The USA has been the biggest deployer of 5G in millimeter wave (mmWave) bands in the world, though mainly through necessity rather than choice. But its operators and their vendors are learning a great deal about how to use this challenging spectrum cost-effectively, and this is being fed into real world solutions as well as into further R&D – for instance, around the potential use of 70 GHz, which actually has better propagation characteristics for many applications than the widely used (unlicensed) 60 GHz. And rising interest was demonstrated by the results of Auction 103, the FCC’s third consecutive mmWave spectrum sale, which were announced last month and generated total revenue of $7.6bn (a total which is split between $3bn…