November 10, 2013, 7:06 PM — Beamforming is one of those concepts that seem so simple that you wonder why no one thought of it before. Instead of broadcasting a signal to a wide area, hoping to reach your target, why not concentrate the signal and aim it directly at the target?
Sometimes the simplest concepts are the most difficult to execute, especially at retail price points. Fortunately, beamforming is finally becoming a common feature in 802.11ac Wi-Fi routers (at least at the high end). Here's how it works.
First, a bit of background: Beamforming was actually an optional feature of the older 802.11n standard, but the IEEE (the international body that establishes these standards) didn't spell out how exactly it was to be implemented. The router you bought might have used one technique, but if the Wi-Fi adapter in your laptop used a different implementation, beamforming wouldn't work.
Some vendors developed pre-paired 802.11n kits (with Netgear's WNHDB3004 Wireless Home Theater Kit being one of the best examples), but these tended to be expensive, and they never had much of an impact on the market.
The IEEE didn't make the same mistake with the 802.11ac standard that's in today's high-end devices. Companies building 802.11ac products don't have to implement beamforming, but if they do, they must do so in a prescribed fashion. This ensures that every company's products will work together. If one device (such as the router) supports beamforming, but the other (such as the Wi-Fi adapter in your router) doesn't, they'll still work together. They just won't take advantage of the technology.
Beamforming can help improve wireless bandwidth utilization, and it can increase a wireless network's range. This, in turn, can improve video streaming, voice quality, and other bandwidth- and latency-sensitive transmissions.
Beamforming is made possible by transmitters and receivers that use MIMO (multiple-input, multiple-output) technology: Data is sent and received using multiple antennas to increase throughput and range. MIMO was first introduced with the 802.11n standard, and it remains an important feature of the 802.11ac standard.
How beamforming works
Wireless routers (or access points) and wireless adapters that don't support beamforming broadcast data pretty much equally in all directions. For a mental picture, think of a lamp without a shade as the wireless router: The bulb (transmitter) radiates light (data) in all directions.