Muroran-Hachinohe: A Domestic Japanese Submarine Cable
The Muroran-Hachinohe submarine cable is a 280-kilometer telecom link connecting
Muroran and
Hachinohe, two cities in Japan. Owned by Softbank, this cable has been listed as in service since 2002 according to GeoCables database records. It is part of Japan's domestic submarine network, facilitating communication and data transfer between the islands of Hokkaido and Honshu.
What makes this cable particularly interesting is the limited publicly available data regarding its design capacity, fiber pair configuration, and supplier. While such details are often disclosed for larger transoceanic systems, domestic cables like Muroran-Hachinohe frequently operate with less visibility in the public domain. This lack of disclosure highlights the challenges in understanding the technical specifics of smaller-scale submarine cables.
Quick facts
| Name | Muroran-Hachinohe |
| Length | 280 km |
| Ready-for-service year | 2002 (GeoCables database value; no conflicting data surfaced) |
| Owner | Softbank |
| Status | In service |
| Design capacity | Not disclosed |
| Fiber pairs | Not disclosed |
| Supplier | Not disclosed |
| Landing points | Muroran (Japan), Hachinohe (Japan) |
| One-way latency (computed) | 1.4 ms |
| Theoretical RTT floor | 2.7 ms |
| Live measurements | None available |
🗺 Show Muroran-Hachinohe on the interactive cable map
Route
The Muroran-Hachinohe cable connects Muroran, located on the southern coast of Hokkaido, to Hachinohe, situated in northern Honshu. Both cities are important regional hubs, and the cable's route spans a relatively short distance of 280 kilometers across the Tsugaru Strait. This corridor is a critical geographic link between Japan's two largest islands, facilitating domestic communication and data exchange.
Why it was built and what it carries
The Muroran-Hachinohe cable was built to support the growing demand for domestic connectivity within Japan, particularly between Hokkaido and Honshu. Japan's dense population and advanced digital economy require reliable infrastructure for telecommunications, data transfer, and internet services. While specific details about the cable's design capacity and technology are not disclosed, it likely serves as a regional link for Softbank's operations, contributing to the broader Japanese telecom network.
History: what can be established
GeoCables records indicate that the Muroran-Hachinohe cable became ready for service in 2002. No conflicting information has surfaced regarding its commissioning year, making this date likely accurate. However, public sources provide little insight into the cable's development history, including its construction timeline, funding, or installation.
Softbank, the cable's owner, is a major telecom operator in Japan with a diverse portfolio of submarine and terrestrial networks. Its involvement suggests the cable plays a role in Softbank's domestic operations, but specifics about its strategic importance remain unclear without further documentation.
Capacity and technology
The design capacity, fiber pair count, and supplier for the Muroran-Hachinohe cable are not disclosed in public records, and attributing these details without operator documentation would be speculative. While larger transoceanic cables often boast capacities in the tens of terabits per second, domestic cables like Muroran-Hachinohe may operate at lower scales tailored to regional needs. Similarly, the technology used for signal amplification, such as repeaters, remains unconfirmed.
Latency: the physics
Based on the cable's length of 280 kilometers, one-way light propagation through fiber is approximately 1.4 milliseconds, assuming a speed of 200,000 to 204,000 kilometers per second in optical fiber. The theoretical round-trip time (RTT) for the wet segment is around 2.7 milliseconds.
However, real-world latency is typically higher due to additional factors such as land-based transmission, terminal equipment delays, and routing inefficiencies. Without live measurements, the actual end-to-end latency for traffic traversing the Muroran-Hachinohe cable cannot be precisely established.
Redundancy: what happens if it breaks
If the Muroran-Hachinohe cable experiences outages, redundancy within Japan's domestic submarine network would likely mitigate disruptions. Japan has an extensive network of submarine cables connecting its islands, and alternative routes across the Tsugaru Strait could provide backup connectivity. Repair logistics for a cable of this scale would follow standard industry practices, including the deployment of cable ships to locate and fix faults.
Bottom line
- The Muroran-Hachinohe cable is a domestic Japanese submarine system spanning 280 kilometers across the Tsugaru Strait.
- Owned by Softbank, it has been in service since 2002, with no conflicting data regarding its ready-for-service year.
- Key technical details, such as design capacity, fiber pairs, and supplier, are not disclosed in public records.
- Computed one-way latency is approximately 1.4 milliseconds, though real-world latency is higher.
- Japan's extensive domestic cable network provides redundancy in case of outages.