The realization of cognitive radio networks is a key solution to meet the raising expectations for high data rates and quality of service in mobile communications. This implies the design of a two-fold cognitive manager for resource management (CM-RM), to manage an opportunistic use of the whitespaces as introduced in this paper, and for Spectrum Management (CM-SM). The proposed CM-RM has been designed to be applicable to all kinds of control topologies (centralised/distributed). This paper presents the study of CM-RM functionalities for several scenarios based on a centralized management of the resources. The scenarios that have been selected are: cognitive ad hoc networks, cognitive femtocells, and cellular extension in TV white spaces. Each of them is introduced, specific mechanisms implemented in the CM-RM are proposed, and performance results are presented for validation purpose. © 2012 IIMC Ltd.