A LTE mobile phone used 3m from a TV will result in disturbance for the cable TV signal in 75 percent of cases, and the cable signal of a neighbour will be affected 50 percent of the time, according to a study by the Dutch radiocommunications regulator AT. The findings were in study requested by the government into the impact of refarming 800MHz frequencies. The AT underlined that the conclusions are not representative, as only 11 measurements were taken with standard settings and four with optimal conditions. The Dutch government is considering redistributing some of the spectrum freed up from the switchover to digital TV, but is concerned about the risks from mobile services in the band to cable TV, which is used by the vast majority of Dutch consumers. The standard tests used a digital cable installation with a well-protected (StAI) cabling for the connection between the TV and subscriber hook-up but no adjustments to other cabling. The LTE phones used were based on transmission capacities given in the concept EU decision. In four cases, the conditions were changed in an attempt to reduce any interference. There was a clear improvement in reception, but the study found that with the commonly used LTE bandwidths of 5-10MHz there was a 50 percent chance of interference when the mobile is used within 1m of the TV. The protection and connection of the other cables in the set-up proved a key factor in optimising the configuration to minimise interference in the home.
