As outdoor mesh WiFi networks face rising interference issues and deployment costs, startup Wavion Inc. said today it has developed a new access-point technology that dramatically strengthens the signal between AP and client devices and sharply reduces the cost of building mesh systems. (See New Muni Models.)

The new "spatially adaptive" access points, designated the Wavion WS410, are three to four times more powerful than conventional APs, the company claims, and can halve operators' capital and operating expenses.

Based in Silicon Valley and Israel, Wavion uses a technology called "beamforming," which involves sending the same signal, at different phases and amplitudes, to client devices from six different antennas on the access point. The signals are coherently assembled at the client to form a more powerful and penetrating signal.

Based on MIMO (multiple-input, multiple-output) technology, beamforming takes advantage of multipath transmission to create a signal-strengthening pattern of interference in the wavefront.

Each antenna operates on a separate radio-frequency propagation path, and the six signals combine coherently at the client, explains Wavion founder and CTO Mati Wax. "In this way you get the strongest signal of the best quality. The result is enhanced signal-to-noise ratio and extra link gain, which translate to increased range and capacity."

A typical mesh set-up, says Wavion vice president Alan Menezes, uses 25 to 30 nodes per square mile. With the six-antenna WS410s using beamforming, the same level of coverage can be achieved using eight to 10 nodes, he claims.

Wavion is hardly the first company to use MIMO principles to build second-generation mesh networks. Ruckus Wireless uses a related technology called "BeamFlex" to automatically select the highest quality signal path and optimum data rate for each client, based on environmental factors.

Past versions of MIMO-based mesh systems, claims Wax, have met with little success. "This is the first time digital beamforming has been successfully productized to address an outdoor wireless environment."

Jeff Blank, CTO of Connxx, which operates one of the oldest municipal networks in the U.S. in Allegany County, Maryland, has tested the new access point and says it changed his views on the RF capabilities of different technologies.

"We had come to the conclusion that from an RF standpoint, all equipment is the same," recalls Blank. "WiFi is basically WiFi."

Wavion's technology, however, "blew us out of the water -- from the RF standpoint it's radically different. It gave us much better performance than anything else."

Menezes declines to say how much the new product will cost other than to say that, while each individual access point will be slightly more expensive than conventional equipment, because fewer will be needed, on a per-square-mile basis Wavion networks will be half the cost of current technology.

If that's true, it could prove a Godsend to corporate and municipal network operators trying to afford full-coverage outdoor networks on limited budgets.

— Richard Martin, Senior Editor, Unstrung