In an attempt to put aside speculation that it might sell its Xohm WiMAX service, Sprint dutifully but formally reminded everyone this morning that it's proceeding with its plans for a soft launch in Chicago, Baltimore, and Washington, D.C.

Furthermore, the company expects to expand the service later this year, though it didn't say where or when.

But now they must be serious - they've hired an ad agency.

WiMAX is a wireless wide-area network built as a complement to the cellular network, so unlike Wi-Fi, it can transmit data up to three miles away, at speeds of from 2 to 5 Mbps. Sprint Nextel had said last year that it expected WiMAX service to be available to 100 million subscribers by this year, and announced the three test cities.

Sprint also has several vendors demonstrating WiMAX technology in its booth. OQO is showing off its ultra mobile PC, while Zyxel, which Sprint had already said would be working on the modems, confirmed it was working with chip supplier Sequans on the MAX-206m2. At CES, Zyxel is expected to demonstrate this new device, which it expects to deliver in the second quarter. ASUStek also said it would develop WiMAX devices.

Amdocs would be the primary systems integrator responsible for the construction and maintenance of the Xohm mobile portal, Sprint added this morning, as well as for a set of systems to establish Xohm's ordering, service activation and provisioning, customer relationship management (CRM) and self-service and billing operations. In addition, SwapDrive said it will provide a hosted storage solution where Xohm subscribers can secure, organize, manage and access their user-generated digital content.

As far as the ad agency, it's Soho Square, one member of a conglomeration called WPP that also includes the venerable Oglivy.

But someone expects to make money out of WiMAX. In-Stat predicted that the WiMAX user terminal chipset market would increase from $27 million in 2007 to almost $500 million in 2012, with WiMAX base station semiconductor revenues rising from $130 million in 2007 to $1.4 billion in 2012. In-Stat expects Altair, Amicus, ApaceWave, Comsys, NextWave, Redpine Signals and XROnet to release WiMAX chipsets this year.