Cognitive Radio: Forging ahead from Concept, Testbed to Large-Scale Deployment

This article first briefly reviews the basic concepts about cognitive radio (CR) technology and CRenabled cognitive wireless communications, and then discusses the differentiating features of CR and the fundamental theories or principles behind CR, especially from the artificial intelligence and machine learning perspective. As a CR testbed plays an important role in the transition of CR technology from concept to large-scale deployment, a survey on the state-of-the-art development on CR testbeds is presented, which indicates the trend of future development. Emerging research topics and potential applications of CR technology in various areas are also discussed which could be further investigated in an innovative CR approach.