CWNA Quality Control & Assurance 5

Question 1

A network administrator uses 802.11k to improve WLAN quality. Which specific capability does 802.11k provide to clients?

Accepted Answer

Neighbor reports that help clients identify candidate APs for roaming without active scanning

Answer

802.11k Radio Resource Management allows APs to provide clients with a neighbor report listing nearby APs, reducing the time clients spend scanning when deciding to roam.

Question 2

An enterprise deploys 802.11ac Wave 2 APs with MU-MIMO. Which condition MUST be met for MU-MIMO to deliver a quality improvement over SU-MIMO?

Accepted Answer

Multiple clients must simultaneously have data to receive and support MU-MIMO

Answer

MU-MIMO transmits to multiple clients simultaneously in the downlink, but only improves throughput when several MU-MIMO-capable clients have queued downlink data at the same time.

Question 3

A WLAN QA process includes validating the CCI (Co-Channel Interference) design. What is the standard recommended minimum cell overlap for proper roaming while minimizing CCI?

Accepted Answer

15–20% cell overlap between adjacent same-channel APs

Answer

A 15–20% cell overlap provides enough signal for clients to roam before losing connectivity while keeping same-channel AP interference at an acceptable level.

Question 4

Which metric directly quantifies the effect of multipath propagation on WLAN quality in an indoor environment?

Accepted Answer

Delay spread (RMS delay spread)

Answer

RMS delay spread measures how long multipath reflections arrive after the direct signal; excessive delay spread causes inter-symbol interference that degrades modulation accuracy.

Question 5

During a QA review, an administrator finds that 40 MHz channels are configured in the 2.4 GHz band. Why is this considered poor practice?

Accepted Answer

40 MHz channels consume most of the 2.4 GHz band, leaving no non-overlapping channels and increasing interference

Answer

The 2.4 GHz band only supports three non-overlapping 20 MHz channels (1, 6, 11); a 40 MHz channel overlaps at least two of them, severely limiting frequency reuse.

CWNA - Wireless Network Administrator Practice Test

CWNA - Wireless Network Administrator Practice Test

CWNA Quality Control & Assurance 5