Clearwire will launch high-speed advanced LTE in 31 U.S. metropolitan markets -- including Chicago, Los Angeles, New York City, San Francisco and Seattle -- beginning in the first half of 2013.

"After collaborating closely with Sprint over the past few months, we have finalized the identification of the first 5,000 sites we intend to build as part of our larger LTE overlay of up to 8,000 sites and have officially kicked off the build," Clearwire CEO Erik Prusch said Thursday. "The initial processes for equipment testing and site preparation are now under way."

Unlike LTE rivals AT&T and Verizon, which are focused solely on providing LTE services directly to their subscribers, Clearwire also intends to enter into LTE wholesale agreements with other U.S. service providers. Leap Wireless' Cricket Communications agreed to a five-year LTE spectrum-capacity Relevant Products/Services deal with Clearwire last month.

Clearwire intends to use a more efficient but incompatible form of long-term evolution data Relevant Products/Services networking known as time division duplexing, or TDD-LTE, compared with the more common frequency division duplexing, or FDD-LTE, used by most U.S. carriers.

The wireless industry is seeing explosive growth in mobile Relevant Products/Services broadband demand, which is driving the need for more spectrum capacity and attracting new entrants to the market, Prusch said.

"It is evident in the reports from other operators and more importantly, we see it in our own results," Prusch told investors during a conference call. "Clearwire's high capacity LTE advanced-ready network Relevant Products/Services will sit at the intersection of these two trends."

A More Robust Pipeline

We asked Clearwire to explain the advantages that the carrier will be able to offer in comparison with rival LTE service offerings. According to a company spokesperson, one of the carrier's top assets is the 160 megahertz of spectrum capacity that Clearwire already holds in the top 100 U.S. cities, on average.

"Due to our spectrum depth, and with the help of the multichannel radios, we can easily and cost-effectively add additional capacity carriers to our cell sites," Clearwire's spokesperson said. "We estimate that we can support up to 10 times more devices on a cell site than another 4G carrier with only 20 MHz of spectrum in a large Top 100 market."

Furthermore, other commercial LTE networks are limited to 5MHz x 5MHz or 10MHz x 10MHz deployments that offer significantly less room to scale with rapidly growing demand. "By comparison, Clearwire will be able to deliver 40MHz x 40MHz deployments in many of these markets -- significantly above what others can offer alone," Clearwire's spokesperson said.

The goal is to become the first U.S. wireless operator to substantially boost the limits currently imposed on the LTE technologies available in the U.S. today.

"[This will] give us the advantage of offering the fastest speeds and the highest capacity network in the nation," Prusch told investors.

Multi-Flavor LTE Devices Coming

The TDD variant of LTE uses the same frequencies for the uplink and downlink rather than having to split them into separate channels.

"Using the TDD flavor of LTE enables us to dedicate more of our spectrum to downlink traffic to better serve the heavily downlink biased mobile Internet," Clearwire's spokesperson said. "And, unlike other LTE networks, we will be able to alter this downlink/uplink ratio in the future depending on how usage evolves on the mobile Internet."

One problem facing Clearwire is TDD-LTE incompatibility with the FDD-LTE variants already deployed by rivals AT&T and Verizon. However, Clearwire's spokesperson said the company expects to see multi-flavor LTE devices coming down the pike from mobile device manufacturers.

Moreover, Prusch said he expects Sprint to be a key partner in furthering Clearwire's TDD-LTE system by deploying several compatible devices throughout 2013.

"We've also made solid progress with chipset vendors and OEMs and expect to have additional details to share in the near future," Prusch added.