Chengliang Zhang, Vice President of China Telecom Beijing Research Institute, gave a plenary speech that laid out the potential demands of a 5G architecture: A much more dense radio access network based on a Cloud RAN (CRAN) design supported by low latency and significant capacity in fronthaul, mid-haul and backhaul links, which in turn requires greater support from metro, regional and long-distance networks. All of this, he noted, will require extensive optical transport investments. (See An Optical Transport Vision for the Cloud, 5G Era.)

So who's actually talking now about 600G? Among the systems vendors, Coriant, Nokia and Infinera are making a case with their latest product developments, the Groove G30, Photonic Service Engine 3 (PSE-3) and ICE5 respectively. (See Coriant Claims Industry Benchmarks With Its Groove G30, Infinera Shifts Up a Gear With Its Latest Optical Engine and Nokia Pushes Optical to the Limit.)