Smart radios stretch spectrum

If you follow the television analog shut-down issue -- which has, without being spelled out that specifically, been in the news again this weekend with the closing recommendations of the 9/11 Commission -- you will find proponents of new uses for that spectrum talk about "smart radios," also known as cognitive radios.  CommsDesign has published a good overview article about the technology by Patrick Mannion with the above title.  The first half of the article should be accessible to non-engineers and I recommend it to broadcasters trying to understand what's being proposed for the current analog frequencies.   Link:  EE Times via CommsDesign.  --Dennis