Spectrum sharing policy at global level

Spectrum sharing developments exploiting cognitive radio technology will change the traditional spectrum management models, which calls for discussions and decisions in the policy making domain. Efficient governance of natural resources such as the radio spectrum requires actions in different policy making levels ranging from national level all the way to the international level. This chapter will introduce spectrum sharing related policy making activities in the global level presenting the actions taken at the International Telecommunication Union Radiocommunication (ITU-R) sector.We will introduce the groups within ITU-R and their related activities and introduce cognitive radio and spectrum sharing related terminology developed at the ITU-R. Special emphasis is put to the ITU-R studies on cognitive radio systems (CRS) with a set of capabilities for obtaining knowledge, decision-making and adjustment, and learning, to enhance the efficiency of spectrum use. We will introduce the CRS capabilities and present scenarios and applications where vertical and horizontal spectrum sharing using CRS capabilities could take place. Other sharing related activities at the ITU-R are also presented including spectrum management, spectrum monitoring and spectrum occupancy measurement studies, as well as more general ongoing work on regulatory tools to enable spectrum sharing and CRS from the point view of spectrum management. Finally, a future outlook is given for spectrum sharing policy developments toward the fifth generation (5G) networks.