U.S. Cellular (NYSE:USM) has started testing Voice over LTE technology but has not yet said when it will launch the service.
The carrier disclosed its VoLTE efforts in a filing with the FCC. "U.S. Cellular is currently testing VoLTE and expects to move forward with VoLTE deployments at some point in the future," the carrier wrote in the filing.
U.S. Cellular spokesman Steve Carlson said that the company began VoLTE trials "with multiple vendors" in the fourth quarter and will continue testing into 2013. He declined to comment further.
U.S. Cellular joins a growing number of U.S. carriers that are testing VoLTE in preparation for deployments. MetroPCS (NYSE:PCS) became one of the first mobile operators in the world--and so far the only operator in the United States--to deploy VoLTE when it launched service this summer in the Dallas-Fort Worth market. In September MetroPCS said it would have VoLTE in all 14 of its LTE markets within the next four to six months. T-Mobile USA, which plans to merge with MetroPCS, will continue supporting those deployments after the merger closes, T-Mobile CTO Neville Ray told FierceBroadbandWireless in October.
Verizon Wireless (NYSE:VZ) CTO Nicola Palmer recently disclosed the operator expects to begin consumer trials of VoLTE in late 2013 with commercial VoLTE service expected in 2014, two years later than initial commercial launch plans.
Although there has been excitement about VoLTE, especially as a method for refarming older spectrum, Metrico Wireless recently authored a study that found that the technology can significantly curb smartphones' battery life. The study compared device battery life for calls placed over an LTE network vs. calls placed over a CDMA network on an unnamed U.S. operator's network in two major markets using a smartphone capable of supporting both CDMA and VoLTE voice calling.
"The device's estimated battery life was reduced by 50 percent or about 252 minutes of talk time when voice calls were placed over the LTE network, compared to voice calls placed over the CDMA network," according to the study, authored by Ardeshir Ghanbarzadeh, director of services development for Metrico, which was acquired by Spirent Communications in September.
- see this FCC filing
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