A third new service is a patent-pending technology called Orthogonal Array Beam Forming (OABF). WLAN vendors over the past two years have been adding support for various optional parts of the 11n standard, (see from May 2010, “Major Wi-Fi changes ahead”) including transmit beam forming (sometimes “beamforming”). The same waveform is sent over 11n’s multiple antennas, with the magnitude and phase adjusted at each transmitter to focus the beam direction toward a particular receiver. This increases the signal’s gain so it’s more stable, and can be “steered around” interferers so it’s more reliable.
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[Ruckus Wireless in 2009 was the first to introduce beam forming for 11n products, exploiting its unique multi-component antenna design. Wireless blogger Craig Mathias used that introduction to explore the topic.]
Meru has created what it says is a more fine-grained alternative. Each Wi-Fi signal is made up of about 60 sub-carriers over a wide swath of spectrum, says Graham Melville, Meru’s director of product management. Meru’s code can optimize each of the sub-carriers and the result, he says, is an improvement in gain, or sensitivity, on the order of 8-10 dB.
The result of the improved gain is a higher signal quality and higher data rates: where Meru saw 36Mbps before applying its beamforming technology, it saw 54Mbps after, for example. “It stays at the high data rates because the signal is stronger, and better quality,” Melville says.
The new access points also can use the optional Meru Proactive Spectrum Analysis as part of another service, called Air Traffic Services. One of the AP400 radios can be assigned the job of continually monitoring the Wi-Fi radio frequencies for unauthorized radios, analyzing the spectrum usage and interference, and running Meru’s integrated wireless intrusion prevention system.
Another network service is called Mobile Application Segregation: administrators can create a dedicated channel for individual applications or groups of them, high definition video, or wireless VoIP.
John Cox covers wireless networking and mobile computing for “Network World.”
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