SÃO PAULO (WiMAX Day). The Brazilian telecoms operator Brasil Telecom Participações (BrT), which owns 3.5 GHz spectrum in Brazil, will offer mobile WiMAX based on the 802.16e standard to business customers in São Paulo and Rio de Janeiro by September this year. According to a report in Cellular News, BrT intends to begin commercial operations of mobile WiMAX in the cities of Porto Alegre and Curitiba later this summer.