03.15.2005 12:00 AM
Requirements Set for Cognitive and Software-Defined Radios
At Thursday's Open Commission Meeting, the FCC adopted a Report and Order
modifying its rules to make it easier to use cognitive radio and software defined radios. The modified rules mainly affect how equipment for existing licensed and unlicensed services can be manufactured and certified and do not change rules regarding sharing of licensed spectrum. In the Report and Order, the FCC states, "At this point, we see no need to adopt any particular technical model for interruptible spectrum leasing. Ultimately, a licensee must itself be satisfied that the technical mechanism being implemented under a lease does in fact provide it with the ability in real time to reclaim use of its spectrum when necessary."
The Report and Order leaves open the option for the FCC to modify its rules in the future to accommodate new technologies, stating, "The development of cognitive radio technology has been and will continue to be evolutionary in nature. As the technology evolves, our intent is to delete, change, or adopt rules in phases so as to ensure that our rules facilitate the market-based development and deployment of these technologies."
Software defined radio technology allows manufacturers to use the same radio in different countries, where spectrum allocations are different from those in the U.S. In the case of Part 15 devices, any use of this technology would require the FCC to certify unlicensed devices that may be capable of operation on non-Part 15 frequencies. In the rulemaking, the Society for Broadcast Engineers opposed the importation and marketing of devices capable of operating in the 2483.5-2500 MHz band, noting that they may interfere with grandfathered broadcast auxiliary service stations using these frequencies.
The FCC decided to allow certification of these devices provided they operate under a master/client model, as defined in its rules for U-NII devices. The "master" would prevent the client from operating on unauthorized frequencies in the U.S. If the master itself is capable of operating on frequencies outside Part 15 band, it would have to incorporate security features in its software that would prevent it from being used on these frequencies inside the U.S. and it would have to be certified as a software defined radio. Client devices that could also operate as a master would have to be certified as software defined radios.
A plan in the Notice of Proposed Rulemaking in this proceeding to allow unlicensed devices that employ cognitive radio technologies to operate at higher power in areas with limited spectrum use was not adopted, but the FCC stated, "We expect to further consider the issue of higher power unlicensed operation at a later date."
The Report and Order
does an excellent job explaining the potential for cognitive radio and the benefits of certifying software defined radios now. Security issues are extensively discussed, along with the specific rules for certifying software defined radios. For another summary of the Report and Order, see FCC Adopts Rule Changes for Smart Radios