Wireless telephone provider T-Mobile complained it has been barred from using radio spectrum that it owns, because federal law-enforcement agencies are using the bandwidth for national-security and other investigations. T-Mobile bought the spectrum space for $4.2 billion last April at a federal auction, intending to use it for mobile broadband service. But various agencies are using the bandwidth to conduct video and audio surveillance of suspects in drug and terrorism cases. The agencies are required to hand over the space, but have not been given a deadline.