Fiber Sensing Watches Undersea Power Cables
Grid operator TenneT is adopting ASN's distributed acoustic sensing software, a research-to-deployment step still in progress.
Updated on Nov. 3, 2026 in Cybersecurity
TenneT has signed a framework agreement with ASN to deploy distributed acoustic sensing for monitoring its subsea and buried power cables. The arrangement is described in the source as a signed agreement with implementation underway; no deployment figures beyond the technical specifications are reported.
Why it matters
Grid operators are looking to fiber-optic sensing to detect threats to undersea power links, such as seabed disturbances, before they cause outages. The move reflects a broader shift toward using existing optical fiber as a continuous sensor rather than relying solely on periodic inspection.
ASN's OptoDAS suite is specified with a gauge length adjustable from 2 m to 40 m in 1 m steps and a distortion-free reach of up to 150 km in standard optical fibre. The source presents these as product specifications and does not report field-measured performance against a baseline.
The players
TenneT
TenneT is a European grid operator that owns and manages high-voltage transmission networks, including undersea power cables.
ASN
ASN is a fiber-optic sensing company whose OptoDAS suite and Cable Threat Monitoring software are designed for distributed acoustic sensing on optical fibre.
The details
Distributed acoustic sensing treats a fibre-optic cable as a line of thousands of sensing points. ASN's OptoDAS suite sends long optical pulses into the fibre using frequency-swept interrogation, a method that varies the light's frequency over time so the returned signal can be resolved without sacrificing spatial resolution. The system's gauge length, the stretch of fibre averaged for each measurement, can be tuned to balance sensitivity and location precision. ASN's proprietary Cable Threat Monitoring software then interprets the returned signal to flag disturbances.
The Tech Race
Distributed acoustic sensing built on existing telecom-grade fibre is competing with dedicated seabed monitoring hardware and periodic survey methods. Vendors such as ASN are positioning software-defined fibre sensing as a lower-cost, continuously running alternative for critical undersea infrastructure.
Power customers are unlikely to see direct changes from this agreement, since the source gives no rollout timeline. Operators and engineers responsible for subsea cable maintenance are the group most affected as monitoring alerts begin to feed the TenneT operating center.
The takeaway
Watch for TenneT or ASN to disclose the scope and go-live date of the monitoring deployment, along with any detection performance data from real cables. Those figures would show whether fibre-based sensing can reliably separate genuine seabed threats from background noise.
Further reading
For broader context on how sensing and monitoring technologies protect critical networks, see our Cybersecurity coverage.
Source note: This article includes information reported by Thefastmode.
