BOSTON — Two developments in the past year have given WiMax, the wireless broadband technology that promises high-speed Internet access to almost any device anywhere, virtually unstoppable momentum. One is Kirkland-based Clearwire's expanding national WiMax rollout. The other was Sprint Nextel's decision to use it to build nationwide wireless broadband networks.

The energy generated by these moves is noticeable at WiMax World, an annual industry conference that kicks off today in Boston, with some preliminary events held Tuesday.

But not every company at the conference is high on WiMax, even though the two major commitments for two nationwide networks clearly put it ahead of other technologies.

Enter Qualcomm.

The San Diego wireless giant is at WiMax World to explain its alternative technology and provide what may be the sole opposition to WiMax at the conference.

Qualcomm was one of the companies competing to win Sprint Nextel's business to help build a national, next-generation network. It was thought to have a good chance, given that it provides the CDMA technology that supports Sprint's cellphone network.

Furthermore, it purchased a company called Flarion Technology, which conducted a successful wireless-broadband trial with Nextel before Sprint acquired Nextel. So the news that WiMax, and not Qualcomm's technology, would be the backbone of Sprint's wireless broadband network, put Qualcomm on the defense.

"There's a lot of excitement [around WiMax] when there should be some relevant skepticism and discussion," Jeff Belk, Qualcomm senior vice president of strategy and market development, said in an interview. "Any wireless technology will come to fruition with enough time, money and smart people. WiMax has all of that, but it doesn't ensure success."

But the excitement around a technology sometimes called "Wi-Fi on steroids" is undeniable, and is evident in WiMax World's attendance history. Two years ago, only 600 people attended and 12 companies exhibited; this week, 5,000 attendees and 140 exhibitors are expected.

There's also a lot of money floating around. Clearwire has raised more than $2 billion to build a network, and Sprint Nextel has pledged at least $3 billion over the next two years.

In a WiMax system, subscribers gain access to the Internet through a powerful broadcast from towers that can be miles away, covering entire cities. There are two flavors: One provides stationary service and can be used to replace DSL or cable Internet access in the home. The other is mobile, and is designed for use with portable devices. Fixed WiMax is available on a limited basis now, while mobile WiMax is still under development.

Research firm Yankee Group estimates there will be 7.3 million WiMax subscribers by 2010.

Berge Ayvazian, Yankee chief strategy officer, said potential applications for these networks are hard to imagine because they have not yet been developed. But he speculated that many devices, such as cameras and printers, will come with WiMax chips.

In a presentation Tuesday, Sprint Nextel Chief Technology Officer Barry West said WiMax offers Sprint a new way of doing business.

"I'm so excited about this stuff, I think we'll look back and say, 'How did we ever live without this level of communications?' " he said.

With cellphones, Sprint subsidizes the price of a phone, builds the network and makes most of its money on voice calls. In the WiMax model, he said Sprint will install a small radio to existing cell towers, and the business model will work similarly to Wi-Fi. In addition, like Wi-Fi chips, WiMax would be relatively inexpensive and could also be added to a camera, a TV or a printer.

West said the new network will not compete with Sprint's current high-speed 3G data network. Although that network is fast, providing up to 700 kilobits per second, chipsets cost about $50 a piece, too pricey to put in many devices.

WiMax networks are also supposed to be faster and provide more bandwidth. WiMax Forum, an industry trade association, said average speeds will reach more than 1 megabit per second.

Belk, the Qualcomm executive, said such predictions promise more than the technology can deliver. He expressed skepticism over WiMax's apparent cost advantage. He also said 3G networks — and their future technology paths — will deliver the network capacity consumers need, and when carriers are ready, Qualcomm will be able to deliver a wireless broadband technology from Flarion.

Tricia Duryee: 206-464-3283 or tduryee@seattletimes.com