Digital switchover raises interference fears


Ringing mobile phones sometimes make radios or televisions crackle, a problem that could soon get worse as the switch to digital technology picks up. As Germany prepares to auction spectrum to telecommunications operators next week, industry experts are worried that as more technologies compete for the same digital bandwidths, the level of interference will rise, disrupting services.

Germany's network regulator, the Bundesnetzagentur, will next week (12 April) auction off the 800 MHz spectrum band to mobile operators Vodafone, E-plus, O2 Telefonica and T-Mobile.

Kabel BW has just lost a court case attempting to stop the deal. 

"We are expecting massive interference on television and other receivers," Uwe Bärmann, chief technology officer at Germany's third largest cable operator, Kabel BW, said in an interview with the German press.

Meanwhile an EU official told EURACTIV that to accommodate every operator and every service, the EU needs to discuss what constitutes "tolerable interference".

Tests were conducted in Germany this year to see whether Long Term Evolution (LTE) networks for mobile phones – regarded as the next generation of broadband technology – would disrupt broadcasting services.

Though the tests seemed to show little interference with broadcasting services, critics argue that there were barely any LTE networks involved in the investigation, making the results of the tests irrelevant.

In the Netherlands, tests showed that even after using cables to reduce receivers' sensitivity to LTE bandwidths, there was a 50% chance of interference when a mobile was used at a distance of one metre from a television set.

"Interference could hinder growth and innovation in digital television and high definition services, as these require a minimum level of channels to make it worth their while," Hans Bakhuizen from Dutch public service broadcaster NOS told EURACTIV.

In countries where there is a high television penetration rate, like 95% in the Netherlands, this could be a big problem, Bakhuizen added.

The industry view, which was set by the International Telecommunication Union (ITU), is that some uncritical interference can be tolerated providing that a certain quality of service has been achieved.

But in Brussels, lobbyists argue that there is a lack of information on how harmful LTE networks would be to digital broadcasting.

"We cannot measure the level of interference there will be on TV from LTE networks because there are few or no LTE networks rolled out in the EU that can be tested," Bridget Cosgrave of Brussels-based advocacy group Digital Europe argued.

In an EU consultation, the European Broadcasters Union argued that "technical mitigation techniques as well as regulatory measures would be needed to prevent harmful interference from the new wireless networks to broadcasting reception".

In a statement aimed at the European Commission, German cable operator Kabel BW argued: "We foresee a great impact on our business models, if the addressed spectrum will be used for mobile telecommunication services, because of interferences between the end-user-devices for TV and broadband and the mobile communication device of LTE."

"Safeguards are essential to avoid any distortion of competition and harmful interferences for consumers," said Michael Bartholomew, director of ETNO, the European telecommunications and network operators association.

As new digital technology replaces the traditional analogue, to meet the 2012 European deadline for the so-called 'digital switchover', the same services can be provided with less spectrum, opening up new opportunities for other operators.

The 'digital dividend' - spectrum that is freed as a result of the switchover - has been hailed in Brussels as a way to boost growth in a highly profitable digital market and bring broadband to remote areas that may not have terrestrial networks.

"The digital dividend is a once in a lifetime opportunity to make 'broadband for all' a reality all over Europe and boost some of the most innovative sectors of our economy," former Information Society Commissioner Viviane Reding underlined last year.

Brussels proposed to allocate the 790-862 MHz sub-band to telecoms operators to allow them to exploit the digital dividend. The 800 MHz band ranks among the most valuable freed frequencies, since it travels long distances and through buildings.

  • 9 April: Deadline for replies to EU spectrum consultation.

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