FCC compliance testing

Master your FCC compliance testing challenges

FCC requirements change as wireless technologies evolve. Keeping up with these changing regulations is a challenge on its own, as revisions must be actively monitored and incorporated into design and verification workflows. In addition, modern devices integrate multiple wireless technologies that operate across various frequency bands, and this increases testing complexity. Another challenge is EMC and emissions testing to comply with radiated and conducted emissions limits, as per CISPR and ANSI C63 standards. It is also important to comply with specific absorption rate (SAR) or power density (PD) limits to meet requirements for human radio frequency exposure.

The introduction of the 6 GHz band (5.925-7.125 GHz) for unlicensed use comes with additional specific regulatory challenges, particularly those related to power control:

• Power adjustment complexity: Devices operating in the 6 GHz band must employ complex WLAN power control mechanisms, as specified in IEEE 802.11.
• Automated frequency coordination (AFC) requirements: For certain devices (like dual client 6CD and standard client 6FX devices, which connect to standard power access points), the AFC system dictates the maximum allowable power levels to protect incumbent services. These devices must be capable of dynamically adjusting their transmit power according to AFC system instructions.
• Testing client power adjustment: In 6 GHz band testing (KDB 987594), there is limited flexibility when testing client devices that require standard-power access point operation under AFC control.
• Dynamic frequency selection (DFS) testing: DFS ensures that Wi-Fi devices can share the spectrum with radar systems (as defined in KDB 905462). Two challenges here are (1) generating and synchronizing complex radar waveforms with high accuracy and (2) ensuring repeatable detection probability results across multiple test cycles.
• Custom test environment setup: Demonstrating compliance often requires the precise emulation of WLAN signaling scenarios (including standard and low-power access points) and manipulating parameters like the transmit power envelope (TPE) element. Achieving this level of customization and flexibility is largely infeasible with off-the-shelf access points.

High-performance solutions for FCC compliance testing

Our test systems deliver end-to-end coverage for FCC testing:

• R&S®TS9975: conducted and radiated EMI measurements
• R&S®TS8996: radiated spurious emissions (RSE) testing
• R&S®TS8997: ETSI and FCC compliance testing and unlicensed band testing (such as WLAN and Bluetooth)

For 6 GHz band compliance testing, the CMX500 supports FCC KDB987594 D02 test cases K and L. Key advantages of the CMX500 include:

• Emulation of various WLAN signaling scenarios, including both standard power and low-power access points. This high degree of customization allows for a wide range of access point combinations - a level of flexibility that is largely infeasible with off-the-shelf access points.
• Advanced TPE features - users can configure the TPE element using the CMX500 WebGUI by setting it to "automatic", "disabled" or "user-defined".
• Ability to support two access points with one unit - the RF paths of both access points can be routed to a single RF connector on the CMX500, reducing the required cabling and mitigating measurement uncertainty.
• Step-by-step standard operating procedure for utilizing the WLAN signaling features to achieve compliance as required by test cases K and L.