1. Report ITU-R SM.2152. Definitions of Software Defined Radio (SDR) and Cognitive Radio System (CRS). International Telecommunication Union (2009)
2. CEPT Report 24. Technical considerations regarding harmonisation options for the Digital Dividend. A preliminary assessment of the feasibility of fitting new/future applications/services into non-harmonised spectrum of the digital dividend (namely the so-called “white spaces” between allotments). Electronic Communications Committee (2008)
3. ECC Report 159. Technical and operational requirements for the possible operation of cognitive radio systems in the ‘white spaces’ of the frequency band 470–790 MHz. Electronic Communications Committee (2011)
4. ECC Report 186. Technical and operational requirements for the operation of white space devices under geo-location approach. Electronic Communications Committee (2013)
5. Draft ECC Report 205. Licensed shared access. Electronic Communications Committee (2013)