Cognitive resource Management for QoS Support in Mobile Opportunistic Communications

Optimizing the Quality of Service (QoS) support and ensuring seamless mobility as well as the protection of incumbent users belong to the challenges appearing when the radio spectrum is accessed in an opportunistic way by the served users. The functional concept of Cognitive Resource Manager (CRM) is presented providing cognition of the environment to optimise the allocation and exploitation of radio resources, to improve the access to these resources and to ensure mobility control in the opportunistic system. Requirements identified for the functional architecture of the CRM are 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 towards the other opportunistic system entities. 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 environment cognition and resource exploitation functionalities in the CRM and consider specific QoS constraints and protection of incumbent users are discussed. Results of simulations conducted for a dedicated scenario illustrate the performance achieved by this concept. Keywords: Cognitive Resource Manager, decision-making, distributed algorithms, functional requirements, functional architecture, mobility, opportunistic environment, quality of service.