Submarine Cable Sensing for Strategic Infrastructure Defense and Arctic Deployment.

A diver approaches a sensing fiber-optic submarine cable beneath the icy waters of the North Atlantic, as a rusting cargo ship floats above and a submarine lurks nearby. The cable’s radiant rings symbolize advanced sensing capabilities, detecting acoustic, seismic, and movement signals. Yet, its exposure also reveals the vulnerability of subsea infrastructure to tampering, espionage, and sabotage, especially in geopolitically tense regions like the Arctic.

WHY WE NEED VISIBILITY INTO SUBMARINE CABLE ACTIVITY.

We can’t protect what we can’t measure. Today, we are mostly blind concerning our global submarine communications networks. We cannot state with absolute certainty whether critical parts of this infrastructure are already compromised by capable hostile state actors ready to press the button at an appropriate time. If the global submarine cable network were to break down, so would the world order as we know it. Submarine cables form the “invisible” backbone of the global digital infrastructure, yet they remain highly vulnerable. Over 95% of intercontinental internet and data traffic traverses subsea cables (which is in the order of between 25% of the total internet traffic worldwide), but these critical assets lie largely unguarded on the ocean floor, exposed to environmental events, shipping activities, and increasingly, geopolitical interference.

In 2024 and early 2025, multiple high-profile incidents involving submarine cable damage have occurred, highlighting the fragility of undersea communication infrastructure in an increasingly unstable geopolitical environment. Several disruptions affected strategic submarine cable routes, raising concerns about sabotage, poor seamanship, and hybrid threats, particularly in sensitive maritime corridors (e.g., Baltic Sea, Taiwan Strait, Red Sea, etc.).

As also discussed in my recent article (“What lies beneath“), one of the most prominent cases of subsea cable cuts occurred November 2024 in the Baltic Sea, where two critical submarine cables, the East-West Interlink between Lithuania and Sweden, and the C-Lion1 cable between Finland and Germany, were damaged in close temporal and spatial proximity. The Chinese cargo vessel Yi Peng 3 was identified as having been in the vicinity during both incidents. During a Chinese-led probe, investigators from Sweden, Germany, Finland, and Denmark boarded the ship in early December. By March 2025, European officials expressed growing confidence that the breaks were accidental rather than acts of sabotage. In December 2025, and also in the Baltic Sea, the Estlink 2 submarine power cable and two telecommunications cables operated by Elisa were ruptured. The suspected culprit was the Eagle S, an oil tanker believed to be part of Russia’s “shadow fleet”, a group of poorly maintained vessels that emerged after Russia’s invasion of Ukraine to circumvent sanctions and transport goods covertly. These vessels are frequently operated by opportunists with little maritime training or seamanship, posing a growing risk to maritime-based infrastructure.

These recent incidents further emphasize the need for proactive monitoring or sensing tools applied to the submarine cable infrastructure. Today, more than 100 subsea cable outages are logged each year globally. Most are attributed to natural or unintentional human-related causes, including poor seamanship and even worse vessels. Moreover, Authorities have noted that, since Russia’s full-scale invasion of Ukraine in 2022, the use of a “ghost fleet” of vessels, often in barely seaworthy condition and operated by underqualified or loosely regulated crews, has grown substantially in scope. These ships, appearing also to be used for hybrid operations or covert missions, operate under minimal oversight, raising the risk of both deliberate interference and catastrophic negligence.

As detailed in my article “What lies beneath“, several particular cable break signatures may be “fingerprints” of hybrid or hostile interference signatures. This may include simultaneous localized cuts, unnatural uniform damage profiles, and activity in geostrategic cable chokepoints, traits that appear atypical of commercial maritime incidents. One notable pattern is the lack of conventional warning signals, e.g., no seismic precursors, known trawling vessels in the area, and rapid phase discontinuities captured in coherent signal traces of the few sensing equipment on submarine cables we have. Equally concerning is the geopolitical context. The Baltic Sea is a critical artery connecting Northern Europe’s cloud infrastructure. Taiwan’s subsea cables are vital to the global chip supply chain and financial systems. Disrupting these routes can create outsized geopolitical pressure, allowing the hostile actor to maintain plausible deniability..

Modern sensing technologies now offer a pathway to detect and characterize such disturbances. Research by Mazur et al. (OFC 2024) has demonstrated real-time anomaly detection across transatlantic submarine cable systems. Their methodology could spot small mechanical vibrations and sudden cable stresses that precede an optical cable failure. Such sensing systems can be retrofitted onto existing landing stations, enabling authorities or cable operations to issue early alerts for potential sabotage or environmental threats.

Furthermore, continuous monitoring allows real-time threat classification, differentiating between earthquake-triggered phase drift and artificial localized cuts. Combined with AI-enhanced analytics and (near) real-time AIS (Automatic Identification System) information, these sensing systems can serve as a digital tripwire along the seabed, transforming our ability to monitor and defend strategic infrastructure.

Without these capabilities, the subsea cable infrastructure landscape remains an operational blind spot, susceptible to exploitation in the next phase of global competition or geopolitical conflict. As threats evolve and hybrid tactics and actions increase, visibility into what lies beneath is advantageous and essential.

Illustration of a so-called Russian “ghost” vessel (e.g., bulk carrier) dragging its stern anchor through a subsea optical communications cable. It is an informal term that describes a Russian vessel operating covertly or suspiciously, often without broadcasting its identity or location using the Automatic Identification System (AIS), the global maritime safety protocol that civilian ships must use.

ISLANDS AT RISK: THE FRAGILE NETWORK BENEATH THE WAVES.

Submarine fiber-optic cables form the “invisible” backbone of global connectivity, silently transmitting over 95% of international data traffic beneath the world’s oceans (note: intercontinental data traffic represents ~25% of the worldwide data traffic). These subsea cables are essential for everyday internet access, cloud services, financial transactions (i.e., over 10 billion euros daily), critical infrastructure operations, emergency response coordination, and national security. Despite their importance, they are physically fragile, vulnerable to natural disruptions such as undersea earthquakes, volcanic activity, and ice movement, as well as to human causes like accidental trawling, ship anchor drags, and even deliberate sabotage. A single cut to a key cable can isolate entire regions or nations from the global network, disrupt trade and governance, and slow or sever international communication for days or weeks.

This fragility becomes even more acute when viewed through the lens of island nations and territories. The figure below presents a comparative snapshot of various islands across the globe, illustrating the number of international subsea cable connections each has (in blue bars), overlaid with the population size in millions (in orange). The disparity is striking: densely populated islands such as Taiwan, Sri Lanka, or Madagascar often rely on only a few cables, while smaller territories like Saint Helena or Gotland may have just a single connection to the rest of the world. These islands inherently depend on subsea infrastructure for access to digital services, economic stability, and international communication, yet many remain poorly connected or dangerously exposed to single points of failure. Some of these Islands may be less important from a global security, geopolitical context and a defense perspective. However, for the inhabitants of those islands, that of course will not matter much, and some islands are of critical importance to a safe and secure world order.

The chart below underscores a critical truth. Island connectivity is not just a matter of bandwidth or speed but a matter of resilience. For many of the world’s islands, a break in the cable doesn’t just slow the internet; it severs the lifeline. Every additional cable significantly reduces systemic risk. For example, going from two to three cables can cut expected unavailability by more than 60–80%, and moving from three to four cables supports near-continuous availability, which is now required for modern economies and national security.

The bar chart shows the number of subsea cable connections, while the orange line represents each island’s population (plotted on a log-scale), highlighting disparities between connectivity and population density.

Reducing systemic risk means lowering the chance that a single point of failure, or a small set of failures, can cause a complete system breakdown. In the context of subsea cable infrastructure, systemic risk refers to the vulnerability that arises when a country’s or island’s entire digital connectivity relies on just one or two physical links to the outside world. With only two international submarine cables connecting a given island in parallel, it would mean that it is deemed acceptable to have up to ~13 minutes of (a total service loss) downtime per year (note: for a single cable, that would be ~2 days per year). This should be compared to the time it may take to get the submarine cable repaired and operational again (after a cut), which may take weeks, or even months, depending on the circumstances and location. Adding a third submarine cable (parallel to the other two) reduces the maximum expected total loss of service to ~4 seconds per year. The likelihood that all 3 would be compromised by naturally occurring incidents would be very small (i.e., one in ten million). Relying on only two submarine cables for an island’s entire international connectivity, at bandwidth-critical scale, is a high-stakes gamble. While dual-cable redundancy may offer sufficient availability on paper, it fails to account for real-world risks such as correlated failures, extended repair times, and the escalating strategic value of uninterrupted digital access. This represents a technical fragility and a substantial security liability for an island economy and a digitally reliant society.

Suppose one cable is accidentally or deliberately damaged, with little or no redundancy. In that case, the entire system can collapse, cutting off internet access, disrupting communication, and halting financial and governmental operations. Reducing systemic risk involves increasing resilience through redundancy, ensuring the overall system continues functioning even if one or more cables fail. This also means not relying on only one type of connectivity, e.g., subsea cables or satellite. Still, combinations of different kinds of connectivity are incredibly important to safeguard continuous connectivity to the outside world from the perspective of an Island, even if alternative or backup connectivity does not match the capacity of the primary means of connectivity. Moreover, islands with relatively low populations tend to rely on one central terrestrial-based switching hub (e.g., typically at the central population hub), without much or meshed connectivity, exposing all communication on an island if such a hub becomes compromised.

Submarine cables are increasingly recognized as strategic targets in a hybrid warfare or full-scale military conflict scenario. Deliberate severance of these cables, particularly in chokepoints, near shore landing zones (i.e., landing stations), or cable branching points, can be a high-impact, low-visibility tactic to cripple communications without overt military action.

Going from two to three (or three to four) subsea cables may offer some strategic buffer. If an attacker compromises one or even two links, the third can preserve some level of connectivity, allowing essential communications, coordination, and early warning systems to remain operational. This may reduce the impact window for disruption and provide authorities time to respond or re-route traffic. However, it is unlikely to make a substantial difference in a conflict scenario, where a capable hostile actor may easily compromise a relatively low number of submarine cable connections. Moreover, if the terrestrial network is exposed to a single point of failure via a central switching hub design, having multiple subsea connections may matter very little in a crisis situation.

And, think about it, there is no absolute guarantee that the world’s critical subsea infrastructure has not already been compromised by hostile actors. In fact, given the strategic importance of submarine cables and the increasing sophistication of state and non-state actors in hybrid warfare, it appears entirely plausible that certain physical and cyber vulnerabilities have already been identified, mapped, or even covertly exploited.

In short, the absence of evidence is not evidence of absence. While major nations and alliances like NATO have increased efforts to monitor and secure subsea infrastructure, the sheer scale and opacity of the undersea environment mean that strategic surprise is still possible (maybe even likely). It is also worth remembering that most submarine cables operate in the dark in the historical and even present-day context. We rely on their redundancy and robustness, but we largely lack the sensory systems that allow us to proactively defend or observe them in real time.

This is what makes submarine cable sensing technologies such a strategic frontier today and why resilience, through redundancy, sensing technologies, and international cooperation, is critical. We may not be able to prevent every act of sabotage, but we can reduce the risk of catastrophic failure and improve our ability to detect and respond in real time.

THE LIKELY SUSPECTS – THE CAPABLE HOSTILE ACTOR SEEN FROM A WESTERN PERSPECTIVE.

As observed in the Western context, Russia and China are considered the most capable hostile actors in submarine cable sabotage. China is reportedly advancing its ability to conduct such operations at scale. These developments underscore the growing need for technological defenses and multilateral coordination to safeguard global digital infrastructure.

Several state actors possess the capability and potential intent to compromise or destroy submarine communications networks. Among them, Russia is perhaps the most openly scrutinized. Its specialized naval platforms, such as the Yantar-class intelligence ships and deep-diving submersibles like the AS-12 “Losharik”, can access cables on the ocean floor for tapping or cutting purposes. Western military officials have repeatedly raised concerns about Russia’s activities near undersea infrastructure. For example, NATO has warned of increased Russian naval activity near transatlantic cable routes, viewing this as a serious security risk impacting nearly a billion people across North America and Western Europe.

China is also widely regarded as a capable actor in this domain. The People’s Liberation Army Navy (PLAN) and a vast network of state-linked maritime engineering firms possess sophisticated underwater drones, survey vessels, and cable-laying ships. These assets allow for potential cable mapping, interception, or sabotage operations. Chinese maritime activity around strategic chokepoints such as the South China Sea has raised suspicions of dual-use missions under the guise of oceanographic research.

Furthermore, credible reports and analyses suggest that China is developing methods and technologies that could allow it to compromise subsea cable networks at scale. This includes experimental systems enabling simultaneous disruption or surveillance of multiple cables. According to Newsweek, recent Chinese patents may indicate that China has explored ways to “cut or manipulate undersea cables” as part of its broader strategy for information dominance.

Other states, such as North Korea and Iran, may not possess full deep-sea capabilities but remain threats to regional segments, particularly shallow water cables and landing stations. With its history of asymmetric tactics, North Korea could plausibly disrupt cable links to South Korea or Japan. Meanwhile, Iran may threaten Persian Gulf routes, especially during heightened conflict.

While non-state actors are not typically capable of attacking deep-sea infrastructure directly, they could be used by state proxies or engage in sabotage at cable landing sites. These actors may exploit the relative physical vulnerability of cable infrastructure near shorelines or in countries with less robust monitoring systems.

Finally, it is not unthinkable that NATO countries possess the technical means and operational experience to compromise submarine cables if required. However, their actions are typically constrained by strategic deterrence, international law, and alliance norms. In contrast, Russia and China are perceived as more likely to use these capabilities to project coercive power or achieve geopolitical disruption under a veil of plausible deniability.

WE CAN’T PROTECT WHAT WE CAN’T MEASURE – WHAT IS THE SENSE OF SENSING SUBMARINE CABLES?

In the context of submarine fiber-optic cable connections, it should be clear that we cannot protect this critical infrastructure if we are blind to the environment around it and along the cables themselves.

While traditionally designed for high-capacity telecommunications, submarine optical cables are increasingly recognized as dual-use assets, serving civil and defense purposes. When enhanced with distributed sensing technologies, these cables can act as persistent monitoring platforms, capable of detecting physical disturbances along the cable routes in (near) real time.

From a defense perspective, sensing-enabled subsea cables offer a discreet, infrastructure-integrated solution for maritime situational awareness. Technologies such as Distributed Acoustic Sensing (DAS), Coherent Optical Frequency Domain Reflectometry (C-OFDR), and State of Polarization (SOP) sensing can detect anomalies like trawling activity, anchor dragging, undersea vehicle movement, or cable tampering, especially in coastal zones or strategic chokepoints like the GIUK gap or Arctic straits. When paired with AI-driven classification algorithms, these systems can provide early-warning alerts for hybrid threats, such as sabotage or unregistered diver activity near sensitive installations.

For critical infrastructure protection, these technologies play an essential role in real-time monitoring of cable integrity. They can detect:

  • Gradual mechanical strain due to shifting seabed or ocean currents,
  • Seismic disturbances that may precede physical breaks,
  • Ice loading or iceberg impact events in polar regions.

These sensing systems also enable faster fault localization. While they are not likely to prevent a cable from being compromised, whether by accidental impact or deliberate sabotage, they dramatically reduce the time required to identify the problem’s location. In traditional submarine cable operations, pinpointing a break can take days, especially in deep or remote waters. With distributed sensing, operators can localize disturbances within meters along thousands of kilometers of cable, enabling faster dispatch of repair vessels, route reconfiguration, and traffic rerouting.

Moreover, sensing technologies that operate passively or without interrupting telecom traffic, such as SOP sensing or C-OFDR, are particularly well suited for retrofitting onto existing brownfield infrastructure or deployment on dual-use commercial-defense systems. They offer persistent, covert surveillance without consuming bandwidth or disrupting service, an advantage for national security stakeholders seeking scalable, non-invasive monitoring solutions. As such, they are emerging as a critical layer in the defense of underwater communications infrastructure and the broader maritime domain.

We should remember that no matter how advanced our monitoring systems are, they are unlikely to prevent submarine cables from being compromised by natural events like earthquakes and icebergs or unintentional and deliberate human activity such as trawling, anchor strikes, or sabotage. However, the sensing technologies offer the ability to detect and localize problems faster, enabling quicker response and mitigation.

TECHNOLOGY OVERVIEW: SUBMARINE CABLE SENSING.

Modern optical fiber sensing leverages the cable’s natural backscatter phenomena, such as Rayleigh, Brillouin, and Raman effects, to extract environmental data from a subsea communications cable. The physics of these effects is briefly described at the end of this article.

In the following, I will provide a comparative outline of the major sensing technologies in use today or may be deployed in future greenfield submarine fiber deployments. Each method has trade-offs in spatial or temporal resolution, compatibility with existing infrastructure, cost, and robustness to background noise. We will focus on defense applications in general applied to Arctic coastal environments, such as around Greenland. The relevance of each optical cable sensing technology described below to maritime defense will be summarized.

Some of the most promising sensing technologies today are based on the principles of Rayleigh scattering. For most sensing techniques, Rayleigh scattering is crucial in transforming standard optical cables into powerful sensor arrays without necessarily changing the physical cable structure. This makes it particularly valuable for submarine cable applications in the Arctic and strategic defense settings. By analyzing the light that bounces back from within the fiber, these systems can enable (near) real-time monitoring of intrusions or seismic activity over vast distances, spanning thousands of kilometers. Importantly, promising techniques are leverage Rayleigh scattering to function effectively even on legacy cable infrastructure, where installing additional reflectors would be impractical or uneconomical. Since Rayleigh-based sensing can be performed passively and non-invasively, it does not interfere with active data traffic, making it ideal for dual-use cables for communication and surveillance purposes. This approach offers a uniquely scalable and resilient way to enhance situational awareness and infrastructure defense in harsh or remote environments like the Arctic.

Before we get started on the various relevant sensing technologies let us briefly discuss what we mean by a sensing technology’s performance and its sensing capability, that is how well it can detect, localize, and classify physical disturbances, such as vibration, strain, acoustic pressure, or changes in light polarization, along a fiber-optic cable. The performance is typically judged by parameters like spatial resolution, detection range, sensitivity, signal-to-noise ratio, and the system’s ability to operate in noisy or variable environments. In the context of submarine detection, these disturbances are often caused by acoustic signals generated by vessel propulsion, machinery noise, or pressure waves from movement through the water. While the fiber does not measure sound pressure directly, it can detect the mechanical effects of those acoustic waves, such as tiny vibrations or refractive index changes in the surrounding seabed or cable sheath. The technologies we deploy have to be able to detect these vibrations as phase shifts in backscattered light. In contrast, other technologies may track subtle polarization changes induced by environmental stress on the subsea optical cables (as a result of an event in the proximity of the cable). A sensing system is considered effective when it can capture and resolve these indirect signatures of underwater activity with enough fidelity to enable actionable interpretation, especially in complex environments like coastal Arctic zones or the deep ocean.

