IEEE 802.11 Standards

IEEE 802.11 Standards

The IEEE 802.11 family defines wireless local area networks. Its specifications cover the physical layer and MAC sublayer, including radio transmission and the rules devices follow when sharing the wireless medium. The standards are developed by the Institute of Electrical and Electronics Engineers (IEEE).

IEEE 802.11 amendments use letter designations such as 802.11n, 802.11ac, 802.11ax, and 802.11be. The Wi-Fi Alliance uses simpler generation names for consumer products. The official scheme starts with Wi-Fi 4 for 802.11n. Wi-Fi 1, Wi-Fi 2, and Wi-Fi 3 are retrospective labels rather than official Wi-Fi Alliance generation names.

These speeds describe maximum physical-layer configurations. Application throughput is lower and depends on channel width, spatial-stream count, signal quality, and network load. Wi-Fi 6E uses 802.11ax mechanisms in the 6 GHz band and is not a separate IEEE amendment.

IEEE 802.11a and 802.11b

IEEE published 802.11a and 802.11b in 1999. 802.11b operated in the $2.4$ GHz band and supported up to $11$ Mbps. This band provided greater indoor range than 5 GHz, but it was shared with other radio systems and industrial, scientific, and medical equipment. Increasing network density raised the risk of interference and transmission collisions.

802.11a operated in the $5$ GHz band and used OFDM, which carries data on multiple orthogonal subcarriers. Its maximum rate was $54$ Mbps. The higher frequency and the cost of radio hardware at the time limited its range and adoption in home equipment.

IEEE 802.11g

IEEE 802.11g, published in 2003, combined OFDM transmission at up to $54$ Mbps with the $2.4$ GHz band. Backward compatibility with 802.11b simplified upgrades to existing networks. Legacy stations could reduce total network efficiency because their lower-rate transmissions occupied the radio medium for longer periods. The standard also retained the congestion and interference limits of the 2.4 GHz band.

Wi-Fi 4 (IEEE 802.11n)

IEEE 802.11n, published in 2009, introduced MIMO (Multiple-Input, Multiple-Output). Multiple spatial streams increased the data rate without a proportional increase in occupied bandwidth. The maximum configuration used four spatial streams and reached $600$ Mbps.

IEEE 802.11n supported $20$ MHz and $40$ MHz channels, frame aggregation, and operation in the 2.4 GHz and 5 GHz bands. Support for both bands did not require every device to operate on both frequencies simultaneously. That capability depended on the number of radio chains and the access point design.

Wi-Fi 5 (IEEE 802.11ac)

IEEE 802.11ac, published in 2013, operated in the $5$ GHz band. It introduced $80$ MHz channels and optional $160$ MHz channels. 256-QAM carried eight bits per symbol but required a higher signal-to-noise ratio than the 64-QAM mode used by 802.11n.

The maximum configuration used eight spatial streams and reached approximately $6.9$ Gbps. IEEE 802.11ac also introduced downlink MU-MIMO, allowing an access point to transmit to several stations. Consumer devices usually supported fewer streams and narrower channels, so their rates were lower than the standard maximum.

Wi-Fi 6 and Wi-Fi 6E (IEEE 802.11ax)

IEEE 802.11ax-2021 increased network efficiency when many stations were active. OFDMA (Orthogonal Frequency-Division Multiple Access) reduces waiting time for small packets because several devices can use different resource units in the same channel.

IEEE 802.11ax supports uplink and downlink MU-MIMO, 1024-QAM, and Target Wake Time, which schedules device activity periods. Its maximum physical-layer rate is approximately $9.6$ Gbps. BSS Coloring helps stations distinguish transmissions from overlapping networks.

Wi-Fi 6E identifies devices that use 802.11ax mechanisms in the 6 GHz band. The additional spectrum provides more wide channels and excludes legacy Wi-Fi generations that operate only in the 2.4 GHz or 5 GHz bands. Available frequencies and permitted transmit power depend on national regulations.

Wi-Fi 7 (IEEE 802.11be-2024)

The IEEE 802.11be-2024 amendment, known as Wi-Fi 7, was approved by the IEEE Standards Board in 2024 and published in 2025. It is an active standard. Its full title, Enhancements for Extremely High Throughput, covers changes to the physical layer and MAC sublayer. The standard defines at least one operating mode that supports a throughput of at least $30$ Gbps at the MAC service access point and a mode that improves worst-case latency and jitter.

Wi-Fi 7 increases the maximum channel width from $160$ to $320$ MHz and introduces 4096-QAM, which carries $12$ bits per symbol. Multi-Link Operation (MLO) uses several radio links to increase throughput, reduce latency, or avoid an interfered channel. Wi-Fi 7 support does not imply simultaneous aggregation of the 2.4 GHz, 5 GHz, and 6 GHz bands. Available links depend on radio design, access point configuration, and regulations governing the 6 GHz band.

Wi-Fi 8 (IEEE P802.11bn Project)

Wi-Fi 8 is under development as IEEE P802.11bn, titled Enhancements for Ultra High Reliability. The project has Active PAR status, so its requirements and mechanisms can still change. The working group schedule targets completion of the approval process in 2028. Another ballot on Draft 2.0 is scheduled for July 2026.

P802.11bn requires a mode that improves throughput by at least $25$% over EHT at a specified signal-to-interference-plus-noise ratio. Separate requirements target a reduction of at least $25$% in the 95th percentile of latency and in MPDU loss. These values are project targets for defined test scenarios, not guaranteed specifications for future products. Current work includes multi-access-point coordination, non-primary channel access, interference management, extended-range operation, and further development of MLO.