BCS North - Phase 2

BCS North - Phase 2: Arelion's Baltic Corridor

BCS North - Phase 2 is a submarine cable system owned by Arelion, connecting Helsinki and Kotka in Finland to Logi in Russia. Spanning 280 kilometers, it is part of the broader BCS North family, which includes Phase 1. The cable is listed as in service, with its ready-for-service (RFS) date recorded in GeoCables' database as 2000. However, public information about its design capacity, fiber pairs, supplier, and technology remains undisclosed. What makes BCS North - Phase 2 particularly interesting is its geographical placement within the Baltic Sea region, a hub for multiple submarine cables. The cable connects Finland and Russia, two countries with significant economic and geopolitical stakes in telecommunications. The corridor's redundancy is strengthened by numerous other cables landing in Helsinki and Kotka, although Logi's alternatives are less documented. Additionally, latency measurements from remote probes reveal the complexities of real-world internet routing, far exceeding the theoretical floor computed for the cable itself.

Quick facts

Name	BCS North - Phase 2
Length	280 km
Ready-for-Service Date	2000 (GeoCables database)
Owner	Arelion
Status	In service
Design Capacity	Not disclosed
Fiber Pairs	Not disclosed
Supplier	Not disclosed
Technology	Not disclosed
Landing Points	Helsinki (Finland), Kotka (Finland), Logi (Russia)

Show BCS North - Phase 2 on the interactive cable map

Route

BCS North - Phase 2 connects three landing points: Helsinki and Kotka in Finland, and Logi in Russia. Helsinki serves as a major hub for submarine cables in the Baltic Sea, hosting connections to Sweden, Estonia, and beyond. Kotka, located on Finland's southern coast, is also connected by the Eastern Light Sweden-Finland I cable. Logi, situated in Russia, is less documented in terms of alternative submarine cable connections. The route spans the Baltic Sea, a region characterized by shallow waters and a relatively stable seabed, which simplifies cable laying and maintenance compared to deeper oceanic environments. The cable's corridor supports data traffic between Finland and Russia, facilitating cross-border connectivity.

Why it was built and what it carries

BCS North - Phase 2 was likely constructed to enhance connectivity between Finland and Russia, supporting both commercial and residential internet traffic. The Baltic Sea region is a critical area for telecommunications, with numerous cables converging to support high-bandwidth demands. While specific details about the cable's design capacity and technology are not publicly available, it is reasonable to assume that it was built to accommodate growing data requirements at the time of its deployment.

History: what can be established

GeoCables records the cable's ready-for-service date as 2000. If alternative industry sources suggest a different year, this discrepancy could arise from delays in documentation, variations in definitions of "ready-for-service," or differences between the cable's physical completion and its operational status. Arelion, the owner, has not publicly disclosed further historical details about the cable's construction or upgrades.

Capacity and technology

Publicly available information does not disclose the design capacity, fiber pair count, supplier, or specific technology used in BCS North - Phase 2. Without operator documentation, attributing these parameters would be speculative. Given its deployment in 2000, it is likely that the cable uses optical fiber technology common at the time, but whether it has been upgraded since remains unknown.

Latency: the physics

The theoretical one-way latency for light propagation over the cable's 280 km wet segment is approximately 1.4 milliseconds, with a round-trip time (RTT) floor of 2.7 milliseconds. However, real-world latency measurements from GeoCables' remote probes show significantly higher values:

• Helsinki -> Logi: Minimum 9.7 ms, average 83.9 ms
• Logi -> Helsinki: Minimum 4.4 ms, average 55.5 ms

These discrepancies arise from additional factors such as land-based routing, terminal equipment, and internet path inefficiencies. For example, traffic between Minsk and Logi exhibits a minimum RTT of 21.5 ms, while connections from Tbilisi or Jerusalem show much higher latencies, reflecting the broader network topology.

Redundancy: what happens if it breaks

In the event of a failure, redundancy for BCS North - Phase 2 is supported by other cables landing in Helsinki, including Baltic Sea Submarine Cable, BCS North - Phase 1, and C-Lion1. Kotka has fewer alternatives, with Eastern Light Sweden-Finland I being the only documented cable. Logi's redundancy options are unclear, as no other cables are explicitly listed for this landing point. Repairing submarine cables typically involves deploying specialized vessels to locate, retrieve, and mend the damaged section. The Baltic Sea's relatively shallow waters facilitate such operations, reducing repair times compared to deeper oceanic environments.

Bottom line

• BCS North - Phase 2 spans 280 km, connecting Helsinki, Kotka, and Logi.
• Owned by Arelion, the cable is listed as in service, with an RFS date of 2000.
• Design capacity, fiber pairs, supplier, and technology are not publicly disclosed.
• Theoretical latency is 2.7 ms RTT, but real-world measurements are significantly higher.
• Redundancy is strong in Helsinki but less documented for Kotka and Logi.