The carrier’s HD voice uses the Adapted Multi-Rate Wide Band codec, which offers upgraded 3G speech coding and 23.85Kbps transmission bandwidth, which is 2.2 times wider than a 3G call.
This means that previously inaudible low and high sound waves are transmitted and improves voice quality by 40% over 3G.
In order to enjoy the service both users on a call will need to be subscribed to SK Telecom’s LTE service and have HD voice-enabled devices. The company will begin selling LTE phones embedded with HD voice from today and will offer firmware upgrades for customers' existing phones during August.
SK Telecom said that it expects VoLTE customers of different carriers to be able to utilise the service through service interworking in the future.
"With the commercialisation of HD voice, SK Telecom firmly establishes itself as top LTE service provider in terms of market share, network infrastructure and technology. Going forward, SK Telecom will continue to provide customers with innovative, lifestyle-enhancing LTE services including those that utilise HD voice," said Bae Joon-dong, president of Network Operation Business at SK Telecom.
SK Telecom has deployed several technologies to ensure voice quality for customers, including QoS Class Identifier, Advanced-SCAN, LTE femtocells and Multi Carrier. The company completed its nationwide LTE roll-out in June 2012 and provides 99% of the Korean population with 4G coverage.
