Technology has been advertised and promoted in some odd over the years. Right now UK listeners are being urged to buy new receivers and "spread the love" for digital radio by a Barry White-style puppet called D Love (pictured).
The connection seems to be that the Walrus of Love is a mainstay of Gold channels and people will be able to pick all of these up through shiny new digital radios. Apart from easier tuning and clear reception in the home and car, D Love steers clear of any technical issues involved with DAB. But as the UK government considers switching over from analogue, with a decision due by the end of the year, broadcasters and receiver manufacturers are pondering some fundamental questions surrounding how to create a full digital network that matches the current FM infrastructure.
Key among these are service following and traffic announcement switching. Service following allows people to travel from one part of the country to another while listening to the same radio station or style of programming. This facility is already part of FM RDS (radio data system), as is traffic announcement switching. In this way radios automatically retune to traffic reports on local stations relating to where the driver is at the time.
Minimum technical specifications for both were drawn up as part of the government's Digital Radio Action Plan (DRAP). Service following and traffic announcement switching are minimum criteria and have to be met by vehicle and receiver manufactures to gain the Digital Radio Switchover Certification Mark (popularly known as the Tick Mark), which shows consumers that equipment offers meets basic performance requirements.
Despite this Digital Radio UK (DRUK), the organisation that will oversee any switchover from analogue, as well as being behind D Love, realised that prior to April 2012 "only limited service following and traffic announcements had been implemented across the UK's DAB network", something compounded by a "lack of understanding about exactly how service following and traffic announcements should be implemented" by service providers, multiplex operators, broadcasters and vehicle and receiver manufacturers.
This led to a test of both technologies between 15 April and 15 August 2012, although such a trial was not a specific task in the DRAP. 27 products were tested, following routes in the southeast of England on a series of multiplexes: London 1 and 2, Kent, Sussex Coast and Berkshire/North Hampshire.
Some details of the trail were given at last year's TechCon but now DRUK and Arqiva, which operates the radio transmitter networks for both BBC and commercial radio, have published a paper outlining the objectives and findings.
Among the intentions of the trial were to ensure UK DAB networks and services meet the requirements for implementing service following and traffic announcement features and provide a platform for manufacturers to test receiver behaviour according to the technical specifications for both.
The tests found that many receivers did not implement service following at all and where it was there was only partial support. It also discovered that hard linking (switching to same station) from DAB to FM RDS services worked correctly but that there was no evidence soft linkage (switching to a similar style of programming if the same channel is not available) was supported by any manufacturer.
The paper recommends that a set of implementation guidelines for manufacturers and broadcasters on how to implement service following and traffic announcements correctly should be drafted. It also proposes that the industry should carry out a switchover trial in a specific area of the UK to "investigate the consumer opinion surrounding traffic announcements", with the aim of finding out whether people want them and find them useful.
Paul Eaton, director of digital radio at Arqiva, comments that existing digital transmitters can accommodate service switching and traffic announcements through software upgrade. "There is a lot of anticipation surrounding what the government will decide at the end of the DRAP but we've got our engineering plan and can make the software changes regardless of anything else," he says.
Sam Bonham, technology development manager for DRUK, observes that the trial was " a useful piece of work" but acknowledges there is "work to do" on making service following understood and an integral part of digital radio's future. Looks as though D Love's job is not over yet.
Story: Kevin Hilton