standard for interactive television comes as New Zealand launches its Freeview HD digital terrestrial television service, with Australia preparing its own Freeview platform.

MHEG is a relatively old open standard for providing interactive television, first developed in the mid 1990s. Applications are based on scenes that can present text and graphics and respond to basic events such as button presses. Currently it is only deployed in the United Kingdom, New Zealand and Hong Kong.

Different profiles have been developed for each of these markets. The Digital Television Group in the UK has now finalised specifications for a new HD MHEG-5 profile.

The HD MHEG-5 profile allows the use of JPEG bitmaps and AAC audio and changes have been made to the way graphics are handled to provide improved rendering on high-definition displays.

Ocean Blue Software has announced a new release of its Voyager MHEG-5 stack. Strategy & Technology has also announced support in a new version of its RedKey software.

It should allow higher resolution graphics to be supported by compatible devices connected to HD Ready displays.

That could be important for the proposed Freesat service, which is supposed to launch “in the Spring” this year, whenever that may be, and which will include high-definition channels. The BBC is promising to provide red button interactive services on Freesat, including news and sport, with interactive coverage of the Beijing Olympics.

It could also be relevant for the proposed Freeview high-definition channels on digital terrestrial television recently announced by Ofcom.

Meanwhile, Freeview HD is launching as a high-definition digital terrestrial television service in major cities in New Zealand this month. It will complement the satellite service launched last May. Channels will be provided in 720p or 1080i formats, initially with much of the output being upscaled standard definition programming, but with the Olympics due to be broadcast in high-definition.

Australia is also planning to rebrand its free-to-air digital terrestrial television under a Freeview banner, again based on the successful model employed in the United Kingdom. The main networks already offer high-definition channels, and are due to launch additional standard definition channels next year.

MHEG advocates cite the ability to run on relatively low performance and therefore inexpensive devices among its advantages. It is also an open standard that can be freely implemented.

MHEG is being promoted as a cost-effective alternative to the DVB MHP standard, which also forms the basis of the Tru2way standard being adopted by cable television operators in the United States. Based on Java, these are more capable and extensible standards, but also more complex and more demanding in their hardware requirements.

Consequently, MHEG is seen as a good candidate for emerging markets where cost is a particular issue.

Conversely, critics argue that MHEG is relatively limited in its scope and despite recent enhancements may be inadequate to deliver more sophisticated interactive applications or the type of interactive experiences that users have come to expect through the latest internet services.