Understand FCC Guidelines
- Identify the category of your wireless device (e.g., unlicensed transmitters, mobile devices, etc.) and review the appropriate Title 47 of the Code of Federal Regulations (CFR) parts applicable to your product. For example, Part 15 covers unlicensed transmissions.
- Study the power limits, bandwidth restrictions, and channel access protocols. This includes understanding frequency allocations and spurious emissions limits.
Conduct a Preliminary Design Review
- Review the design for minimizing interference. This could include ensuring proper shielding and using filters to eliminate unwanted frequencies.
- Validate the choice of components and antenna to ensure they meet the necessary FCC criteria for emission and transmission.
Perform Pre-Compliance Testing
- Set up a test environment using RF test equipment like spectrum analyzers and signal generators to check emissions and susceptibility.
- Conduct tests to measure radiated and conducted emissions. This should align with FCC's recommended methods in the applicable CFR parts.
- Validate that the device operates within the allowed frequency bands and power levels without frequency drift.
Optimize Firmware for Compliance
- Implement software controls for power management to ensure the device adheres to power limits even under worst-case scenarios.
- Use the following code example to manage transmission power level in a device with radio module support:
#include <radio_module_api.h>
void setTransmitPower(int level) {
if (level < MIN_POWER || level > MAX_POWER) {
return; // invalid power level
}
radio_set_power_level(level);
}
- Develop adaptive frequency hopping algorithms, particularly for devices operating under Part 15 rules, to minimize interference and enhance coexistence.
Documentation and Record Keeping
- Keep detailed records of all testing data and design decisions. Document any design changes made to achieve compliance.
- Prepare the technical documentation required for FCC submission, including schematic diagrams, block diagrams, and test reports.
Engage with Certified Testing Labs
- Partner with a certified testing laboratory to conduct official compliance testing. Choose a lab with experience in FCC testing relevant to your device category.
- Coordinate with the lab to ensure all necessary tests are conducted, and any potential issues are identified and addressed promptly.
Prepare for FCC Submission
- Compile all test results, device schematics, and user manuals for FCC submission. Ensure everything is in the format required by the FCC.
- Submit the complete package, along with the appropriate fees, through the FCC’s online system or through an accredited Telecommunications Certification Body (TCB).
Post-Compliance Responsibilities
- Monitor any post-market compliance requirements, such as regular audits or renewals of certification.
- Maintain a process for continued compliance as product upgrades or changes occur. Ensure any firmware updates or hardware modifications remain within the scope of the granted FCC certification.
