CHICAGO -- 4G World -- Clearwire LLC (Nasdaq: CLWR) has launched its Silicon Valley WiMax test network as the firm's new CEO says that Long Term Evolution (LTE) technology could be in its future.

The plan to develop a WiMax Silicon Valley "sandbox" that would give developers a chance to experience WiMax in the air was unveiled in April. The Kirkland, Wash.-based operator launched the network today, saying that it will cover more than 20 square miles in Santa Clara, Mountain View, and parts of downtown Palo Alto, California. (See Clearwire Plays in 4G Sandbox.)

The network will eventually become part of Clearwire's Bay Area commercial launch, which is slated for 2010. (See WiMax's Bay Window and Clearwire Launches in 10 New Markets.)

New Clearwire CEO Bill Morrow will likely have more controversial issues to deal with during his keynote here today in Chicago, however. The new WiMax head honcho told Dow Jones Newswires Tuesday that Clearwire could use LTE if it wanted to in the future.

This shouldn't be a huge surprise for any Unstrung readers. WiMax and LTE are based on the same underlying radio technology and have a great deal in common. Also, previous Clearwire CEO Ben Wolff had suggested something similar. (See WiMax & LTE: Kissin' Cousins.) In fact, in terms of network infrastructure requirements for such a shift, at least one of Clearwire's radio access providers, Motorola Inc. (NYSE: MOT), has based its LTE base stations on its previously developed WiMax platform. This means that Clearwire could simply do a software upgrade to move to LTE. (See Moto Joins LTE Club, Moto Supports WiMax, LTE, Motorola Enlists Starent for 4G Push, Moto Trials LTE in UK, Moto Demos TV-Over-LTE in Sweden, and 4G World: LTE Climbs on WiMax's Shoulders.)

The one issue then -- and it is a big issue -- is whether the operator could find LTE devices that operate on its 2.5 GHz spectrum footprint. Users with early 700 MHz gadgets aren't likely to be able to switch between the two, although that might change over time.

— Dan Jones, Site Editor, Unstrung