Low latency communications are a critical enabling factor of various 5G use cases. Since their initial conceptions, 5G technologies for the various elements of the network (i.e. air interface, fronthaul, backhaul, edge, core, transport) have been designed to pursue a drastic reduction of latency at the various segments of the communication service and eventually end-to-end. Various research projects within the 5G PPP programme are working to optimize latency-critical use cases and are developing solutions to reduce delay at user plane and at control plane in specific vertical application contexts. In light of the need for a coherent benchmarking framework, this paper briefly introduces latency definitions and use cases evaluation scenarios from four 5G PPP Phase 2 projects: NGPaaS, 5GCity, 5G ESSENSE and MATILDA. Teams from these project are working towards achieving a common understanding of latency key performance indicators (KPI), trying to converge on common definitions and measurement methodologies to be applied