FCC §15.407

FCC §15.407 forms part of the FCC requirements for unlicensed intentional radiators. It establishes technical and operational requirements for U-NII devices in the 5 GHz and 6 GHz frequency ranges, including equipment used for Wi-Fi 6E and Wi-Fi 7.

The rule addresses transmit power, power spectral density, unwanted emissions and, where applicable, dynamic spectrum access. The applicable requirements depend on the operating band, device class and deployment conditions.

Scope and U-NII Bands

The current scope extends beyond the four traditional 5 GHz sub-bands. It includes:

• U-NII-1, U-NII-2A, U-NII-2C and U-NII-3 from 5.15 to 5.85 GHz;

• U-NII-4 from 5.85 to 5.895 GHz; and

• U-NII-5 through U-NII-8 from 5.925 to 7.125 GHz.

The 6 GHz provisions distinguish device classes such as standard-power access points, indoor access points, subordinate devices, clients, geofenced variable-power devices and very-low-power devices. Automated Frequency Coordination (AFC) is required for device classes and operating modes specified by the rule; it is not a universal requirement for every 6 GHz device.

Power and Spectral-Density Limits

• U-NII-1: Access points may use up to 1 W conducted output power. Outdoor access points are also subject to the elevation-angle EIRP restriction specified in the rule; client devices have a lower limit of 250 mW.

• U-NII-2A and U-NII-2C: Conducted output power is limited to the lesser of 250 mW or the bandwidth-dependent limit in §15.407. Power spectral density is limited to 11 dBm/MHz.

• U-NII-3: Conducted output power may be up to 1 W. The applicable power spectral-density limit uses 500 kHz as its reference bandwidth.

The often-cited value of 17 dBm/MHz applies to U-NII-1 and must not be treated as a universal limit across all U-NII bands. Separate limits and conditions apply to U-NII-4 and the 6 GHz device classes.

DFS, TPC and Unwanted Emissions

• Dynamic Frequency Selection (DFS) applies to the relevant U-NII-2 operations. Following radar detection, all transmissions on the operating channel must cease within 10 seconds.

• Transmit Power Control (TPC) applies where specified and must provide the power-reduction capability required by the rule.

• The −27 dBm/MHz unwanted-emission limit applies to U-NII-1, U-NII-2A and U-NII-2C under the stated measurement conditions. U-NII-3 uses a band-edge emission mask and must not be summarized by that single value.

Channels or modes involving more than one regulatory range must be assessed against every applicable band-specific requirement.

Certification and Compliance

U-NII devices subject to §15.407 require FCC Certification. A recognized Telecommunications Certification Body (TCB), accredited to ISO/IEC 17065, reviews the application and grants the equipment authorization.

The compliance measurements are performed by an FCC-recognized testing laboratory accredited to ISO/IEC 17025. Depending on the device, the test program may include conducted and radiated emissions, output power, bandwidth, unwanted-emission measurements and DFS validation. The TCB and the testing laboratory have separate roles, even when both functions are provided by the same organization.

Product Lifecycle

• Classification: Determine every operating band, device class and power mode before testing.

• Testing: Assess the final radio, antenna and software configuration against the applicable band-specific requirements.

• Changes: Evaluate changes to radio parameters, antennas, firmware, enclosure or deployment restrictions for their effect on the certified configuration.

• Rule monitoring: Track FCC rule changes, equipment-class requirements and applicable transition provisions throughout the product lifecycle.

Need help with FCC §15.407 certification?
IB-Lenhardt supports device classification, test planning, accredited radio testing, DFS validation and FCC certification projects. Learn more about FCC certification and market access.