DAB started as a European Union funded research project called Eureka 147, and the outcome of that work was the original DAB system standard, way back in 1994. The development of additional standards and maintenance of the core DAB standard, ETSI EN 300 401, has been carried out by the WorldDMB Technical Committee for many years. 20 years on from the initial standard, what is the TC doing now?
The TC is the biggest WorldDMB committee with 125 registered members. The TC meets three times a year and the main objectives are to maintain and augment the DAB standards; provide advice and guidance to the Steering Board; and respond to changes in technology that might have some impact on the DAB family. The TC Vice-Chair, Mathias Coinchon, EBU, organises seminars to discuss issues in some depth – providing local services, contribution and distribution interfaces, issues with on-air signalling and receiver reaction. Many members benefit from attending the seminars that take place in the afternoon preceding the TC plenary meeting as a they provide an opportunity for the free exchange of information that accompanies the presentations, but for those that can’t make it, all the presentations are posted on the website.
Some activities happen directly in the TC – a member may bring forward an idea for new functionality, or an issue may be raised that requires input from the broad range of members represented in the TC in order to determine if there is a problem with the standards, with an implementation, or whether some new circumstance has been discovered that requires additional guidance. As TC Chair, I regularly report back to the Steering Board on these topics.
For larger technical activities, a Task Force is usually set up. Currently the TC has two active Task Forces – TF Hybrid and TF Service Lists. The Task Forces have Terms of Reference agreed by the Steering Board and the output is usually new or modified standards documents.
TF Hybrid has been working to integrate the DAB SlideShow and EPG specifications with the RadioDNS equivalents to create specifications that can be used for broadcast and IP delivered content. Of course there were already many commonalities between the standards, but as well as merging the functional descriptions, it has been necessary to work through the implications of lack of broadcast coverage and loss of IP connectivity to ensure that the user gets the best possible experience, and that the resulting standards are fully compatible with the original DAB and RadioDNS standards. The output of TF Hybrid is expected very soon.
TF Service Lists is working on new rules of operation for the way broadcasters provide signalling and receiver manufacturers decode signalling so that the list of available services is kept up-to-date and meaningful. This is not as simple as it sounds, because as DAB markets mature, new services are launched whilst others disappear; services may move between multiplexes; services may be part-time only or “pop-up” for a special event. The task force has so far collected a set of use cases to study, and proposals as to how to address each case will be examined.
The TC is open to all members and really is the place to go to
learn, share and experience the technical aspects of the DAB family.
For more information on the role of the Technical Committee or membership enquires, contact the Project Office.