SK Telecom is to launch a high-definition voice calling service on its LTE network tomorrow, becoming the first mobile operator in the world to commercially switch on Voice-over-LTE (VoLTE) services.

South Korea’s largest operator says its VoLTE service will be known as ‘HD Voice’ and will “dramatically” push up audio quality by using high-quality audio codec capable of handling 2.2 times wider frequency bandwidth than that of 3G voice calls. Moreover, SK claimed that the call connection time will be as much as 20 times quicker, at 0.25 to 2.5 seconds compared to the average of 5 seconds required to connect a 3G voice call.
 
In order to take advantage of the service, both parties on the call will need to be subscribed to SK’s LTE service and have HD Voice-capable devices.

The operator will begin selling the LTE-enabled Samsung S3 with HD Voice included from tomorrow, while existing users of the device are able to add the feature via a firmware upgrade due soon. It plans to embed the service as a “basic feature” in most of its LTE smartphones from now on.

“Going forward, high-quality voice call is expected to be realised among VoLTE customers of different carriers through service interworking among three Korean mobile carriers,” the firm said in a statement.

It plans to combine HD Voice with the commercial launch of RCS services in the second half of this year, enabling services such as in-call voice-to-video call switching and content sharing.

SK has already achieved 99 percent population coverage for its LTE network (first launched in July 2011), and claims to be the world’s second-largest LTE operator after Verizon Wireless in the US. It hit 4.22 million LTE subscribers at the end of July 2012 and says it is on track to achieve its target of 7 million LTE subscribers by year-end.

Its move to VoLTE places it ahead of US operators Verizon Wireless and MetroPCS, which plan to launch the technology in 2013 and H2 2012, respectively. Although SK has talked up the ‘new’ high-definition aspect of its VoLTE service, it is expected that the majority of commercial VoLTE launches will support HD technology.