Permissive Changes against Full Retest after a Firmware Update
Firmware updates altering output power, channels, or DFS logic trigger mandatory permissive change filings or retests before distribution.
Full Retest
Meaning
Complete evaluation cycles involve repeating every laboratory measurement to verify that hardware changes have not degraded performance. A full retest is often required when the main radio chipset or the antenna layout of a device is modified after the initial certification. This ensures that the product still complies with all legal requirements for emissions and immunity.
It is the most thorough way to validate a major design change. This prevents the shipment of hardware that might violate international radio laws.
Validation Scope
The process covers every frequency band and every mode of operation supported by the hardware. During a full retest, the lab engineers repeat the measurements for radiated power, occupied bandwidth, spurious emissions and receiver sensitivity. This generates a new set of data that replaces the old test reports.
Design Integrity
Comparing the new results to the original baseline helps to find any hidden problems. If a full retest shows higher levels of noise, the designer must identify which component is causing the issue. This prevents a faulty product from reaching the customer.
Certification Update
Regulators use the new reports to issue a fresh grant. This document is the final proof that the device is safe for use.