In underwater acoustics, sound is measured in units of decibels relative to 1 micro Pascal, expressed as “dB re 1 µPa”, which defines a standard reference pressure level. The notation “dB re 1 µPa @ 1 m” refers to the sound pressure level of an underwater source, expressed in decibels relative to 1 micro Pascal and measured at a standard distance of one meter from the source. This metric quantifies how loud an object, such as a submarine, diver, or vessel, sounds when observed at close range, and is essential for modeling how sound propagates underwater and estimating detection ranges. In contrast, noise floor measurements use “dB re 1 µPa/√Hz,” which describes the distribution of background acoustic energy across frequencies, normalized per unit bandwidth. While source level describes how powerful a sound is at its origin, noise floor values indicate how easily such a sound could be detected in a given underwater environment.

Measurements are often normalized to bandwidth to assess sound or noise frequency characteristics, using “dB re 1 µPa/√Hz”. For example, stating a noise level of 90 dB re 1 µPa/√Hz in the 10 to 1000 Hz band means that within that frequency range, the acoustic energy is distributed at an average pressure level referenced per square root of Hertz. This normalization allows fair comparison of signals or noise across different sensing bandwidths. It helps determine whether a signal, such as a submarine’s acoustic signature, can be detected above the background noise floor. The effectiveness of a sensing technology is ultimately judged by whether it can resolve these types of signals with sufficient clarity and reliability for the specific use case.

In the mid-latitude Atlantic Ocean, typical noise floor levels range between 85 and 105 dB re 1 µPa/√Hz in the 10 to 1000 Hz frequency band. This environment is shaped by intense shipping traffic, consistent wave action, wind-generated surface noise, and biological sources such as whales. The noise levels are generally higher near busy shipping lanes and during storms, which raises the acoustic background and makes it more challenging to detect subtle events such as diver activity or low-signature submersibles (e.g., ballistic missile submarine, SSBN). In such settings, sensing techniques must operate with high signal-to-noise ratio thresholds, often requiring filtering or focusing on specific narrow frequency bands and enhanced by machine learning applications.

On the other hand, the Arctic coastal environment, such as the waters surrounding Greenland, is markedly quieter than, for example, the Atlantic Ocean. Here, the noise floor typically falls between 70 and 95 dB re 1 µPa/√Hz, and in winter, when sea ice covers the surface, it can drop even lower to around 60 dB. In these conditions, noise sources are limited to occasional vessel traffic, wind-driven surface activity, and natural phenomena such as glacial calving or ice cracking. The seasonal nature of Arctic noise patterns means that the acoustic environment is especially quiet and stable during winter, creating ideal conditions for detecting faint mechanical disturbances. This quiet background significantly improves the detectability of low-amplitude events, including the movement of stealth submarines, diver-based tampering, or UUV (i.e., unmanned underwater vehicles) activity.

Distributed Acoustic Sensing (DAS) uses phase-sensitive optical time-domain reflectometry (φ-OTDR) to detect acoustic vibrations and dynamic strain in general. Dynamic strain may arise from seismic waves or mechanical impacts along an optical fiber path. DAS allows for structural monitoring at a resolution of ca. 10 meters and a typical distance with amplification of 10 to 100 kilometers (can be extended by more amplifiers). It is an active sensor technology. DAS can be installed on shorter submarine cables (e.g., less than 100 km), although installing on a brownfield subsea cable is relatively complex. For long submarine cables (e.g., transatlantic), DAS would be greenfield deployed in conjunction with the subsea cable rollout, as retrofitting on an existing fiber installation would be impractical.

Phase-sensitive optical time domain reflectometry is a sensing technique that allows an optical fiber, like those used in subsea cables, to act like a long string of virtual microphones or vibration sensors. The method works by sending short pulses of laser light into the fiber and measuring the tiny reflections that bounce back due to natural imperfections inside the glass. When there is no activity near the cable, the backscattered light has a stable pattern. But when something happens near the cable, like a ship dragging an anchor, seismic shaking, or underwater movement, those vibrations cause tiny changes in the fiber’s shape. This physically stretches or compresses the fiber, changing the phase of the light traveling through it. φ-OTDR is specially designed to be sensitive to these phase changes. What is being detected, then, is not a “sound” per se, but a tiny change in the timing (phase) of the light as it reflects back. These phase shifts happen because mechanical energy from the outside world, like movement, stress, or pressure, slightly changes the length of the fiber or its refractive properties at specific points. φ-OTDR is ideal for detecting vibrations, like footsteps (yes, the technique also works on terra firma), vehicle movement, or anchor dragging. It is best suited for acoustic sensing over relatively long distances with moderate resolution.

So, in simple terms:

  • The “event” is not inside the fiber but in sufficient vicinity to cause a reaction in the fiber.
  • That external event causes micro-bending or stretching of the fiber.
  • The fiber cable’s mechanical deformation changes the phase of light that is then detected.
  • The sensing system uses these changes to pinpoint where along the fiber the event happened, often with meter-scale precision.

DAS has emerged as a powerful tool for transforming optical fibers into real-time acoustic sensor arrays, capable of detecting subtle mechanical disturbances such as vibrations, underwater movement, or seismic waves. While this capability is very attractive for defense and critical infrastructure monitoring, its application across existing long-haul subsea cables, particularly transoceanic systems, is severely constrained. The technology requires dark fibers or at least isolated, unused wavelengths, which are generally unavailable in (older) operational submarine systems already carrying high-capacity data traffic. Moreover, most legacy subsea cables were not designed with DAS compatibility in mind, lacking the bidirectional amplification or optical access points required to maintain sufficient signal integrity for acoustic sensing over long distances.

Retrofitting existing transatlantic or pan-Arctic submarine cables for DAS would be technically complex and, in most scenarios, likely economically unfeasible. These systems span thousands of kilometers, are deeply buried or armored along parts of their route, and incorporate in-line repeaters that do not support the backscattering reflection needed for DAS. As a result, implementing DAS across such long-haul infrastructure would entail replacing major cable components or deploying parallel sensing fibers. Both options may likely be inconsistent with the constraints of an already-deployed system. Suppose this kind of sensing capability is deemed strategically necessary. In that case, it may be operationally much less complex and more economical to deploy a greenfield cable with the embedded sensing technology, particularly for submarine cables that are 10 years old or older.

Despite these limitations, DAS offers significant potential for defense applications over shorter submarine segments, particularly near coastal landing points or within exclusive economic zones. One promising use case involves the Arctic and sub-Arctic regions surrounding Greenland. As geopolitical interest in the Arctic intensifies and ice-free seasons expand, the cables that connect Greenland to Iceland, Canada, and northern Europe will increasingly represent strategic infrastructure. DAS could be deployed along these shorter subsea spans, especially within fjords, around sensitive coastal bases, or in narrow straits, to monitor for hybrid threats such as diver incursions, submersible drones, or anchor dragging from unauthorized vessels. Greenland’s coastal cables often traverse relatively short distances without intermediate amplifiers and with accessible routes, making them more amenable to partial DAS coverage, especially if dark fiber pairs or access points exist at the landing stations.

The technology can be integrated into the infrastructure in a greenfield context, where new submarine cables are being designed and laid out. This includes reserving fiber strands exclusively for sensing, installing bidirectional optical amplifiers compatible with DAS, and incorporating coastal and Arctic-specific surveillance requirements into the architecture. For example, new Arctic subsea cables could be designed with DAS-enabled branches that extend into high-risk zones, allowing for passive real-time monitoring of marine activity without deploying sonar arrays or surface patrol assets (e.g., not actively communicate for example a ballistic missile submarine that it has been found as would have been the case with an active sonar).

DAS also supports geophysical and environmental sensing missions relevant to Arctic defense. When deployed along the Greenlandic shelf or near tectonic fault lines, DAS can contribute to early-warning systems for undersea earthquakes, landslides, or ice-shelf collapse events. These capabilities enhance environmental resilience and strengthen military situational awareness in a region where traditional sensing infrastructure is sparse.

DAS is best suited for detecting mid-to-high frequency acoustic energy, such as propeller cavitation or hull vibrations. However, stealth submarines may not produce strong enough vibrations to be detected unless they operate close to the fiber (e.g., <1 km) or in shallow water where coupling to the seabed is enhanced. Detection is plausible under favorable conditions but uncertain in deep-sea environments. However, in shallow Greenlandic coastal waters, DAS may detect a submarine’s acoustic wake, cavitation onset, or low-frequency hull vibrations, especially if the vessel passes within several hundred meters of the fiber.

Deploying φ-OTDR on brownfield submarine cables requires minimal infrastructure changes, as the sensing system can be installed directly at the landing station using a dedicated or wavelength-isolated fiber. However, its effective sensing range is limited to the segment between the landing station and the first in-line optical amplifier, typically around 80 to 100 kilometers. This limitation exists because standard submarine amplifiers are unidirectional and amplify the forward-traveling signal only. They do not support the return of backscattered light required by φ-OTDR, effectively cutting off sensing beyond the first repeater in brownfield systems. Even in a greenfield deployment, φ-OTDR is fundamentally constrained by weak backscatter, incoherent detection, poor long-distance SNR, and amplifier design, making it a technology mainly for coastal environments.

Coherent Optical Frequency Domain Reflectometry (C-OFDR) employs continuous-wave frequency-chirped laser probe signals and measures how the interference pattern (of the reflected light) changes (i.e., coherent detection). It offers high resolution (i.e., 100 -200 meters) and, for telecom-grade implementations, long-range sensing (i.e., 100s km), even over legacy submarine cables without Bragg gratings (i.e., period variation of the refractive index of the fiber). It is an active sensor technology. C-OFDR is one of the most promising techniques for high-resolution distributed sensing over long distances (e.g., transatlantic distances), and it can, in fact, be used on existing operational subsea cables without any special modifications to the cable itself, although with some practical considerations on older systems and limitations due to a reduced dynamic range. However, this sensing technology does require coherent detection systems with narrow-linewidth lasers and advanced DSP, which might make brownfield integration complex without significant upgrades. In contrast, greenfield deployments can seamlessly incorporate C-OFDR by leveraging the coherent optical infrastructure already standard in modern long-haul submarine cables. C-OFDR technique, like φ-OTDR, also relies on sensing changes in lights properties as it is reflected from imperfections in the fiber optical cable (i.e., Rayleigh backscattering). When something (an “event”) happens near the fiber, like the ground shakes from an earthquake, an anchor hits the seabed, or temperature changes, the optical fiber experiences microscopic stretching, squeezing, or vibration. These tiny changes affect how the light reflects back. Specifically, they change the phase and frequency of the returning signal. C-OFDR uses interferometry to measure these small differences very precisely. It is important to understand that the “event” we talk about is not inside the fiber, but its effects are causing changes to the fiber that can be measured by our chosen sensing technique. External forces (like pressure or motion) cause strain or stress in the glass fiber, which changes how the light moves inside. C-OFDR detects those changes and tells you where along the cable these changes happened, sometimes within a few centimeters.

Deploying C-OFDR on brownfield submarine cables is more challenging, as it typically requires more changes to the landing station, such as coherent transceivers with narrow-linewidth lasers and high-speed digital signal processing, which are normally not present in legacy landing stations. Even if such equipment is added at the landing station, like φ-OTDR, sensing may be limited to the segment up to the first in-line amplifier unless modified as shown in the work by Mazur et al.. C-OFDR, compared to φ-OTDR, leverages coherent receivers, DSP, and telecom-grade infrastructure to overcome those barriers, making C-OFDR a very relevant long-haul subsea cable sensing technology.

An interesting paper using a modified C-OFDR technique,  “Continuous Distributed Phase and Polarization Monitoring of Trans-Atlantic Submarine Fiber Optic Cable” by Mazur et al., demonstrates a powerful proof-of-concept for using existing long-haul submarine telecom cables, equipped with more than 70 amplifiers, for real-time environmental sensing without interrupting data transmission. The authors used a prototype system combining a fiber laser, FPGA (Field-Programmable Gate Array), and GPU (Graphical Processing Unit) to perform long-range optical frequency domain reflectometry (C-OFDR) over a 6,500 km transatlantic submarine cable. By measuring phase and polarization changes between repeaters, they successfully detected a 6.4 magnitude earthquake near Ferndale, California, showing the seismic wave propagating in real-time from the West Coast of the USA, across North America, and was eventually observed by Mazur et al. in the Atlantic Ocean. Furthermore, they demonstrated deep-sea temperature measurements by analyzing round-trip time variations along the full cable spans. The system operated for over two months without service interruptions, underscoring the feasibility of repurposing submarine cables as large-scale oceanic sensing arrays for geophysical and defense applications. Their system’s ability to monitor deep-sea environmental variations, such as temperature changes, contributes to situational awareness in remote oceanic regions like the Arctic or the Greenland-Iceland-UK (GIUK) Gap, areas of increasing strategic importance. It is worth noting that while the basic structure of the cable (in terms of span length and repeater placement) is standard for long-haul subsea cable systems, what sets this cable apart is the integration of a non-disruptive monitoring system that leverages existing infrastructure for advanced environmental sensing, a capability not found in most subsea systems deployed purely for telecom.

Furthermore, using C-OFDR and polarization-resolved sensing (SOP) without disrupting live telecommunications traffic provides a discreet means of monitoring infrastructure. This is particularly advantageous for covert surveillance of vital undersea routes. Finally, the system’s fine-grained phase and polarization diagnostics have the potential to detect disturbances such as anchor drags, unauthorized vessel movement, or cable tampering, activities that may indicate hybrid threats or espionage. These features position the technology as a promising enabler for real-time intelligence, surveillance, and reconnaissance (ISR) applications over existing subsea infrastructure.

C-OFDR is very sensitive over long distances and, when optimized with narrowband probing, may detect subtle refractive index changes caused by waterborne pressure variations. While more robust than DAS at long range, its ability to resolve weak, broadband submarine noise signatures remains speculative and would likely require AI-based classification. In Greenland, C-OFDR might be able to detect subtle pressure variations or cable stress caused by passing submarines, but only if the cable is close to the source.

Phase-based sensing, which φ-OTDR belongs to, is an active sensing technique that tracks the phase variation of optical signals for precise mechanical event detection. It requires narrow linewidth lasers and sensitive DSP algorithms. In phase-based sensing, we send very clean, stable light from a narrow-linewidth laser through the fiber cable. We then measure how the phase of that light changes as it travels. These phase shifts are incredibly sensitive to tiny movements, smaller than a wavelength of light. As discussed above, when the fiber is disturbed, even just a little, the light’s phase changes, which is what the system detects. This sensing technology offers a theoretical spatial resolution of 1 meter and is currently expected to be practical over distances less than 10 kilometers. In general, phase-based sensing is a broader class of fiber-optic sensing methods that detect optical phase changes caused by mechanical, thermal, or acoustic disturbances.

Phase-based sensing technologies detect sub-nanometer variations in the phase of light traveling through an optical fiber, offering exceptional sensitivity to mechanical disturbances such as vibrations or pressure waves. However, its practical application over the existing installed base of submarine cable infrastructure remains extremely limited. Some of the more advanced implementations are largely confined to laboratory settings due to the need for narrow-linewidth lasers, high-coherence probe sources, and low-noise environments. These conditions are difficult to achieve across real-world subsea spans, especially those with optical amplifiers and high traffic loads. These technical demands make retrofitting phase-based sensing onto operational subsea cables impractical, particularly given the complexity of accessing in-line repeaters and the susceptibility of phase measurements to environmental noise. Still, as the technology matures and can be adapted to tolerate noisy and lossy environments, it could enable ultra-fine detection of small-scale events such as underwater cutting tools, diver-induced vibrations, or fiber tampering attempts.

In a defense context, phase-based sensing might one day be used to monitor high-risk cable landings or militarized undersea chokepoints where detecting subtle mechanical signatures could provide an early warning of sabotage or surveillance activity. Its extraordinary resolution could also contribute to low-profile detection of seabed motion near sensitive naval installations. While not yet field-deployable at scale, it represents a promising frontier for future submarine sensing systems in strategic environments, typically in proximity to coastal areas.

Coherent MIMO Distributed Fiber Sensing (DFS) is another cutting-edge active sensing technique belonging to the phase-based sensing family that uses polarization-diverse probing for spatially-resolved sensing on deployed multi-core fibers (MCF), enabling robust, high-resolution environmental mapping. This technology remains currently limited to laboratory environments and controlled testbeds, as the widespread installed base of submarine cables does not use MCF and lacks the transceiver infrastructure required to support coherent MIMO interrogation. Retrofitting existing subsea systems with this capability would require complete replacement of the fiber plant, making it infeasible for legacy infrastructure, but potentially interesting for greenfield deployments.

Despite these limitations, the future application of Coherent MIMO DFS in defense contexts is compelling. Greenfield deployments, such as new Arctic cables or secure naval corridors, could enable real-time acoustic and mechanical activity mapping across multiple parallel cores, offering spatial resolution that rivals or exceeds existing sensing platforms. This level of precision could support the detection and classification of complex underwater threats, including stealth submersibles or distributed tampering attempts. With further development, it might also support wide-area surveillance grids embedded directly into the fiber infrastructure of critical sea lanes or military installations. While not deployable on today’s global cable networks, it represents a next-generation tool for submarine situational awareness in future defense-grade fiber systems.

State of Polarization (SOP) sensing technology detects changes in light polarization that allow sensing environmental disturbances to a submarine optical cable. It can be implemented passively using existing coherent transceivers and thus can be used on existing operational submarine cables. The SOP sensing technology does not offer spatial resolution by default. However, it has a very high temporal sensitivity on a millisecond level, allowing it to resolve temporally localized SOP anomalies that may often be precursors for a structurally compromised submarine cable. SOP sensing provides timely and actionable information even without pinpoint spatial resolution for applications like cable break prediction, anomaly detection, and hybrid threat alerts. However, if the temporal information can be mapped back to the compromised physical location within 10s of kilometers. The SOP sensing can cover up to 1000s of kilometers of a submarine system.

SOP sensing provides path-integrated information about mechanical stress or vibration. While it lacks spatial resolution, it could register anomalous polarization disturbances along Arctic cable routes that coincide with suspected submarine activity. Even global SOP anomalies may be suspicious in Greenland’s sparse traffic environment, but localizing the source would remain challenging. It is likely a technique that, combined with C-OFDR, would offer both a spatial and temporal picture that, in combination, could become a promising use case. SOP provides fast, passive temporal detection, while C-OFDR (or DAS) delivers spatial resolution and event classification. The combination may offer a more robust and operationally viable architecture for strategic subsea sensing, suitable for civilian and defense applications across existing and future cable systems.

Deploying SOP-based sensing on brownfield submarine cables requires no changes to the cable infrastructure, such as landing stations. It passively monitors changes in the state of polarization at the transceiver endpoints. However, this method does not provide spatial resolution and cannot localize events along the cable. It also does not rely on backscatter, and therefore its sensing capability is not limited by the presence of amplifiers, unlike φ-OTDR or C-OFDR. The limitation, instead, is that SOP sensing provides only a global, integrated signal over the entire fiber span, making it effective for detecting disturbances but not pinpointing their location.

Table: Performance characteristics of key optical fiber sensing technologies for subsea applications.
The table summarizes spatial resolution, operational range, minimum detectable sound levels, activation state, and compatibility with existing subsea cable infrastructure. Values reflect current best estimates and lab performance where applicable, highlighting trade-offs in detection sensitivity and deployment feasibility across sensing modalities. Range depends heavily on system design. While traditional C-OFDR typically operates over short ranges (<100 m), advanced variants using telecom-grade coherent receivers may extend reach to 100s of km at lower resolution. This table, as well as the text, considers the telecom-grade variant of C-OFDR.

