The story of unlicensed cellular reads rather like that of mobile broadcast – if you at first you don’t succeed, try, try and try again. The tale dates back almost a decade to the development of LTE-Unlicensed (LTE-U) for the existing 3GPP Releases of the time (10/11/12). This quickly fell foul of the WiFi community because it was designated for rapid launch in countries, chiefly the USA and China, that did not mandate use of the listen-before-talk (LBT) technique to mitigate clashes. LTE-U allowed MNOs to boost capacity without having to offload onto a separate WiFi network. It retained LTE as an anchor for signalling and control, but all data including phone calls was rooted over the unlicensed 5 GHz band,…