Understanding FCC Rule Parts for Cellular Devices
Manufacturers developing LTE and 5G products often encounter references to FCC Part 22, Part 24, and Part 27 during the certification process. Determining which rule parts apply is an important step because cellular devices frequently operate across multiple licensed spectrum bands governed by different sections of the FCC rules.
Unlike many unlicensed wireless technologies that are certified under a single rule part, cellular devices often require evaluation under multiple FCC standards depending on the supported frequency bands.
Understanding how Part 22, Part 24, and Part 27 relate to modern LTE and 5G deployments can help manufacturers streamline certification planning and avoid unnecessary delays.
Why Multiple FCC Rule Parts Exist
The FCC organizes licensed wireless spectrum into various services, each governed by its own regulatory framework.
Part 22, Part 24, and Part 27 were created at different points in the evolution of cellular communications as new spectrum became available for commercial mobile services. Today, these rule parts collectively support many of the LTE and 5G bands used throughout the United States.
As a result, modern cellular modules commonly support frequency bands that fall under more than one FCC rule part.
What Is FCC Part 22?
FCC Part 22 governs Public Mobile Services and includes the Cellular Radiotelephone Service contained within Subpart H. Historically, Part 22 covers the original cellular spectrum allocations that formed the foundation of commercial mobile communications in the United States.
The most commonly encountered spectrum associated with Part 22 is the Cellular 850 MHz band.
Examples of technologies that may operate under Part 22 include:
- LTE Band 5
- NR Band n5
- Cellular IoT deployments
- Legacy cellular network infrastructure
Although newer spectrum bands have been introduced over the years, Part 22 spectrum continues to play an important role due to its favorable propagation characteristics and wide geographic coverage.
What Is FCC Part 24?
FCC Part 24 governs Personal Communications Services (PCS). The rule part establishes licensing and technical requirements for PCS operations and includes both narrowband and broadband PCS services.
The PCS spectrum is commonly associated with the 1900 MHz frequency range.
Examples of technologies commonly deployed within PCS spectrum include:
- LTE Band 2
- NR Band n2
- Voice and data services
- Mobile broadband applications
PCS spectrum has been widely deployed by major U.S. carriers and remains an important component of many LTE and 5G network architectures.
What Is FCC Part 27?
FCC Part 27 governs Miscellaneous Wireless Communications Services and encompasses a broad collection of licensed wireless spectrum bands that support modern broadband services.
Part 27 includes numerous spectrum allocations used by LTE and 5G networks, including:
- AWS spectrum
- 700 MHz services
- 600 MHz services
- Certain 900 MHz broadband services
- AWS-1, AWS-3, and related allocations
- Multiple mid-band spectrum allocations
Examples of cellular bands commonly associated with Part 27 include:
- LTE Band 4
- LTE Band 12
- LTE Band 13
- LTE Band 17
- LTE Band 66
- Various 5G NR bands
Many modern LTE and 5G devices primarily operate within Part 27 spectrum.
Which FCC Rule Part Applies to LTE and 5G Devices?
The answer is often all three.
A typical cellular module may support:
| Cellular Band | Typical FCC Rule Part |
| Band 5 / n5 | Part 22 |
| Band 2 / n2 | Part 24 |
| Band 4 / n66 | Part 27 |
| Band 12 | Part 27 |
| Band 13 | Part 27 |
| Band 66 | Part 27 |
Because cellular modules are designed to operate across multiple carrier networks, it is common for a single device to require compliance evaluations under Part 22, Part 24, and Part 27 simultaneously.
Manufacturers should therefore review all supported frequency bands rather than assuming a single rule part governs the entire device.
Typical FCC Testing Requirements
Although specific requirements vary by frequency band and technology, cellular certifications commonly include:
| RF Output Power |
| Verification that transmitter power remains within applicable limits. |
| Occupied Bandwidth |
| Measurement of the frequency range occupied by the transmitted signal. |
| Frequency Stability |
| Verification of frequency accuracy under environmental and operating variations. |
| Band Edge Compliance |
| Evaluation of emissions near the boundaries of licensed frequency allocations. |
| Spurious Emissions |
| Assessment of unwanted emissions outside the assigned operating band. |
| RF Exposure |
| Evaluation of Maximum Permissible Exposure (MPE) or Specific Absorption Rate (SAR) requirements where applicable. |
Cellular Modules and Host Integrations
Many manufacturers integrate pre-certified cellular modules into finished products.
While a certified module may simplify portions of the approval process, additional evaluations may still be required depending on:
- Host device configuration
- Antenna selection
- Simultaneous transmission scenarios
- RF exposure conditions
- Co-location with other transmitters
Understanding the scope and limitations of existing module certifications is critical when planning a product launch.
Common Certification Challenges
| Incorrect Rule Part Identification |
| Manufacturers sometimes assume all cellular bands fall under a single FCC rule part, resulting in incomplete certification planning. |
| Antenna Changes |
| Modifying antennas from those evaluated during original certification may require additional assessment. |
| Multi-Radio Configurations |
| Products combining cellular, Wi-Fi, Bluetooth, GNSS, or other radios often require additional analysis. |
| RF Exposure Requirements |
| Portable devices frequently require additional RF exposure evaluations beyond standard transmitter testing. |
| Carrier-Specific Requirements |
| Passing FCC certification does not automatically satisfy carrier approval programs. |
How MiCOM Labs Supports Cellular Certification Projects
MiCOM Labs provides testing and certification support for LTE, Cat-M, NB-IoT, and 5G-enabled products.
Our services include:
- FCC certification testing
- Cellular module integration reviews
- RF exposure evaluations
- Antenna assessments
- Regulatory consulting
- Global market access support
- Carrier certification assistance
By identifying applicable FCC rule parts early in development, manufacturers can streamline certification activities and reduce project risk.
Conclusion
FCC Part 22, Part 24, and Part 27 each govern different licensed wireless services used by modern cellular networks. Because LTE and 5G devices frequently support multiple frequency bands, it is common for a single product to operate under more than one FCC rule part.
Understanding which rule parts apply, and how they relate to supported cellular bands, is an important step in developing an effective certification strategy and achieving timely market access.