802.11ac, also known as Gigabit Wi-Fi, is a proposed specification in the 802.11 family applicable to WLANs (wireless local area networks). 802.11ac represents an extension or update of the current 802.11a standard.
Networks using 802.11ac will operate in the 5-GHz (gigahertz) band using OFDM (orthogonal frequency-division multiplexing), just as 802.11a does. The enhancements supported by 802.11ac will facilitate simultaneous streaming of HD (high definition) video to multiple clients in homes and businesses, as well as faster wireless synchronization and backup of large files.
New features that will exist in 802.11ac, in addition to those carried over from 802.11a, include:
- Channel width up to 160 MHz (megahertz).
- Single-link throughput of 500 Mbps (megabits per second) or more.
- Multi-station WLAN throughput of 1 Gbps (gigabit per second) or more.
- 400-ns (nanosecond) short guard interval.
- Low-density parity check code.
- Space-time block coding.
- Up to eight spatial streams.
- Transmit beamforming.
Finalization of the 802.11ac standard is expected in late 2012, with formal approval taking place by the end of 2013.
For information about other specifications in the 802 family, see the IEEE 802 Wireless Standards Fast Reference.