Sprint Nextel Corp announced yesterday the completion of its first device designed to work on the high-speed WiMax network currently prepared by Clearwire Corp and also on Sprint's existing mobile network.

The dual-mode modem, called Sprint 3G/4G USB Modem U300, will be available starting with December 21 at a price of $149.99, which includes a $50 rebate for the customers under a two-year contract. The company’s officials explained that the new 4G Clearwire network will allow download speeds between 2 Mbps and 4Mbps, but the network will only be available for some of the customers. For those users who will be out of range and unable to connect to the 4G wireless network, the modem will automatically access Sprint's 3G network, offering average downloads of between 600 Kbps and 1.4 Mbps.

The 4G WiMax network called Xohm was launched in October in Baltimore and will be available across the country in 2009.

"It will take a while for the new (4G) network to be built ubiquitously," explained Sprint's CEO Dan Hesse during the Baltimore press event. "And we will have new multimode devices that will use 4G where it's available, and when it's not, it will downshift to 3G to provide that ubiquitous data coverage," he added.

The news has been received with great enthusiasm by customers and manufacturers, and several companies, including Asus, Toshiba, Acer and Lenovo are currently including Intel's WiMax/Wi-Fi module in their new laptops, which will allow users to access the 4G WiMax Network. Still, the laptops will not include Sprint’s 3G wireless technology and users will have to subscribe to a 4G WiMax Clearwire service, available for $45 per month, and also Sprint’s 3G wireless service, which is available for a monthly fee of $59.99.

A Sprint spokesman explained that the company and its partners plan to eventually offer embedded dual-mode 3G/4G technology in other devices. Still, he pointed out that the devices that use Intel's embedded WiMax technology and the dual mode 3G/4G modem are actually aimed at different sets of customers.

Sprint and Clearwire managed to complete their WiMAX joint venture earlier this month with a $3.2 billion help from Google, Intel, Comcast, Time Warner Cable, and Bright House Networks. The company has most of the 2.5GHz licenses in the United States, including 100MHz or more in most US markets. This should be sufficient for a good WiMAX coverage.

Sprint announced some of its plans for early 2009, which include the release of its WiMax service in Chicago and Washington DC. The problem for Sprint and Clearwire is that the investments needed to complete building the network, which have been estimated between $3 billion and $5 billion, will be extremely difficult to find. Clearwire’s CEO Ben Wolff recently talked to the Wall Street Journal and explained that his company might slow things down if the credit crunch affects his company. Still, it might also be a good long term plan to make and effort and complete the process.