FCC §15.247
FCC §15.247 is a section of Title 47 of the U.S. Code of Federal Regulations (CFR) that governs the operation of certain intentional radiators in the 2.4 GHz ISM band (2400–2483.5 MHz). It defines technical and operational requirements for unlicensed spread spectrum and digitally modulated devices operating under Part 15 rules.
Scope and Application
This rule applies to unlicensed transmitters using:
Digital modulation techniques, including OFDM as used in Wi-Fi and Bluetooth
It is commonly applied in:
Wi-Fi (802.11b/g/n)
Bluetooth (Classic and BLE)
Zigbee and similar low-power communication systems
Devices operating under §15.247 must not cause harmful interference and must accept interference from authorized services.
Key Technical Requirements
Output Power and EIRP
Maximum conducted output power: 1 W (30 dBm)
Maximum EIRP: up to 4 W allowed when using high-gain antennas
→ Antenna gain above 6 dBi must be offset by a corresponding reduction in transmitter power.
Bandwidth Requirements
DSSS / digital modulation systems: ≥ 500 kHz bandwidth
FHSS systems:
≥ 1 MHz bandwidth if using fewer than 75 hopping channels
Minimum 25 hopping channels required
Channel Separation (FHSS only)
≥ 25 kHz or two-thirds of the 20 dB bandwidth
Emission Limits
Strict limits for spurious emissions, harmonics, and out-of-band radiation
Compliance with defined masks for conducted and radiated emissions
Certification and Compliance
Devices operating under §15.247 require FCC Certification through a recognized Telecommunications Certification Body (TCB).
Required steps include:
Testing for conducted and radiated emissions
Measurement of occupied bandwidth and power levels
Verification of compliance with modulation and emission rules
Upon approval:
A grantee code and FCC ID are assigned
Devices must be labeled and accompanied by Part 15 compliance information
Need Help?
Support is available for FCC Part 15 certification, including emission testing, TCB coordination, and labeling review. → FCC Certification & Market Access
Further Reading & Official Resources
Official FCC Rule Text (eCFR, Title 47, Part 15)
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§ 15.247 Operation within the bands 902-928 MHz, 2400-2483.5 MHz, and 5725-5850 MHz.
This is a curated selection of key sources. For full and up-to-date regulatory documentation, please refer to the official portals of the relevant authorities. All references were verified as of April 2025.