Is Clearwire (Nasdaq: CLWR) preparing to put the final nail in WiMAX's coffin? On Wednesday, the company announced plans to begin testing next-generation LTE technology that could function at speeds four to six times faster than competitors such as AT&T and Verizon (NYSE: VZ).

RIP, WiMAX
Clearwire had been the last major WiMAX backer in the U.S. The once-promising technology now suffers from eroding support worldwide. While WiMAX will remain an integral part of Clearwire's network -- the company still plans to continue its WiMAX buildout through the end of the year -- Clearwire can't ignore LTE's momentum.

Pressure is most likely coming from Clearwire majority owner Sprint (NYSE: S). CEO Dan Hesse recently hinted that Sprint might join the LTE bandwagon. It's no secret that Sprint's fairly desperate to turn its losing ways around; to do so, the wireless carrier might team up with fellow laggard T-Mobile to create an LTE network. Clearwire's press release mentioned that "a number of large wireless operators are expected to participate with Clearwire on these tests." To me, that looks like a not-so-subtle suggestion of T-Mobile's involvement in the endeavor.

With WiMAX losing its last major U.S. backer, the following three companies stand to gain or lose from WiMAX's continuing decline.

In the winners' circle ...
While Qualcomm (Nasdaq: QCOM) has patents in both LTE and WiMAX, it's no secret that the telecom giant is better-positioned for LTE to succeed in the next generation. Qualcomm has worked out LTE licensing with some of the largest handset manufacturers. LTE's continuing domination will keep Qualcomm's position as the patent kingpin assured for yet another generation of mobile networks.

Even with LTE hegemony in the U.S., almost every major carrier here uses different "spectral bands" to transmit data. For investors, that means there's tremendous opportunity in finding wireless companies with expertise in creating communication semiconductors that can operate equally well with varying frequencies. That's the exact niche TriQuint (Nasdaq: TQNT) targets.

And the biggest losers ...
DragonWave (Nasdaq: DRWI), which produces wireless backhaul equipment, has historically relied on Clearwire for the majority of its sales. While Clearwire is still committed to WiMAX buildouts through the end of the year, its LTE ambitions cast a shadow over Dragonwave's future. 

Fellow WiMAX specialist Ceragon Networks (Nasdaq: CRNT) could also be in trouble if more wireless companies defect from its technology of choice. However, Ceragon has a larger base of international customers that might be more dedicated to building out WiMAX networks.

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