Japan’s NTT DoCoMo, South Korea’s KT and US-based Verizon Wireless have completed voice-over-LTE (VoLTE) roaming trials demonstrating HD voice and video calls between different countries.
The trials used the S8 home routed (S8HR) architecture, a technology based on the existing LTE data roaming platform, which claims to allow for the commercialisation of VoLTE for HD voice and video roaming services with full carrier-grade voice and video quality.
DoCoMo said it is now preparing to offer customers the same VoLTE experiences they have in Japan when travelling to other countries.
As part of the trials DoCoMo and KT claimed to have completed the world’s first high-definition voice and video call. In addition, DoCoMo and Verizon said they completed the world’s first transoceanic high-definition VoLTE roaming calls.
The calls were made on an IPX and network equipment to replicate commercial networks. DoCoMo said that with only two months of preparation – “which also showed the technology’s feasibility of speedy commercialisation” – the quality of VoLTE roaming calls using S8HR architecture over both short and long distances was proven to be better than that of existing 3G voice roaming services.
In October China Mobile, KPN and iBasis said they completed the first international VoLTE roaming call between mobile operators based on IMS local breakout architecture.