The US regulator, the FCC, is finalizing its plans to open up the 3.5 GHz band under an innovative though complicated three-tiered system for spectrum sharing. More elegant approaches will hopefully evolve, but the FCC does at least deserve credit for highlighting the need for sharing, not just so that underused bands can be harnessed for data capacity, but also to enable new business models and new service providers. Unlicensed spectrum, notably with WiFi, has shown the potential for open airwaves to drive new services and operators. However, the limitations of unlicensed bands in terms of security, quality assurance and so on mean that the cellular operators have been less disrupted, especially in the high value end of their business,…