Beyond the sensing technologies already discussed, such as DAS (including φ-OTDR), C-OFDR, SOP, and Coherent MIMO DFS, several additional, lesser-known sensing modalities can be deployed on or alongside submarine cables. These systems differ in physical mechanisms, deployment feasibility, and sensitivity, and while some remain experimental, others are used in niche environmental or energy-sector applications. Several of these have implications for defense-related detection scenarios, including submarine tracking, sabotage attempts, or unauthorized anchoring, particularly in strategically sensitive Arctic regions like Greenland’s West and East Coasts.

One such system is Brillouin-based distributed sensing, including Brillouin Optical Time Domain Analysis (BOTDA) and Brillouin Optical Time Domain Reflectometry (BOTDR). These methods operate by sending pulses down the fiber and analyzing the Brillouin frequency shift, which varies with temperature and strain. The spatial resolution is typically between 0.5 and 1 meter, and the sensing range can extend to 50 km under optimized conditions. The system’s strength is detecting slow-moving structural changes, such as seafloor deformation, tectonic strain, or sediment pressure buildup. However, because the Brillouin interaction is weak and slow to respond, it is poorly suited for real-time detection of fast or low-amplitude acoustic events like those produced by a stealth submarine or diver. Anchor dragging might be detected, but only if it results in significant, sustained strain in the cable. These systems could be modestly effective in shallow Arctic shelf environments, such as Greenland’s west coast, but they are not viable for real-time defense monitoring.

Another temperature-focused method is Raman-based distributed temperature sensing (DTS). This technique analyzes the ratio of Stokes and anti-Stokes backscatter to detect temperature changes along the fiber, with spatial resolution typically on the order of 1 meter and ranges up to 10–30 km. Raman DTS is widely used in the oil and gas industry for downhole monitoring, but is not optimized for dynamic or mechanical disturbances. It offers little utility in detecting diver activity, submarine motion, or anchor drag unless such events lead to secondary thermal effects. Furthermore, Raman DTS is unsuitable for detecting fast-moving threats like submarines or divers. It can detect slow thermal anomalies caused by prolonged contact, buried tampering devices, or gradual sediment buildup. Thus, it may serve as a background “health monitor” for defense-relevant subsea critical infrastructures. As its enabling mechanism is Raman scattering, which is even weaker than Rayleigh and Brillouin scattering, it is likely to make this sensor technology unsuitable for Arctic defense applications. Moreover, the cold and thermally stable Arctic seabed provides a limited dynamic range for temperature-induced sensing.

A more advanced but experimental method is optical frequency comb (OFC)-based sensing, which uses an ultra-stable frequency comb to probe changes in fiber length and strain with sub-picometer resolution. This offers unparalleled spatial granularity (down to millimeters) and could, in theory, detect subtle refractive index changes induced by acoustic coupling or mechanical perturbation. However, range is limited to short spans (<10 km), and implementation is complex and not yet field-viable. This technology might detect micro-vibrations from nearby submersibles or diver-induced strain signatures in a future defense-grade network, especially greenfield deployments in Arctic coastal corridors. The physical mechanism is interferometric phase detection, amplified by comb coherence and time-of-flight mapping. Frequency comb-based techniques could be the foundation for a next-generation submarine cable monitoring system, especially in greenfield defense-focused coastal deployments requiring excellent spatial resolution under variable environmental conditions. Unlike traditional reflectometry or phase sensing, the laser frequency comb should be able to maintain calibrated performance in fluctuating Arctic environments, where salinity and temperature affect refractive index dramatically, and therefore, a key benefit for Greenlandic and Arctic deployments.

Another emerging direction is Integrated Sensing and Communication (ISAC), where linear frequency-modulated sensing signals are embedded directly into the optical communication waveform. This approach avoids dedicated dark fiber and can achieve moderate spatial resolution (~100–500 meters) with ranges of up to 80 km using coherent receivers. ISAC has been proposed for simultaneous data transmission and distributed vibration sensing. In Arctic coastal areas, where telecom capacity may be underutilized and infrastructure redundancy is limited, ISAC could enable non-invasive monitoring of anchor strikes or structural cable disturbances. It may not detect quiet submarines unless direct coupling occurs, but it could potentially flag diver-based sabotage or hybrid threats that cause physical cable contact.

Lastly, hybrid systems combining external sensor pods, such as tethered hydrophones, magnetometers, or pressure sensors, with submarine cables are deployed in specialized ocean observatories (e.g., NEPTUNE Canada). These use the cable for power and telemetry and offer excellent sensitivity for detecting underwater acoustic and geophysical events. However, they require custom cable interfaces, increased power provisioning, and are not easily retrofitted to commercial or legacy submarine systems. In Arctic settings, such systems could offer unparalleled awareness of glacier calving, seismic activity, or vessel movement in chokepoints like the Kangertittivaq (i.e., Scoresby Sund) or the southern exit of Baffin Bay (i.e., Avannaata Imaa). The main limitation of hybrid systems lies in their cost and the need for local infrastructure support. The economics relative to such systems’ benefits requires careful consideration compared to more conventional maritime sensor architectures.

DEFENSE SCENARIOS OF CRITICAL SUBSEA CABLE INFRASTRUCTURE.

Submarine cable infrastructure is increasingly recognized as a medium for data transmission and a platform for environmental and security monitoring. With the integration of advanced optical sensing technologies, these cables can detect and interpret physical disturbances across vast underwater distances. This capability opens up new opportunities for national defense, situational awareness, and infrastructure resilience, particularly in coastal and Arctic regions where traditional surveillance assets are limited. The following section outlines how different sensing modalities, such as DAS, C-OFDR, SOP, and emerging MIMO DFS, can support key operational objectives ranging from seismic early warning to hybrid threat detection. Each scenario case reflects a unique combination of acoustic signature, environmental setting, and technological suitability.

  • Intrusion Detection: Detect tampering, trawling, or vehicle movement near cables in coastal zones.
  • Seismic Early Warning: Monitor undersea earthquakes with high fidelity, enabling early warning for tsunami-prone regions.
  • Cable Integrity Monitoring: Identify precursor events to fiber breaks and trigger alerts to reroute traffic or dispatch response teams.
  • Hybrid Threat Detection: Monitor signs of hybrid warfare activities such as sabotage or unauthorized seabed operations near strategic cables. This also includes anchor-dragging sounds.
  • Maritime Domain Awareness: Track vessel movement patterns in sensitive maritime zones using vibrations induced along shore-connected cable infrastructure.

Intrusion Detection involving trawling, tampering, or underwater vehicle movement near the cable is best addressed using Distributed Acoustic Sensing (DAS), especially on coastal Arctic subsea cables where environmental noise is lower and mechanical coupling between the cable and the seafloor is stronger. DAS can detect short-range, high-frequency mechanical disturbances from human activity. However, this is more challenging in the open ocean due to poor acoustic coupling and cable burial. Coherent Optical Frequency Domain Reflectometry (C-OFDR) combined with State of Polarization (SOP) sensing offers a more passive and feasible alternative in such environments. C-OFDR can detect strain anomalies and localized pressure effects, while SOP sensing can identify anomalous polarization drift patterns caused by motion or stress, even on live traffic-carrying fibers.

For Seismic Early Warning, phase-based sensing (including both φ-OTDR and C-OFDR) is well suited across coastal and oceanic deployments. These technologies detect low-frequency ground motion with high sensitivity and temporal resolution. Phase-based methods can sense teleseismic activity or tectonic shifts along the cable route in deep ocean environments. The advantage increases in the Arctic coastal zones due to low background noise and shallow deployment, enabling the detection of smaller regional seismic events. Additionally, SOP sensing, while not a primary seismic tool, can detect long-duration cable strain or polarization shifts during large quakes, offering a redundant sensing layer.

Combining C-OFDR and SOP sensing is most effective for Cable Integrity Monitoring, particularly for early detection of fiber stress, micro-bending, or fatigue before a break occurs. SOP sensing works especially well for long-haul ocean cables with live data traffic, where passive, non-intrusive monitoring is essential. C-OFDR is more sensitive to local strain patterns and can precisely locate deteriorating sections. In Arctic coastal cables, this combination enables operators to detect damage from ice scouring, sediment movement, or thermal stress due to permafrost dynamics.

Hybrid Threat Detection benefits most from high-resolution, multi-modal sensing, such as detecting sabotage or seabed tampering by divers or unmanned vehicles. Along coastal regions, including Greenland’s fjords, Coherent MIMO Distributed Fiber Sensing (DFS), although still in its early stages, shows great promise due to its ability to spatially resolve overlapping disturbance signatures across multiple cores or polarizations. DAS may also contribute to near-shore detection if acoustic coupling is sufficient. On ocean cables, SOP sensing fused with AI-based anomaly detection provides a stealthy, always-on layer of hybrid threat monitoring, especially when other modalities (e.g., sonar, patrols) are absent or infeasible.

Finally, DAS is effective along coastal fiber segments for Maritime Domain Awareness, particularly tracking vessel movement in sensitive Arctic corridors or near military installations. It detects the acoustic and vibrational signatures of passing vessels, anchor deployment, or underwater vehicle operation. These signatures can be classified using spectrogram-based AI models to differentiate between fishing boats, cargo vessels, or small submersibles. While unable to localize the event, SOP sensing can flag cumulative disturbances or repetitive mechanical interactions along the fiber. This use case becomes less practical in oceanic settings unless vessel activity occurs near cable landing zones or shallow fiber stretches.

These scenario considerations have been summarised in the Table below.

Table: Summarises of subsea sensing use cases and corresponding detection performance.
The table outlines representative sound power levels, optimal sensing technologies, environmental suitability, and estimated detection distances for key maritime and defense-related use cases. Detection range is inferred from typical source levels, local noise floors, and sensing system capabilities in Arctic coastal and oceanic environments.

LEGACY SUBSEA SENSING NETWORKS: SONOR SYSTEMS AND THEIR EVOLVING ROLE.

The observant reader might at this point feel (rightly) that I am totally ignoring the good old sonar (e.g., sound navigation and ranging), which has been around since World War I and is thus approximately 110 years old as a technology. In the Cold War era, at its height from the 1950s to the 1980s, sonar technology advanced further into the strategic domain. The United States and its allies developed large-scale systems like SOSUS (Sound Surveillance System) and SURTASS (Surveillance Towed Array Sensor System) to detect and monitor the growing fleet of Soviet nuclear submarines. These systems enabled long-range, continuous underwater surveillance, establishing sonar as a tactical tool and a key component of strategic deterrence and early warning architectures.

So, let us briefly look at Sonar as a defensive (and offensive) technology.

Undersea sensing as a cornerstone of naval strategy and maritime situational awareness; for example, see the account “66 Years of Undersea Surveillance” by Taddiken et al. Throughout the Cold War, the world’s major powers invested heavily in long-range underwater surveillance systems, especially passive and active sonar networks. These systems remain relevant today, providing persistent monitoring for submarine detection, anti-access/area denial operations, and undersea infrastructure protection.

Passive sonar systems detect acoustic signatures emitted by ships, submarines, and underwater seismic activity. These systems rely on the natural propagation of sound through water and are often favored for their stealth since they do not emit signals. Their operation is inherently covert. In contrast, active sonar transmits acoustic pulses and measures reflected signals to detect and range objects that might not produce detectable noise, such as quiet submarines or inert objects on the seafloor.

The most iconic example of a passive sonar network is the U.S. Navy’s Sound Surveillance System (SOSUS), initially deployed in the 1950s. SOSUS comprises a series of hydrophone arrays fixed to the ocean floor and connected by undersea cables to onshore processing stations. While much of SOSUS remains classified, its operational role continues today with mobile and advanced fixed networks under the Integrated Undersea Surveillance System (IUSS). Other nations have developed analogous capabilities, including Russia’s MGK-series networks, China’s emerging Great Undersea Wall system, and France’s SLAMS network. These systems offer broad area acoustic coverage, especially in strategic chokepoints like the GIUK (Greenland-Iceland-UK) gap and the South China Sea.

Despite sonar’s historical and operational value, traditional sonar networks have significant limitations. Passive sonar is susceptible to acoustic masking by oceanic noise and may struggle to detect vessels employing acoustic stealth technologies. Active sonar, while more precise, risks disclosing its location to adversaries due to its emitted signals. Furthermore, sonar performance is constrained by water conditions, salinity, temperature gradients, and depth, affecting acoustic propagation. Additionally, sonar coverage is inherently sparse and highly dependent on the geographical layout of sensor arrays and underwater topology. Furthermore, deployment and maintenance of sonar arrays are logistically complex and costly, often requiring naval support or undersea construction assets. These limitations suggest a decreasing standalone effectiveness of sonar systems in high-resolution detection, mainly as adversaries develop quieter and more agile underwater vehicles.

This table summarizes key sonar technologies used in naval and infrastructure surveillance, highlighting typical unit spacing, effective coverage radius, and operational notes for systems ranging from deep-ocean fixed arrays (SOSUS/IUSS) to mobile and nearshore defense systems.

Think of sonar as a radar for the sea, sensing outward into the subsea environment. Due to sound propagation characteristics (i.e., in water sound travels more than 4 times faster and attenuates very slowly compared to sound waves in air), sonar is an ideal technology for submarine detection and seismic monitoring. In contrast, optical sensing in subsea cables is like a tripwire or seismograph, detecting anything that physically touches, moves, or perturbs the cable along its length. The emergence of distributed sensing over fiber optics has introduced a transformative approach to undersea and terrestrial monitoring. Distributed Acoustic Sensing (DAS), Distributed Fiber Sensing (DFS), and Coherent Optical Frequency Domain Reflectometry (C-OFDR) leverage the existing footprint of submarine telecommunications infrastructure to detect environmental disturbances, including vibrations, seismic activity, and human interaction with cables, at high spatial and temporal resolution. Unlike traditional sonar, these fiber-based systems do not rely on acoustic wave propagation in water but instead monitor the optical fiber’s phase, strain, or polarization variations. So, very simple sonar uses acoustics to sense sound waves in water, while fiber-based sensing is based on optics and how lights travel in an optical fiber. When embedded in submarine cables, such sensing techniques allow for continuous, covert, and high-resolution surveillance of the cable’s immediate environment, including detection of trawler interactions, anchor dragging, subsea landslides, and localized mechanical disturbances. They operate within the optical transmission spectrum without interrupting the core data service. While sonar systems excel at broad ocean surveillance and object tracking, their coverage is limited to specific regions and depths where arrays are installed. Conversely, fiber-based sensing offers persistent surveillance along entire transoceanic links, albeit restricted to the immediate vicinity of the cable path. Together, these systems should not be seen as competitors but very much complementary tools. Sonar covers the strategic expanse, while fiber-optic sensing provides fine-grained visibility where infrastructure resides.

This table contrasts traditional active and passive sonar networks with emerging fiber-integrated sensing systems (e.g., DAS, DFS, and C-OFDR) across key operational dimensions, including detection medium, infrastructure, spatial resolution, and security characteristics. It highlights the complementary strengths of each technology for undersea surveillance and strategic infrastructure monitoring.

The future of sonar sensing lies in hybridization and adaptive intelligence. Ongoing research explores networks that combine passive sonar arrays with intelligent edge processing using AI/ML to discriminate between ambient and threat signatures. There is also a push to integrate mobile platforms, such as Unmanned Underwater Vehicles (UUVs), into sonar meshes, expanding spatial coverage dynamically based on threat assessments. Material advances may also lead to miniaturized or modular hydrophone systems that can be ad hoc or embedded into multipurpose seafloor assets. Some navies are exploring Acoustic Vector Sensors (AVS), which can detect the pressure and direction of incoming sound waves, offering a richer data set for tracking and identification. Coupled with improvements in real-time ocean modeling and environmental acoustics, these future sonar systems may offer higher fidelity detection even in shallow and complex coastal waters where passive sensors are less effective. Moreover, integration with optical fiber systems is an area of active development. Some proposals suggest co-locating acoustic sensors with fiber sensing nodes or utilizing fiber backhaul for sonar telemetry in real-time, thereby merging the benefits of both approaches into a coherent undersea surveillance architecture.

THE ARCTIC DEPLOYMENT CONCEPT.

As global power competition extends into the Arctic, military planners and analysts are increasingly concerned about the growing strategic role of Greenland’s coastal waters, particularly in the context of Russian nuclear submarine operations. For decades, Russia has maintained a doctrine of deploying ballistic missile submarines (SSBNs) capable of launching nuclear retaliation strikes from stealth positions in remote ocean zones. Once naturally shielded by persistent sea ice, the Arctic has become more navigable due to climate change, creating new opportunities for submerged access to maritime corridors and concealment zones.

Historically, Russian submarines seeking proximity to U.S. and NATO targets would patrol areas along the Greenland-Iceland-UK (GIUK) gap and the eastern coast of Greenland, using the remoteness and challenging acoustic environment to remain hidden. However, strategic speculation and evolving threat assessments now suggest a westward shift, toward the sparsely monitored Greenlandic West Coast. This region offers even greater stealth potential due to limited surveillance infrastructure, complex fjord geography, and weaker sensor coverage than traditional GIUK chokepoints. Submarines could strike the U.S. East Coast from these waters in under 15 minutes, leveraging geographic proximity and acoustic ambiguity. Even if the difference in warning time would be no more than about 2–4 minutes depending on launch angle, trajectory, and detection latency, in the context of strategic warning systems and nuclear command and control, the loss of several minutes of additional reaction time can matter significantly, especially for early-warning systems, evacuation orders, or launch-on-warning decisions.

U.S. and Canadian defense communities have increasingly voiced concern over this evolving threat. U.S. Navy leadership, including Vice Admiral Andrew Lewis, has warned that the U.S. East Coast is “no longer a sanctuary,” underscoring the return of great power maritime competition and the pressing need for situational awareness even in home waters. As Russia modernizes its submarine fleet with quieter propulsion and longer-range missiles, its ability to hide near strategic seams like Greenland becomes a direct vulnerability to North American security.

This emerging risk makes the case for integrating advanced sensing capabilities into subsea cable infrastructure across Greenland and the broader Arctic theatre. Cable-based sensing technologies, such as Distributed Acoustic Sensing (DAS) and State of Polarization (SOP) monitoring, could dramatically enhance NATO’s ability to detect anomalous underwater activity, particularly in the fjords and shallow coastal regions of Greenland’s western seaboard. In a region where traditional sonar and surface surveillance are limited by ice, darkness, and remoteness, the subsea cable system could become an invisible tripwire, transforming Greenland’s digital arteries into dual-use defense assets.

Therefore, advanced sensing technologies should not be treated as optional add-ons but as foundational elements of Greenland’s Arctic defense architecture. Particular technologies that can work well and are relatively uncomplicated to operationalize on brownfield subsea cable installations. These would offer a critical layer of redundancy, early warning, and environmental insight, capabilities uniquely suited to the high north’s emerging strategic and climatic realities.

