Sprint Nextel Corp. is promising to launch three more of what it calls "4G" markets this summer, piggybacking on the mobile WiMax infrastructure from Clearwire LLC that the carrier uses to provide the mobile broadband service.

A spokeswoman for Sprint emails Unstrung that "4G will be available in Portland, Las Vegas, Atlanta, and other markets this summer." This follows Clearwire's recent "soft" launch of its Clear service in Atlanta and Las Vegas. (See Clearwire Goes Soft in Vegas and Clear Is in Atlanta.)

It's not 4G?

Like Clearwire and rival Verizon Wireless, Sprint is referring to its mobile broadband service as "4G." Strictly speaking, however, neither mobile WiMax nor Long Term Evolution (LTE) technology meets the download requirements to actually qualify as a fourth-generation wireless network.

The International Telecommunication Union (ITU)'s official requirements for 4G include average downlink speeds of 100 Mbit/s in the wide area network, and up to 1 Gbit/s for local access or low mobility scenarios. Sprint says that its current WiMax network in Baltimore offers peak download speeds of 12 Mbit/s. (See WiMax & LTE Meet the Real World for more on WiMax and LTE speeds.)

The next versions of WiMax and LTE are expected to meet the ITU's requirements to be classed as a 4G technology. The ITU approved both 802.16m and LTE-Advanced as potential 4G specs back in July 2008. (See ITU Approves New 4G Specs.)

8 XOHMs to go
Sprint is working as a mobile virtual network operator (MVNO) over Clearwire's infrastructure, offering customers a dualmode USB modem so that they can switch between Sprint's 3G CDMA network and the mobile network. So far, however, Sprint only has one mobile WiMax network, its XOHM site in Baltimore. (See Clearwire Considering WiMax Polygamy .)

"Not for long," says the Sprint spokeswoman. In all, the third-ranked U.S. operator hopes to go commercial with eight dualmode markets in 2009, including Chicago, Dallas/Ft. Worth, Honolulu, Philadelphia, and Seattle.

Of course, with its dualmode approach, sourcing devices that can run across both networks is an important part of the operator's strategy. Unstrung first reported in March that the operator has a number of devices on its roadmap for 2009 and 2010, including a tri-mode phone that would support CDMA, WiMax, and WiFi. (See Sprint to Extend '4G' in Clearwire Markets.)

Among the other devices planned are "a singlemode 4G data card, embedded laptops, small-office-home-office devices, and a personal hotspot router," the spokeswoman says. All of these are planned for this year or 2010, she notes, but the operator isn't releasing any further details yet.

— Dan Jones, Site Editor, Unstrung