The US incentive auction of 600 MHz broadcast spectrum is set to start on Tuesday, though the intense attention of last year has been partly diverted to other future sources of mobile spectrum, including the millimeter wave bands, which will prove as controversial as the TV airwaves – and, in a capacity-obsessed world, more important to the future expansion of wireless services. The impact of the 600 MHz winners and losers will be diluted by the growing attention to high frequency, ‘5G’ bands, and by the time it will take to activate the spectrum commercially. FCC chairman Tom Wheeler this week acknowledged, to the House Subcommittee on Communications and Technology, that the 600 MHz spectrum would take years to repurpose…