| Generation | IEEE standard |
Adopted | Maximum link rate (Mb/s) |
Radio frequency (GHz) |
|---|---|---|---|---|
| (Wi-Fi 0*) | 802.11 | 1997 | 1–2 | 2.4 |
| (Wi-Fi 1*) | 802.11b | 1999 | 1–11 | 2.4 |
| (Wi-Fi 2*) | 802.11a | 1999 | 6–54 | 5 |
| (Wi-Fi 3*) | 802.11g | 2003 | 2.4 | |
| Wi-Fi 4 | 802.11n | 2009 | 6.5–600 | 2.4, 5 |
| Wi-Fi 5 | 802.11ac | 2013 | 6.5–6933 | 5[a] |
| Wi-Fi 6 | 802.11ax | 2021 | 0.4–9608[1] | 2.4, 5 |
| Wi-Fi 6E | 2.4, 5, 6[b] | |||
| Wi-Fi 7 | 802.11be | exp. 2024 | 0.4–23,059 | 2.4, 5, 6[2] |
| Wi-Fi 8 | 802.11bn | exp. 2028[3] | 100,000[4] | 2.4, 5, 6[5] |
| *Wi‑Fi 0, 1, 2, and 3 are named by retroactive inference. They do not exist in the official nomenclature.[6][7][8] | ||||
IEEE 802.11n-2009, or 802.11n, is a wireless-networking standard that uses multiple antennas to increase data rates. The Wi-Fi Alliance has also retroactively labelled the technology for the standard as Wi-Fi 4.[9][10] It standardized support for multiple-input multiple-output (MIMO), frame aggregation, and security improvements, among other features, and can be used in the 2.4 GHz or 5 GHz frequency bands.
Being the first Wi-Fi standard to introduce MIMO support, devices and systems which supported the 802.11n standard (or draft versions thereof) were sometimes referred to as MIMO Wi-Fi products, especially prior to the introduction of the next generation standard.[11] The use of MIMO-OFDM (orthogonal frequency division multiplexing) to increase the data rate while maintaining the same spectrum as 802.11a was first demonstrated by Airgo Networks.[12]
The purpose of the standard is to improve network throughput over the two previous standards—802.11a and 802.11g—with a significant increase in the maximum net data rate from 54 Mbit/s to 72 Mbit/s with a single spatial stream in a 20 MHz channel, and 600 Mbit/s (slightly higher gross bit rate including for example error-correction codes, and slightly lower maximum throughput) with the use of four spatial streams at a channel width of 40 MHz.[13][14]
IEEE 802.11n-2009 is an amendment to the IEEE 802.11-2007 wireless-networking standard. 802.11 is a set of IEEE standards that govern wireless networking transmission methods. They are commonly used today in their 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac and 802.11ax versions to provide wireless connectivity in homes and businesses. Development of 802.11n began in 2002, seven years before publication. The 802.11n protocol is now Clause 20 of the published IEEE 802.11-2012 standard and subsequently renamed to clause 19 of the published IEEE 802.11-2020 standard.
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