The BBC’s Lindsay Cornell delivered a Digital Radio technical update covering DAB, DRM and RadioDNS.
Cornell is Chair of the World DAB Technical Committee and Principal Systems Architect at BBC Digital, working across all the digital radio platforms. He gave an update on developments and changes for digital radio, beginning with receiver testing.
Updates have been done to the technical standards “to ensure that consumers have the equipment they need to receive the services being delivered on digital radio.”
The ETSI TS 103 461 standard for digital radio receivers and has been updated to include new standards for car radio digital radio receivers. The latest standard was published in October 2020, it guarantees that all DAB receivers can handle all the requirements, including scripts for all world languages so they can be displayed on digital radio screens.
The standards also ensure that chips in consumer devices work well and properly in all devices around the world.
For DRM, the technical committee has completed a project to simplify the DRM specifications. “When new technologies are built, people plan for everything, but over time as it is used, some of the features were found not be used and not necessary, so we have reduced complexity to avoid any potential interoperability problems,” said Cornell.
Hierarchical modulation has been removed from the standard and unequal error protection is no longer needed, so this area has been simplified as well. Some things have been added to the standard, such as universal text in the same way as it has for DAB.
A data application directory certification also allows DRM to use apps and the alarm warning indicator standard allows emergency warnings to wake the devices and override other functions, so as to give priority to emergency messages and lengthen battery life.
“Because all of the capabilities need to be incorporated in radios we want to make sure we have exactly what is needed in the standards… too many standards and it is more expensive, too few and it is less functional,” he said.
The standards for text scripts are particularly important for the EU because digital radio is now mandated in all cars. They includes Latin, Greek and Cyrillic scripts.
Hybrid radio is a combination of broadcast and IT radio. The standards work across DAB, DRM and the hybrid system RadioDNS. In this technical area the standards have been updated to improve geolocation capability for coverage. “It helps with rights management and also helps minimise amount of unnecessary traffic to your IP service and the geolocation specifications signal if the receiver is allowed to use the IP service.
Broadcast coding and modulation has also had some new solutions which improve the economy, power management and cloud based multiplexing for DAB and remote monitoring for DRM, explained Cornell.