Music festivals could be under threat
Ofcom looks set to change the way it auctions off the airwaves freed up by the shift to digital TV.
It plans to make a wider band of spectrum available for services, such as mobile broadband, than was originally proposed.
The move has been welcomed by mobile operators who say it will make for cheaper and more flexible services.
But for organisers of concerts, outside broadcasts and musicals the news may mean changes to the spectrum they use.
Originally Ofcom promised to safeguard a channel in the 800Mhz band for wireless microphones and digital terrestrial TV services, but it is now consulting on its fresh plans for the frequency.
It is proposing to turn over much of the 800MHz band to mobile broadband and related services and find "alternative spectrum" for wireless microphones and digital terrestrial TV.
For digital terrestrial TV viewers, it will mean that set-top boxes will have to be retuned, something Ofcom described as "a simple procedure that usually takes a few minutes to complete".
Ofcom estimates that the net benefits to consumers of changing the way spectrum is divvyed up could be worth £2-3bn over 20 years.
Industry figures believe the change has come about because of pressure to harmonise with Europe.
"Ofcom has realised that there is momentum in Europe for mobile broadband so has had to co-operate," said Matthew Howett, an analyst with research firm Ovum.
Finland, France, Sweden, and Switzerland have already decided to release the wider block of spectrum for mobile broadband services and if the UK follows suit it will mean lower equipment prices for consumers.
T-Mobile's head of regulatory affairs, Robyn Durie, welcomed the move.
"It is good news for us. Mobile broadband needs a big chunk of spectrum and previously we didn't have that," she said.
"It means that consumers will be able to use the same services abroad that they can use at home."
But not everyone is happy about the proposals.
For the PSME industry (Programme Making and Special Events), worth an estimated £15bn, radio mics - which rely on spectrum to work - are crucial.
Under the proposals PSME firms face eviction from Channel 69, which operates at the top of the 800Mhz band and, according to the British Entertainment Industry Radio Group (BEIR) is the only channel where radio mics can be guaranteed to work from any location in the UK.
While Ofcom has proposed safeguarding Channel 38 as a new home, not everyone is reassured by its commitment.
"We are not very confident at all," said Duncan Bell, a member of the steering committee of BEIR.
"What Ofcom will announce as an alternative is as yet unknown. It shouldn't be selling anything off until it can tick the box that says the PSME industry can still operate," he said.
While West End shows will not be affected by a shift to another channel, others may be.
"I predict that bigger scale productions and touring shows will struggle to find enough spectrum in some locations," said Mr Bell.
He also thinks that 90% of equipment - with a value of around £100m - could be rendered worthless. Ofcom has put an £18m price tag on affected equipment.
Ofcom has offered funding so that those being evicted from Channel 69 in the 800Mhz band "do not have to bear extra costs as a result of these changes". The consultation period for the Ofcom proposals ends in mid-April.
Mobile broadband will become ever more spectrum-hungry as more people use it.
According to the GSM Association there are 200 mobile broadband networks across 94 countries with some 75m subscribers around the world, 26m of whom are in Europe.
The GSM Association predicts that the global figure will rise to 1bn by 2012, the year that much of the spectrum will be freed up.