Verizon

A pedestrian walks by a Verizon Wireless retail store in October 2010 in San Francisco. Verizon has launched 4G LTE in more markets than its competitors. (Justin Sullivan / Getty Images / October 3, 2010)

Verizon Wireless proclaimed its roll-out of 4G LTE is "substantially complete" two and half years after it began, announcing Thursday the high-speed mobile data network is available in 500 U.S. markets.

The New Jersey-based mobile carrier has led the way in providing widespread 4G coverage. But it is struggling to consistently provide data speeds as fast as on AT&T’s younger and less congested network. Verizon now is turning to improving its 4G service to handle consumers' growing appetite for mobile data. It also has begun to test audio and video calling on the more robust network.

In places such as Alaska, Verizon has a 4G network but no 3G network. While Verizon customers can browse the web using the 4G network, they must use the towers of other carriers to make phone calls.

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By next year, it hopes to let devices tap into 4G towers across the country to make audio and video phone calls.  The company said 95% of the U.S. population has access to 4G, up from 90% eight months ago.

To counter growing data usage, Verizon plans to slowly convert 3G signals to 4G signals in some areas as early next year. Verizon will be adding additional capacity by deploying 4G in the Advanced Wireless Spectrum that it purchased last year.

Verizon then will be able to use functions made available by LTE Advanced technology to increase the amount of data it can quickly serve up to customers in dense urban environments.

“Now that we're done with our initial LTE build, we are looking to the Advanced Wireless spectrum to add depth and longevity to our network,” said Nicola Palmer, Verizon’s chief technology officer.

But T-Mobile, Sprint and AT&T are right on Verizon’s tail. They’ve also vowed to speed up their networks by adopting LTE-Advanced features. AT&T has LTE coverage in 315 markets, Sprint in 110 and T-Mobile in seven.

Samsung launched an LTE-A-capable version of the Galaxy S4 on Wednesday. Carriers declined to say whether they would support the device.

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