The embattled WiMAX communications standard is taking another hit as WiMAX vendor Clearwire Communications is the recipient of a class-action lawsuit by users contending that its service is slow and unreliable.

While the lawsuit is not about Clearwire's WiMAX service specifically, Clearwire is the main company providing WiMAX services in the U.S., after taking over Sprint Network's XOHM service in the fall of 2008. Currently Clearwire offers WiMAX in two cities, Baltimore and Portland. Damage to the company from the lawsuit, even though it is about a service Clearwire refers to as "pre-WiMAX," could affect the company's ability to support and continue to roll out WiMAX services.

WiMAX was supposed to be the next generation wifi standard but it has not been adopted as quickly as expected, and major vendors such as Nokia are backing the 4G wireless standard LTE instead.

The lawsuit, through the Washington, D.C. law firm of Tycko & Zavareei LLP and the Seattle, Washington law firm of Peterson Young Putra, consists of five users, ranging from Washington, Hawaii, Minnesota, and North Carolina, who complained that after finding the service to be slow and unreliable, they were hit with large early-termination fees, even if it was due to a situation such as moving away from a coverage area.

"The complaint also alleges that Clearwire engages in false advertising of its Internet and telephone services. Although Clearwire advertises its internet service offering as a reliable, comparable, and “always-on” alternative to cable Internet or DSL, the complaint alleges that Clearwire’s Internet service is actually far inferior to cable Internet and DSL," according to a statement from the attorneys.

No dollar figure is named in the complaint, but the plaintiffs ask for actual damages, treble damages, punitive damages, attorneys' fees, and so on.