The next generation of mobile phones after 3G has hit a significant hitch after it emerged that early tests showed the devices may stop televisions working, or even those in a neighbour's home.
The issue was first flagged in Germany and the Netherlands.
The telecoms regulator in the Netherlands,
a country with huge take-up of cable TV, published a study which showed that in 75 per cent of cases the picture of cable television showed interference when 4G devices were used up to 3m away.
Half the time, the neighbours' televisions were hit as well, the study found.
Britain, meanwhile, is switching from analogue television to digital by 2012.
The valuable bandwidth freed up will then be auctioned to mobile phone operators to use for next generation phone services.
New Zealand is grappling with reliable 3G networks, and so the 4G problems should be ironed out before the technology arrives.
Lee Sanders, a partner at Analysys Mason, said: "The value of this frequency for high-speed broadband is unquestioned. This is not an insignificant problem."
Industry insiders added that the problem "must be sorted out before the auction".
Analysts at Credit Suisse, who raised concerns over the issue, said several comments gave credibility "to the concern that the digital dividend spectrum may interfere with cable TV systems and set-top boxes of other TV systems".
"The particular concern is that ... digital signals being sent in the air at this [4G] frequency interfere with signals being sent over cables at the same frequency."
Cable and mobile operators in the UK are confident a solution can be found in time for the digital switchover.
Analysts said Virgin Media believes this could also affect personal video recorders, VCRs and games consoles.
Industry insiders also believe the state-of-the-art mobiles could affect other television formats.
"We, and frankly the industry, need to understand more about how big the interference problem is. If the problem is large ... the issue could stop the digital dividend process, and the German spectrum auction in particular, in its tracks."
- INDEPENDENT
