Virtualization was one of the biggest themes of Mobile World Congress, as expected. There were impressive demonstrations and progress updates from the operators in the vanguard of NFV (Network Functions Virtualization), such as Telefonica with its Unica program – although the high profile of such projects often obscures just how many carriers will not think of deploying NFV, let alone broader software-defined networking (SDN) for many years to come. One of the factors delaying mass uptake is the sheer complexity of virtualizing network functions and running them in software, which has a long-term pay-off period, and also involves significant cultural and structural change in the organization – NFV and SDN often go hand-in-hand with broader shifts towards IT/telecoms convergence and,…