(Telecompaper) NTT Docomo announced that its Xi network will offer Japan's first LTE service for voice and video calls using VoLTE technology, beginning late June. Four smartphones and two tablets in Docomo's summer lineup will become compatible with the new service after a software update scheduled in or after late June. The service will enable users to receive Area Mail disaster-information notifications while making VoLTE voice/video calls. Also, users will be able to access up to 150 Mbps high-speed LTE data communication during VoLTE voice calls. Docomo's new VoLTE service will require a subscription to Xi.