Brazil’s SET warns that LTE could cause DTT interference

20 Feb 2014

Brazil’s Society of Television Engineering (SET) is warning that the launch of 4G Long Term Evolution (LTE) mobile services in the 700MHz band would cause interference to digital terrestrial television (DTT) broadcasts in the country. SET, which commissioned a seven-month study at Mackenzie University in Sao Paulo, says that interference could cause ‘disruption in programming, frozen images or a black screen’. Telecoms regulator Anatel published Resolution 625/2013 last year, establishing the 698MHz-806MHz band for LTE-based services, with a spectrum auction expected to be called later this year; TV transmissions in Brazil use the adjacent 470MHz-698MHz band. SET has expressed concerns that Anatel has failed to lay down adequate guidelines to avoid interference between the two bands. The TV organisation’s president, Franco Jose Olympio, commented: ‘The results obtained in the tests from Mackenzie University show that in critical cases, a combination of various mitigation measures are needed to preserve the quality of the reception of TV signal. Among them, change the antennae and add filters in TV and LTE transmitters.’