CWDP WLAN Standards and Protocols — Questions and Answers
Question 1: Which IEEE 802.11 amendment introduced OFDMA and target wake time (TWT)?
- 802.11ax (Wi-Fi 6) (Correct answer)
- 802.11ac (Wi-Fi 5)
- 802.11n (Wi-Fi 4)
- 802.11be (Wi-Fi 7)
Correct answer: 802.11ax (Wi-Fi 6)
IEEE 802.11ax (Wi-Fi 6) introduced Orthogonal Frequency Division Multiple Access (OFDMA) for efficient multi-user uplink/downlink and Target Wake Time (TWT) for improved power management.
Question 2: What is the primary advantage of MU-MIMO over SU-MIMO in wireless network design?
- It allows the AP to communicate with multiple clients simultaneously (Correct answer)
- It provides longer range for individual clients
- It uses less power than SU-MIMO
- It eliminates the need for multiple antennas
Correct answer: It allows the AP to communicate with multiple clients simultaneously
Multi-User MIMO allows an access point to transmit to or receive from multiple clients at the same time using spatial multiplexing, significantly improving network capacity in dense environments.
Question 3: What frequency bands does Wi-Fi 6E operate in?
- 2.4 GHz, 5 GHz, and 6 GHz (Correct answer)
- 2.4 GHz and 5 GHz only
- 5 GHz and 6 GHz only
- 6 GHz only
Correct answer: 2.4 GHz, 5 GHz, and 6 GHz
Wi-Fi 6E extends Wi-Fi 6 capabilities into the 6 GHz band while maintaining backward compatibility with 2.4 GHz and 5 GHz, providing up to 1200 MHz of additional spectrum.
Question 4: What is the purpose of BSS Coloring in 802.11ax?
- To reduce co-channel interference by allowing devices to differentiate between their BSS and overlapping BSSs (Correct answer)
- To change the color of the LED indicators on access points
- To encrypt wireless frames with color-coded keys
- To assign different frequencies to different access points
Correct answer: To reduce co-channel interference by allowing devices to differentiate between their BSS and overlapping BSSs
BSS Coloring assigns a unique identifier (color) to each Basic Service Set, allowing devices to quickly determine if a detected frame belongs to their own BSS or an overlapping one, improving spatial reuse.
Question 5: What is the maximum channel width supported by 802.11ac Wave 2?
- 160 MHz (Correct answer)
- 80 MHz
- 320 MHz
- 40 MHz
Correct answer: 160 MHz
802.11ac Wave 2 supports channel widths up to 160 MHz (either contiguous or as 80+80 MHz non-contiguous), enabling higher throughput compared to Wave 1's maximum of 80 MHz.
Question 6: What role does the 802.11k amendment play in wireless network design?
- It provides neighbor report information to help clients make better roaming decisions (Correct answer)
- It establishes security protocols for WPA3
- It defines QoS prioritization for voice traffic
- It sets power output limits for access points
Correct answer: It provides neighbor report information to help clients make better roaming decisions
802.11k provides radio resource measurement capabilities, including neighbor AP reports that help clients identify the best AP to roam to, reducing scanning time and improving roaming performance.
CWDP WLAN Standards and Protocols
Which IEEE 802.11 amendment introduced OFDMA and target wake time (TWT)?