The mobile industry has been increasingly dependent on optical communications, firstly for backhaul and more recently for fronthaul. Rising wireless data capacity has, in turn, helped drive innovation in optical transmission, and that has reached new levels with the more stringent demands of 5G fronthaul. That came in with small cells to connect with macrocells, then Open RAN tightened timing demands further with its disaggregation of fronthaul between Radio Units RUs) and Baseband Units (BUs), leading to the development of new split interface specifications in 2003. Until quite recently, the main optical focus for telcos has been on DWDM (Dense Wave Division Multiplexing) to increase the capacity of individual fibers, along with improved modulation over each of the constituent wavelength…