This chapter presents a selection of potential deployment and application scenarios for Cognitive Radio and Software Defined Radio. The chapter goes beyond a simple review of scenarios by focusing on the viewpoint of several key players in wireless communication research and applications: regulators, researchers from the engineering and economic/business community, industrial partners and companies, either directly or through their involvement in national and EU-funded European projects. In this framework, two key issues related to scenario definition are addressed:\ud
• An analysis of players that determine the evolution of scenarios, including both technical and economic/business aspects;\ud
• Study of approaches for classification of CR deployment scenarios, with the aim of identifying a set of elements that allow creating taxonomy capable of fit-ting existing and new scenarios relevant to CR and SDR.\ud
The chapter opens with an analysis of scenarios as proposed by ITU (Section 2.1, authored by Mustonen and Matinmikko), followed by the vision of a wide set of EU projects on CR scenarios (Section 2.2, by Matinmikko and Paavola). The im-pact of different regulatory and environmental conditions on application sce-narios is addressed in Section 2.3, where Sridhar and Basaure provide a compari-son between feasible scenarios in India and Finland. Section 2.4, by Mueck, Sri-kanteswara, Macdonald and El-Refaey, moves to the analysis of upcoming scenar-ios in Europe focusing on the concept of Licensed Shared Access as defined based on activities carried out in ETSI and CEPT. \ud
Next, the chapter moves to aspects related to planning and classification of scenar-ios. In section 2.5 Medeisis and von der Emden propose a scenario plan-ning methodology aiming to support planning and classification of scenarios for Cogni-tive Radio and to help identify relevant business models. In Section 2.6 Medeisis, Holland and De Nardis propose an approach to the definition of a taxonomy of CR application scenarios, aiming at fitting present and future applications in a coher-ent framework. Finally, Section 2.7 by Cesar Gutierrez and Hamid Reza Karimi offers an example of very practical application scenario for deployment of White Space Devices in TV Bands as established by a harmonised European standard EN 301 598