Definition - What does IEEE 802.11ac mean?
IEEE 802.11ac is a pending amendment to the IEEE 802.11 standard that defines proper implementation and/or deployment of wireless local area network (WLAN) technology. Currently under development, IEEE 802.11ac's primary benefit is a theoretical throughput of 1 GBps.
Techopedia explains IEEE 802.11ac
IEEE 802.11ac is expected to be finalized by the end of 2012. Final approval by the IEEE 802.11 Working Group is set to occur in late 2013, and mass implementation will be rolled out in gradual stages over the next few years.
IEEE 802.11ac differs from earlier IEEE 802.11 amendments because it operates on the 5 GHz frequency band, which should provide for more wireless access point (WAP) channel options. Like IEEE 802.11n, IEEE 802.11ac uses multiple-in/multiple-out (MIMO) technology. However, IEEE 802.11ac translates MIMO into eight spatial streams, versus the four of 802.11n. Thus, increased spatial streams should be delivered at a considerably higher throughput than current IEEE 802.11n provisions.