The FCC has a unique and authoritative reference known as the Radio Spectrum Dashboard. It provides a public means of reviewing how spectrum bands are allocated and for what uses, and who holds licenses and in what areas.
This version provides basic, plain language information about frequencies generally deemed appropriate for mobile broadband (225 MHz to 3700 MHz.) In addition, Spectrum Dashboard contains more detailed information, mapping, and research capabilities for the bands where broadband service is either already available, or potentially could be provided.
If you’re interested in who uses those relatively unknown radio bands, and particularly if you want to conduct research using a software defined radio (SDR), this resource is invaluable.
In addition to the webpage inquiry services, the FCC announced two new APIs on the FCC developer page. These APIs leverage data from the Spectrum Dashboard and provide the developer community with direct access to these assets.