Collaborative adaptation of cognitive radio parameters using ontology and policy based approach
Shujun Li · 2011
Cognitive radio technology has attracted an increasing interest in academic and industrial communities. One of the motivations of cognitive radio is to enable opportunistic spectrum access through sensing the environment, detecting the underutilized spectrum at a specific time and location, and adjusting the radio's transmission parameters to conform to spectrum utilization regulations and policies. In general, cognitive radio is expected to have the capabilities to (1) sense the environment and collect information of the environment; (2) be aware of the external situation, the internal state and its own capabilities; (3) automatically adapt its parameters and optimize multiple objectives; (4) reason about communications situations, objectives and radio configurations. Some of these capabilities, such as spectrum sensing and opportunistic utilization, are currently actively pursued by various wireless research projects. The conceptual architecture that incorporates the capabilities of awareness, reasoning and adaptation has been previously considered under the name of Ontology Based Radio (OBR). This thesis presents a continuation of this line of research. In particular, this dissertation focuses on using a combined approach of ontology and policy-based control to enable collaborative adaptation of cognitive radio parameters and thus improving the link performance. First, we developed a cognitive radio ontology that covers the basic terms of wireless communications from the PHY and MAC layers. Second, we selected a use case of collaborative link adaptation. Third, we developed a set of policies that are needed for this use case. The whole framework was implemented on the USRP/GNU Radio platform. The validity, cost and benefits of the ontology and policy based approach to collaborative radio control was assessed using both Matlab simulations and the implementation on the GNU radio platform.