Denmark-Sweden 18

Overview

Denmark-Sweden 18 is a submarine cable system that connects Denmark and Sweden across the Øresund strait, one of the narrowest and busiest sea passages in northern Europe. Operational since 1996, this cable provides a direct telecommunications link between the two neighboring Scandinavian nations. Its strategic location serves as a vital infrastructure component for cross-border connectivity, facilitating communication and data transfer in a region known for its strong economic and cultural ties.

The cable's short length reflects the compact geography of the Øresund strait, which separates Denmark's Zealand region from Sweden's Skåne province. Denmark-Sweden 18 plays an important role in ensuring reliable connectivity between these two countries, supporting both local and international telecommunications traffic in a densely interconnected part of Europe.

Route and Landings

Denmark-Sweden 18 spans the Øresund strait, landing at Helsingør in Denmark and Helsingborg in Sweden. Helsingør is situated at the northeastern tip of Zealand, Denmark's largest island, and marks the narrowest point of the strait. This coastal town is historically significant as a hub for maritime traffic and trade, making it an ideal location for the cable's Danish landing.

On the Swedish side, the cable lands at Helsingborg, a city directly opposite Helsingør on the western coast of Skåne. The two towns are separated by only a few kilometers of open water, making this one of the shortest submarine cable routes in the Nordic region. The proximity of the landing points reflects the practical geography of the Øresund, where minimal cable length is required to connect two well-established national networks. The route avoids deeper and more challenging waters, ensuring efficient installation and maintenance.

Ownership and History

Denmark-Sweden 18 is jointly owned by TDC Group and Telenor, two major telecommunications operators in Scandinavia. TDC Group is Denmark's leading telecom provider, while Telenor is headquartered in Norway and operates extensively across the region. This joint ownership underscores the bilateral importance of the cable, which serves as a shared infrastructure link for both Danish and Swedish networks.

The cable entered service in 1996, marking an early milestone in cross-border submarine connectivity between Denmark and Sweden. Its deployment predates many of the larger and more recent systems in the region, such as Havhingsten/North Sea Connect (2022) and Havfrue/AEC-2 (2020). Denmark-Sweden 18 remains a critical part of the Øresund corridor, which has since grown to include additional cables serving broader Scandinavian and international routes.

What Our Measurements Show

Our live monitoring of Denmark-Sweden 18 has measured the cable's performance along one corridor, with a best round-trip time (RTT) of 25 milliseconds and an average RTT of 25 milliseconds. These metrics indicate consistent and reliable latency for data transmission across the Øresund strait. The short distance between Helsingør and Helsingborg contributes to the cable's low latency, making it well-suited for high-speed communication and data exchange.

The cable's performance metrics align with its role as a direct and efficient link between Denmark and Sweden. By minimizing latency, Denmark-Sweden 18 supports seamless connectivity between the two countries, benefiting both local users and international traffic passing through this strategic route. The cable's stable operation over decades highlights its durability and effectiveness in serving the telecommunications needs of the region.