The Arctic Deployment Concept outlines a forward-looking strategy to integrate submarine cable sensing technologies into the defense and intelligence infrastructure of the Arctic region, particularly Greenland, as geopolitical tensions and environmental instability intensify. Greenland’s strategic location at the North Atlantic and Arctic Ocean intersection makes it a critical node in transatlantic communications and military situational awareness. As climate change opens new maritime passages and exposes previously ice-locked areas, the region becomes increasingly vulnerable, not only to environmental hazards like shifting ice masses and undersea seismic activity, but also to the growing risks of geopolitical friction, cyber operations, and hybrid threats targeting critical infrastructure.

In this context, sensing-enhanced submarine cables offer a dual-use advantage: they carry data traffic and serve as real-time monitoring assets, effectively transforming passive infrastructure into a distributed sensor network. These capabilities are especially vital in Greenland, where terrestrial sensing is sparse, the weather is extreme, and response times are long due to the remoteness of the terrain. By embedding Distributed Acoustic Sensing (DAS), Coherent Optical Frequency Domain Reflectometry (C-OFDR), and State of Polarization (SOP) sensing along cable routes, operators can monitor for ice scouring, tectonic activity, tampering, or submarine presence in near real time.

This chart illustrates the Greenlandic telecommunications provider Tusass’s infrastructure (among other things). Note that Tussas is the incumbent and only telecom provider in Greenland. Currently, five hydropower plants (shown above; location is only indicative) provide more than 80% of Greenland’s electricity demand. Greenland’s new international airport became operational in Nuuk in November 2024. Source: from the Tusass Annual Report 2023 with some additions and minor edits.

As emphasized in the article “Greenland: Navigating Security and Critical Infrastructure in the Arctic”, Greenland is not only a logistical hub for NATO but also home to increasingly digitalized civilian systems. This dual-use nature of Arctic subsea cables underscores the need for resilient, secure, and monitored communications infrastructure. Given the proximity of Greenland to the GIUK gap, a historic naval choke point between Greenland, Iceland, and the UK, any interruption or undetected breach in subsea connectivity here could undermine both civilian continuity and allied military posture in the region.

Moreover, the cable infrastructure along Greenland’s coastline, connecting remote settlements, research stations, and defense assets, is highly linear and often exposed to physical threats from shifting icebergs, seabed movement, or vessel anchoring. These shallow, coastal environments are ideally suited for sensing deployments, where good coupling between the fiber and the seabed enables effective detection of local activity. Integrating sensing technologies here supports ISR (i.e., Intelligence, Surveillance, and Reconnaissance) and predictive maintenance. It extends domain awareness into remote fjords and ice-prone straits where traditional radar or sonar systems may be ineffective or cost-prohibitive.

The map of Greenland’s telecommunications infrastructure provides a powerful visual framework for understanding how sensing capabilities could be integrated into the nation’s subsea cable system to enhance strategic awareness and defense. The western coastline, where the majority of Greenland’s population resides (~35%) and where the main subsea cable infrastructure runs, offers an ideal geographic setting for deploying cable-integrated sensing technologies. The submarine cable routes from Nanortalik in the south to Upernavik in the north connect critical civilian hubs such as Nuuk, Ilulissat, and Qaqortoq, while simultaneously passing near U.S. military installations like Pituffik Space Base. While essential for digital connectivity, this infrastructure also represents a strategic vulnerability if left unsensed and unprotected.

Given that Russian nuclear-powered submarines (e.g., SSBMs) are suspected of operating closer to the Greenlandic coastline, shifting from the historical GIUK gap to potentially less monitored regions along the west, Greenland’s cable network could be transformed into an invisible perimeter sensor array. Technologies such as Distributed Acoustic Sensing (DAS) and State of Polarization (SOP) monitoring could be layered onto the existing fiber without disrupting data traffic. These technologies would allow authorities to detect minute vibrations from nearby vessel movement or unauthorized subsea activity, and to monitor for seismic shifts or environmental anomalies like iceberg scouring.

The map above shows the submarine cable backbone, microwave-chain sites, and satellite ground stations. If integrated, these components could act as hybrid communication-and-sensing relay points, particularly in remote locations like Qaanaaq or Tasiilaq, further extending domain awareness into previously unmonitored fjords and inlets. The location of the new international airport in Nuuk, combined with Nuuk’s proximity to hydropower and a local datacenter, also suggests that the capital could serve as a national hub for submarine cable-based surveillance and anomaly detection processing.

Much of this could be operationalized using existing infrastructure with minimal intrusion (at least in the proximity of Greenland’s coastline). Brownfield sensing upgrades, mainly using coherent transceiver-based SOP methods or in-line C-OFDR reflectometry, may be implemented on live cable systems, allowing Greenland’s existing communications network to become a passive tripwire for submarine activity and other hybrid threats. This way, the infrastructure shown on the map could evolve into a dual-use defense asset, vital in securing Greenland’s civilian connectivity and NATO’s northern maritime flank.

POLICY AND OPERATIONAL CONSIDERATIONS.

As discussed previously, today, we are essentially blind to what happens to our submarine infrastructure, which carries over 95% of the world’s intercontinental internet traffic and supports more than 10 trillion euros daily in financial transactions. This incredibly important global submarine communications network was taken for granted for a long time, almost like a deploy-and-forget infrastructure. It is worthwhile to remember that we cannot protect what we cannot measure.

Arctic submarine cable sensing is as much a policy and sourcing question as a technical one. The integration of sensing platforms should follow a modular, standards-aligned approach, supported by international cooperation, robust cybersecurity measures, and operational readiness for Arctic conditions. If implemented strategically, these systems can offer enhanced resilience and a model for dual-use infrastructure governance in the digital age.

As Arctic geostrategic relevance increases due to climate change, geopolitical power rivalry, and the expansion of digital critical infrastructure, submarine cable sensing has emerged as both a technological opportunity and a governance challenge. The deployment of sensing techniques such as State of Polarization (SOP) monitoring and Coherent Optical Frequency Domain Reflectometry (C-OFDR) offers the potential to transform traditionally passive infrastructure into active, real-time monitoring platforms. However, realizing this vision in the Arctic, particularly for Greenlandic and trans-Arctic cable systems, requires a careful approach to policy, interoperability, sourcing, and operational governance.

One of the key operational advantages of SOP-based sensing is that it allows for continuous, passive monitoring of subsea cables without consuming bandwidth or disrupting live traffic​. When analyzed using AI-enhanced models, SOP fluctuations provide a low-impact way to detect seismic activity, cable tampering, or trawling events. This makes SOP a highly viable candidate for brownfield deployments in the Arctic, where live traffic-carrying cables traverse vulnerable and logistically challenging environments. Similarly, C-OFDR, while slightly more complex in deployment, has been demonstrated in real-world conditions on transatlantic cables, offering precise localization of environmental disturbances using coherent interferometry without the need for added reflectors​.

From a policy standpoint, Arctic submarine sensing intersects with civil, commercial, and defense domains, making multinational coordination essential. Organizations such as NATO, NORDEFCO (Nordic Defence Cooperation), and the Arctic Council must harmonize protocols for sensor data sharing, event attribution, and incident response. While SOP and C-OFDR generate valuable geophysical and security-relevant data, questions remain about how such data can be lawfully shared across borders, especially when detected anomalies may involve classified infrastructure or foreign-flagged vessels.

Moreover, integration with software-defined networking and centralized control planes can enable rapid traffic rerouting when anomalies are detected, improving resilience against natural or intentional disruptions. This also requires technical readiness in Greenlandic and Nordic telecom systems, many of which are evolving toward open architectures but may still depend on legacy switching hubs vulnerable to single points of failure.

Sensory compatibility and strategic trust must guide the acquisition and sourcing of sensing systems. Vendors like Nokia Bell Labs, which developed AI-based SOP anomaly detection models, have demonstrated in-band sensing on submarine networks without service degradation. A sourcing team may want to ensure that due diligence is done on the foundational models and that high-risk countries or vendors have not compromised their origin. I would recommend that sourcing teams follow the European Union’s 5G security framework as guidance in selecting the algorithmic solution, ensuring that no high-risk vendor/country has been involved at any point in the model development, training, or operational aspects of inferences and updates that are involved in applications of such models. By the way, it might be a very good and safe idea to extend this principle to the submarine cable construction and repair industry (just saying!).

When sourcing such systems, governments and operators should prioritize:

  • Proven compatibility with coherent transceiver infrastructure (i.e., brownfield submarine cable installations). Needless to say, solutions are tested before final sourcing (e.g., PoC).
  • Supplier alignment with NATO or Nordic/Arctic security frameworks. At a minimum, guidance should be taken from the EU 5G security framework and its approach to high-risk vendors and countries.
  • Firmware and AI models need clear IP ownership and cybersecurity compliance. Needless to say, the foundational models must originate from trusted companies and markets.
  • Inclusion of post-deployment support in Arctic (and beyond Arctic) operational conditions.

It cannot be emphasized enough that not all sensing systems are equally suitable for long-haul submarine cable stretches, such as transatlantic routes. Different sensing strategies may be required for the same subsea cable at different cable parts or spans (e.g., the bottom of the Atlantic Ocean vs coastal areas or proximity). A hybrid sensing approach is often more effective than a single solution. The physical length, signal attenuation, repeater spacing, and bandwidth constraints inherent to long-haul cables introduce technical limitations that influence which sensing techniques are viable and scalable.

For example, φ-OTDR (phase-sensitive OTDR) and standard DAS techniques, while powerful for acoustic sensing on terrestrial or coastal cables, face significant challenges over ultra-long distances due to signal loss and diminishing signal-to-noise ratio. These methods typically require access to dark fiber and may struggle to operate effectively across repeated links or when deployed mid-span across thousands of kilometers without amplification. Contrastingly, techniques like State of Polarization (SOP) sensing and Coherent Optical Frequency Domain Reflectometry (C-OFDR) have demonstrated strong potential for brownfield integration on transoceanic cables. SOP sensing can operate passively on live, traffic-carrying fibers and has been successfully demonstrated over 6,500 km transatlantic spans without an invasive retrofit​. Similarly, C-OFDR, particularly in its in-line coherent implementation, can leverage existing coherent transceivers and loop-back paths to perform long-range distributed sensing across legacy infrastructure..

This leads to the reasonable conclusion that a mix of sensing technologies tailored to cable type, length, environment, and use case is appropriate and necessary. For example, coastal or Arctic shelf cables may benefit more from high-resolution φ-OTDR/DAS deployments. In contrast, transoceanic cables call for SOP, or C-OFDR-based systems compatible with repeated, live traffic environments. This modular, multi-modal approach ensures maximum coverage, resilience, and relevance, especially as sensing is extended across greenfield and brownfield deployments.

Thus, hybrid sensing architectures are emerging as a best practice, with each technique contributing unique strengths toward a comprehensive monitoring and defense capability for critical submarine infrastructure.

Last but not least, cybersecurity and signal integrity protections are critical. Sensor platforms that generate real-time alerts must include spoofing detection, data authentication, and secured telemetry channels to prevent manipulation or false alarms. SOP sensing, for instance, may be vulnerable to polarization spoofing unless validated against multi-parameter baselines, such as concurrent C-OFDR strain signatures or external ISR (i.e., Intelligence, Surveillance, and Reconnaissance) inputs.

CONCLUSION AND RECOMMENDATION.

Submarine cables are indispensable for global connectivity, transmitting over 95% of international internet traffic, yet they remain primarily unmonitored and physically vulnerable. Recent events and geopolitical tensions reveal that hostile actors could target this infrastructure with plausible deniability, especially in regions with low surveillance like the Arctic. As described in this article, enhanced sensing technologies, such as DAS, SOP, and C-OFDR, can provide real-time awareness and threat detection, transforming passive infrastructure into active security assets. This is particularly urgent for islands and Arctic regions like Greenland, where fragile cable networks (in the sense of few independent international connections) represent single points of failure.

Key Considerations:

  • Submarine cables are strategic, yet “blind & deaf” infrastructures.
    Despite carrying the majority of global internet and financial data, most cables lack embedded sensing capabilities, leaving them vulnerable to natural and hybrid threats. This is especially true in the Arctic and island regions with minimal redundancy.
  • Recent hybrid threat patterns reinforce the need for monitoring.
    Cases like the 2024–2025 Baltic and Taiwan cable incidents show patterns (e.g., clean cuts, sudden phase shifts) that may be consistent with deliberate interference. These events demonstrate how undetected tampering can have immediate national and global impacts.
  • The Arctic is both a strategic and environmental hotspot.
    Melting sea ice has made the region more accessible to submarines and sabotage, while Greenland’s cables are often shallow, unprotected, and linked to critical NATO and civilian installations. Integrating sensing capabilities here is urgent.
  • Sensing systems enable early warning and reduce repair times.
    Technologies like SOP and C-OFDR can be applied to existing (brownfield) subsea systems without disrupting live traffic. This allows for anomaly detection, seismic monitoring, and rapid localization of cable faults, cutting response times from days to minutes.
  • Hybrid sensing systems and international cooperation are essential.
    No single sensing technology fits all submarine environments. The most effective strategy for resilience and defense involves combining multiple modalities tailored to cable type, geography, and threat level while ensuring trusted procurement and governance.
  • Relying on only one or two submarine cables for an island’s entire international connectivity at a bandwidth-critical scale is a high-stakes gamble. For example, a dual-cable redundancy may offer sufficient availability on paper. However, it fails to account for real-world risks such as correlated failures, extended repair times, and the escalating strategic value of uninterrupted digital access.
  • Quantity doesn’t matter for capable hostile actors: for a capable hostile actor, whether a country or region has two, three, or a handful of international submarine cables is unlikely to matter in terms of compromising those critical infrastructure assets.

In addition to the key conclusions above, there is a common belief that expanding the number of international submarine cables from two to three or three to four offers meaningful protection against deliberate sabotage by hostile state actors. While intuitively appealing, this notion underestimates a determined adversary’s intent and capability. For a capable actor, targeting an additional one or two cables is unlikely to pose a serious operational challenge. If the goal is disruption or coercion, a capable adversary will likely plan for multi-point compromise from the outset (including landing station considerations).

However, what cannot be overstated is the resilience gained through additional, physically distinct (parallel) cable systems. Moving from two to three truly diverse and independently repairable cables improves system availability by a factor of roughly 200, reducing expected downtime from over hours per year to under one minute. Expanding to four cables can reduce expected downtime to mere seconds annually. These figures reflect statistical robustness and operational continuity in the face of failure. Yet availability alone is not enough. Submarine cable repair timelines remain long, stretching from weeks to months, even under favorable conditions. And while natural disruptions are significant, they are no longer our only concern. Undersea infrastructure has become a deliberate target in hybrid and kinetic conflict scenarios in today’s geopolitical climate. The most pressing threat is not that these cables might be compromised, but that they may already be; we are simply unaware. The undersea domain is poorly monitored, poorly defended, and rich in asymmetric leverage.

Submarine cable infrastructure is not just the backbone of global digital connectivity. It is also a strategic asset with profound implications for civil society and national defense. The reliance on subsea cables for internet access, financial transactions, and governmental coordination is absolute. Satellite-based communications networks can only carry an infinitesimal amount of the traffic carried by subsea cable networks. If the global submarine cable network were to break down, so would the world order as we know it. Integrating advanced sensing technologies such as SOP, DAS, and C-OFDR into these networks transforms them from passive conduits into dynamic surveillance and monitoring systems. This dual-use capability enables faster fault detection and enhanced resilience for civilian communication systems, but also supports situational awareness, early-warning detection, and hybrid threat monitoring in contested or strategically sensitive areas like the Arctic. Ensuring submarine cable systems are robust, observable, and secured must therefore be seen as a shared priority, bridging commercial, civil, and military domains.

THE PHYSICS BEHIND SENSING – A BIT OF BACKUP.

Rayleigh Scattering: Imagine shining a flashlight through a long glass tunnel. Even though the glass tunnel looks super smooth, it has tiny bumps and little specks you can not see. When the light hits those tiny bumps, some bounce back, like a ball bounces off a wall. That bouncing light is called Rayleigh scattering.

Rayleigh scattering is a fundamental optical phenomenon in which light is scattered by small-scale variations in the refractive index of a medium, such as microscopic imperfections or density fluctuations within an optical fiber. It occurs naturally in all standard single-mode fibers and results in a portion of the transmitted light being scattered in all directions, including backward toward the transmitter. The intensity of Rayleigh backscattered light is typically very weak, but it can be detected and analyzed using highly sensitive receivers. The scattering is elastic, meaning there is no change in wavelength between the incident and scattered light.

In distributed fiber optic sensing (DFOS), Rayleigh backscatter forms the basis for several techniques:

  • Distributed Acoustic Sensing (DAS):
    The DAS sensing solution uses phase-sensitive optical time-domain reflectometry (i.e., φ-OTDR) to measure minute changes in the backscattered phase caused by vibrations. These changes indicate environmental disturbances such as seismic waves, intrusions, or cable movement.
  • Coherent Optical Frequency Domain Reflectometry (C-OFDR):
    C-OFDR leverages Rayleigh backscatter to measure changes in the fiber over distance with high resolution. By sweeping a narrow-linewidth laser over a frequency range and detecting interference from the backscatter, C-OFDR enables continuous distributed sensing along submarine cables. Unlike earlier methods requiring Bragg gratings, recent innovations allow this technique to work even over legacy subsea cables without them.
  • Coherent Receiver Sensing:
    This technique monitors Rayleigh backscatter and polarization changes using existing telecom equipment’s DSP (digital signal processing) capabilities. This allows for passive sensing with no additional probes, and the sensing does not interfere with data traffic.

Brillouin Scattering: Imagine you are talking through a long string tied between two cups, like a string telephone most of us played with as kids (before everyone got a smartphone when they turned 3 years old). Now, picture that the string is not still. It shakes a little, like shivering or wiggling in the wind or the strain of the hands holding the cups. When your voice travels down that string, it bumps into those little wiggles. That bumping makes the sound of your voice change a tiny bit. Brillouin scattering is like that. When light travels through our string (that could be a glass fiber), the tiny wiggles inside the string make the light change direction, and the way that light and cable “wiggles” work together can tell our engineers stories about what happens inside the cable.

Brillouin scattering is a nonlinear optical effect that occurs when light interacts with acoustic (sound) waves within the optical fiber. When a continuous wave or pulsed laser signal travels through the fiber, it can generate small pressure waves due to a phenomenon known as electrostriction. These pressure waves slightly change the optical fiber’s refractive index and act like a moving grating, scattering some of the light backward. This backward-scattered light experiences a frequency shift, known as the Brillouin shift, which is directly related to the temperature and strain in the fiber at the scattering point.

Commercial Brillouin-based systems are technically capable of monitoring subsea communications cables, especially for strain and temperature sensing. However, they are not yet standard in the submarine communications cable industry, and integration typically requires dedicated or dark fibers, as the sensing cannot share the same fiber with active data traffic.

Raman Scattering: Imagine you are shining a flashlight through a glass of water. Most of the light goes straight through, like cars driving down a road without turning. But sometimes, a tiny bit of light bumps into something inside the water, like a little water molecule, and bounces off differently. It’s like the car suddenly makes a tiny turn and changes its color. This little bump and color change is what we call Raman scattering. It is a special effect as it helps scientists figure out what’s inside things, like what water is made of, by looking at how the light changes when it bounces off.

