See also: Digital radio switch-over under fire
The government wants digital switchover to take place in 2015, but not everyone is happy with this plan, including the House of Lords.
Critics point to the high cost of replacing FM radios, the higher receiver power consumption and poor DAB coverage.
But there are business benefits to be gained from switching to digital, according to broadcasters industry body Digital Radio UK.
The organisation, whose shareholders include the BBC, commercial radio companies, transmitter operator Arqiva, Intellect, and the Society of Motor Manufacturers, is candid about its desire to switch off FM.
"One of the problems is the cost of both digital and analogue transmission. Broadcasters want to move to the point of only having one cost," says Digital Radio UK spokesman Tony Moretta.
A second benefit of the switchover is that there is no room on analogue frequencies for the BBC to transmit its five digital-only stations to more of the population, according to Moretta. "The BBC will use money saved from switching off FM to increase digital coverage," he says.
Last month, the BBC revealed plans to add 60 more transmitters, extending DAB coverage to a further million people. The plan is to complete the roll-out by the end of 2011, when there should be 90% coverage of the population. But this is still less than FM coverage.
Replacement hardware
Moretta accepts that households will have to replace FM receivers with DAB receivers, but suggests the blow will be softened by changes in listening behaviour.
"The price of a basic DAB receiver now is £25 and we are working with retailers and own-brand manufacturers to bring those costs down," he says. "We expect it to be about £20 by Christmas, and as digital radio takes off worldwide we think the price will come down to around £15."
UK prices are affected by worldwide launches because the DAB chip industry is working towards so-called 'profile 1' chipsets and modules for radios which will work in most countries, decoding all DAB-related standards including DAB+ and DMB.
Also, by the time of switchover, many more listeners will already be taking radio content through digital TVs and streamed over the internet, says Moretta. "A third of UK households already own a DAB radio, and 21% of radio listening is done digitally."
FM-equipped phones are already used by pedestrians for listening, and speaker-equipped phones are available for casual listening without headphones.
Moretta predicts that mobile phones will eventually include profile 1 chipsets, so a significant amount of casual and pedestrian listening will already be through DAB by the 2015 target.
If this is the case, the drift from conventional pocket and battery portables will go some way to counter the argument that switchover alone will be responsible for FM receivers languishing in cupboards.
Energy concerns
The other issue is the power consumption needed to decode a DAB signal. It is unlikely that this will ever be as low as that of FM demodulation, but Moretta argues the gap will narrow.
"Power consumption has already improved substantially, and DAB has not been around long," he says.
Roberts has even introduced a solar-powered DAB radio.
That said, switchover will still mean the end of £5 'transistor' radios that run for weeks on AA cells, and as a result tens of millions of working radios are destined for landfill.