The IST WINNER (WINNER is part of the European Union research programme within the Sixth Framework Programme (FP6) of the European Information Society Technology (IST) programme. Accepted for the Wireless World Research Forum (WWRF) 2006 Industrial Forum (Kermoal, J.-P. et al. (2006). Spectrum deployment scenarios and advanced functionalities development in WINNER.) project is a major European research activity to develop a flexible and scalable radio access system for 4G, which is addressing the challenging requirements for future systems such as those of the International Telecommunication Union (ITU) in terms of overall performance, flexibility, scalability and optimized spectrum usage. In this article, the Radio Resource Management (RRM) spectrum functionalities are defined and subsequently analyzed. The proposed RRM spectrum architecture developed will result in reducing the time required to tailor new services to network operators. Furthermore, the flexible spectrum access and usage leads to more capable and faster services with high Quality-of-Service (QoS) giving more user satisfaction than conventional networks. The inherent centralization and decentralization degree for the functionalities is outlined and discussed since flexible spectrum techniques on both fast and slow basis will lead to a better utilization of spectrum.