Abstract

Optimizing the Quality of Service (QoS) support, providing seamless mobility and ensuring the protection of incumbent users are some of the challenges that arise when the radio spectrum is accessed in an opportunistic way. The functional concept of Cognitive Resource Manager (CRM) is presented providing cognition of the environment to optimize the allocation and exploitation of radio resources, to improve the access to these resources and to ensure mobility control in the opportunistic system. Requirements for the functional architecture of the CRM are identified and addressed by defining building blocks to manage cognitive access and mobility control as well as resource allocation and usage. These functional entities are described together with their interfaces inside the CRM and with other opportunistic system entities like the Spectrum Manager. Particular decision-making cases for resource control and usage are presented by means of message sequence flows taking the overall cognitive and opportunistic context into account. Finally selected algorithms for distributed power control that implement parts of the functionalities of the CRM while considering specific QoS constraints and protection of incumbent users are discussed. Results of simulations conducted for these algorithms in a dedicated scenario illustrate the performance achieved by this concept.