Raman scattering is primarily used in submarine fiber cable sensing for Distributed Temperature Sensing (DTS). This technique exploits the temperature-dependent nature of Raman scattering to measure the temperature along the entire length of an optical fiber, which can be embedded within or run alongside a submarine cable. Raman scattering has several applications in submarine cables. It is used for environmental monitoring by detecting gradual thermal changes caused by ocean currents or geothermal activity. Regarding cable integrity, it can identify hotspots that might indicate electrical faults or compromised insulation in power cables. In Arctic environments, Raman-based Distributed Temperature Sensing (DTS) can help infer changes in surrounding ice or seawater temperatures, aiding in ice detection. Additionally, it supports early warning systems in the energy and offshore sectors by identifying overheating and other thermal anomalies before they lead to critical failures.

However, Raman scattering has notable limitations. Because it is a weak optical effect, DTS systems based on Raman scattering require high-powered lasers and highly sensitive detectors. It is also unsuitable for detecting dynamic events such as vibrations or acoustic signals, better sensed using Rayleigh or Brillouin scattering. Furthermore, Raman-based DTS typically offers spatial resolutions of one meter or more and has a slow response time, making it less effective for identifying rapid or short-lived events like submarine activity or tampering.

Commercial Raman-DTS solutions exist and are actively deployed in subsea power cable monitoring. Their use in telecom submarine cables is less common but technically feasible, particularly for infrastructure integrity monitoring rather than data-layer diagnostics.

FURTHER READING.

ACKNOWLEDGEMENT.

I greatly acknowledge my wife, Eva Varadi, for her support, patience, and understanding during the creative process of writing this article. I am furthermore indebted to Andreas Gladisch, VP Emerging Technologies – Deutsche Telekom AG, for sharing his expertise on fiber-optical sensing technologies with me and providing some of the foundational papers on which my article and research have been based. I always come away wiser from our conversations.

Greenland: Navigating Security and Critical Infrastructure in the Arctic – A Technology Introduction.

The securitization of the Arctic involves key players such as Greenland (The Polar Bear), Denmark, the USA (The Eagle), Russia (The Brown Bear), and China (The Red Dragon), each with strategic interests in the region. Greenland’s location and resources make it central to geopolitical competition, with Denmark ensuring its sovereignty and security. Greenland’s primary allies are Denmark, the USA, and NATO member countries, which support its security and sovereignty. Unfriendly actors assessed to be potential threats include Russia, due to its military expansion in the Arctic, and China, due to its strategic economic ambitions and influence in the region. The primary threats to Greenland include military tensions, sovereignty challenges, environmental risks, resource exploitation, and economic dependence. Addressing these threats requires a balanced, cooperative approach to ensure regional stability and sustainability.

Cold winds cut like knives, Mountains rise in solitude, Life persists in ice. (Aqqaluk Lynge, “Harsh Embrace” ).

I have been designing, planning, building, and operating telecommunications networks across diverse environmental conditions, ranging from varied geographies to extreme climates. I sort of told myself that I most likely had seen it all. However (and luckily), the more I consider the complexities involved in establishing robust and highly reliable communication networks in Greenland, the more I realize the uniqueness and often extreme challenges involved with building & maintaining communications infrastructures there. The Greenlandic telecommunications incumbent Tusass has successfully built a resilient and dependable transport network that connects nearly every settlement in Greenland, no matter how small. They manage and maintain this network amidst some of the most severe environmental conditions on the planet. The staff of Tusass is fully committed to ensuring connectivity for these remote communities, recognizing that any service disruption can have severe repercussions for those living there.

As an independent board member of Tusass Greenland since 2022, I have witnessed Tusass’s dedication, passion, and understanding of the importance of improving and maintaining their network and connections for the well-being of all Greenlandic communities. To be clear, the opinions I express in this post are solely my own and do not necessarily reflect the views or opinions of Tusass. I believe that my opinions have been shaped by my Tusass and Greenlandic experience, by working closely with Tusass as an independent board member, and by a deep respect for Tusass and its employees. All information that I am using in this post is publicly available through annual reports (of Tusass) or, in general, publicly available on the internet.

Figure 1 Illustrating a coastal telecommunications site supporting the microwave long-haul transport network of Tusass up along the Greenlandic west coast. Courtesy: Tusass A/S (Greenland).

Greenland’s strategic location, its natural resources, environmental significance, and broader geopolitical context make it geopolitically a critical country. Thus, protecting and investing in Greenland’s critical infrastructure is obviously important. Not only from a national and geopolitical security perspective but also with respect to the economic development and stability of Greenland and the Arctic region. If a butterfly’s movements can cause a hurricane, imagine what an angry “polar bear” will do to the global weather and climate. The melting ice caps are enabling new shipping routes and making natural resources much more accessible, and they may also raise the stakes for regional security. For example, with China’s Polar Silk Road initiative where, China seeks to establish (or at least claim) a foothold in the Arctic in order to increase its trade routes and access to resources. This is also reflected in their 2018 declaration stating that China sees itself as a “Near-Arctic State” and concludes that China is one of the continental states that are closest to the Arctic Circle. Russia, which is a real neighboring country to the Arctic region and Circle, has also increased its military presence and economic activities in the Arctic. Recently, Russia has made claims in the Arctic to areas that overlap with what Denmark and Canada see as their natural territories, aiming to secure its northern borders and exploit the region’s resources. Russia has also added new military bases and has conducted large-scale maneuvers along its own Arctic coastline. The potential threats from increased Russian and Chinese Arctic activities pose significant security concerns. Identifying and articulating possible threat scenarios to the Arctic region involving potential hostile actors may indeed justify extraordinary measures and also highlight the need for urgent and substantial investments in and attention to Greenland’s critical infrastructure.

In this article, I focus very much on what key technologies should be considered, why specific technologies should be considered, and how those technologies could be implemented in a larger overarching security and defense architecture driving towards enhancing the safety and security of Greenland:

  • Leapfrog Quality of Critical Infrastructure: Strengthening the existing critical communications infrastructure should be a priority. With Tusass, this is the case in terms of increasing the existing transport network’s reliability and availability by adding new submarine cables and satellite backbone services and the associated satellite infrastructure. However, the backbone of the Tusass economy is a population of 57 thousand. The investments required to quantum leap the robustness of the existing critical infrastructure, as well as deploying many of the technologies discussed in this post, will not have a positive business case or a reasonable return on investment within a short period (e.g., a couple of years) if approached in the way that is the standard practice for most private corporations around the worlds. External subsidies will be required. The benefit evaluation would need to be considered over the long term, more in line with big public infrastructure projects. Most of these critical infrastructure and technology investments discussed are based on particular geopolitical assumptions and serve as risk-mitigating measures with substantial civil upside if we maintain a dual-use philosophy as a boundary condition for those investments. Overall I believe that a positive case might be made from the perspective of the possible loss of not making them rather than a typical gain or growth case expected if an investment is made.
  • Smart Infrastructure Development: Focus on building smart infrastructure, integrating sensor networks (e.g., DAS on submarine cables), and AI-driven automation for critical systems like communication networks, transportation, and energy management to improve resilience and operational efficiency. As discussed in this post, Tusass already has a strong communications network that should underpin any work on enhancing the Greenlandic defense architecture. Moreover, Tusass are experts in building and operating critical communications infrastructures in the Arctic. This is critical know-how that should be heavily relied upon in what has to come.
  • Automated Surveillance and Monitoring Systems: Invest in advanced automated surveillance technologies, such as aquatic and aerial drones, satellite-based monitoring (SIGINT and IMINT), and IoT sensors, to enhance real-time monitoring and protection of Greenland.
  • Autonomous Defense Systems: Deploy autonomous systems, including unmanned aerial vehicles (UAVs) and unmanned underwater vehicles (UUVs), to strengthen defense capabilities and ensure rapid response to potential threats in the Arctic region. These systems should be the backbone of ad-hoc private network deployments serving both defense and civilian use cases.
  • Cybersecurity and AI Integration: Implement robust cybersecurity measures and integrate artificial intelligence to protect critical infrastructure and ensure secure, reliable communication networks supporting both military and civilian applications in Greenland.
  • Dual-Use Infrastructure: Prioritize investments in infrastructure solutions that can serve both military and civilian purposes, such as communication networks and transportation facilities, to maximize benefits and resilience.
  • Local Economic and Social Benefits: Ensure that defense investments support local economic development by creating new job opportunities and improving essential services in Greenland.

I believe that Greenland needs to build a solid Greenlandic-centered know-how on a foundational level around autonomous and automated systems. In order to get there Greenland will need close and strong alliances that is aligned with the aim of achieving a greater degree of independence through clever use of the latest technologies available. Such local expertise will be essential in order to reduce the dependency on external support (e.g., from Denmark and Allies) and ensure that they can maintain operational capabilities independently, particularly during a security crisis. Automation, enabled by digitization and AI-enabled system architectures, would be key to managing and monitoring Greenland’s remote and inaccessible geography and resources efficiently and securely, minimizing the need for extensive human intervention. Leveraging autonomous defense and surveillance technologies and stepping up in digital maturity is an important path to compensating for Greenland’s small population. Additionally, implementing robust, with respect to hardware AND software, automated systems will allow Greenland to protect and maintain its critical infrastructure and services, mitigating the risks associated with (too much) reliance on Denmark or allies during a time of crisis where such resources may be scarce or impractical to timely move to Greenland.

Figure 2 A view from Tusass HQ over Nuuk, Greenland. Courtesy: Tusass A/S (Greenland).

GREENLAND – A CONCISE INTRODUCTION.

Greenland, or Kalaallit Nunaat as it is called in Greenlandic, has a surface area of about 2.2 million square kilometers with ca. 80% covered by ice and is the world’s largest island. It is an autonomous territory of Denmark with a population of approximately 57 thousand. Its surface area is comparable to that of Alaska (1.7 million km2) or Saudi Arabia (2.2 million km2). It is predominantly covered by ice, with a population scattered in smaller settlements along the western coastlines where the climate is milder and more hospitable. Greenland’s extensive coastline measures ca. 44 thousand kilometers and is one of the most remote and sparsely populated coastlines in the world. This remoteness contrasts with more densely populated and developed coastlines like the United States. The remoteness of Greenland’s coastline is further emphasized by a lack of civil infrastructure. There are no connecting roads between settlements, and most (if not all) travel between communities relies on maritime or air transport.

Greenland’s coastline presents several unique security challenges due to its particularities, such as its vast length, rugged terrain, harsh climate, and limited population. These factors make Greenland challenging to monitor and protect effectively, which is critical for several reasons:

  • The vast and inaccessible terrain.
  • Harsh climate and weather conditions.
  • Sparse population and limited infrastructure.
  • Maritime and resource security challenges.
  • Communications technology challenges.
  • Geopolitical significance.

The capital and largest city is Nuuk, located on the southwestern coast. With a population of approximately 18+ thousand or 30+% of the total, Nuuk is Greenland’s administrative and economic center, offering modern amenities and serving as the hub for the island’s limited transportation network. Sisimiut, north of Nuuk on the western coast. It is the second-largest town in Greenland, with a population of around 5,500+. Sisimiut is known for its fishing industry and serves as a base for much of the Greenlandic tourism and outdoor activities.

On the remote and inhospitable eastern coast, Tasiilaq is the largest town in the Ammassalik area, with a population of little less than 2,000. It is relatively isolated compared to the western settlements and is known for its breathtaking natural scenery and opportunities for adventure tourism (check out https://visitgreenland.com/ for much more information). In the far north, on the west coast, we have Qaanaaq (also known as Thule), which is one of the world’s most northern towns, with a population of ca. 600. Located near Qaanaaq, is the so-called Pituffik Space Base which is the United States’ northernmost military base, established in 1951, and a key component of NATO’s early warning and missile defense systems. The USA have had a military presence in Greenland since the early days of the World War II and strengthened during the Cold War. It also plays an important role in monitoring Arctic airspace and supporting the region’s avionics operations.

As of 2023, Greenland has approximately 56 inhabited settlements. I am using the word “settlement” as an all-inclusive covering communities with a population of 10s of thousands (Nuuk) down to 100s or lower. With few exceptions, there are no settlements with connecting roads or any other overland transportation connections with other settlements. All person- and goods transportation between the different settlements is taken by plane or helicopter (provided by Air Greenland) or seaborne transportation (e.g., Royal Artic Line, RAL).

Greenland is rich in natural resources. Apart from water (for hydropower), this includes significant mining, oil, and gas reserves. These natural resources are largely untapped and present substantial opportunities for economic development (and temptation for friendly as well as unfriendly actors). Greenland is believed to have one of the world’s largest deposits of rare earth elements (although by far not comparable to China), extremely valuable as an alternative to the reliance of China and critical for various high-tech applications, including electronics (e.g., your smartphone), renewable energy technologies (e.g., wind turbines and EVs), and defense systems. Graphite and platinum are also present in Greenland and are important in many industrial processes. Some estimates indicate that northeast Greenland’s waters could hold large reserves of (yet) undiscovered oil and gas reserves. Other areas are likewise believed to contain substantial hydrocarbon reserves. However, Greenland’s arctic environment presents severe exploration and extraction challenges, such as extreme cold, ice cover, and remoteness, that so far has made it also very costly and complicated to extraxt its natural resources. With the global warming the economical and practical barrier for exploitation is contineously reducing.

FROM STRATEGIC OUTPOST TO ARCTIC STRONGHOLD: THE EVOLVING SECURITY SIGNIFICANCE OF GREENLAND.

Figure 3 illustrates Greenland’s reliance on and the importance of critical communications infrastructure connecting local communities as well as bridging the rest of the world and the internet. Courtesy: DALL-E.

From a security perspective Greenland has evolved significantly since the Second World War. During World War II, its importance was primarily based on its location as a midway point between North America and Europe serving as a refueling and weather station for allied aircrafts crossing the Atlantic to and from Europe. Additionally, its remote geographical location combined with its harsh climate provided a “safe haven” for monitoring and early warning installations.

During the Cold War era, Greenland’s importance grew (again) due to its proximity to the Soviet Union (and Russia today). Greenland became a key site for early warning radar systems and an integral part of the North American Aerospace Defense Command (NORAD) network designed to detect Soviet bombers and missiles heading toward North America. In 1951, the USA-controlled Thule Air Base, today it is called Pituffik Space Base, located in northwest Greenland, was constructed with the purpose of hosting long-range bombers and providing an advanced point (from a USA perspective) for early warning and missile defense systems.

As global tensions eased in the post-Cold War period, Greenland’s strategic status diminished somewhat. However, its status is now changing again due to Russia’s increased aggression in Europe (and geopolitically) and a more assertive China with expressed interest in the Arctic. The arctic ice is melting due to climate change and has resulted in new maritime routes being possible, such as the Northern Sea Route. Also, making Arctic resources more accessible. Thus, we now observe an increased interest from global powers in the Arctic region. And as was the case during the cold-War period (maybe with much higher stakes), Greenland has become strategically critical for monitoring and controlling these emerging routes, and the Arctic in general. Particularly with the observed increased activity and interest from Russia and China.

Greenland’s position in the North Atlantic, bridging the gap between North America and Europe, has become a crucial spot for monitoring and controlling the transatlantic routes. Greenland is part of the so-called Greenland-Iceland-UK (GIUK) Gap. This gap is a critical “chokepoint” for controlling naval and submarine operations, as was evident during the Second World War (e.g., read up on the Battle of the Atlantic). Controlling the Gap increases the security of maritime and air traffic between the continents. Thus, Greenland has again become a key component in defense strategies and threat scenarios envisioned and studied by NATO (and the USA).

GREENLANDS GEOPOLITICAL ROLE.

Greenland’s recent significance in the Arctic should not be underestimated. It arises, in particular, from climate change and, as a result, melting ice caps that have and will enable new shipping routes and potential (easier) access to Greenland’s untapped natural resources.

Greenland hosts critical military and surveillance assets, including early warning radar installations as well as air & naval bases. These defense assets actively contributes to global security and is integral to NATO’s missile defense and early warning systems. They provide data for monitoring potential missile threats and other aerial activities in the North Atlantic and Arctic regions. Greenland’s air and naval bases also support specialized military operations, providing logistical hubs for allied forces operating in the Arctic and North Atlantic.

From a security perspective, Greenland’s control is not only about monitoring and defense. It is also about deterring potential threats from potential hostile actors. It allows for effective monitoring and defense of the Arctic and North Atlantic regions. Enabling the detection and tracking of submarines, ships, and aircraft. Such capabilities enhance situational awareness and operational readiness, but more importantly, it sends a message to potential adversaries (e.g., maybe unaware, as unlikely as it may be, about the deficiencies of Danish Arctic patrol ships). The ability to project power and maintain a military presence in this area is necessary for deterring potential adversaries and protecting he critical communications infrastructure (e.g., submarine cables), maritime routes, and airspace.

The strategic location of Greenland is key to contribute to the global security dynamics. Ensuring Greenland’s security and stability is essential for also maintaining control over critical transatlantic routes, monitoring Arctic activities, and protecting against potential threats from hostile actors. Making Greenland a cornerstone of the defense infrastructure and an essential area for geopolitical strategy in the North Atlantic and Arctic regions.

INFRASTRUCTURE RECOMMENDATIONS.

Recent research has focused on Greenland in the context of Arctic security (see “Greenland in Arctic Security: (De)securitization Dynamics under Climatic Thaw and Geopolitical Freeze” by M. Jacobsen et al.). The work emphasizes the importance of maintaining and enhancing surveillance and early warning systems. Greenland is advised to invest in advanced radar systems and satellite monitoring capabilities. These systems are relevant for detecting potential threats and providing timely information, ensuring national and regional security. I should point to the following traditional academic use of the word “securitization,” particularly from the Copenhagen School, which refers to framing an issue as an existential threat requiring extraordinary measures. Thus, securitization is the process by which topics are framed as matters of security that should be addressed with urgency and exeptional measures.

The research work furthermore underscores the Greenlandic need for additional strategic infrastructure development, such as enhancing or building new airport facilities and the associated infrastructure. This would for example include expanding and upgrading existing airports to improve connectivity within Greenland and with external partners (e.g., as is happening with the new airport in Nuuk). Such developments would also support economic activities, emergency response, and defense operations. Thus, it combines civic and military applications in what could be defined as dual-purpose infrastructure programs.

The above-mentioned research argues for the need to develop advanced communication systems, Signals Intelligence (SIGINT), and Image Intelligence (IMINT) gathering technologies based on satellite- and aerial-based platforms. These wide-area coverage platforms are critical to Greenland due to its vast and remote areas, where traditional communication networks may be insufficient or impractical. Satellite communication systems such as GEO, MEO, and LEO (and combinations thereof), and stratospheric high-altitude platform systems (HAPS) are relevant for maintaining robust surveillance, facilitating rapid emergency response, and ensuring effective coordination of security as well as search & rescue operations.

Expanding broadband internet access across Greenland is also a key recommendation (that is already in progress today). This involves improving the availability and reliability of communications-related connectivity by additional submarine cables and by new satellite internet services, ensuring that even the most remote communities have reliable broadband internet connectivity. All communities need to have access to broadband internet, be connected, enable economic development, improve quality of life in general, and integrate remote areas into the national and global networks. These communication infrastructure improvements are important for civilian and military purposes, ensuring that Greenland can effectively manage its security challenges and leverage new economic opportunities for its communities. It is my personal opinion that most communities or settlements are connected to the wider internet, and the priority should be to improve the redundancy, availability, and reliability of the existing critical communications infrastructure. With that also comes more quality in the form of higher internet speeds.

