ITU-R standardization activities on Cognitive Radio Systems

The current radio environment is characterized by its heterogeneity. Different aspects of this heterogeneity include: multiple operators and services, various radio access technologies, different network topologies, broad range of radio equipment, and multiple frequency bands. Such environment has a lot of technical and business opportunities. The examples are: joint management of several radio access networks within one operator to balance load of these networks; detecting and using unused spectrum in the allocated frequency bands without interrupting the operation of the primary users of such frequency bands; spectrum trading between several operators. To exploit such opportunities, the concept of Cognitive Radio System (CRS) has been developed. A lot of CRS usage scenarios and business cases are possible. This has triggered a lot of standardization activity at all levels, including ITU, IEEE, ETSI, and ECMA, where each of these organizations considers multiple CRS deployment scenarios and business directions. This paper presents current ITU-R standardization activities on CRS.