What is Beamforming ?

Beamforming is a method used in antenna arrays for directional signal transmission or reception. The directionality is achieved by combining elements of a phased array in such a way that particular signals experience constructive intefrerence while others experience destructive interference to directinally boost signal strength and improve SNR.

Beamforming is being used in wireless networking in some newer 802.11n/ac devices (since November 2010), allowing for automatic focusing of the wireless signal directly where it is needed, providing a 2x-3x improvement over previous wireless solutions.

In a basic (single stream) system, beamforming works by coordinating the phases of transmit signals to improve directivity. Transmit beamforming is specified in the IEEE 802.11n specification and takes advantage of the multiple transmit antennas available in a multiple-input multiple-output (MIMO) system.

Beamforming enables higher data rates and reduces number of retries, increasing the overall capacity of the system, leading to more efficient use of the spectrum. As part of the 802.11ac wireless specification, beamforming is expected to become standard on most wireless devices.