Question

Difficulty: HardWireless Networking Standards and Technologies

A enterprise network administrator is upgrading an organization's wireless infrastructure and analyzing legacy and modern IEEE 802.11 wireless standards. Match each IEEE 802.11 wireless standard to its distinguishing technical characteristics and operating features.

  • 802.11aOperates exclusively in the 5 GHz band using OFDM modulation with a maximum theoretical bandwidth of 54 Mbps.
  • 802.11n (Wi-Fi 4)Operates in both 2.4 GHz and 5 GHz bands, introducing Multiple-Input Multiple-Output (MIMO) with spatial streaming.
  • 802.11ac Wave 2 (Wi-Fi 5)Operates primarily in the 5 GHz band, adding Downlink Multi-User MIMO (MU-MIMO) and supporting channel bonding up to 160 MHz.
  • 802.11ax (Wi-Fi 6)Introduces Orthogonal Frequency-Division Multiple Access (OFDMA), bi-directional MU-MIMO, and Target Wake Time (TWT) across 2.4 GHz, 5 GHz, and 6 GHz bands.

Answer

802.11a matches the 5 GHz OFDM 54 Mbps description; 802.11n (Wi-Fi 4) matches dual-band operation with MIMO; 802.11ac Wave 2 (Wi-Fi 5) matches 5 GHz primary operation with Downlink MU-MIMO and 160 MHz channels; 802.11ax (Wi-Fi 6) matches OFDMA, bi-directional MU-MIMO, TWT, and multi-band support up to 6 GHz.
Each IEEE 802.11 standard introduces distinct physical layer specifications: 802.11a introduced 54 Mbps in the 5 GHz band using OFDM; 802.11n brought MIMO and dual-band operation; 802.11ac Wave 2 added Downlink MU-MIMO and 160 MHz channel widths exclusive to 5 GHz; and 802.11ax introduced OFDMA, Target Wake Time, and 6 GHz spectrum access.

Step-by-Step Solution

1
Identify frequency bands and modulation for legacy standards
802.11a operates exclusively on 5 GHz using OFDM up to 54 Mbps.
802.11a was designed for 5 GHz and uses OFDM, distinguishing it from 802.11b (2.4 GHz DSSS).
2
Identify features introduced in 802.11n (Wi-Fi 4)
802.11n supports both 2.4 GHz and 5 GHz and introduced MIMO technology.
Wi-Fi 4 was the first standard to utilize multiple antennas (MIMO) and dual-band capability.
3
Differentiate 802.11ac Wave 2 features from 802.11ax
802.11ac Wave 2 operates on 5 GHz and introduced Downlink MU-MIMO with up to 160 MHz channel bonding.
Wi-Fi 5 is 5 GHz-only for data frames, while Wave 2 added Downlink MU-MIMO.
4
Analyze high-efficiency features of 802.11ax (Wi-Fi 6)
802.11ax introduces OFDMA, Uplink/Downlink MU-MIMO, Target Wake Time, and operates in 2.4 GHz, 5 GHz, and 6 GHz (Wi-Fi 6E).
OFDMA and TWT are core innovations of 802.11ax designed to handle high client density and improve battery life.

Key Concept

Wireless 802.11 Standards, Frequency Bands, and Technological Capabilities
Estimated Time:2m 0s
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