T-Mobile USA is rolling out its 2.5 GHz 5G network at high speed, looking to take advantage of its headstart in midband spectrum before its rivals strengthen their own position in these key bands during the upcoming C-band auction. But while acquiring Sprint brought TMO this treasure trove of beachfront 5G airwaves, the operator has not taken on board Sprint’s former experimental approach to new technology. While Sprint was renowned for taking bets on emerging technologies, with mixed commercial results, TMO has been more conservative, and relied on its powerful marketing propositions to achieve the increases in revenue and market share of recent years. It remains cautious, voicing public doubts about some of the most fashionable 5G-related innovations that other…