SHANGHAI ― KT Corp., South Korea’s largest telecom company, showcased the world’s first cross-border roaming services based on the Voice over Long Term Evolution at the 2014 GSMA Mobile Asia Expo Thursday.

The Korean mobile carrier partnered up with China Mobile, China’s leading mobile operator, to develop the VoLTE roaming services.

“KT and China Mobile have solved technical barriers that hampered faster and more stable roaming services than the current ones,” said KT CEO Hwang Chang-gyu, while visiting China Mobile’s booth at the trade show.

He added that he would reinforce collaboration with the Chinese counterpart as Hwang and China Mobile chairman Xi Gouhua made high-definition video calls through the VoLTE network. 

The KT chairman said the roaming services will be commercialized in Korea and China in November, enabling mobile users to make high-quality voice and video calls.

KT also collaborated with NTT DoCoMo for the commercialization of the new LTE roaming services in Japan.

KT explained in a statement that as KT’s LTE-Frequency Division Duplex and China Mobile’s LTE-Time Division Duplex networks have become compatible, the new roaming services will be fully available in both markets.

LTE-FDD, a common LTE standard used in Korea and Japan, needs a pair of spectrum bands for data uplink and downlink. LTE-TDD, which is mostly used in China, only needs a single channel to transmit and download data.

By Kim Young-won, Korea Herald correspondent
(wone0102@heraldcorp.com)