SAN ANTONIO -- CCA Global Expo -- When asked about his biggest concern around small cells, C Spire's Manager of RF Design Engineering Mitchell Jordan had one clear answer: VoLTE.

"One concern I have on small cell is it's all LTE focused, and I get that, but in a lot of places, we need that voice option for the small cell," Jordan said on a panel here. "I guess we have to depend on VoLTE for that. I just have major concerns about VoLTE."

His concern with the 4G voice technology is that the Tier 1 operators have said it would be deployed in 2013, then pushed it back to 2014, and now he worries it will be several more years out. The reason that worries him is C Spire is waiting on the Tier 1s to see how VoLTE goes before making any moves of its own. (See VoLTE: So Close You Can Hear It.)

Alcatel-Lucent (NYSE: ALU) will power VoLTE for the operator, but C Spire hasn't laid out its own timeline for the technology. Jordan said its CDMA network won't be going anywhere until at least 2020, and it won't do VoLTE until the quality is comparable to voice on its CDMA network. (See C Spire Picks AlcaLu for 4G LTE Depolyment.)

That said, the carrier is moving forward on LTE. The engineer said that two-thirds of its network, which spans four southeastern US states, will be overlaid by LTE by the end of 2014, and it will convert nearly all, if not all, of its cell sites to LTE by the end of 2015.

It is also planning to start public-access small cell trials in the second or third quarter this year, and it has WiFi indoors through an agreement with Devicescape Software Inc. , but is working on expanding its managed access points outdoors. (See C-Spire Picks Devicespace for Wi-Fi Reach.)

The regional operator offers unlimited data plans, including a new $65 option it introduced this week, which Jordan said has really challenged its capacity constraints. He said C Spire's vendors have been surprised about how high its per-user data usage is, higher than most other carriers. That's why it's so interested in deploying small cells to help bolster capacity, but is also concerned about the cost of deployment, as well as the significant backhaul challenge. (See Poll: Backhaul Holds Up City Small Cells and Public Access Small Cells: Off to a Slow Start.)

"We embraced [WiFi] because we had to," Jordan said. "That's why femtocells, small cells come in too. We just don't have any other options to address the capacity crunch."

And, given its smaller size, it can't use dedicated carriers and it doesn't have a "war chest of spectrum," Jordan said. Self-organizing network (SON) technology will be critical to its small cell rollout.

"We need better coordination between networks to maximize spectrum," he said. "The FCC is not giving us spectrum as fast as we need it... We haven't deployed SON yet; we are still evaluating. A concern I have is as quickly as you can improve your performance on a network, you can destroy it as well."

— Sarah Reedy, Senior Editor, Light Reading