802.11n

Wi-Fi world goes forward. The future 802.11n standard will be based on MIMO. MIMO stands for multiple in multiple out and describes a technology that can boost the capacity and coverage area of wireless networks. The 802.11n standard isn’t expected to be ratified for another two years, according to the Wi-Fi alliance.
An array of four receive and four transmit antennas in a MIMO configuration (4 x 4) would use 40 MHz of bandwidth, or about twice that used in current 802.11b and g, to achieve speeds up to 540 Mbps (raw throughput). But in countries in which those configurations weren’t allowed, the devices would fall back to 2 x 2 antennas and 20 MHz of spectrum. This would also allow backwards compatibility with 802.11b and g. The article says that in the 2 x 2 by 20 MHz configuration, speed would top out at 135 Mbps. More news and information about Wi-Fi can be found from Wi-Fi Networking News