Wifi Revolution

As mobility comes into increasingly greater demand, wireless technologies must be adapted and evolved to support demands for increased capacity, availability, and speed. WiFi is certainly the most popular of today’s wireless technologies, and it works admirably — in those situations for which it was designed, namely, indoor deployments. For outdoor and mobile scenarios, however, 802.11 technology has proven largely inadequate.

Cohda Wireless’ CEO Martin Suter explained that one of the limitations of standards-based technologies, like 802.11, is that they are not robust enough to handle the harsh environmental factors in an outdoor deployment. On the other hand, he also says that proprietary solutions, while offering the mobile robustness, tend not to scale commercially.

Suter added, though, “There is an opportunity, without changing the standard, to employ unconventional OFDM receiver techniques to provide coherence to devices in a way that a conventional approach doesn’t.”

Which is precisely what Cohda Wireless has built: an enabling technology that is designed as an adjunct to existing wireless technologies to extend their range. As Suter explains, regardless of the enclosures surrounding the radio, and regardless of the antennas attached to it, the radio is still the radio, and they all come from the same manufacturers. So, wireless devices from different manufacturers are still going to have the same limitations because they are built from the same components.

The advantage Cohda offers is the ability to extend the range of all wireless devices without actually being in the handset — instead, Cohda’s NLOS (non-line of sight) technology is put into the base stations and access points, thus filling in black spots and delivering connectivity where it previously did not exist — and greater coverage with fewer nodes.

“Cohda Wireless’ advanced receiver technology is fundamentally changing the performance characteristics and economics of 802.11 in outdoor, mobile environments,” said Suter.  “Current 802.11 devices use chips designed for indoor use at pedestrian speeds, and which perform poorly in outdoor, mobile environments.”

Cohda’s technology is being tested within a typical outdoor 802.11 network, and is also ongoing in conditions typical first responder scenarios, high-speed, harsh multipath, and typical urban/suburban interference environments.  Testing has included real-time streaming of dash-mounted video cameras in multiple vehicles, GPS and AVL applications, and three-way VoIP conference calling, all run simultaneously. The tests resulted in seamless handoff between access points, which, as Suter notes, is crucial to the overall user experience.

“We have tried to push the network using real-time applications that are not tolerant of latency,” he said.

Cohda’s patent pending, zero-latency OFDM receiver architecture and algorithms are interoperable with IEEE standards and are designed to resist the detrimental effects of outdoor mobile deployments. Testing has shown an average increase of 7 to 12 dB in sensitivity of Cohda-enhanced equipment, including the ability to maintain NLOS at speeds of up to 200 mph — these tests effectively double the range of standard wireless equipment.

With the growing popularity of things like YouTube and MySpace, and the development of various other mobile applications, the limits of wireless access technologies will be tested, and Cohda is positioning itself to extend those limits — a feature that will likely be well received by service providers and end users alike. Because Cohda believes deploying standard 802.11 equipment outdoors is “an unnatural act,” it has developed a solution that will not only extend networks and help increase the value of wireless devices, but will also provide greater ROI for service providers, enterprises, schools, and municipalities deploying outdoor wireless networks.

---------

Erik Linask is Associate Editor of INTERNET TELEPHONY. Prior to joining TMC, he was Managing Editor at Global Custodian, an international securities services publication. To see more of his articles, please visit Erik Linask’s columnist page.

Back to WiFi Revolution home