Because the failure was so widespread, it probably was caused by a problem on the back end of Verizon's network rather than any flaw in LTE radio technology, analysts said. The radio network is too distributed and was supplied by two different vendors, Ericsson and Alcatel-Lucent, said Phil Marshall of Tolaga Research. More likely, a configuration change or software update that was propagated throughout the network led to the failure, which could explain the wait of several hours before the error was corrected everywhere, he said.

The company was lucky that the outage occurred while the LTE network is still relatively small, analysts said. Verizon only introduced LTE in December, in 38 metropolitan areas. It plans to have the system up in 140 other areas by the end of this year and across its entire 3G footprint by the end of 2013.

"I think this is a wake-up call to Verizon," said analyst Jack Gold of J. Gold Associates. The outage may indicate there is a single point of failure in Verizon's LTE infrastructure, which would be a poor design, he said.

Verizon has been rolling out the new technology quickly while simultaneously integrating it with its existing 3G network, Marshall said.

"They've been extremely aggressive in the rate at which they've launched this network. And you've got to give them credit for that," Marshall said. However, this does entail risk, he added. "I think we're seeing the impact of that," he said.