Clearwire, the company that is trying to roll out unproven WiMax broadband technology, has filed for an IPO, even though it is more and more money as it builds out its technology.

WiMax differs from WiFi in that it has much longer ranges — as much as 10 miles vs. WiFi’s reach of a few hundred feet. Intel, one of Clearwire’s main backers so far, wants to us this to technology to allow someone to get wireless access on a laptop anywhere. It has already raised $2 billion in equity and debt from private backers such as Intel Capital and Motorola Ventures.

So far, the only place WiMAX has been deployed is in South Korea. More recently, the Kirkland, Wash.-based Clearwire has made it available to 9.5 million people in the U.S. and Europe, it said. Somehow, this feels like another Vonage. The technology may work, and may actually be useful, but there are plenty of other competing technologies in the communications industry. While Clearwire may survive in some form (Intel has a huge 32 percent stake in this company, and will not want to see it fail), public investors may lose their shirt in the process, if the company stays in the red for years while trying to build out its network. Intel could then buy it at a loss.

It suffered $191.9 million in losses during the nine months ended Sept. 30.

Earlier this year, Sprint Nextel agreed to invest about $3 billion on its own WiMax network over the next couple of years, giving a boost to Clearwire’s prospects. However, it isn’t clear whether other carriers will make the move.