Wireless Network Administrator MCQ Flashcards

Which 802.11 amendment introduced OFDMA as a key technology to improve multi-user efficiency in dense environments?

Answer: 802.11ax

802.11ax (Wi-Fi 6) introduced OFDMA, allowing the channel to be divided into smaller resource units shared among multiple clients simultaneously.

A wireless engineer needs to reduce co-channel interference on a 2.4 GHz network. Which set of non-overlapping channels should be used?

Answer: 1, 6, 11

In the 2.4 GHz band (US regulatory domain), channels 1, 6, and 11 are the only three non-overlapping 20 MHz channels.

What is the primary function of the Distribution System (DS) in an 802.11 BSS architecture?

Answer: Connects multiple APs to form an ESS

The Distribution System interconnects multiple APs and their BSSs to form an Extended Service Set (ESS), typically using a wired backbone.

Which EAP method uses a server-side certificate only and generates dynamic session keys via a TLS tunnel?

Answer: EAP-TTLS

EAP-TTLS requires only a server-side certificate to create a TLS tunnel, inside which legacy authentication methods run to authenticate the client.

A CWNA candidate measures a received signal of -65 dBm and a noise floor of -90 dBm. What is the SNR?

Answer: 25 dB

SNR = Signal – Noise = -65 dBm – (-90 dBm) = 25 dB.

Which antenna type radiates power equally in all directions in the horizontal plane and is commonly used for general indoor coverage?

Answer: Dipole/omnidirectional

Omnidirectional antennas (such as dipoles) radiate in a 360° pattern around the antenna axis and are the most common choice for general indoor AP coverage.

What does the term 'cell breathing' refer to in WLAN design?

Answer: The change in cell coverage area as client load increases or decreases

Cell breathing occurs when adding more clients causes the AP to lower data rates, effectively shrinking the usable coverage cell boundary.