802.11n is an IEEE (Institute of Electrical and Electronics Engineers) industry standard for local Wi-Fi network communications, ratified in 2009. It replaced older 802.11a, 802.11b, and 802.11g Wi-Fi technologies but was superseded by the 802.11ac in 2013 and 802.11ax (Wi-Fi 6) in 2019. 802.11ay (Wi-Fi 7) is up next.
Each standard is faster and more reliable than the one that came before it and is generally backward-compatible.
The Wi-Fi Alliance refers to the various technologies by a simplified Wi-Fi version number. In this scheme, 802.11n is known as Wi-Fi 4.
The packaging of any Wi-Fi device you purchase reflects which of these standards the device supports.
Key Wireless Technologies in 802.11n
802.11n uses multiple wireless antennas in tandem to transmit and receive data. The associated term MIMO (multiple input, multiple output) refers to the ability of 802.11n and similar technologies to coordinate multiple simultaneous radio signals. 802.11n supports up to four simultaneous streams. MIMO increases both the range and throughput of a wireless network.
An additional technique employed by 802.11n involves increasing the channel bandwidth. As in 802.11a/b/g networking, each 802.11n device uses a preset Wi-Fi channel on which to transmit. The 802.11n standard uses a broader frequency range than the earlier standards, which increases data throughput.
802.11n connections support maximum theoretical network bandwidth up to 300 Mbps, depending primarily on the number of wireless radios in the devices. 802.11n devices operate in both the 2.4 GHz and 5 GHz bands.
802.11n vs. Pre-n Network Equipment
In the last few years before 802.11n was officially ratified, network equipment manufacturers sold pre-N or draft N devices based on preliminary drafts of the standard. This hardware is generally compatible with current 802.11n gear, although older devices might require firmware upgrades.
The Successors to 802.11n
802.11n served as the fastest Wi-Fi standard for five years before the 802.11ac (Wi-Fi 5) protocol was approved in 2014. 802.11ac offers speeds ranging from 433 Mbps up to several gigabits per second, which approaches the speed and performance of wired connections. It functions in the 5 MHz band and supports up to eight simultaneous streams.
As mentioned in the introduction, 802.11ax (Wi-Fi 6) is the latest standard, introduced in 2019.