THOUSANDS of television viewers countrywide could lose their picture or face serious interference from the rollout of new high-speed mobile phone networks.
Households who switched to the new Saorview digital service could lose channels or experience interference especially if they live near a mast, the Irish Independent has learnt.
The problems could arise when the new 4G mobile networks, currently being rolled out, go live in a few months' time. This could leave Saorview consumers with aerials facing a bill of over €100 each for filters to correct the problem.
That's even though the Government is enjoying a windfall of €850m from the sale of airwave space for 4G networks to mobile phone companies.
Experts are still unable to quantify how many homes will be affected here but it is an identical problem to that in Britain, where two million homes are facing TV interference as their 4G network is rolled out. This suggests thousands of homes in Ireland could be affected.
It will not hit customers who get their service from firms like UPC or Sky.
The Department of Communications said Minister Pat Rabbitte had set up a special working group to see what needed to be done.
The issue of who will have to pay for technical measures needed to adjust household equipment would also be looked at, a spokesman said.
Experts from the department, the regulator Comreg and RTE are involved.
In Britain, the government has set aside £180m (€217m) to pay for filters, but consumer experts have warned many households could still have to pay more than £100 (€120) each to get a technician to fit these filters to their aerials.
A department spokesman confirmed that homes within 2km of a mobile base station were most likely to face disruption.
Comreg said that the problem was one of radio-frequency overload, where TV amplifiers were overwhelmed by very strong signals such as those used in 4G mobile services.
"If you receive off-air reception of the national services (RTE, TG4, TV3) by means of a rooftop aerial which is fitted with a masthead amplifier you may suffer degradation or even loss of television reception when LTE [4G] services come on stream from early 2013," Comreg said.
Removing the masthead amplifier on television aerials would resolve the reception problem as an amplifier was probably not needed to receive a TV signal, Comreg said.
If necessary, a filter could be placed between the aerial and amplifier to fix the problem.
Filters were available for €15-€20, but TV users were advised to get an aerial installer to fit them, because access to the rooftop was normally required.
Comreg said it was the responsibility of the end user to make sure their television reception was installed in a way that it would not be overloaded by 4G signals.