NTT reveals plans for new Trans-Pacific Submarine Cable


NTT Ltd. Japan Corporation, Mitsui & Co., Ltd., PC Landing Corp, and JA Mitsui Leasing, Ltd. today announced the launch of a new company, Seren Juno Network Co., Ltd. (“Seren”) which has been founded to construct and operate “JUNO”, the new and largest trans-Pacific submarine cable system (providing the maximum capacity of 350Tbps) that will run between Japan and the US.

According to leading telecommunications industry analyst firm, TeleGeography, global internet bandwidth has risen by 29 percent in 2021. This growth trajectory is expected to continue upward driven by the deployment of 5G, IoT and edge compute technologies. And with existing Japan-US cables nearing capacity, JUNO is very much needed to meet the increasing demand for global internet bandwidth.

“With the rapid growth of the global digital economy and an increasing demand for cloud solutions and lower latency, the undersea internet cable sector is quickly becoming more critical to global internet infrastructure,” said Takanobu Maeda, President and Chief Executive Officer, NTT Ltd. Japan Corporation. “This new subsea cable is the latest joint effort NTT has led in a long and proud history of providing reliable global internet infrastructure.”

Japan in particular, located midway between the US and key Asian markets, has played the important role of “Data Hub” in the Asia-Pacific region. As such, JUNO is expected to be an ideal addition to the undersea cable network and key to supporting the global internet backbone, and further growth in Asia-Pacific countries and worldwide.

JUNO, the new trans-Pacific submarine cable system, offers several unique benefits to customers:

  • It will introduce leading-edge SDM (Space Division Multiplexing) technology, enabling the provision of 20 optical fiber pairs (40 cores) per cable, (conventional technology currently provides a maximum of 16 fiber pairs or 32 cores).
  • It provides the maximum capacity of 350Tbps, the largest among any existing cable system between Japan and the US.
  • It offers high resiliency by connecting to two separate landing stations in between Japan and the US, providing additional security and resilience against any potential disturbances due to rough weather conditions, particularly along the coastal areas of Japan.
  • It provides flexibility, as JUNO can alter the amount of bandwidth to each branch route according to demand and in response to customers’ evolving requirements.

Seren will provide fast and reliable network services to global major global technology companies, OTTs, telecommunication carriers, etc. enabling them to strengthen the telecommunications environment in the US and Asia, through reliable and secure sales, operations and management support.

NTT has been at the centre of global internet infrastructure development and operations for many years with an instrumental role in several subsea cable projects, including JUPITER, MIST, ASE, APG, PC-1, APRICOT and now JUNO. JUNO is expected to begin operating at the end of 2024.

JUNO Summary

Cable name JUNO
Total Bandwidth Approximate 350Tbps (Preliminary design)
Total Distance Approximate 10,000km
Planned Landing site Japan (Chiba prefecture, Mie prefecture), US (CA)
Planned Ready for Service End of 2024