IEEE 802.11n is a wireless networking standard that uses multiple antennas to increase data rates. With this tag should be marked the questions relative to this specific version of the protocol.

IEEE 802.11n is a wireless networking standard that uses multiple antennas to increase data rates. It is an amendment to the IEEE 802.11-2007 wireless networking standard published in 2009.

  • IEEE 802 refers to a family of IEEE standards dealing with local area networks (LAN) and metropolitan area networks (MAN).

  • IEEE 802.11 is a set of media access control (MAC) and physical layer (PHY) specifications for implementing wireless local area network (WLAN) computer communication in the 2.4, 3.6, 5, and 60 GHz frequency bands

  • IEEE 802.11n is a set of media access control (MAC) and physical layer (PHY) specifications for implementing wireless local area network (WLAN); specifically it is an amendment published in 2009 that improves upon the previous 802.11 standards by adding multiple-input multiple-output antennas (MIMO).

With this tag should be marked the questions relative to this specific version of the protocol.
To have a more complete panorama about the protocols you can see this table of protocols.

Some details:

802.11n operates on both the 2.4 GHz and the lesser-used 5 GHz bands. Support for 5 GHz bands is optional. It operates at a maximum net data rate from 54 Mbit/s to 600 Mbit/s. The IEEE has approved the amendment, and it was published in October 2009.[15][16] Prior to the final ratification, enterprises were already migrating to 802.11n networks based on the Wi-Fi Alliance's certification of products conforming to a 2007 draft of the 802.11n proposal.

More details on the wikipedia page of IEEE 802.11n-2009.
Source of the standard in ieee.org site, 1076 pages.