An Evaluation of Costs and Benefits of an Ontology and Policy Based Cognitive Radio

Cognitive radio is expected to have the capability to sense the changes of the environment and adapt its communications parameters accordingly. Ideally, adaptation shall be done autonomously and collaboratively. In [1], we proposed an ontology and policy based approach to enable autonomous and collaborative adaptation of cognitive radio parameters. In this approach, an ontology is developed to capture the core concepts in wireless communications. This ontology is written in a formal language (Web Ontology Language) that has computer interpretable semantics and can be processed by an inference engine. The ontology is shared by the transmitter and receiver and provides a common knowledge base for them. Using the vocabularies provided by the ontology, a set of policies is developed to implement the adaption algorithm and a set of control messages are developed to enable collaboration between the transmitter and receiver. The interpretation and execution of the policies and incoming control messages are done in the inference engine. This paper focuses on evaluating the costs of benefits of the ontology and policy based cognitive radio in terms of time delay, communications overhead and performance improvement.