RIO DE JANEIRO, BRAZIL - Brazil is at the heart of the 21st-century cold war, with the coveted auction to take over the country's new cell phone frequency, 5G. The dispute for a new communication band in the technology market has the two wealthiest nations in the world clashing: the United States and China. At stake is a market that can attract up to R$180 billion (US$36 billion) in investments for Brazil, a country that has more cell phones than inhabitants - 225.3 million devices for 209.5 million people.
At the heart of this competition are . . .