The applicability of at least some of the specific securitization recommendations for Greenland, as outlined in Marc Jacobsen’s “Greenland in Arctic Security: (De)securitization Dynamics Under Climatic Thaw and Geopolitical Freeze,” may be somewhat impractical given the unique characteristics of Greenland with its vast area and very small population. Quite a few recommendations (in my opinion), even if in place “today or tomorrow,” would require a critical scale of expertise, human, and industrial capital that Greenland does not have available on its own (and also is unlikely to have in the future). Thus, some of the recommendations depend on such resources to be delivered from outside Greenland, posing inherent availability risks to provide in a crisis (assuming that such capacity would even be available under normal circumstances). This dependency on external actors, particularly Danish and International investors, complicates Greenland’s ability to independently implement policies recommended by the securitization framework. It could lead to conflicts between local priorities and the interests of external stakeholders, particularly in a time of a clear and present security crisis (e.g., Russia attempting to expand west above and beyond Ukraine).

Also, as a result of Greenland’s small population there will be a limited pool of available local personnel with the needed skills to draw upon for implementing and maintaining many of the recommendations in “Greenland in Arctic Security: (De)securitization Dynamics under Climatic Thaw and Geopolitical Freeze”. Training and deploying enough high-tech skilled individuals to cover Greenland’s vast territory and technology needs is a very complex challenge given the limited human resources and challenges in getting external high-tech resouces to Greenland.

I believe Greenland should focus on establishing a comprehensive security strategy that minimizes its dependency on its natural allies and external actors in general. The dual-use approach should be integral to such a security strategy, where technology investments serve civil and defense purposes whenever possible. This approach ensures that Greenlandic society benefits directly from investments in building a robust security framework. I will come back to the various technologies that may be relevant in achieving more independence and less reliance on the external actors that are so prevalent in Greenland today.

HOW CRITICAL IS CRITICAL INFRASTRUCTURE TO GREENLAND

Communications infrastructure is seen as critical in Greenland. It has to provide a reliable and good quality service despite Greenland having some of the most unfavorable environmental conditions in which to build and operate communications networks. Greenland is characterized by vast distances between relatively small, isolated communities. Thus, this makes effective communication essential for bridging those gaps, allowing people to stay connected with each other and as well as the outside world irrespective of weather or geography. The lack of a comprehensive road network and reliance on sea and air travel further emphasize the importance of reliable and available telecommunications services, ensuring timely communication and coordination across the country.

Telecommunications infrastructure is a cornerstone of economic development in Greenland (as it has been elsewhere). It is about efficient internet and telephony services and its role in business operations, e-commerce activities, and international market connections. These aspects are important for the economic growth, education, and diversification of the many Greenlandic communities. The burgeoning tourism industry will also depend on (maybe even demand) robust communication networks to serve those tourists, ensure their safety in remote areas, and promote tourism activities in general. This illustrates very firmly that the communications infrastructure is critical (should there be any doubts).

Telecommunications infrastructure also enables distance learning in education and health services, providing people in remote areas with access to high-quality education that otherwise would not be possible (e.g., Coursera, Udemy Academy, …). Telemedicine has obvious benefits for healthcare services that are often limited in remote regions. It allows residents to receive remote medical consultations and services (e.g., by video conferencing) without the need for long-distance and time-consuming travels that often may aggravate a patient’s condition. Emergency response and public safety are other critical areas in which our communications infrastructure plays a crucial role. Greenland’s harsh and unpredictable weather can lead to severe storms, avalanches, and ice-related incidents. It is therefore important to have a reliable communication network that allows for timely warnings, supporting rescue operations & coordination, and public safety. Moreover, maritime safety also depends on a robust communication infrastructure, enabling reliable communication between ships and coastal stations.

A strong communication network can significantly enhance social connectivity, and help maintaining social ties, such as among families and communities across Greenland. Thus reduce the feeling of isolation. Supporting social cohesion in communities as well as between settlements. Telecommunications can also facilitate sharing and preserving the Greenlandic culture and language through digital media (e.g., Tusass Music), online platforms, and social networks (e.g., Facebook used by ca. 85% of the eligible population, that number is ca. 67% in Denmark).

For a government and its administration, maintaining effective and reliable communication is essential for well-functioning public services and its administration. It should facilitate coordination between different levels of government and remote administration. Additionally, environmental monitoring and research benefit greatly from a reliable and available communication infrastructure. Greenland’s unique environment attracts scientific research, and robust communication networks are essential for supporting data transmission (in general), coordination of research activities, and environmental monitoring. Greenland’s role in global climate change studies should also be supported by communication networks that provide the means of sharing essential climate data collected from remote research stations.

Last but not least. A well-protected (i.e., redundant) and highly available communications infrastructure is a cornerstone of any national defense or emergency situation. If it is well functioning, the critical communications infrastructure will support the seamless operation of military and civilian coordination, protect against cyber threats, and ensure public confidence during a crisis situation (natural or man-made). The importance of investing in and maintaining such a critical infrastructure cannot be underestimated. It plays a critical role in a nation’s overall security and resilience.

TUSASS: THE BACKBONE OF GREENLANDS CRITICAL COMMUNICATIONS INFRASTRUCTURE.

Tusass is the primary telecommunications provider in Greenland. It operates a comprehensive telecom network that includes submarine cables with 5 landing stations in Greenland, very long microwave (MW) radio chains (i.e., long-haul backbone transmission links) with MW backhaul branches to settlements along its way, and broadband satellite connections to deliver telephony, internet, and other communication services across the country. The company is wholly owned by the Government of Greenland (Naalakkersuisut). Positioning Tusass as a critical company responsible for the nation’s communications infrastructure. Tusass faces unique challenges due to the vast, remote, and rugged terrain. Extreme weather conditions make it difficult, often impossible, to work outside for at least 3 – 4 months a year. This complicates the deployment and maintenance of any infrastructure in general and a communications network in particular. The regulatory framework mandates that Tusass fulfills a so-called Public Service Obligation, or PSO. This requires Tusass to provide essential telecommunications services to all of Greenland, even the most isolated communities. This requires Tusass to continue to invest heavily in expanding and enhancing its critical infrastructure, providing reliable and high-quality services to all residents throughout Greenland.

Tusass is the main and, in most areas, the only telecommunications provider in Greenland. The company holds a dominant market position where it provides essential services such as fixed-line telephony, mobile networks, and internet services. The Greenlandic market for internet and data connections was liberalized in 2015. The liberalization allowed private Internet Service Providers (ISPs) to purchase wholesale connections from Tusass and resell them. Despite liberalization, Tusass remains the dominant force in Greenland’s telecommunications sector. Tusass’s market position can be attributed to its extensive communications infrastructure and its government ownership. With a population of 57 thousand and its vast geographical size, it would be highly uneconomical and human-resource wise very chalenging to have duplicate competing physical communications infrastructures and support organizations in Greenland. Not to mention that it would take many years before an alternative telco infrastructure could be up an running matching what is already in place. Thus, while there are smaller niche service providers, Tusass effectively operates as Greenland’s sole telecom provider.

Figure 4 Illustrates one of many of Tusass’s long-haul microwave site along Greenland’s west coast. Accessible only by helicopter. Courtesy: Tusass A/S (Greenland).

CURRENT STATE OF CRITICAL COMMUNICATIONS INFRASTRUCTURE.

The illustration below provides an overview of some of the major and critical infrastructures available in Greenland, with a focus on the communications infrastructure provided by Tusass, such as submarine cables, microwave (MW) radios radio chains, and satellite ground stations, which all connect Greenland and give access to the Internet for all of Greenland.

Figure 5 illustrates the Greenlandic telecommunications provider Tusass infrastructure. Note that Tusass is the incumbent and only telecom provider in Greenland. Currently, five hydropower plants (shown above, location only indicative) provide more than 80% of Greenland’s electricity demand. A new international airport is expected to be operational in Nuuk from November 2024. Source: from Tusass Annual Report 2023 with some additions and minor edits.

From the south of Nanortalik up to above Upernavik on the west coast, Tusass has a 1,700+ km long microwave radio chain connecting all settlements along Greenland’s west coast from the south to the north distributed, supported by 67 microwave (MW) radio sites. Thus, have a microwave radio equipment located for every ca. 25 km ensuring very high performance and availability of connectivity to the many settlements along the West Coast. This setup is called a long-haul microwave chain that uses a series of MW radio relay stations to transmit data over long distances (e.g., up to thousands of kilometers). The harsh climate with heavy rain, snow, and icing makes it very challenging to operate high-frequency, high-bandwidth microwaves (i.e., the short distances between the radio chain sites). The MW radio sites are mainly located on remote peaks in the harsh and unforgiving coastal landscape (ensuring line-of-site), making helicopters the only means of accessing these locations for maintenance and fueling. The field engineers here are pretty much superheroes maintaining the critical communications infrastructure of Greenland and understanding its life-and-death implications for all the remote communities if it breaks down (with the additional danger of meeting a very hungry polar bear and being stuck for several days on a location due to poor weather preventing the helicopter from picking the engineers up again).

Figure 6 illustrates a typical housing for field service staff when on site visits. As the weather can change very rapidly in Greenland it is not uncommon that field service staff have to wait for many days before they can be picked up again by the helicopter. Courtesy: Tusass A/S (Greenland).

Greenland relies on the “Greenland Connect” submarine cable to connect to the rest of the world and the wider internet with a modern-day throughput. The submarine cable connecting Greenland to Canada and Iceland runs from Newfoundland and Labrador in Canada to Nuuk and continues from Qaqortoq in Greenland to land in Iceland (that connects further to Copenhagen and the wider internet). Tusass, furthermore, has deployed submarine cables between 5 of the major Greenlandic settlements, including Nuuk, up the west coast and down to the south (i.e., Qaqortoq). The submarine cables provide some level of redundancies, increased availability, and substantial capacity & quality augmentation to the long-haul MW chain that carries the traffic from surrounding settlements. The submarine cables are critical and essential for the modernization and digitalization of Greenland. However, there are only two main submarine broadband cable connection points, the Canada – Nuuk and Qaqortoq – Iceland submarine connections, to and from Greenland. From a security perspective, this poses substantial and unique risks to Greenland, and its role and impact need to be considered in any work on critical infrastructure strategy. If both international submarine cables were compromised, intentionally or otherwise, it would become challenging, if possible, to sustain today’s communications demand. Most traffic would have to be supported by existing satellite capacity, which is substantially lower than the existing submarine cables can support, leaving the capacity mainly for mission-critical communications. Allowing little spare capacity for consumer and non-critical business communication needs. This said, as long as Greenlandic submarine cables, terrestrial transport, and switching infrastructure are functional, it would be possible to internally to Greenland maintain a resemblance of internet services and communication means between connected settlements using modern day network design thinking.

Moreover, while the submarine cables along the west coast offer redundancy to the land-based long-haul transport solution, there are substantial risks to settlements and their populations where the long-haul MW solution is the only means of supporting remote Greenlandic communities. Given Greenland’s unique geographic and climate challenges it is not only very costly but also time-consuming to reduce the risk of disruption to the existing lesser redundant critical infrastructure already in place (e.g., above Aasiaat north of the Arctic Circle).

Using satellites is an additional dimension, and part of the connectivity toolkit, that can be used to improve the redundancy and availability of the land- and water-based critical communications infrastructures. However, the drawback of satellite systems is that they generally are bandwidth/throughput limited and have longer signal delays (latency and round-trip time) than terrestrial-based communications systems. These issues could pose some limitations on how well some services can be supported or will function and would require a versatile traffic management & prioritization system in case the satellite solution would be the only means of connecting a relatively high-traffic area (e.g., Tasiilaq) used to ground-based support of broadband transport means with substantial more available bandwidth than accessible to the satellite solution. Particular for GEO stationary satellite services, with the satellite located at 36 thousand kilometer altitude, the data traffic flow needs to be carefully optimized in order to function well irrespective of the substantial latency experienced on such connections that at the very best can be 239 milliseconds and in practice might be closer to twice that or more. This poses significant challenges to particular TCP/IP data flows on such response-time-challenged connections and applications sensitivity short round trip times.

Optimizing and stabilizing TCP/IP data flows over GEO satellite connections requires a multi-faceted approach involving enhancements to the TCP protocol (e.g., window scaling, SACK, TCP Hypla, …), the use of hybrid and proxy solutions, application-layer adjustments, error correction mechanisms, Quality of Service (QoS) and traffic shaping, DNS optimizations, and continuous network monitoring. Combining these strategies makes it possible to mitigate some of the inherent challenges of high-latency satellite links and ensure more effective and efficient IP flows and better utilization of the available satellite link bandwidth. Optimizing control signals and latency-sensitive data flows over GEO and LEO satellite connections may also substantially reduce the sensitivity to the prohibitive long delays experienced on GEO connections, using the lower latency LEO connection (RTT < ~ 50 ms @ 500 km altitude), or, if available as a better alternative a long-haul microwave link or submarine connection.

Tusass, in collaboration with the Spanish satellite company Hispasat, make use of the Greenland geostationary satellite, Greensat. Tusass signed an agreement with Hispasat to lease space capacity (800 MHz @ Ku-band) on the Amazonas Nexus satellite until the end of its lifetime (i.e., 2038+/-). Greensat was taken into operation in the last quarter of 2023 (note: it was launched in February 2023), providing services to the satellite-only settlement areas around Qaanaaq, the northernmost settlement on the west coast of Greenland, and Tasiilaq and Ittoqortormiut (north of Tasiilaq), on the remote east coast. All mobile and fixed traffic from a satellite-only area is routed to a satellite ground station that is connected to the geostationary satellite (see the illustration below). The satellite’s primary mission is to provide broadband services to areas that, due to geography & climate and cost, are impractical to connect by submarine cable or long-haul microwave links. The Greensat satellite closes the connection to the rest of the world and the internet via a ground station on Gran Canaria. It also connects to Greenland via submarine cables in Nuuk (via Canada and Qaqortoq).

Figure 7 The image shows a large geostationary satellite ground-station antenna located in Greenland’s cold and remote area. The antenna’s primary purpose is to facilitate communication with geostationary satellites 36 thousand kilometers away, transmitting and receiving data. It may support various services such as Internet, television broadcasting, weather monitoring, and emergency communications. The components are (1) a parabolic reflector (dish), (2) a feed horn and receiver, (3) a mount and support structure, (4) control and monitoring systems, and (5) a radome (not shown on the picture) which is a structural, weatherproof enclosure that protects the antenna from environmental elements without interfering with the electromagnetic signals it transmits and receives. The LEO satellite ground stations are much smaller as the distance between the ground and the low-earth satellite is much smaller, i.e., ca. 350 – 650 km, resulting in less challenging receive and transmit conditions (compared to the connection to a geostationary satellite).

In addition, Tusass also makes use of UK-based OneWeb (Eutelsat) LEO satellite backhaul services at several locations where an area fixed and mobile traffic is routed to a point-of-presence connected to a satellite ground station that connects to a OneWeb satellite that connects to the central switching center in Nuuk (connected to another ground station).

CRITICAL PROPERTIES FOR RELIABLE AND SECURE TRANSPORT NETWORKS.

A physical transport network comprises many tangible components, such as cables, routers, and switches, which form an interconnected system capable of transmitting data. The network is designed and planned according to a given expected coverage, use and level of targeted quality (e.g., speed, latency, priority and security). Moreover, we are also concerned about such a networks availability as well as reliability. We design the physical and logical (i.e., related to higher levels of the OSI stack than the physical) network according to a given target availability, that is how many hours in a year should the network minimum be operational and available to our customers. You will see availability given in percentage of the total hours in a year (e.g., 8,760 hours in a normal year and 8,784 hours in a leap year). So an availability of 99.9% means that we target a minimum operational time of our network of 8,751 hours, or, alternatively, accept a maximum of 9 hours of downtime. The reliability of a network refers to the probability hat the network will continue to function without failure for a given period. For example, say you have a mean time between failures (MTBF) of 8750 hours and you want to figure out what the likelihood is of operating without failure for 4,380 hours (half a year), you find that there is a ca. 60% chance of operating without a failure (or 40% that a failure may occur within the next 6 months). For a critical infrastructure the availability and reliability metrics are very important to consider in any design and planning process.

In contrast to the physical network depiction, a network graph representation abstracts the physical transport network into a mathematical model where graph nodes (or vertexes) represent the network’s many components and edges (or links) represent the physical and logical connections between these network’s many components. Modellizing the physical (and logical) network allows designers and planners to study in detail a networks robustness against many types of disruptions as well as its general functioning and performance.

Suppose we are using a graph approach in our design of a critical communications network. We then need to carefully consider various graph properties critical for the network’s robustness, security, reliability, and efficiency. To achieve this, one must strive for resilience and fault tolerance by designing for increased redundancy and availability involving multiple paths, edges, or connections between nodes, preventing single points of failure (SPoF). This involves creating a network where the number of independent paths between any two nodes is maximized (often subject to economics and feasibility boundary conditions). An optimal average degree of nodes should also be a design criterion. A higher degree of nodes enhances the graph’s, and thus the underlying network’s, resilience, thus avoiding increased vulnerability.

Scalability is a crucial network property. This is best achieved through a hierarchical structure (or topology) that allows for efficient network management as the network expands. The Modularity, which is another graph KPI, ensures that the network can integrate new nodes and edges without major reconfigurations, supporting civilian expansion and military operations or dual-purpose operations. To meet low-latency and high-throughput requirements, the shortest-path routing algorithms should be applied to allow us to minimize the latency or round-trip time (and thus increase throughput). Moreover, bandwidth management should be implemented, allowing the network to handle large data volumes in a prioritized manner (if required). This also ensures that the network can accommodate peak loads and prioritize critical communication when it is compromised.

Security is a paramount property of any communications network. In today’s environment with many real and dangerous cyber threats, it may be one of the most important topics to consider. Each node and link (or edge) in a network requires robust defenses against cyber threats. In our design, we need to think about encryption, authentication, intrusion, and anomaly detection systems. Network segmentation will help isolate critical defense communications from civilian traffic, preventing breaches from compromising the entire network. Survivability is enhanced by minimizing the Network Diameter, a graph property. A low (or lower) network diameter ensures that a network can quickly reroute traffic in case of failures and is an important design element for robustness against targeted attacks and random failures.

Likewise, interoperability is essential for seamless integration between civilian and military communication systems. Flexible protocols and specifications (e.g., Open API) enable different types of traffic and varying security requirements. These frameworks provide the structure, tools, and best practices needed to build and maintain secure communication systems. Thereby protecting against the various cyber threats we have today and expect in the future. Efficiency is achieved through effective load balancing (e.g., on a logical as well as physical level) to distribute traffic evenly across the network, prevent bottlenecks, optimize performance, and design for energy-efficient operations, particularly in remote or harsh environments or in case a part of the network has been compromised.

