FEATURE
THE VALUE OF UNREPEATERED SYSTEMS IN REGIONAL SUBSEA CONNECTIVITY BY ANDERS LJUNG
U
nrepeatered cables play a crucial role in regional submarine connectivity, providing essential links that are both cost-effective and relatively simple to implement. Despite their importance, these systems have largely been overlooked within the industry. This oversight stems from their straightforward design and distance limitations, which have largely kept them under the radar compared to more complex repeatered systems. Nevertheless, unrepeatered links offer significant benefits, particularly when considering disaggregated supply models and their applications in various markets. This article aims to summarise the advantages of unrepeatered subsea cable systems, both technically, commercially and from an economic perspective.
HISTORICAL CONTEXT AND BASIC DESIGN
Unrepeatered links were among the first “Open Systems” in submarine cable technology, primarily due to their passive nature. Their design omits the need for power-feeding equipment and repeaters, resulting in simpler, more cost-effective systems. Typically, these systems connect neighbouring countries, regions, and islands, providing short pointto-point links that enhance international connectivity. They are often used for crossing harbours, rivers, and lakes, making them indispensable in regional contexts. The simplicity of their design allows unrepeatered systems to be procured in a disaggregated manner. This approach involves sourcing components from multiple suppliers, which can lead to reduced costs and increased
44 SUBMARINE TELECOMS FORUM MAGAZINE
flexibility. The lack of active components like repeaters means that unrepeatered cables are less complex to manage, further supporting the case for disaggregation.
APPLICATIONS IN VARIOUS MARKETS
Unrepeatered systems are not limited to traditional telecommunications. They are widely used in the oil and gas industry, offshore wind farms, and ocean observatories. These cables provide critical connectivity to and between offshore installations, offering telecoms paths that either integrate with power systems or function as separate outrider cables. In environments where high-power equipment is undesirable or impractical—such as oil platforms—unrepeatered systems offer a safer and more reliable alternative. For instance, in the oil and gas sector, the installation of repeaters near power cables can pose not insignificant risks, including electrical interference and complicated maintenance procedures. Unrepeatered cables eliminate these issues, providing a more straightforward and secure solution. Similarly, offshore wind farms benefit from the uncomplicated design of unrepeatered systems, which can be seamlessly integrated with power cables to deliver robust connectivity.
MARKET TRENDS AND DATA ANALYSIS
According to our internal sales data and market analysis, the number of installed unrepeatered links significantly exceeds publicly announced projects. We at Hexatronic estimate that for every announced system, approximately