Changed RCWA Exam Questions

Ahidden node problemoccurs when two or more client devices are within range of the AP butcannot hear each other, causing frame collisions that lead to degraded performance.

According toRUCKUS One Online Help – RF Interference and Hidden Node DetectionandRUCKUS AI Documentation – Airtime Efficiency Analysis, the symptoms include:

(A) Retransmissions:Frequent retries due to undetected collisions.

(D) Reduced throughput:Effective throughput decreases as airtime is wasted on retransmissions and ACK delays.

The issue is common in high-density or obstructed environments. EnablingRTS/CTSorBeamFlex+can mitigate it by improving communication coordination.

“Channel changes” occur in interference mitigation, not hidden-node detection; “Excessive roaming” and “Increased Tx power” are unrelated effects.

PD-MRC (Polarization Diversity – Maximal Ratio Combining)is a patented RUCKUS technology that enhances Wi-Fi signal reception bylistening to client transmissions on both the horizontal and vertical polarization planes. This approach helps overcome signal degradation caused by multipath, reflections, and client device orientation.

According to theRUCKUS One Online HelpandRUCKUS AI technical documentation, PD-MRC dynamically selects and combines the signal from both polarization domains to maximize the received signal-to-noise ratio (SNR). This technology works synergistically withBeamFlex, RUCKUS’s adaptive antenna system, to provide optimal signal gain and link reliability per client.

SmartCastis used for traffic prioritization and QoS management,ChannelFlyhandles dynamic channel selection using machine learning, andTx Beamformingoptimizes transmit signal direction. However, none of these specifically analyze both horizontal and vertical planes simultaneously.

Therefore,PD-MRCis the correct answer—it provides improved reception performance and overall RF robustness, especially for mobile clients in variable orientations.

TheWi-Fi Alliance (WFA)is the global organization responsible fortesting and certifying interoperabilityof wireless LAN products based on the IEEE 802.11 standards. While theIEEEdevelops and maintains the technical specifications (e.g., 802.11a/b/g/n/ac/ax), it doesnotperform certification or compliance testing. Instead, the Wi-Fi Alliance ensures that certified devices from different manufacturers operate together seamlessly under the“Wi-Fi CERTIFIED™”program.

According toRUCKUS One Online Helpand theRUCKUS AI documentation, RUCKUS access points and controllers undergo Wi-Fi Alliance certification to ensure compatibility with a wide range of client devices, including those using WPA3, Wi-Fi 6 (802.11ax), and Wi-Fi 6E technologies. This certification is critical for enterprise environments where heterogeneous client ecosystems exist.

TheIETFfocuses on internet protocols (e.g., IP, TCP), and theISOhandles broader international standards, not wireless interoperability. Therefore, theWi-Fi Allianceis the correct organization ensuring cross-vendor interoperability for Wi-Fi.

DPSK (Dynamic Pre-Shared Key)technology in RUCKUS SmartZone provides individual or group-based pre-shared keys to enhance WLAN security while maintaining user simplicity.

According to theRUCKUS One Online Help – DPSK ConfigurationandSmartZone WLAN Authentication Guide, aGroup DPSKallows multiple devices to authenticate using a single passphrase while still maintaining encryption isolation per device. This feature is typically used in shared-device environments such as classrooms, labs, or conference rooms.

TheBound DPSKtype is assigned to specific devices or user accounts, ensuring individual control, whileUnboundDPSKs are not tied to any particular user or MAC address.

Group DPSKs balance security and convenience by permitting shared access under one key but with independent encryption sessions, which prevents data leakage among group members.