Carriers Verify International VoLTE Roaming

NTT DOCOMO, KT and Verizon Wireless have successfully verified the feasibility of international voice-over-LTE (VoLTE) roaming between different regions of the world.

The carriers have completed a series of tests using S8 Home Routed (S8HR) architecture, a technology based on the existing LTE data roaming platform, which allows speedy commercialization of VoLTE for high-definition voice and video roaming services with full end-to-end carrier-grade voice and video quality.

DOCOMO said it is now prepared to offer its customers the same VoLTE experiences they have in Japan when traveling to other countries.

In the trials, DOCOMO and KT achieved the world's first high-definition voice and video call with full end-to-end quality of service. Also, DOCOMO and Verizon achieved the world's first transoceanic high-definition VoLTE roaming calls. DOCOMO has existing commercial 3G and 4G roaming relations with Verizon Wireless and KT.

The calls were made on an IP eXchange (IPX) and network equipment to replicate commercial networks. With only two months of preparation, which also proved the technology's feasibility of speedy commercialization, 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.

DOCOMO will continue to collaborate with these and other companies in the GSMA to drive the industry's ongoing discussion of international VoLTE roaming architecture, and to develop related operational guidelines aiming at the accelerated global deployment as part of the GSMA's Network 2020 Programme. DOCOMO will continue to carry out related R&D as it prepares to commercialize international VoLTE roaming services by the end of 2015.

https://www.nttdocomo.co.jp/english/info/media_center/pr/2015/pdf/20150226_attachment01.pdf