Concerns over 4G/DTT interference once again blighting 700MHz auction plans

12 May 2014

BNAmericas reports that a ‘war of words’ has broken out in Brazil over concerns of possible 4G/digital TV (DTT) interference when the regulator Anatel auctions off 700MHz spectrum for mobile services later this year. The frequencies in question currently sit uncomfortably alongside a number of analogue transmissions in the country.

Brazil’s electrical and electronics association Abinee has completed tests on the possible impact of interference, concluding that the installation of filters will stop any interference problems between 4G and DTT signals. As such, it has endorsed Anatel’s plan to forge ahead with the 700MHz auction this August. However, Brazil’s TV industry reportedly refuses to accept the test results, with local TV engineering society SET arguing that ‘coexistence could only be possible if Anatel widens the guard band, the unused part of the spectrum between bands for the purpose of preventing interference’. SET says that its separately held tests showed that ‘in the more critical cases, the mere use of filters, even when installed in both TV receivers and radio base stations, does not allow for the successful coexistence of LTE mobile and digital television services.’ For their part, Abinee and telecoms equipment providers defend the full use of the spectrum for 4G LTE services.