In order to support both civilian services and defense operations, accessibility and high availability are very important design requirements to consider when having a network with extensive large-scale coverage, including in very remote areas. Incorporating redundant communication links, such as satellite, fiber optic, and wireless, are design choices that allow for high availability even under adverse and disruptive conditions. It makes good sense in an environment such as Greenland to ensure that long-haul microwave links have a given level of redundancy either by satellite backhaul, submarine cable, or additional MW redundancy. While we always strive for our designs to be cost-effective, it may be a challenge if the circumstances dictate that the best redundancy (availability) solution is solved by non-terrestrial means (e.g., by satellite or submarine means). However, efficiency should be addressed by optimizing resource allocation to balance cost with performance, ensuring civil and defense needs are met without excessive expenditure, and sharing infrastructure where feasible to reduce costs while maintaining security through logical separation.

Ultra-secure transport networks are designed to meet stringent reliability, resilience, and security requirements. These type of networks are critical for civil and defense applications, ensuring continuous operation and protection against various threats. The important graph properties that such networks should exhibit include high connectivity, redundancy, low diameter, high node degree, network segmentation, robustness to attacks, scalability, efficient load balancing, geographical diversity, and adaptive routing.

High connectivity ensures multiple independent paths between any pair of nodes in the network, which is crucial for a communication network’s resilience and fault tolerance. This allows the network to maintain functionality even if several nodes or links fail, making it capable of withstanding targeted attacks or random failures without significant performance degradation. Redundancy, which involves having multiple backup paths and nodes, enhances fault tolerance and high availability by providing alternative routes for data transmission if primary paths fail. Redundancy also applies to critical network components such as switches, routers, and communication links, ensuring no or uncritical single point of failure.

A low diameter, the longest-shortest path between any two nodes, ensures data can travel quickly across the network, minimizing latency. This is especially important in time-sensitive applications. High node degree, meaning nodes are connected to many other nodes, increases the network’s robustness and allows for multiple paths for data to traverse, contributing to security and availability. However, it is essential to manage the trade-off between having a high node degree and the complexity of the network.

Network segmentation and compartmentalization will enhance security by limiting the impact of breaches or failures on a small part of the network. This is of particular importance when having a dual-use network design. Network segmentation divides the network into multiple smaller subnetworks. Each segment may have its own security and access control policies. Network compartmentalization involves designing isolated environments where, for example, data and functionalities are separated based on their criticality and sensitivity (this is, in general, a logical separation). Both strategies help contain cyber threats as well as prevent them from spreading across an entire network. Moreover, it also allows for a more granular control over network traffic and access. With this consideration, we should have a network that is robust against various types of attacks, including both physical and cyber attacks, by using secure protocols, encryption, authentication mechanisms, and intrusion detection systems. The aim of the network topology should be to minimize the impact of potential attacks on critical network nodes and links.

In a country such as Greenland, with settlements spread out over a very long distance and supported by very long and exposed transmission links (e.g., long-haul microwave links), geographical diversity is an essential design consideration that allows us to protect the functioning of services against localized disasters or failures. Typically, this involves distributing switching and management nodes, including data centers, across different geographic locations, ensuring that a failure in one area or with a main transport link does not disrupt the major parts of a network. This is particularly important for disaster recovery and business continuity. Finally, the network should support adaptive and dynamic routing protocols that can quickly respond to changes in the network topology, such as node failures or changes in traffic patterns. Such protocols will enhance the network’s resilience by automatically finding the best real-time data transmission paths.

TUSASS NETWORK AS A GRAPH.

Real maps, such as the Greenland map shown below at the left side of Figure 8, provide valuable geographical context and are essential for understanding the physical layout and extent of, for example, a transport network. A graph representation, as shown on the right side of Figure 8, on the other hand, offers a powerful and complementary perspective of the real-world network topology. It can emphasize the structural properties (and qualities) without those disappearing in geographical details that often are not relevant to the network functioning (if designed appropriately). A graph can contain many layers of network information that pretty much describe the network stack if required (e.g., from physical transport up through IP, TCP/IP, and to the application layers). It also supports many types of advanced analysis, design scenarios, and different types of simulations. A graph representation of a communications network is an invaluable tool for network design, planning, troubleshooting, analysis, and management.

Thus, the network graph approach offers several benefits for planning and operations. Firstly, the approach can often visualize the network’s topology better than a geographical map. It facilitates the understanding of various network (and graph) relationships and interconnections between the various network components. Secondly, the graph algorithms can be applied to the network graph and support the analysis of its characteristics, such as availability and redundancy scores, connectivity in general, the shortest paths, and so forth. This kind of analysis helps us identify critical nodes or links that may be sensitive to network and service disruption. It can also help significantly in maintaining and optimizing a network’s operation.

So, analyzing the our communication network’s graph representation makes it possible to identify potential weaknesses in the physical transport network, such as single points of failure (SPoF), bottlenecks, or areas with limited or weak redundancy. These identified weaknesses can then be addressed to enhance the network’s resilience, e.g., improving our network’s redundancy, availability and thus its overall reliability.

Figure 8 The chart above shows on the left side the topology of the (real) transport network of Tusass with the reference point in the Greenlandic settlements it connects. It should be noted that the actual transport network is slightly different as there are more hops between settlements than is shown here. On the right side is a graph representation of the Tusass transport network, shown on the left. The network graph represents the transport network on the west coast north and southbound. There are three main connection categories: (Black dashed line) Microwave (MW), (Orange dashed line) Submarine Cable, and (Blue solid line) Satellite, of which there are a GEO and a LEO arrangement. The size of the node, or settlements, represents the size of the population, which is also why Nuuk has the largest circle. The graph has been drawn consistent with the Kamada-Kawai layout, which is particularly useful for small to medium graphs, providing a reasonable, intuitive visualization of the structural relationship between nodes.

In the following, it is important to understand that due to Greenland’s specific conditions, such as weather and geography, building a robust transport network regarding reliability and redundancy will always be challenging, particularly when relying on the standard toolbox for designing, planning, and creating such networks. With geographical challenges should for example be understood the resulting lack of civil infrastructure connecting settlements … such as the lack of a road network.

The Table below provides key performance indicators (KPIs) for the Greenlandic (Tusass) transport network graph, as illustrated in Figure 8 above. It represents various aspects of the transport network’s structure and connectivity. This graph consists of 93 vertices (e.g., settlements and other connection points, such as long-haul MW radio sites) and 101 edges (transport connections), and it is fully connected, meaning all nodes are reachable within the network. There is only one subgraph, indicating no isolated segments as expected.

The Average Path Length suggests that it takes on average 39 steps to travel between any two nodes. This is a relatively high number, which may indicate a less efficient network. The Diameter of a network is defined as the longest shortest path between any two nodes. It can be shown that the value of the diameter lies between the value of the radius and twice that value (and not higher;-). The diameter is found to be 32, indicating a quite high maximum distance between the most distant nodes. This suggests that the network has a quite extensive reach, as is also obvious from the various illustrations of the transport network above (Figure 8) and below (Figure 11 & 12). Apart from the fact that such a high diameter may indicate potential inefficiencies, a large diameter can also mean that, in the worst-case scenarios, such as a compromised link or connectivity issues in general, communication between some nodes involves many steps (or hops), potentially leading to higher latency and slower data transmission. Related to the Diameter, the network Radius is the minimum eccentricity of any node, which is the shortest path from the most central node to the farthest node. Here, we find the radius to be 16, which means that even the most centrally located node is relatively far from some other nodes in the network. Something that is also very obvious from the various illustrations of the transport network. This emphasizes that the network has nodes that are significantly far apart. Without sufficient redundancy in place, such a transport network may be more sensitive to disruption of the connectivity.

From the perspective of redundancy, a large diameter and radius may imply that the network has fewer alternative paths between distant nodes (i.e., a lower redundancy score). This is, for example, the case between the northern point of Kullorsuaq and Aasiaat. Aasiaat is the first settlement (from the North) to be connected both by microwave and submarine cable and thus has an alternative connectivity solution to the long-haul microwave chain. If a critical node or link fails, the alternative path latency might be considerably longer than the compromised connectivity, such as would be the case with the alternative connectivity being satellite-based, leading to inefficiencies and possible reduced performance. This can also suggest potential capacity bottlenecks where specific paths are heavily relied upon without having enough capacity to act as the sole connectivity for a given transmission path. Thus, the vulnerability of the network to failures increases, resulting in reduced performance for customers in the affected area.

We find a Graph Density, at 0.024. This value indicates a sparse network with relatively few connections compared to the number of possible connections. The Clustering Coefficient is 0.014 and indicates that there are very few tightly-knit groups of nodes (again easily confirmed by visual inspection of the graph itself, see the various figures). The value of the Average Betweenness (ca. 423) measures how often nodes act as bridges along the shortest path between other nodes, indicating a significant central node (i.e., Nuuk).

The Average Closeness of 0.0003 and the Average Eigenvector Centrality of 0.105 provide insights into settlements’ influence and accessibility within the transport network. The Average Closeness measures of how close, on average, nodes are to each other. A high value indicates that nodes (or settlements) are close to each other meaning that the information (e.g., user data, signaling) being transported over the network spreads quickly and efficiently. And not surprisingly the opposite would be the case for a low average value. For our Tusass network the average closeness is very low and suggests that the network may face challenges in accessibility and efficiency, with nodes (settlements) being relatively far from one another. This typically will have an impact on the speed and effectiveness of communication across the network. The Average Eigenvector Centrality measures the overall importance (or influence) of nodes within a network. The term Eigenvector is a mathematical concept from linear algebra that represents the stable state of the network and provides insights into the structure of the graph and thus the network. For our Tusass network the average eigenvector value is (very) low and indicates a distribution of influence across several nodes that may actually prevent reliance on a single point of failure and, in general, such structures are thought to enhance a network’s resilience and redundancy. An Average Degree of ca. 2 means that each node has about 2 connections on average, indicating a hierarchical network structure with fewer direct connections and with a somewhat low level of redundancy, consistent with what can be observed from the various illustrations shown in this post. This do indicate that our network may be more vulnerable to disruption and failures and have a relative high latency (thus, a high round trip time).

Say that for some reason, the connection to Ilulissat, a settlement north of Aasiaat on the west coast with a little under 5 thousand people, is disrupted due to a connectivity issue between Ilulissat and Qasigiannguit, a neighboring settlement to Ilulissat with ca. a thousand people. This would today disconnect ca. 11 thousand people from receiving communications services or ca. 20% of Tusass’s customer base as all settlements north of Ilulissat would likewise be disconnected because of the reliance on the broken connection to also transport their data towards Nuuk and the internet using the submarine cables out of Greenland. In the terminology of the network graph, a broken connection (or edge as it is called in graph theory) that breaks up the network into two (or more) disconnected parts is called a Bridge. Thus, the connection between Ilulissat and Qasigiannguit is a bridge, as if it is broken, disconnecting the northern part of the long-haul microwave network above Ilulissat. Similarly, if Ilulissat were a central switching hub disrupted, it would disconnect the upper northern network from the network south of Ilulissat, and we would call Ilulissat an Articulation Point. For example, a submarine cable between Aasiaat and Ilulissat would provide redundancy for this particular event, mitigating a disruption of the microwave long-haul network between Ilulissat and Aasiaat that would disconnect at least 20% of the population from communications services.

The transport network has 44 Articulation Points and 57 Bridges, highlighting vulnerabilities where node or link failures could significantly disrupt the connectivity between parts of the network, disconnecting major parts of the network and thus disrupting services. A Modularity of 0.65 suggests a moderately high presence of distinct communities, with the network divided into 8 such communities (see Figure below).

Figure 9 In network analysis, a “natural” community (or cluster) is a group of nodes that are more densely connected to each other than to nodes outside the group. Natural communities are denser subgraphs within a larger network. Identifying such communities helps in understanding the structure and function of the network. In the above analysis of how Tusass’s transport network connects to the various settlements illustrates quiet well the various categories of connectivity (e.g., long-haul microwaves only, submarine cable redundancy, satellite redundancy, etc..) in the communications network of Tusass,

A Throughput (or Degree) of 202 indicates a network with an overall capacity for data transmission. The Degree is the average number of connections per node for a network graph. In a transport network, the degree indicates how many direct connections it has to other settlements. A higher degree implies better connectivity and potentially a higher resilience and redundancy. In a fully connected network with 93 nodes, the total degree would be 93 multiplied by 92, which equals 8,556. Therefore, a value of 202 is quite low in comparison, indicating that the network is far from fully connected, which anyway would be unusual for a transport network on this side. Our transport network is relatively sparse and, thus, resulting in a lower total degree, suggesting that fewer direct paths exist between nodes. This may potentially also mean less overall network redundancy. In the case of a node or link failure, there might be fewer alternative routes, which, as a consequence, can impact network reliability and resilience. Lower degree values can also indicate limited capacity for data transmission between nodes, potentially leading to congestion or bottlenecks if certain paths become over-utilized. This can, of course, then affect the efficiency and speed of data transfer within the network as traffic congestion levels increase.

The KPIs, shown in Table 1 below, collectively indicate that our Greenlandic transport network has several critical points and connections that could affect redundancy and availability. Particularly if they become compromised or experience outages. The high number of articulation points and bridges indicates possible design weaknesses, with the low density and average degree suggesting a limited level of redundancy. In fact, Tusass has, over several years, improved its transport network resilience, focusing on increasing the level of redundancy and reducing critical single points of failure. However, the changes and additions are costly and, due to the environmental conditions of Greenland, are also time-consuming, having fewer working days available for outdoor civil work projects.

Table 1 illustrates the most important graph KPIs, also described in the text above and below, that are associated with the graph representation of the Tusass transport network represented by the settlement connectivity (approximating but not one-to-one with the actual transport network).

In graph theory, an articulation point (see Figure 10 below) is a node that, if it is removed from the network, would split the network into disconnected parts. In our story, an articulation point would be one of our Greenlandic settlements. These types of points are thus important in maintaining network connectivity and serve as points in the network where alternative redundancy schemes might serve well. Therefore, creating additional redundancy in the network’s routing paths and implementing alternative connections will mitigate the impact of a failure of an articulation point, ensuring continued operations in case of a disruption. Basically, the more redundancy that a network has, the fewer articulation points the network will have; see also the illustration below.

Figure 10 The figure above illustrates the redundancy and availability of 3 simple undirected graphs with 4 nodes. The first graph is fully connected, with no articulation points or bridges, resulting in a redundancy and availability score of 100%. Thus I can remove a Node or a Connection from the graph and the remainder will remain full connected. The second graph, which is partly connected, has one articulation point and one bridge, leading to a redundancy and availability score of 75%. If I remove the third Node or the connection between Node 3 and Node 4, I would end with a disconnected Node 4 and a graph that has been broken up in 2 (e.g., if Node 3 is removed we have 2 sub-graphs {1,2} and {4}), The third graph, also partly connected, contains two articulation points and three bridges, resulting in a redundancy score of 0% and an availability score of 50%. Articulation points and bridges are highlighted in red to emphasize their critical roles in graph connectivity. Note: An articulation point is a node whose removal disconnects the graph and a bridge is an edge whose removal disconnects the graph.

Careful consideration of articulation points is crucial in preventing network partitioning, where removing a single node can disconnect the overall network into multiple sub-segments of the network. The connectivity between different segments is obviously critical for continuous data flow and service availability. Often, design and planning requirements dictate that if a network is broken into parts due to various disruption scenarios, these parts will remain functional and continue to provide a service that is possible with reduced performance. Network designers would make use of different strategies, such as increasing the physical redundancy of the transmission network as well as making use of routing algorithms on a higher level, such as multipath routing and diverse routing paths. Moreover, optimizing the placement of articulation points and routing paths (i.e., how traffic flows through the communications network) also maximizes resource utilization and may ensure optimal network performance and service availability for an operator’s customers.

Figure 11 illustrates the many articulation points of our Greenlandic settlements, represented as red stars in the graph of the Greenlandic transport network. Removing an articulation point (a critical node) would partition the graph into multiple disconnected components and may lead to severe service interruption.

In graph theory, a bridge is a network connection (or edge) whose removal would split the graph into multiple disconnected components. This type of connection is obviously critical for maintaining connectivity and facilitating communication between different network parts. In real life with real networks, the network designers would, in general, spend considerable time to ensure that such critical connections (i.e., so-called bridges) do not have an over-proportional impact on their network availability by, for example, building alternative connections (i.e., redundant connections) or ensuring that the impact of a compromised bridge would have a minimum impact in terms of the number of customers.

For our transport network in Greenland, the long-haul microwave transport network is overall less sensitive to disruption on a settlement level, as the underlying topology is like a long spine at high capacity and reasonable redundancy built-in with branches of MW radios that connect from the spine to a particular settlement. Thus, in most cases in this analysis, the long-haul MW radio site, in proximity to a given settlement, is the actual articulation point (not the settlement itself). The Nuuk data center, a central switching hub, is, by definition, an articulation point of very high criticality.

As discussed above and shown below (Figure 12), in the context of our transport network, bridges may play a crucial role in network resilience and fault tolerance. In our story, bridges represent the transport connections connecting Greenlandic settlements and the core network back in Nuuk (i.e., the master network node). In our representations, a bridge can, for example, be (1) a Microwave connection, (2) A submarine cable connection, and (3) a satellite connection provided by Tusass’s geo stationary satellite (e.g., Greensat) or by the low-earth orbiting OneWeb satellite. By identifying and managing bridges, network designers can mitigate the impact of link failures and disruptions, ensuring continuous operation and availability of services. Moreover, keeping network bridges in mind and minimizing them when planning a transport network will significantly reduce the risk of customer-affecting outages and keep the impact of transport disruption and the subsequent network partitioning to a minimum.

Figure 12 illustrates the many (edge) bridges and transport connections present in the graph of the Greenlandic transport network. Removing a bridge would split the network (graph) into multiple disconnected components, leading to network fragmentation and parts that may no longer sustain services. The above picture is common for long microwave chains with many hops (the connections themselves). The remedy is to make shorter hops, as Tusass is doing, and ensure that the connection itself is redundant equipment-wise (e.g., if one radio fails, there is another to take over). However, such a network would remain sensitive to any disruption of the MW site location and the large MW dish antenna.

Network designers should deploy redundancy mechanisms that would minimize the risk of the disruptive impact of compromised articulation points and bridges. They have several choices to choose from, such as multipath routing (e.g., ring topologies), link aggregation, and diverse routing paths to enhance redundancy and availability. These mechanisms will help minimize the impact of bridge failures and improve the overall network availability by increasing the level of network redundancy on a physical and logical level. Moreover, optimizing the placement of bridges and routing paths in a transport network will maximize resource utilization and ensure optimal network performance and service availability.

Knowing a given networks Articulation Points and Bridges will allow us to define an Availability and a Redundancy Score that we can use to evaluate and optimize a network’s robustness and reliability. Some examples of these concepts for simpler graphs (i.e., 4 nodes) are also shown in Figure 10 above. In the context of the Greenland transport network used here, these metrics can help us understand how resilient the network is to failures.

