Perspectives and problems of opportunistic and dynamic spectrum management

Possibly the most fundamental change ever is happening in the history of spectrum regulation - the allowing of secondary users to share spectrum with primary users, for free - subject to the condition that the secondary users, with licence-exempt equipment, do not interfere with the primary users. Cognitive Radio (CR) is an enabling technology that allows such sharing without causing interference to the primary users or to other secondary users. It opens the way for opportunistic and dynamic spectrum management, where wireless equipment is required to interface with cognitive algorithms, sensing mechanisms and databases. The first opportunity for spectrum sharing by secondary users is occurring with the UHF Digital TV spectrum, in what is commonly called TV Whitespace (TVWS). Use-cases for secondary use of spectrum broadband include access to rural and underserved communities, coverage of the street from inside buildings and future home networks. These are discussed and conclusions drawn regarding feasibility and commercial importance of these use-cases.