NTIA commends the Commission for initiating this proceeding to examine issues related to the development and deployment of cognitive radio (CR) technology. NTIA believes that CR technology has the potential to provide more innovative, flexible, and comprehensive use of the radio frequency spectrum, while at the same time minimizing the risk of interference to other spectrum users. CRs can be developed that have the technical capability to adapt their use of the spectrum in response to information external to the radio. As a result of this technical and operational flexibility, CR technologies may also make it possible to use spectrum that may be available in a particular geographic location or during a particular period of time and would otherwise go unused. At this time, there is not a clear boundary between CR and software defined radio (SDR) technologies. In many instances, SDR will be used as the basic platform on which to build CR technology. For this reason, the comments will in certain cases address SDR issues as well as CR, since certain aspects of the SDR regulatory framework could influence the transition from SDR to CR. NTIA offers the following comments in response to the specific issues raised by the Commission in the Notice of Proposed Rulemaking (NPRM).