In an enterprise environment, not all devices on the network need beamforming to reap the benefits of the technology. An access point with implicit beamforming technology can still directly "beamform" to an end device without it, enabling better performance. Inversely, a tablet with beamforming technology can better leverage the wireless signal from an access point that does not have beamforming.
Devices leveraging beamforming, from access points to end devices, have been shipping in volume since November 2010. As enterprise IT departments upgrade their infrastructure and invest in new equipment for employees, it will be beneficial to work with technology suppliers to ensure new investments boast beamforming technology.
Users can identify that beamforming is supported by their product if the vendor touts the technology as a differentiating feature. For example, Cisco brands beamforming as ClientLink/ClientLink 2.0 on its enterprise access point products.
Beamforming is a technique implemented in digital signal processing (DSP) logic to improve range and data rate for a given client. In a basic system (single stream), it works on the principle that signals sent on separate antennas can be coordinated to combine constructively at the receive antenna.
Specifically, the phases of the transmit signals are manipulated 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. Efficient steering of individual streams in such a system provides overall gain. This can be achieved through knowledge of the channel between the transmitter and receiver. Thus, it can be viewed as a form of transmit diversity with a known channel.
Beamforming enables higher data rates and reduced number of retries, which increases the overall capacity of the system, leading to more efficient use of the spectrum. For example, in the case of a four transmit antenna system beamforming to a one receive antenna system, the gain improvement can be up to 12 decibel and range improvement can be up to twice over a system without beamforming.
Additionally, beamforming provides up to 12db of perceptible gain in over-the-air tests in home and enterprise environments, and increases the rate at range of HD video streaming applications by about two times their current range with the same bandwidth.