Cohda Launches Trial Deployment

By Eric Griffith

December 11, 2006

The company is putting its claims of outdoor Wi-Fi superiority to the test in Adelaide, Australia.

There’s no lack of companies that look down on using plain old Wi-Fi to bring wireless broadband to the masses. At least, not without some kind of proprietary technology, usually going beyond even mesh. Among them are InspiAir, Go Networks, and Wavion. The latest to actually put its equipment to the test is Cohda Wireless. The company has a trial deployment in place in Adelaide, Australia, home of the University of South Australia's Institute for Telecommunications Research, which Cohda spun out of in 2003.

“We’re running a set of qualitative and quantitative tests on our performance,” says Cohda CEO Martin Suter. The company is running full-motion digital video stream, VoIP, and Automatic Vehicle Location (AVL) tracking applications, among other things. Cohda claims it can do all this with fewer APs that don’t require line-of-sight for communication.

Earlier this year the company gave its first push into the industry by launching a Web site called The Dirty Little Secret that warned municipalities about the “secrets” of the industry, namely that “plain vanilla” Wi-Fi wasn’t suitable for outdoor use. Questionable as that may have been, Suter says the approach let “people see our cogent analysis of why 802.11 has impairments in mobile scenarios.  I call it ‘performing unnatural acts.’”

Cohda’s technology is backed by an improved receiver that can support single or multiple antennas and exploits spatial diversity and beam-forming techniques. “We’re able to take energy available in the air and produce a coherent signal to pass through an off-the-shelf 802.11 chip set.”

Cohda’s customers will ultimately be the AP and mesh node vendors, Suter hopes. “Our chip sits on their board between other off-the-shelf components. Vendors are seeing acute pain from using $5 radios in a $1,000 device deployed outdoors. They’re frustrated by the lack of chip innovation, but understand why. The chip makers are focused on higher volume markets. It’s a multi-billion dollar equipment opportunity, but the number of chips are low. That’s insufficient quantity for [chipmakers such as] Atheros and Broadcom to go after. That’s our market opportunity."

The Adelaide deployment is on a “typical outdoor 802.11n network” using prototype hardware. The network is running in 4.9GHz (the spectrum licensed for public safety use) and the unlicensed 5.8GHz band. Cohda also supports 2.4, 3.65 and 5.9, but isn’t testing them in Adelaide. It plans to test “conditions regularly faced by first responders including high-speed mobility, harsh multipath (i.e. buildings, cars, and trees) and interference caused by typical urban and suburban environments,” according to a statement. That includes vehicles staying in touch on the network even at high speeds. A command center tracks the vehicles using global positioning (GPS).

Suter claims that in early tests, it lost a signal with standard Wi-Fi to a vehicle as soon as the car went out of sight around a building. This is Wi-Fi in a ruggedized AP enclosure designed for the outdoors. Using Cohda receivers it got several more meters of range at the same junction.

“Our prototype hardware is going out to some vendors to test in labs and in the air,” says Suter. “We’re in discussions on how to get our basic system on their boards. It’s low complexity, but the performance gains are significant.” He expects that in 2007 Cohda will be announcing some funding, a product path, and initial partners for its technology.

Comment and Contribute
(Maximum characters: 1200). You have
characters left.