Lindsay Cornell, Principal Systems Architect, BBC and Chairman, WorldDMB Technical Committee
The role of the Technical Committee to provide a focal point for members to discuss technical issues that affect the DAB system and its various interfaces, applications and protocols. It has representatives from almost all WorldDMB member organisations and meets three times a year to progress the various tasks that form its workload.
As Chair of the Technical Committee, I see my main objectives as:
– to ensure that the TC works efficiently
– to maintain and augment the DAB standards
– to provide advice and guidance to the SB
– to support WorldDMB’s overall goals
The tasks in the TC can be divided into three main areas: monitoring developments and resolving problems; discussing, developing and disseminating best practice; developing and revising technical standards and guidelines.
During the past 12 months, the TC has looked into the presentation of characters on DAB receivers, especially accented letters. With more and more countries adopting DAB, the range of characters being used has increased, and the TC has looked into ways to help ensure that manufacturers have all the information they need to produce readable displays. This work has resulted in an additional annex C in the Registered Tables specification which shows all the characters in the Latin-based character set along with their unicode names and numbers. This is published as ETSI TS 101 756v1.6.1.
Discussions regarding characters needed for display in other parts of the world have also begun. We have also discussed the implementation of Emergency Warning Systems and multiplexer communications – both topics that have implications across the breadth of the broadcast chain, from service provider through equipment manufacturers to end-users. The interactions with existing features, and the risks associated with making changes, have been considered but more progress is needed before coming to conclusions.
The meetings of the TC have established a pattern: The February meeting of the TC was hosted by the EBU in Geneva during their Digital Radio Week. At this meeting we accepted guests who had attended the EBU Summit to see the work of the TC. In May we were hosted by MVTA in Budapest and the TC seminar, organised by Vice-Chair, Mathias Coinchon, was entitled “Maximising the consumer DAB experience – a look at networks and receivers”. Speakers from different countries with different roles in the digital radio chain shared and discussed the close co-operation needed to ensure that complex broadcasting requirements are enjoyed by consumers, and the huge role that clear rules of operation, with requirements specified for service providers and transmission operators on one hand and receiving devices on the other, play in this.
The third meeting was in November, hosted by the IRT in Munich, which was paired with an interoperability workshop at which members brought equipment for testing new and existing features against ETI streams provided by others. Topics included signalling, information presentation (text, images, …), multiplex reconfiguration and service following. The event was characterised by huddles of experts discussing details, with good knowledge transfer.
The final activity is the development or revision of specifications and guidelines in Task Forces. Two TFs have been operating in the last year: TF Hybrid Radio and TF Service Lists. The former has been integrating two Radio DNS applications, Radio EPG and Radio VIS, into the existing DAB applications, EPG and SlideShow respectively, to enable a truly seamless hybrid radio experience, and simplify the requirements for both content generation by service providers and content presentation to users by devices. The work has been completed and ETSI are currently processing the draft specifications for approval and publication. The TF Service Lists has been examining the requirements for creating rules of behaviour for both service providers and devices to ensure consistent and accurate service selection lists, which change dynamically according to the available services, without duplicate services appearing, part-time services disappearing or new services needing button pushes and rescanning to access.
Of course all this activity needs a lot of support, and many members of the Technical Committee regularly contribute. As Chair, I have been helped especially by the Vice Chair, Mathias Coinchon (EBU); the Task Force Chairs, Nick Piggott (Global Radio) and Jan Ossfeldt (Teracom); the EBU, MTVA and IRT for hosting TC meetings, and of course, last but not least, the WorldDMB Project Office who ensure that all runs smoothly.