Introduction to Cognitive Radio

The concept of Cognitive Radio (CR) appeared as a new paradigm in 1999 as an extension of Software Defined Radio (SDR). It describes the situation where intelligent radio devices and associated network entities communicate in such a manner that they are able to adjust their operating parameters according to the needs of the user/network, and learning from experience at the same time. Since then, there has been a significant amount of effort in the research community on CR-related topics. Standardization activities on Cognitive Radio Systems (CRS) (including TV WhiteSpaces—TVWS) have also been initiated and progressed in many standardization bodies. Almost all regulatory bodies in the USA, Europe and Asia–Pacific regions have acknowledged the importance of CRS on shaping the way spectrum is allocated. Regulators like FCC in USA and Ofcom in UK have opened the door for secondary access to unlicensed devices on TV bands. Finally, world radiocommunication conference (WRC) 2012 witness discussions on the required regulatory changes to allow the introduction of CRS. Despite all this progress, CR is mostly a research topic today, and the wireless market has not seen a mass commercial deployment/exploitation of the CR technology yet. Mitola’s full CR still remains a futuristic concept where a ubiquitous cognition is embedded into all types of devices/equipments/applications which are aware of our needs/wishes, executing them and rendering our daily lives easier.