CWNA V1.0 4

Question 1

Which 802.11 QoS amendment introduced Wi-Fi Multimedia (WMM) to prioritize traffic by access category?

Accepted Answer

802.11e

Answer

802.11e defined EDCA (Enhanced Distributed Channel Access) and is the foundation for WMM, which prioritizes voice, video, best-effort, and background traffic.

Question 2

A technician measures a received signal of -67 dBm and a noise floor of -90 dBm. What is the SNR?

Accepted Answer

23 dB

Answer

SNR = Signal − Noise = −67 dBm − (−90 dBm) = 23 dB, indicating a clean signal well above the noise floor.

Question 3

Which 802.11 amendment enables fast BSS transition (fast roaming) to reduce handoff latency for voice and real-time applications?

Accepted Answer

802.11r

Answer

802.11r (Fast BSS Transition) pre-caches PMK security keys at neighboring APs to drastically reduce re-association time during roaming.

Question 4

What is the primary function of MU-MIMO in 802.11ac Wave 2 and 802.11ax access points?

Accepted Answer

Transmitting simultaneously to multiple clients using spatial streams

Answer

MU-MIMO (Multi-User MIMO) allows an AP to transmit unique spatial streams to multiple clients at the same time, increasing aggregate throughput.

Question 5

In WLAN design, what does the term 'cell overlap' refer to and what is the recommended minimum percentage?

Accepted Answer

AP coverage areas should overlap 15–20% to ensure seamless roaming

Answer

A 15–20% cell overlap ensures clients maintain association while roaming between APs without experiencing coverage gaps.

CWNA - Wireless Network Administrator Practice Test

CWNA - Wireless Network Administrator Practice Test

CWNA V1.0 4