Licensing, Frequency Coordination, and Regulatory Compliance
What this domain tests
Domain 5 covers the paperwork and physics of lawful operation: FCC Part 90 authorisations, station classes, emission designators, coordination bodies and the technical limits written into a licence.
Core rules
- Public safety land mobile operates under 47 CFR Part 90. Applications are filed in the FCC Universal Licensing System and grant a call sign for a defined area, frequency, power and antenna height.
- Station classes: FB2 (base serving mobiles), FB4, FB6 and FB8 (base with differing protection), MO (mobile) and FX1/FX2 (fixed links). Applying for the wrong class is a common error.
- Emissions are described by designators: 11K2F3E for 12.5 kHz analog voice, 8K10F1E for P25 Phase 1 voice, and a TDMA designator for Phase 2. Bandwidth, modulation and information type are all encoded.
- Narrowbanding: VHF and UHF public safety channels moved to 12.5 kHz by 2013, with a 6.25 kHz-equivalent efficiency requirement; 700 MHz and 800 MHz follow their own band plans.
- Coordination: 800 MHz NPSPAC and 700 MHz Regional Planning Committees review applications, and regional databases such as CAPRAD check interference. Border areas need Canadian or Mexican coordination.
- Technical limits: ERP caps, antenna height above average terrain, RF exposure limits under OET-65, and Antenna Structure Registration for towers above 200 ft.
Worked example
An agency files for a 700 MHz trunked site. The application must show an emission designator matching Phase 2 TDMA operation, ERP within the regional plan, and coordinates that clear RPC review. If the antenna exceeds the ASR height threshold, the tower must be registered alongside construction. Filing an 11K2F3E analog designator while operating Phase 2 is a mismatch that an inspector can cite.
Traps
Confusing ERP with EIRP on the application, assuming a nationwide interoperability channel needs no licence or programming discipline, forgetting the construction deadline attached to a grant, and skipping RF-exposure documentation at shared sites.