CWS CWS 802.11 Standards and Protocols 2 — Questions and Answers
Question 1: Which 802.11 amendment introduced the concept of mesh networking (MBSS)?
- 802.11s (Correct answer)
- 802.11r
- 802.11k
- 802.11v
Correct answer: 802.11s
802.11s introduced the Mesh Basic Service Set (MBSS) architecture enabling self-forming, self-healing wireless mesh networks.
Question 2: What is the maximum channel width supported by 802.11ac Wave 2?
- 40 MHz
- 80 MHz
- 160 MHz (Correct answer)
- 320 MHz
Correct answer: 160 MHz
802.11ac Wave 2 supports up to 160 MHz channel widths (either contiguous or as two 80 MHz non-contiguous segments).
Question 3: Which modulation scheme achieves the highest data rates in 802.11ax (Wi-Fi 6)?
- 64-QAM
- 256-QAM
- 1024-QAM (Correct answer)
- 4096-QAM
Correct answer: 1024-QAM
802.11ax introduced 1024-QAM, encoding 10 bits per symbol to achieve higher throughput compared to the 256-QAM used in 802.11ac.
Question 4: The 802.11e amendment primarily addressed which aspect of wireless networking?
- Security enhancements
- Quality of Service (QoS) (Correct answer)
- Frequency band expansion
- Power save mechanisms
Correct answer: Quality of Service (QoS)
802.11e added QoS mechanisms including EDCA and HCCA to prioritize traffic types such as voice and video.
Question 5: What is the guard interval introduced by 802.11ax to improve efficiency in dense environments?
- 400 ns
- 800 ns
- 1600 ns
- 3200 ns (Correct answer)
Correct answer: 3200 ns
802.11ax introduced a 3200 ns guard interval option (in addition to 800 ns and 1600 ns) to better handle multipath in outdoor and dense deployments.
Question 6: 802.11p is a variant of 802.11 designed specifically for use in which environment?
- Underwater communications
- Vehicular networks (V2X) (Correct answer)
- Industrial control systems
- Satellite uplinks
Correct answer: Vehicular networks (V2X)
802.11p (WAVE – Wireless Access in Vehicular Environments) is designed for vehicle-to-vehicle and vehicle-to-infrastructure communications.
Question 7: Which 802.11 standard first introduced MIMO (Multiple Input, Multiple Output) antenna technology?
- 802.11a
- 802.11g
- 802.11n (Correct answer)
- 802.11ac
Correct answer: 802.11n
802.11n was the first standard to formally incorporate MIMO, supporting up to 4 spatial streams to increase throughput and reliability.
CWS CWS 802.11 Standards and Protocols 2
Which 802.11 amendment introduced the concept of mesh networking (MBSS)?