A Cognitive Plane is a decentralised system (e.g. component-ware, multi-agent system, etc) enabling self-management, self-control and self-optimization of network and service platforms. Specifically Cognitive Plane exploits data mining, reasoning and machine learning algorithms and techniques to extract the knowledge on the status of the network and service platforms. Moreover, Cognitive Plane is in charge of enacting decentralised autonomic behaviours, on the basis of acquired knowledge, to assure (cross-layer, cross-node and cross-network domain) self-management, self-control and self-optimization of resources and applications.