Search FCC ULS licenses and spectrum leases by callsign, licensee name, FCC Registration Number (FRN), radio service, status, and licensee state, returning one row per record with its unique system identifier (USI) for fcc_spectrum_get_license. At least one of callsign, licensee, frn, radio_service, or state is required; status only narrows. Defaults to active records; pass status "any" to include expired, cancelled, and terminated ones. Licensee name matching is word-based (every word must appear as a word prefix), not fuzzy.
Fetch one FCC ULS license or spectrum lease in full by callsign or unique system identifier (USI): licensee (the lessee on a lease), status and key dates, its locations with coordinates, elevation, structure height, and ASR number, each location's antennas, and each antenna's authorized frequencies with power, ERP/EIRP, station class, transmitter, and emission designators; geographic-area licenses list their market and spectrum blocks, and lease links are shown in both directions. Large records are paged: one call lists whole locations up to 50 sites and 100 antennas, up to max_frequencies frequency rows, and 100 leases, and names the location_offset or lease_offset that reads the rest. Technical detail is kept for active, pending-legal, and term-pending records only. A callsign shared by several records returns the active one, else the most recent.
Find FCC-licensed transmitter sites within a radius of a coordinate, nearest first, each with its callsign, licensee, distance, coordinates, ground elevation, structure height, and the frequencies authorized there. Filter by frequency or band, radio service, and live status (active by default). Coordinates are decimal degrees or DMS strings; mobile-only and area-wide authorizations without a fixed coordinate are not returned, and market-area licenses without site records are found with fcc_spectrum_search_frequencies.
Find FCC ULS authorizations whose occupied band overlaps a frequency or band. Site assignments (land mobile, microwave, paging, cellular sites) return one row per site and frequency with the site's state and coordinates; market-area licenses and leases (PCS, AWS, 700 MHz, 3.45 and 3.7 GHz, and other auctioned blocks) return one row per spectrum block with its market code and name; 3.5 GHz Priority Access Licenses file no frequency, so list them with fcc_spectrum_search_licenses and radio_service PL. Filter by state, radio service, licensee, and live status (active by default). For transmitter sites near a coordinate, use fcc_spectrum_find_transmitters.
Decode FCC ULS codes used by the other tools — radio service codes, license statuses, location types, antenna types, applicant types, amateur operator classes — or report coverage: which service groups this index holds, record counts, and when each was last updated. Works before the index is built.