Radio imaging

A UK research team is developing a system that would allow the next generation of digital radios to display high-quality images on built-in screens.

The project, led by Loughborough University, aims to enable visual add-ons such as ads, diagrams and maps to be carried by Digital Audio Broadcasting (DAB) radio transmissions.

DAB, the major global technical standard for digital radio, is gradually emerging on to the mass-market with the launch of new dedicated radio stations and the appearance of low-cost audio hardware.

Quality and consistency

The standard is based on multiplexes – digitised bundles of signals that can be carried together on a single frequency – and brings big benefits in the quality and consistency of radio broadcasts compared to existing analogue transmissions.

As a useful by-product, DAB multiplexes also offer the chance to use digital capacity not required for the audio signal to carry other types of data alongside it.

The dDAB (delivering DAB) team plans to tap into this spare bandwidth and develop a system that allows visual elements to be encoded and synchronised with the audio stream. ‘Depending on the configuration of the DAB multiplex, you can be quite flexible over how much you allocate to audio,’ said Iain Duncumb, project manager for dDAB.

Duncumb said it would be feasible to achieve data rates of between 10 and 20kbp/s, enough for fairly sophisticated images to be sent.

Delivery of the data would be efficient and cheap compared to the internet, added Duncumb, because the bandwidth needed to carry it would be completely independent of the number of people receiving it.

Duncumb said a good example of dDAB’s potential use would be a continuously updated cricket scoreboard broadcasting alongside radio coverage of a match.The system’s developers also hope it will eventually allow radio stations to interact with their listeners through a combination of dDAB processing modules and other communications standards such as SMS text messaging.

Loughborough’s Impact research group – which specialises in digital broadcasting – is working with several commercial partners on the project. These include Virgin Radio, broadcast technology group Unique Interactive and mobile phone systems specialist TTPCom.

Duncomb said dDAB would mark a huge advance on current technologies such as Radio Data System (RDS), the text-based service available via some analogue FM radios which can display information such as station name and song title.

Visual benefits

‘We’re not trying to turn radio into television, but there are undoubtedly some elements of a radio broadcast that would benefit from a visual dimension,’ said Duncomb.

He also claimed dDAB could boost the overall economic viability of digital radio by giving broadcasters a chance to earn additional revenue from advertising.The Impact group has already developed several working prototype dDAB systems. But Duncomb said it would be at least several years before dDAB became a mass-market service.

The two-year project has been backed by £350,000 by research funding bodies, including the Department of Trade and Industry.