T-Mobile customers in the country’s biggest cities may have recently noticed their 4G speeds boosted considerably. On T-Mobile’s Q3 earnings call, CEO John Legere revealed that it has doubled the amount of spectrum used by its LTE networks in 40 of the top 50 U.S. metro markets, effectively doubling the theoretical speeds of its 4G service and dramatically increasing the overall capacity available to its customers. T-Mobile US CEO John Legere T-Mobile is now using 20 MHz of Advanced Wireless Service (AWS) spectrum for LTE in these upgraded cities, which puts its networks on par with the systems launched by Verizon Wireless and AT&T.