A. Spectrum sharing innovation test bed and spectrum sensing tools
B. Spectrum sharing innovation test bed and spectrum management tools
C. Cross-layer innovation test bed and spectrum sensing tools
D. Cross-layer innovation test bed and spectrum management tools
Explanation: Spectrum Sharing Innovation Testbed and Spectrum Management Tools are the recommendations proposed in the Spectrum Policy Initiative created in 2003. Most of the recommendations pertained to the modification of the spectrum management infrastructure. The initiative states that technological advances can be exploited to overcome spectrum scarcity by spectrum sharing.