Latest southern Colorado news, weather and sports from FOX21 News

COLORADO SPRINGS, COLO. -- Cell phones continue to become a larger part of the daily lives for most people, so dead zones can become inconvenient.

What causes them?

"Dead zones can be caused by a number of different things," said Sprint public spokesman, Dave Mellin. "It might just be that we don't even have a cell site in that area. That's a possibility, Or it could be that we have coverage in that area..and the towers aren't talking that well to each other. If you've got a cell site right here and a coverage area that's this big with nobody on the network, if you get 50 people that are on that cell site at any given time, that coverage area starts to shrink. There could be a high capacity or a high strain on the network and it could cause little gaps in that area where coverage takes place. So there's moments like that where that can occur."

As for Verizon, the company said it covers most of the state with its 3G network.

"Our coverage within the state, uh, for our 3G Network....not the 4G LTE Network...is closing in on 98 percent. of the population is covered," said Bob Kelley of Verizon Wireless. "There are or could be pockets of areas, and as we get calls they are opened a ticket by our network team. They're checked out and we'll look at possibilities in the short term. Maybe it's facing an antenna a little differently."

Thousands of hours and millions of dollars are spent each year in the state of Colorado to provide the best possible cell phone coverage to current and potential customers. And so far the billions Verizon has invested is paying off. In an independent, third-party cellular study called the RootScore report, by RootMetrics.

Verizon ranks number one in overall categories including..fastest and most reliable network, fastest text service, and data speed. But when RootMetrics analyzed call performance by measuring both dropped calls and blocked calls. Cricket, Sprint and Verizon each delivered statistically indistinguishable results.

"We consider ourselves to be the leader in 4G LTE and high-speed data coverage," said Kelley. "And when you look at the growth of things like smart phones and tablets and people wanting to use those devices, not just in their home but wherever they may be, we pride ourselves on providing that coverage where they want to use it."

For Sprint, 2013 will be a year of growth. With expected expansion and introduction of their own 4G network to Colorado Springs.

"We'll have a better experience once 4G deploys, but they'll have a better 3G experience," said Mellin. "Better voice experience as a result of that."