The Japanese equipment vendor NEC Corp has contributed to the entry of NTT DOCOMO’s Voice-over-Long Term Evolution (VoLTE) service by providing core network and wireless base station devices, Telegeography.com reports, and quoting a joint press release saying that NEC has provided NTT DOCOMO with video call and Single Radio Voice Call Continuity (SRVCC) functions for existing IMS core network devices. It also provided software updates for EPC core network devices already used in LTE services, making the devices VoLTE–service compatible.

NEC also noted that it had been chosen to develop NTT DOCOMO LTE-Advanced (LTE-A) base stations. In commenting on this, NEC’s CEO, Shunichiro Tejima, said that they “will continue to work with NTT DOCOMO in developing 5G and other next-generation mobile communication technology to contribute to the advancement of communications infrastructure.”

NTT DOCOMO announced this past May that it will introduce VoLTE technology in late June and users would likely benefit from download speeds of up to 150-Mbps on VoLTE voice calls, while the service would also provide “Area mail” disaster notifications while they’re making calls.

Four smartphones and two tablets in DOCOMO’s summer line-up will be VoLTE-service compatible after a software update by late June. The operator has also said that additional data charges for the VoLTE service won’t start until September 2015.