Spectrum properties and the physical layout of cell towers and base stations are ongoing concerns of the carriers. At AT&T, engineers are moving forward with LTE after carefully testing WiMax, which is "very good technology," said AT&T spokesman Mark Siegel. "It appears to be very good for fixed mobility, such as a neighborhood or shopping mall, but it's not clear yet how it will perform over wide distances as people are mobile," he said.

Motorola, Intel and others demonstrated mobile WiMax at the CES and the CTIA conferences earlier this year in Las Vegas, driving cars through busy city streets to show connections to WiMax antennas installed for the tests. The WiMax handoff of signals from tower to tower worked the majority of times on two separate runs conducted, but failed at least once on each run. Last year, a boat on the Chicago River made smooth handoffs as it cruised along, allowing video streaming to laptops and handheld prototype devices.

Siegel said AT&T is convinced it can find cost efficiencies with LTE as an upgrade to GSM, allowing it to use its current infrastructure of 48,000 towers and related base station equipment nationally. "By comparison, WiMax has to start from ground zero," he said.

Sprint disputes that characterization, noting it has long held the 2.5 GHz spectrum being used for WiMax, among other basics, including the rights to use its existing cell towers.

The bottom line

For end users, the current debate over WiMax vs. LTE is largely theoretical but is nonetheless important. Technology investors are the most interested now, because billions of dollars being invested today will have clear implications for millions of users in, perhaps, three years.

Analysts see a clear dominance by LTE in a few years. Among other things, it could support global roaming for users of high-speed wireless devices, since so many carriers are bound to adopt it. However, that won't serve every user or every company, Redman noted.

"The bottom line is that one technology will not cover all the user needs for home, office, local or international services," Redman said. "It is still going to be a combination of technologies and developers. WiMax may be one of those, but LTE will predominate."

For users, technology competition should always be considered beneficial, noted Jack Gold, an analyst at J.Gold Associates. "One thing is certain," he said. "The new Clearwire joint venture will spur the other guys to get their act together and get LTE out in the field."