ABSTRACT
Those looking to reform the command-and-control approach to spectrum have always been very interested in cognitive radio, which senses whether a frequency is being used and only transmits in unoccupied bands. Cognitive radio was appealing for two reasons: it means that spectrum could be used more efficiently but it could also be the foundation for a sophisticated commercial market in spectrum. In 1998, Eli Noam* explained how cognitive radio could allow many buyers and sellers to take part in real-time automated electronic auctions to gain access to frequencies, ending the structural problems with the spectrum market.
