MIMO, Multiple Input Multiple Output, is a wireless technology used to boost wireless bandwidth and range by taking advantage of multiplexing. MIMO uses algorithms in a radio chipset to send information out over two or more antennas. As a wireless signal goes between an access point and wireless card, it will be bounced from walls, ceilings, and any other obstacle and also causes multiple reflections of the original signal arriving by different paths at the end. The current 802.11g technologies use single transmitting and dual receiving antennas.
Usually these signals arrive at fractionally different times as they have gone through different distances by different routes, and can cause some interference when using just one antenna. With MIMO of using multiple antenna, these reflections can be used to improve the signal, as instead of having just one copy of the original signal, the hardware now has multiple copies and can use whichever one is the best.
With many signals to choose from, MIMO allows the wireless hardware to reach much greater ranges. As a result, signal strength will be much better and the speed is much faster.
MIMO provides improvements in wireless LAN or WLAN including range and reliability. It also broadens the usefulness of wireless for applications and allows for more intensive applications to run over wireless.
In the near future, there should be an IEEE 802.11n standard for MIMO that will raise wireless network data rates well above the 100Mbps mark and will hopefully fill those wireless dead spots most people experience around their home and office wireless network.
There is one thing that you should note that the different manufactures products may not necessarily work together with each other. Both wireless adapters and access points may have to be the same brand. Also, the best results are obtained with a true MIMO implementation on both ends of the connection. "True MIMO" requires multiple antennas and radios on both the transmitting and receive sides of the link.
