Sprint this week unveiled plans for a commercial launch of its WiMAX 4G network by the end of 2008 in the Baltimore and Washington, DC area, capping about a year of testing with Samsung and other wireless vendors.

Yesterday, Sprint announced the latest battery of tests of its Xohm network in the Baltimore/Washington, DC area launched last month, show it has passed "commercial acceptance" criteria, including overall performance, handoff performance, and handoff delay. That milestone having been passed, the company can now concentrate on its first commercial service rollouts.

Xohm got a huge boost earlier this month when Sprint and Clearwire renewed a previously tabled WiMAX agreement in a resounding manner, combining their WiMAX holdings in a new broadband company funded by $3.2 billion in investments from Google, Intel Capital, Comcast, Time Warner, and Bright House Networks.

Meanwhile, Samsumg, Sprint's partner in the Xohm test, introduced WiMAX-enabled devices that include the E100 PC Card and a WiMAX-embedded UMPC.

Earlier milestones in the Baltimore-Washington, DC WiMAX test have included the first data session in the lab (June, 2007); the first data session on the live network (October, 2007); and successful interoperability testing with multiple other device vendors (April, 2008).

Sprint CEO Dan Hesse first went public with news of tests in the Baltimore/Washington and Chicago areas, during a conference call with analysts last February.

"Now taking data to the next level [will be] 4G or fourth generation [wireless], which is often referred to as WiMAX. I am extremely encouraged with what I have seen. Our soft launches in Baltimore, Washington, and Chicago offer confidence in the performance of the technology," Hesse said.

The combined WiMAX holdings of Sprint and Clearwire operate in the 2.5 GHz wireless spectrum. As previously reported, Sprint invested in WiMAX long before the recent buys by Verizon and AT&T of 700 MHz spectrum. Sprint's initial intent revolved around getting into broadband before any major rivals.

But last November, when financially challenged Sprint scrapped an earlier WiMAX deal with Clearwire signed some five months before, many began wondering whether WiMAX could stay the 4G course.