LTE and TV services can co-exist in Brazil

LONDON, ENGLAND: The GSMA released findings of a new study from ATDI1, which examines ways to mitigate interference between new LTE mobile signals and existing and planned television services.

In October, Brazilian regulator ANATEL made the decision to allocate the Digital Dividend to mobile and adopt the Asia Pacific (APT) 700MHz band plan, which would free up the spectrum band for new LTE mobile services.

Forecasts show that using the 700MHz band for mobile broadband will create substantial socio-economic benefits for Brazil, contributing an additional $1.4 billion to GDP, providing over 4,300 job opportunities and generating additional tax revenue of $1.3 billion by 20202.

"Mobile operators want to work closely with ANATEL and the broadcast community to explore how their respective services can best coexist and ensure the optimum experience of LTE mobile services and television viewing for the people of Brazil," said Tom Phillips, chief regulatory officer, GSMA. "Through rigorous modelling, the study shows that careful planning of spectrum usage can mitigate potential interference from mobile and broadcast services operating in close proximity to one another."

The study focused on the cities of Brasilia, Campinas and Sao Paulo as these are likely to be some of the areas where potential interference with television and mobile reception could present the greatest issues. Potential interference problems should be less acute in other areas and therefore easier to mitigate.

Compatibility with analogue television signals was also factored into the equation due to the anticipated long-term plans for digital switchover. As digital television in Brazil uses ISDB-T technology, this study also has relevance for other markets including Chile, Costa Rica and Ecuador where Digital Dividend spectrum has also been allocated for mobile.

Although the study is not designed to prescribe a single, specific solution, it provides an objective viewpoint from which mobile operators and broadcasters can base any future decisions on mitigating interference between the mobile and television systems. Key findings of the report include:

* The population affected is generally small, and can be reduced by applying suitable mitigation techniques for potential interference areas. For example, in Brasilia and Campinas, the population that could be affected is generally fewer than 10,000 people and through mitigation, the issue could be virtually eliminated;

* Applying filters to both ISDB-T television transmitters and to LTE mobile base stations can help to significantly lower the probability of out-of-band and blocking interference;

* The probability of interference of LTE consumer devices, such as smartphones and tablets, with the ISDB-T television system from blocking and out-of-band emissions is low; and

* Adopting plans that avoid high power emissions in the upper television channels (especially channels 48-51) will support coexistence as the potential interference problem is more acute where frequency separation from the lowest LTE band is small.

"We appreciate the concerns around potential interference between mobile and broadcast services, which we aim to address through this new study," continued Phillips. "However, these concerns should not overshadow the undeniable socio-economic benefits that the Digital Dividend spectrum for mobile will bring. Through mitigation, we are working to ensure the successful coexistence of LTE mobile and television services for the enjoyment of the people of Brazil."