Within the week, Sprint will turn live its WiMAX networks in Chicago and Baltimore-Washington, D.C., Sprint officials said today. The soft launch will extend only to Sprint employees and is intended to prepare the networks for a broader customer trial in the first quarter.

Sprint spokesman John Polivka said the soft launches will cover the downtown cores of Chicago, Baltimore and Washington but will rapidly expand outward, following existing cellular data traffic patterns throughout their respective cities. Though Sprint has set no date for the broader customer trials, Polivka said, Sprint intends to keep the trial short, using it as an opportunity to optimize the network for a full commercial launch in the second quarter.

A WiMAX launch this week puts Sprint just under deadline for its promised trial deployment by the end of the year. Sprint has stated it would turn up Chicago and the Washington metro area this quarter, followed by other markets in early 2007. Motorola is building the Chicago network, while Samsung is handling the eastern seaboard launches. Sprint’s third equipment vendor, Nokia Siemens Networks, is expected to bring its first networks live in the first quarter in metropolitan centers in Texas.

While other smaller and international operators have already launched Mobile WiMAX networks using pre-certified IEEE 802.16e equipment, Sprint’s Xohm has been the launch everyone in the industry has been waiting for due to its scale and scope. Sprint not only plans to expand the network to 100 million people by the end of the year, but unlike other operators deploying the technology for fixed broadband, Sprint plans a fully mobile launch from the get-go, starting with laptop wireless cards and eventually moving to mobile devices as they become available. In addition, Sprint is planning to offer the service on an open basis, allowing any device or service provider to access the network.

The grand scope of its plans may change next year, however, as Sprint has said it will re-examine its Xohm plans early next year in the wake of financial difficulties that led to CEO Gary Forsee’s departure. Last month, Sprint and Clearwire called off plans to combine their networks in a venture that would have given both companies a much bigger footprint for a much lower cost. Though Sprint publicly has said it is still committed to seeing WiMAX through, its capital investment in the new network only totaled $73 million in the third quarter, a fraction of the $2.5 billion it said it would spend on WiMAX in 2007 and 2008.

Polivka said Sprint is proceeding with its deployment schedule as planned, however, and will continue to do so unless Sprint management decides to change up its strategy next quarter. Sprint has 10,000 base station sites readied for deployment, Polivka said, many of them cell sites for its existing CDMA network. In addition, Polivka said Sprint has orders in 1750 base stations from its three vendors as well as 20,000 antennas, which could significantly drive up its WiMAX spend for the current quarter.