WiMAX Facing Death by Fence-Sitting?

By Tim Scannell

August 04, 2006

Despite some giddy predictions, not everyone is convinced WiMAX is a next big thing with legs.

Is the WiMAX buzz more hype than happening?

It depends on who you ask about the wireless protocol known as 802.16a. WiMAX is the commonly used term for fixed broadband wireless metropolitan access networks (MANs) that use a point-to-multipoint architecture. In short, the protocol supports blazing fast download and upload rates from distances of up to 30 miles.

Although plenty of carriers and networking providers are in the midst of WiMAX trials, all of which are promising, the future of the technology, in North American markets at least, is still an open question.

"There's just no infrastructure supporting WiMAX today," said Craig Mathias, an analyst with research firm Farpoint Group. Plus, there's lots of existing capacity from cellular providers and metro-scale Wi-Fi networks already in the air, said the self-described WiMAX curmudgeon. "Converged Wi-Fi and cellular networks also give the best of both worlds."

Others, such as Dave Park, vice president of product development for BelAir Networks, are staying on the fence about it for now. "You have to have a network to get users, but if you have no users then it's hard to [build] a network," he said.

The WiMAX Forum trade group has another take. For starters, WiMAX is no newbie technology. The trade group counts more than 150 fixed WiMAX (802.16d) deployments and trials worldwide.

Unlike Wi-Fi (define), which operates over the unlicensed communications spectrum and is designed for networking at short distances, WiMAX operates on licensed bandwidths over multiple communications frequencies. It is designed for wide scale broadband deployments.

The latest version is a mobile protocol called 802.16e. It provides broadband-class wireless coverage across large areas where user congestion is an issue.

But Wi-Fi can also operate over wide areas when deployed as part of a "mesh network" (define) that ties together multiple Wi-Fi systems and access points. However, Wi-Fi's performance can be impacted by the number of users on a network and physical barriers -– moreso than WiMAX, experts say.

WiMAX can also be more aggressive than its smaller cousin Wi-Fi about signal congestion. "Wi-Fi fundamentally handles congestion in a very brute force way," explained Greg Caltabiano, president and chief operating officer at SOMA Networks, a broadband services solutions provider. Whereas Wi-Fi is designed to back off and randomly try again when it bumps into conflicting radio signals, WiMAX bullies its way through such communications congestion.

After all, WiMAX operates a lot like cellular, providing every subscriber with a specific set of frequencies instead of time slots. That's why it's called frequency division multiplex technology.

Ultimately, cellular technology may be hardest hit by mobile WiMAX, since 3G technology operates at much slower transmission speeds than WiMAX, said Ellen Kirk, vice president of marketing for Tropos Networks, a provider of mesh (define) networking technology. For example, the latest version of CDMA 2000 (define) promises speeds of up to 1.8 megabits per second, she noted. "But you won't get that and will probably average 1 mbps. It's fast, but still not as fast as the promised 5 mbps average speed of WiMAX, she added.

"Clearly the speed of 3G mobile networks is going up, but speeds and bandwidth are not enough to hit broadband performance," noted SOMA's Caltabiano. This is why "mobile WiMax is really a direct competitor to mobile cellular, and we will soon be seeing a clash of titans," he added.

For all the WiMAX testing underway, however, timetables for commercial deployments are hard to peg. Right now, experts say, fixed WiMAX technology is also not compatible with the coming mobile WiMAX protocol.

This is a major reason why Motorola decided to skip right over 802.11d fixed WiMAX deployments and turn its attention to the mobile flavor. The company has also put its money where its mouthpiece is by kicking in about $300 million to invest in Clearwire Corp., a wireless broadband service provider.

Intel upped he ante by adding $600 million to that investment, with the idea of positioning Clearwire as a first user of its mobile WiMAX chips, which also support fixed deployments.

Article courtesy of internetnews.com



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