ATDI is helping to expand the burgeoning Brazilian economy with a plan that will enable people to watch television and talk on the phone at the same time.
The country is planning to re-use its digital dividend 700MHz frequencies for new 4G mobile services. These will be in a band adjacent to existing television signals and ATDI has been tasked by the GSMA to plan and model the re-shaped spectrum usage to identify and mitigate potential interference issues.
The project is being overseen by ATDI lead engineer Paul Grant who notes: “Terrestrial, free-to-air television is particularly significant in Brazil given the country’s modest uptake of cable and satellite services. A lot of people would be at risk of being very unhappy if we had been anything other than entirely accurate in our planning and modelling.”
A complicating issue is that analogue television had to be factored into the equation due to the envisaged long transition to digital. Paul comments. “It has been a very challenging but very rewarding task.”
Paul has now delivered ATDI’s report which examines ways to mitigate interference between the proposed new mobile signals and the existing and planned television services. It presents a number of options for ensuring clear signals including filtering and minimising TV transmission powers in channels immediately adjacent to LTE services.
“The advent of fourth-generation mobile services globally has meant we have now conducted this kind of survey and report in places from the mountains of north Europe to the icecaps of Iceland to Brazil,” Paul says. “It is exciting to know we can develop techniques that work no matter what the terrain, the climate or the population density.”