Definition: beamforming

Beamforming directs the signals on transmitters and receivers with multiple antennas to improve transmission speed. It is accomplished by detecting the signals and sending feedback to the transmitter to adjust the phase and amplitude of the signals at its antennas. Starting with the 802.11ac version of Wi-Fi, beamforming was standardized for vendor interoperability (see 802.11ac).

Beamforming can also work with devices that only receive and do not transmit. For example, certain hearing aids can be configured to emphasize sound coming directly in front or from the left or right. See MIMO and antenna diversity.

Bouncing Signals

In this WiGig example, beamforming bounces signals from the router (red arrow) off the wall to the laptop (see WiGig and WirelessHD). (Image courtesy of the Wi-Fi Alliance.)