Leap Wireless (NYSE: LEAP) announced Wednesday that there is now a fourth mobile carrier in the U.S. offering 4G LTE service. Leap said that its company Cricket Wireless has begun its transition to LTE with its test deployment of the technology in Tucson, Arizona.

Cricket joins major carriers Verizon (NYSE: VZ) and AT&T (NYSE: T), and fellow second-tier carrier MetroPCS (NYSE: PCS) as providers of the latest mobile broadband technology. A statement released by Cricket claims that pre-launch testing has shown a marked improvement in speed, from five to ten times faster than its 3G network. This first LTE network covers 90 percent of Tucson and will expand next year into nearby Nogales. Leap said last month that it plans to cover two-thirds of its present network with LTE service within two or three years.

All aboard!
MetroPCS rolled out its LTE network in Las Vegas, Nevada in September of 2010, along with what it said was the world's first commercially available LTE handset, the Samsung Craft. Metro has since been working with phone vendors on bringing the cost of LTE handsets way down.

Another smaller carrier, U.S. Cellular (NYSE: USM), has said it plans to launch its LTE network in early 2012. Even DISH Network has plans to get into the wireless carrier business, this scheme with a hybrid satellite/terrestrial LTE network.

But customers of Sprint Nextel (NYSE: S), the third largest U.S. carrier may have to wait until the second half of 2012 -- at least that's what Sprint CFO Joseph Euteneuer told the attendees at a UBS conference in New York City earlier this month. He said that before Sprint had worked out some of the financial kinks it had in its relationship with its current 4G WiMAX network provider Clearwire (Nasdaq: CLWR).

You need a phone to make phone calls
One problem here for Cricket: The company is not yet offering an LTE handset for its network. The one LTE device it now has available is a modem, the Huawei Boltz. The company says it will offer LTE-compatible smartphones and tablets in the future.

Obviously, until actual LTE mobile phones are added to the LTE mobile network, Cricket's foray into 4G is not going to shake up the industry. For now, this rollout still has to be filed under "W," for wait-and-see.

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