US Cellular has been conducting a technical trial of Long Term Evolution (LTE) in Madison, Wisc., for the past nine months and plans to begin a customer trial next year, followed by commercial launches in the latter part of 2011 or early 2012.

CFO Steven Campbell first outlined the carrier's plans at a Wells Fargo & Co. conference last week, and CTO Michael Irizarry provided more details to Light Reading Mobile on how the trial has been progressing.

Irizarry says the technical trial will continue throughout this year and next as the US's sixth-largest carrier works out the kinks. It is working with multiple radio access network (RAN) vendors, not just one or two, he said, so it's a complex process. It plans to pick an equipment vendor in early 2011.

As part of the trial, US Cellular is testing out Service Provider Information Technology (SPIT) principles like Policy Charging and Rules Function (PCRF) and an IMS framework with multiple vendors. Irizarry says that they quickly found out which companies were ready to support their needs and which weren't. The same went for Femtocell suppliers.

"We believe in femtocells and think it's an important technology, but one thing we believe in is having a diverse product ecosystem," Irizarry says. "We figured out pretty quickly that interoperability between different femtocell gateways and boxes isn't quite where it needs to be. The management algorithms between macrosystem and femtocells still need some work to optimize the experience."

As it works out the issues, the Chicago-based carrier is also figuring out where to hold its first customer trial. Irizarry says it plans to take LTE live in the later part of 2011, although that could be pushed back or moved forward depending on the competitive environment and device ecosystem. Once a solid device portfolio of smartphones and data dongles is available, it will move quickly on more LTE launches throughout 2012, he says. (See CTIA 2010: The LTE Smartphone Scramble and Samsung Unveils LTE Handset.)

Fellow small telco MetroPCS Inc. (NYSE: PCS) was the first to launch LTE in the US, and the much larger Verizon Wireless will make its move before the end of the year, leaving US Cellular trialing the pack. (See MetroPCS Plots LTE Smartphones, VoLTE Trials, LTE Starts Here, and MetroPCS Beats Verizon to LTE in Sin City.)

When it does launch, it will use same 700MHz spectrum Verizon and AT&T Inc. (NYSE: T) own. Campbell said at the conference that he feels good about its spectrum position, but is looking to fill in the holes. The carrier has been making small spectrum acquisitions in the 700MHz band every quarter, he said.

Campbell also noted that US Cellular is open to buying capacity on LightSquared or Clearwire LLC (Nasdaq: CLWR), but he doesn't share his competitors' need for urgency on getting LTE off the ground.

"I don't think we're feeling any sense of crisis or urgency about not having spectrum we need right now," he said.

— Sarah Reedy, Senior Reporter, Light Reading Mobile