While you are correct that Leap Wireless won the AWS E-block license for the Central region in FCC auction 66, it is rather unlikely that they will use it to build their own network and offer service in Dallas anytime soon. As has been said before, Dallas is metroPCS territory and from a marketing and financial perspective it makes little sense to construct a duplicate infrastructure and then compete with metroPCS over the same customers, as they essentially offer the same product and cater to the same market segment. You'd be basically getting only half the return on your investment versus building out a market where metroPCS is not present.