802.11n is a set of specs proposed for networking and wireless communication. The Institute of Electrical and Electronic Engineers (IEEE) 802.11 wireless networking standard would be ammended to dramatically improve the usability, reliability and speed over the previous standards including 802.11b and 802.11g.
While the proposed 802.11n standard is not expected to be finalized until November 2009, there are already products on the market that are marketed as "draft N" which provide significant improvements over other hardware.
The RAW data rate would be increased from the current 54 Mbit/s to a maximum of 600 Mbit/s. Devices on the market today can support up to 300 Mbit/s (802.11n draft 2.0) by using 2 Spatial Streams at 40 MHz.
The addition of multiple-input multiple-output (MIMO) to improve system performance, channel bonding to the physical layer, frame aggregation to the MAC layer, antenna diversity and spatial multiplexing builds upon he older 802.11a, 802.11b and 802.11g standards.
Currently, the WiFi Alliance is certifying products based on IEEE 802.11n Draft 2.0 and are available to buy with maximum throughput of 144.4 Mbit/s for 20 MHz and 300 Mbit/s for 40MHz.