Japan's NTT has launched a cable route linking Japan to the Trans-Pacific Express (TPE) submarine cable network, which runs between Southeast Asia and the United States.
The TPE now has a capacity of up to 5.12 Tbps, and comprises around 18,000 km of cable, NTT said.
The construction and startup of the Japan-Asia leg is the second phase of construction for TPE. It has been operational since September 30 last year, interconnecting Mainland China, South Korea, Taiwan and the US.
The Japanese leg of the project has been completed ahead of schedule - construction had been originally scheduled to conclude in March.
NTT said it will primarily use the new link to enhance the redundancy and capacity of its Arcstar global IP-VPN service, as well as its IP network services.
The TPE cable is operated by a partnership between NTT, China Telecom, China Unicom, Taiwan's Chunghwa Telecom, Korea's KT and the US's AT&T and Verizon Business.
The parties had allocated around $500 million for the project, with ownership of the cable split evenly between them.
DoCoMo reportedly invested around $80 million for the Japan leg of the cable.
NTT this year purchased trans-Pacific cable owner Pacific Crossing – operator of the PC-1 ring network between the west coast of the US and Japan - for over $105 million. Analysts had speculated that the purchase could affect DoCoMo's participation in the TPE, but the suspicions have not been borne out.