The most notable aspect of the Open Patent Alliance, a new group launched on Monday, may be which companies aren't involved.

Cisco, Intel, Samsung and Alcatel-Lucent, along with operators Clearwire and Xohm, introduced the Open Patent Alliance, a central pool for patents relevant to WiMax. Companies, such as consumer electronics developers that are interested in building WiMax into their products, can use the OPA to discover which companies have relevant patents for WiMax and to figure out how much it would cost them to license those patents.

The companies involved in the announcement were keen to stress that they expect other relevant organizations to join, but they made it easy to notice the absences while describing the patent situation behind WiMax.

"The essential [intellectual property] for WiMax is much more broadly held than some of the traditional cellular technology," said Barry West, chief technology officer at Sprint and head of Xohm, Sprint's WiMax network.

The companies initially involved in the OPA would not say how many of the patents behind WiMax that they control, although Samsung said that it owns 25 percent of the patents behind certain components of WiMax. Other companies that have essential patents include Nortel and Motorola, said Phil Solis, an analyst with ABI Research.

Another notable owner of relevant patents that is not involved in OPA at the launch is Qualcomm, which has been accused by Nokia and other mobile vendors of charging inflated prices for access to its patents. Qualcomm owns relevant patents to WiMax through its own development, as well as through acquisitions of companies including Flarion and Airgo Networks, said Solis. Qualcomm has signed licensing agreements for some of the technology to companies including Soma Networks for use in WiMax products.

Qualcomm did not respond to questions about whether it might join the OPA.

Other WiMax contributors will likely join the group, although possibly not all of them, Solis said. "This isn't going to be some catch-all type of solution," he said. "But what it does is start a foundation to push other companies to join, so you have this openness in terms of patent transparency."

Members of the OPA won't actually give their patents to the group. "Patents remain with the originator and they are free to work in any way they wish," West said. However, members will be required to openly declare their patents and the rates at which they license them. A third-party "referee" not affiliated with any of the involved companies will study patent contributions and accept them if it finds they are essential to the WiMax standard, said Sriram Viswanathan, vice president of Intel Capital and general manager of Intel's WiMax program.