WorldDAB gathers DAB+ signal distribution experts in Geneva

15.03.2023 by Will Jackson

WorldDAB – the global forum for DAB digital radio – brought together experts from across Europe on 9 March for a seminar on signal distribution.

The event, with speakers covering a range of technical aspects of delivering the broadcast signal from the multiplexer to the transmitter, was held in person at the EBU in Geneva and online, and coordinated by WorldDAB’s Spectrum and Network Implementation Committee (SNIC). The significant interest in this specialist area of DAB operations was highlighted by over 300 delegates from 55 countries registering to attend the free event.

The event moderator was Hanns Wolter, Technical Director of DAB Italia, and Chair of the WorldDAB SNIC. The committee provides guidance on regulatory approaches to facilitate the introduction of DAB services internationally, monitors and lobbies to ensure frequency for DAB and DAB network development and implementation. Topics and activities of the SNIC include advice and best practices on transmission site building, DAB multiplexing and sound processing, DAB monitoring and signal distribution and data service implementation.

Wolter opened the event with an update on the global growth of DAB+, noting progress on consumer receivers, and that DAB is now standard in almost all new cars in Europe. He highlighted the continuing need to work with car makers on innovation, and WorldDAB’s critical role in sharing best practice.

Hanns Wolter (left) of DAB Italia introduces Tork Niendorf from 2wcom Systems.

Tork Niendorf of 2wcom Systems covered EDI/ETI distribution over satellite. He used the example of Norway to demonstrate the need for DAB distribution over satellite: a high number of transmitter stations, a large country with very remote locations, and many low-power gap-fillers. Niendorf said that satellite distribution enables cost-efficient feeds to remote transmitters with or without unstable IP connections, and backup feeds for IP-based distribution.

Stanislas Roehrich, Chief Technical Officer at digris, covered regional DAB+ network feeding via IP links. Digris offers solutions based on Open Digital Radio (ODR) software, with in-house integration services for management, monitoring, and ticketing. It uses a full IP based network for contribution and distribution. Roehrich explained that the digris network was growing, with specific developments in progress to implement reliable timing information transport and management. He noted that numerous tests had been carried out to validate compatibility with various transmitter brands, with the goal of ensuring stable SFN operation under problematic connectivity.

Emanuele Mancuso from DAB Italia covered DAB+ signal distribution over IP using EDI and Secure Reliable Transport (SRT). SRT is an open-source low-latency live video transport protocol. Mancuso argued that the SRT protocol increased the reliability of transmission of the EDI stream over the internet, adding that to obtain an additional degree of stability, it is good practice to have connectivity with a guaranteed bandwidth. He noted that only a few hundred euros were needed to start using the SRT protocol, with the only initial costs being the purchase of the SRT encoder/decoder units, and then the costs of the connectivity.

Finally, UK small-scale implementations were covered by Lawrie Hallett, Operations Director of Future Digital Norfolk which operates the small-scale DAB multiplex in Norwich in the east of England. He detailed the set-up of the multiplex, which he described as “an interesting hybrid.” The original ODR equipment – part of an earlier Ofcom trial - remains in use at the original Markham Tower transmitter site. A GatesAir ‘Maxiva Ultra Compact’ has been installed at the second site at Norfolk County Hall. The two sites are connected by a point-to-point microwave link, currently configured to transport as an internet connection. Individual EDI feeds arrive at Markham Tower and are fed over to County Hall where a NUC is used to create a composite EDI stream. The EDI stream feeds the GatesAir transmitter and is also sent back over the microwave to feed the ODR system located there.

Left to right: Hanns Wolter, DAB Italia and Chair, WorldDAB SNIC; Emanuele Mancuso, DAB Italia; Stanislas Roehrich, digris; Lawrie Hallett, Future Digital Norfolk; Tork Niendorf, 2wcom Systems.

A lively Q&A session with questions from both online and in-person attendees closed the seminar. Presentations and full video from the session are now available on the WorldDAB website. Further seminars on technical topics planned for later in the year, to be kept informed of these and other WorldDAB events sign up to our mailing lists.

To find out more about the benefits of membership and the work of the SNIC and other WorldDAB committees, visit the WorldDAB website.

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