The US is becoming a patchwork quilt in spectrum terms, as operators seize airwaves in a growing variety of bands to meet their capacity needs. As the 600 MHz incentive auction kicks off, some of these are proving more contentious than others. The first stage of the 600 MHz process will be the reverse auction, in which the broadcasters agree how much spectrum they will part with. The broadcasters had until Wednesday this week to register their interest and that is now followed by a period in which the FCC reconfigures the airwaves for mobile use and establishes its targets for the amount that can be cleared. The forward auction, in which those airwaves are sold, will start in June…