What's Open Spectrum?

In this article Kevin Werbach explains the idea of open spectrum. This idea challenges the assumption that wireless spectrum is a scarcity that must be spit up, licensed and restricted in use to prevent interference. With spread spectrum technology (e.g. CDMA) however many devices can use the same frequency without interference. This is accomplished by intelligence in the receiving devices. The idea of open spectrum is to open up a significant amount of spectrum for common use.