The Availability Score measures the proportion of nodes that are not articulation points, which might compromise our network’s overall availability if compromised. This score measures the risk of exposure to service disruption in case of a disconnection. As a reminder, the articulation point, or cut-vertex, is a node that, when removed, increases the number of components of the network and, thus, potentially the amount of disconnecting parts. The formula that is used to calculate the availability score is given by the total number of settlements (e.g., 93) minus the number of articulation points (e.g., 44) divided by the total number of settlements (e.g., 93). In this context, a higher availability score indicates a more robust network where fewer nodes are critical points of failure. Suppose we get a score that is close to one. In that case, this indicates that most nodes are not articulation points, suggesting that the network can sustain multiple node failures without significant loss of connectivity (see Figure 10 for a relatively simple illustration of this).

The Redundancy Score measures the proportion of connections that are not bridges, which could result in severe service disruptions to our customers if compromised. When a bridge is compromised or removed, it increases the number of network parts. The formula for the redundancy score is the total number of transport connections (edges, e.g., 101) minus the number of bridges (e.g., 57) divided by the total number of transport connections (edges, e.g., 101). Thus, in this context of redundancy, a higher redundancy score indicates a more resilient network where fewer edges are critical points of failure. If we get a redundancy score that is close to 100%, it would indicate that most of our (transport) connections cannot be categorized as bridges. This also suggests that our network can sustain multiple connectivity failures without it, resulting in a significant loss of overall connectivity and a severe service interruption.

Having more switching centers, or central hubs, can significantly enhance a communications network’s resilience, availability, and redundancy. It also reduces the consequences and impact of disruption to critical bridges in the network. Moreover, by distributing traffic, isolating failures, and providing multiple paths for data transmission, these central hubs may ensure continuous service to our customers and improve the overall network performance. In my opinion, implementing strategies to support multiple switching centers is essential for maintaining a robust and reliable communications infrastructure capable of withstanding various disruptions and enabling scaling to meet any future demands.

For our Greenlandic transport network shown above, we find an Availability Score of 53% and a Redundancy Score of 44%. While the scores may appear on the low side, we need to keep in mind that we are in Greenland with a population of 57 thousand mainly distributed along the west coast (from south to the north) in about 50+ settlements with 30%+ living in Nuuk. Tusass communications network connects to pretty much all settlements in Greenland, covering approximately 3,500+ km on the west coast (e.g., comparable to the distance from the top of Norway all the way down to the most southern point of Sicily), and irrespective of the number of people living in them. This is also a very clear desire, expectation, and direction that has been given by the Greenlandic administration (i.e., via the universal service obligation imposed on Tusass). The Tusass transport network is not designed with strict financial KPIs in mind and with the financial requirement that a given connection to a settlement would need to have a positive return on investment within a few years (as is the prevalent norm in our Industry). The transport network of Tusass has been designed to connect all communities of Greenland to an adequate level of quality and availability, prioritizing the coverage of the Greenlandic population (and the settlements they live in) rather than whether or not it makes hard financial sense. Tusass’s network is continuously upgraded and expanded as the demand for more advanced broadband services increases (as it does anywhere else in the world).

CRITICAL TECHNOLOGIES RELEVANT TO GREENLAND AND THE WIDER ARCTIC.

Greenland’s strategic location in the Arctic and its untapped natural resources, such as rare earth elements, oil, and gas, has increasingly drawn the attention of major global powers like the United States, Russia, and China. The melting Arctic ice due to climate change is opening new shipping routes and making these resources more accessible, escalating the geopolitical competition in the region.

Greenland must establish a defense and security strategy that minimizes its dependency on its natural allies and external actors to mitigate a situation where such may not be available or have the resources to commit to Greenland. An integral part of such a security strategy should be a dual-use, civil, and defense requirement whenever possible. Ensuring that Greenlandic society gets an immediate and sustainable return on investments in establishing a solid security framework.

5G technology offers significant advancements over previous generations of wireless networks, particularly in terms of private networking, speed, reliability, and latency across a variety of coverage platforms, e.g., (normal fixed) terrestrial antennas, vehicle-based (i.e., Cell on Wheels), balloon-based, drone-based, LEO-satellite based. This makes 5G ideal for setting up ad-hoc mobile coverage areas for military and critical civil applications. One of the key capabilities of 5G that supports these use cases is network slicing, which allows for the creation of dedicated virtual networks optimized for specific requirements.

Telia Norway has conducted trials together with the Norwegian Armed Forces in Norway to demonstrate the use of 5G for military applications (note: I think this is one of the best examples of an operator-defense collaboration on deployment innovation and directly applies to Arctic conditions). These trials included setting up ad-hoc 5G networks to support various military scenarios (including in an Arctic-like climate). The key findings demonstrated the ability to provide high-speed, low-latency communications in challenging environments, supporting real-time situational awareness and secure communications for military personnel. Ericsson has also partnered with the UK Ministry of Defense to trial 5G applications for military use. These trials focused on using 5G to support secure communications, enhance situational awareness, and enable the use of autonomous systems in military operations. NATO has conducted exercises incorporating 5G technology to evaluate its potential for improving command and control, situational awareness, and logistics in multi-national military operations. These exercises have shown the potential of 5G to enhance interoperability and coordination among allied forces. It is a very meaningful dual-use technology.

5G private networks offer a dedicated and secure network environment for specific organizations or use cases, which can be particularly beneficial in the Arctic and Greenland. These private networks can provide reliable communication and data transfer in remote and harsh environments, supporting military and civil applications. For instance, in Greenland, 5G private networks can enhance communication for scientific research stations, ensuring that data from environmental monitoring and climate research is transmitted securely and efficiently. They can also support critical infrastructure, such as power grids and transportation networks, by providing a reliable communication backbone. Moreover, in Greenland, the existing public telecommunications network may be designed in such a way that it essentially could operate as a “private” network in case transmission lines connecting settlements would be compromised (e.g., due to natural or unnatural causes), possibly a “thin” LEO satellite connection out of the settlement.

5G provides ultra-fast data speeds and low latency, enabling (near) real-time communication and data processing. This is crucial for military operations and emergency response scenarios where timely information is vital. Network slicing allows a single physical 5G network to be divided into multiple virtual networks, each tailored to specific applications or user groups. This ensures that critical communications are prioritized and reliable even during network congestion. It should be considered that for Greenland, the transport network (e.g., long-haul microwave network, routing choices, and satellite connections) might be limiting how fast the ultra-fast data speeds can become and may, at least along some transport routes, limit the round trip time performance (e.g., GEO satellite connections).

5G Enhanced Mobile Broadband (eMBB) provides high-speed internet access to support applications such as video streaming, augmented reality (AR), and virtual reality (VR) for situational awareness and training. Massive Machine-Type Communications (mMTC) supports a large number of IoT devices for monitoring and controlling equipment, sensors, and vehicles in both military and civil scenarios. Ultra-Reliable (Low-Latency) Communications (URLLC) ensures dependable and timely communication for critical applications such as command and control systems as well as unmanned and autonomous communication platforms (e.g., terrestrial, aerial, and underwater drones). I should note that designing defense and secure systems for ultra-low latency (< 10 ms) requirements would be a mistake as such cannot be guaranteed under all scenarios. The ultra-reliability (and availability) of transport connectivity is a critical challenge as it ensures that a given system has sufficient autonomy. Ultra-low latency of a given connectivity is much less critical.

For military (defense) applications, 5G can be rapidly deployed in the field using portable base stations to create a mobile (private) network. This is particularly useful in remote or hostile environments where traditional infrastructure is unavailable or has been compromised. Network slicing can create a secure, dedicated network for military operations. This ensures that sensitive data and communications are protected from interception and jamming. The low latency of 5G supports (near) real-time video feeds from drones, body cameras, and other surveillance equipment, enhancing situational awareness and decision-making in combat or reconnaissance missions.

Figure 13 The hierarchical coverage architecture shown above is relevant for military or, for example, search and rescue operations in remote areas like Greenland (or the Arctic in general), integrating multiple technological layers to ensure robust communication and surveillance. LEO satellites provide extensive broadband and SIGINT & IMINT coverage, supported by GEO satellites for stable links and data processing through ground stations. High Altitude Platforms (HAPs) offer 5G, IMINT, and SIGINT coverage at mid-altitudes, enhancing communication reach and resolution. The HAP system offers an extremely mobile and versatile platform for civil and defense scenarios. An ad-hoc private 5G network on the ground ensures secure, real-time communication for tactical operations. This multi-layered architecture is crucial for maintaining connectivity and operational efficiency in Greenland’s harsh and remote environments. The multi-layered communications network integrates IOT networks that may have been deployed in the past or in a specific mission context.

In critical civil applications, 5G can provide reliable communication networks for first responders during natural disasters or large-scale emergencies. Network slicing ensures that emergency services have priority access to the network, enabling efficient coordination and response. 5G can support the rapid deployment of communication networks in disaster-stricken areas, ensuring that affected populations can access critical services and information. Network slicing can allocate dedicated resources for smart city applications, such as traffic management, public safety, and environmental monitoring, ensuring that these services remain operational even during peak usage times. Thus, for Greenland, ensuring 5G availability would be through coastal settlements and possibly coastal coverage (outside settlements) of 5G at a lower frequency range (e.g., 600 – 900 MHz), prioritizing 5G coverage rather than 5G enhanced mobile broadband (i.e., any coverage at a high coverage probability is better than no coverage at certainty).

Besides 5G, what other technologies would otherwise be of importance in a Greenland Technology Strategy as it relates to its security and ensuring its investments and efforts also return beneficially to its society (e.g., a dual-use priority):

  • It would be advisable to increase the number of community networks within the overall network that can continue functioning if cut off from the main communications network. Thus, communications services in smaller and remote settlements depend less on a main or very few central communications control and management hubs. This requires on a local settlement level, or grouping of settlements, self-healing, remote (as opposed to a central hub) management, distributed databases, regional data center (typically a few racks), edge computing, local DNS, CDNs and content hosting, satellite connection, … Most telecom infrastructure manufacturing companies have today network in a box solutions that allow for such designs. Such solutions enable private 5G networks to function isolated from a public PLMN and fixed transport network.
  • It is essential to develop a (very) highly available and redundant digital transport infrastructure leveraging the existing topology strengthened by additional submarine cables (less critical than some of the other means of connectivity), increased transport ring- & higher-redundancy topologies, multi-level satellite connections (GEO, MEO & LEO, supplier redundancy) with more satellite ground gateways on Greenland (e.g., avoiding “off-Greenland” traffic routing). In addition, a remotely controlled stratospheric drone platform could provide additional connectivity redundancy at very high broadband speeds and low latencies.
  • Satellite backhaul solutions, operating, for example, from a Low Earth Orbit (LEO), such as shown in Figure below, are extending internet services to the farthest reaches of the globe. These satellites offer many benefits, as already discussed above, in connecting remote, rural, and previously un- and under-served areas with reliable internet services. Many remote regions lack foundational telecom infrastructure, particularly long-haul transport networks for carrying traffic away from remote populated areas. Satellite backhauls do not only offer a substantially better financial solution for enhancing internet connectivity to remote areas but are often the only viable solution for connectivity. The satellite backhaul solution is an important part of the toolkit to improve on redundancy and availability of particular very long and extensive long-haul microwave transport networks through remote areas (e.g., Greenland’s rugged and frequently hostile harsh coastal areas) where increasing the level of availability and redundancy with terrestrial means may be impractical (due to environmental factors) or incredibly costly.
    – LEO satellites provide several security advantages over GEO satellites when considering resistance to hostile actions to disrupt satellite communications. One significant factor is the altitude at which LEO satellites operate, which is between 500 and 2,000 kilometers, compared to GEO satellites, which are positioned approximately 36,000 kilometers above the equator. The lower altitude makes LEO satellites less vulnerable to long-range anti-satellite (ASAT) missiles.
    – LEO satellite networks are usually composed of large constellations with many satellites, often numbering in the dozens to hundreds. This extensive LEO network constellation provides some redundancy, meaning the network can still function effectively if some satellites are “taken out.” In contrast, GEO satellites are typically much fewer in number, and each satellite covers a much larger area, so losing even one GEO satellite will have a significant impact.
    – Another advantage of LEO satellites is their rapid movement across the sky relative to the Earth’s surface, completing an orbit in about 90 to 120 minutes. This constant movement makes it more challenging for hostile actors to track and target individual satellites for extended periods. In comparison, GEO satellites remain stationary relative to a fixed point on Earth, making them easier to locate and target.
    LEO satellites’ lower altitude also results in lower latency than GEO satellites. This can benefit secure, time-sensitive communications and is less susceptible to interception and jamming due to the reduced time delay. However, any security architecture of the critical transport infrastructure should not only rely on one type of satellite configuration.
    – Both GEO and LEO satellites have their purpose and benefits. Moreover, a hierarchical multi-dimensional topology, including stratospheric drones and even autonomous underwater vehicles, is worth considering when designing critical communications architecture. It is also worth remembering that public satellite networks may offer a much higher degree of communications redundancy and availability than defense-specific constellations. However, for SIGINT & IMINT collection, the defense-specific satellite constellations are likely much more advanced (unfortunately, they are also not as numerous as their civilian “cousins”). This said, a stratospheric aerial platform (e.g., HAP) would be substantially more powerful in IMINT and possibly also for some SIGINT tasks (or/and less costly & versatile) than a defense-specific satellite solution.
Figure 14 illustrates the architecture of a Low Earth Orbit (LEO) satellite backhaul system used by providers like OneWeb as well as StarLink with their so-called “Community Gateway” (i.e., using their Ka-band). It showcases the connectivity between terrestrial internet infrastructure (i.e., Satellite Gateways) and satellites in orbit, enabling high-speed data transmission. The network consists of LEO satellites that communicate with each other (inter-satellite Comms) using the Ku and Ka frequency bands. These satellites connect to ground-based satellite gateways (GW), which interface with Points of Presence (PoP) and Internet Exchange Points (IXP), integrating the space-based network with the terrestrial internet (WWW). Note: The indicated speeds and frequency bands (e.g., Ku: 12–18 GHz, Ka: 28–40 GHz) and data speeds illustrate the network’s capabilities.
Figure 15 illustrates an LEO satellite direct-to-device communication in remote areas without terrestrially-based communications infrastructure. Satellites are the only means of communication by a normal mobile device or classical satellite phone. Courtesy: DALL-E.
  • Establish an unmanned (remotely operated) stratospheric High Altitude Platform System (HAPS) (i.e., an advanced drone-based platform) or Unmanned Aerial Vehicles (UAV) over Greenland (or The Arctic region) with payload agnostic capabilities. This could easily be run out of existing Greenlandic ground-based aviation infrastructure (e.g., Kangerlussuaq, Nuuk, or many other community airports across Greenland). This platform could eventually become autonomous or require little human intervention. The high-altitude platform could support mission-critical ad-hoc networking for civil and defense applications (over Greenland). Such a multi-purpose platform can be used for IMINT and SIGINT (i.e., for both civil & defense) and civil communication means, including establishing connectivity to the ground-based transport network in case of disruptions. Lastly, a HAPS may also permanently offer high-quality and capacity 5G mobile services or act as a private ultra-secure 5G network in an ad-hoc mission-specific scenario. For a detailed account of stratospheric drones and how these compared with low-earth satellites, see my recent article “Stratospheric Drones & Low Earth Satellites: Revolutionizing Terrestrial Rural Broadband from the Skies?”.
    Stratospheric drones, which operate in the stratosphere at altitudes around 20 to 50 kilometers, offer several security advantages over traditional satellite communications and submarine communication cables, especially from a Greenlandic perspective. These drones are less accessible and harder to target due to their altitude, which places them out of reach for most ground-based anti-aircraft systems and well above the range of most manned aircraft. This makes them less vulnerable to hostile actions compared to satellites, which can be targeted by anti-satellite (ASAT) missiles, or submarine cables, which can be physically cut or damaged by underwater operations. The drones would stay over Greenlandic, or NATO, territory while by nature, design, and purpose, submarine communications cables and satellites, in general, are extending far beyond the territory of Greenland.
    – The mobility and flexibility of stratospheric drones allow them to be quickly repositioned as needed, making it difficult for adversaries to consistently target them. Unlike satellites that follow predictable orbits or submarine cables with fixed routes, these drones can change their location dynamically to respond to threats or optimize their coverage. This is particularly advantageous for Greenland, whose vast and harsh environment makes maintaining and protecting fixed communication infrastructure challenging.
    – Deploying a fleet of stratospheric drones provides redundancy and scalability. If one drone is compromised or taken out of service, others can fill the gap, ensuring continuous communication coverage. This distributed approach reduces the risk of a single point of failure, which is more pronounced with individual satellites or single submarine cables. For Greenland, this means a more reliable and resilient communication network that can adapt to disruptions.
    – Stratospheric drones can be rapidly deployed and recovered, making it an easier platform to maintain and upgrade them as needed compared to for example satellite based platforms and even terrestrial deployed networks. This quick deployment capability is crucial for Greenland, where harsh weather conditions can complicate the maintenance and repair of fixed infrastructure. Unlike satellites that require expensive and complex launches or submarine cables that involve extensive underwater laying and maintenance efforts, drones offer a more flexible and manageable solution.
    – Drones can also establish secure, line-of-sight communication links that are less susceptible to interception and jamming. Operating closer to the ground compared to satellites allows the use of higher frequencies narrower beams that are more difficult to jam. Additionally, drones can employ advanced encryption and frequency-hopping techniques to further secure their communications, ensuring that sensitive data remains protected. Stratospheric drones can also be equipped with advanced surveillance and countermeasure technologies to detect and respond to threats. For instance, they can carry sensors to monitor the electromagnetic spectrum for jamming attempts and deploy countermeasures to mitigate these threats. This proactive defense capability enhances their security profile compared to passive communication infrastructure like satellites or cables.
    – From a Greenlandic perspective, stratospheric drones offer significant advantages. They can be deployed over specific areas of interest, providing targeted communication coverage for remote or strategically important regions. This is particularly useful for covering Greenland’s vast and sparsely populated areas. Modern stratospheric drones are designed to support multi-dimensional payloads, or as it might also be called, payload agnostic (e.g., SIGINT & IMINT equipment, 5G base station and advanced antenna, laser communication systems, …) and stay operational for extended periods, ranging from weeks to months, ensuring sustained communication coverage without the need for frequent replacements or maintenance.
    – Last but not least, Greenland may be an ideal safe testing ground due to its vast, remote and thinly populated regions.
Figure 16 illustrates a Non-Terrestrial Network consisting of a stratospheric High Altitude Platform (HAP) drone-based constellation providing terrestrial Cellular broadband services to terrestrial mobile users delivered to their normal 5G terminal equipment that may range from smartphone and tablets to civil and military IOT networks and devices. Each hexagon represents a beam inside the larger coverage area of the stratospheric drone. One could assign three HAPs to cover a given area to deliver very high-availability services to a rural area. The operating altitude of a HAP constellation is between 10 and 50 km, with an optimum of around 20 km. It is assumed that there is inter-HAP connectivity, e.g., via laser links. Of course, it is also possible to contemplate having the gNB (full 5G radio node) in the stratospheric drone entirely, allowing easier integration with LEO satellite backhauls, for example. There might even be applications (e.g., defense, natural & unnatural disaster situations, …) where a standalone 5G SA core is integrated.
  • Unmanned Underwater Vehicles (UUV), also known as Autonomous Underwater Vehicles (AUV), are obvious systems to deploy for underwater surveillance & monitoring that may also have obvious dual-use purposes (e.g., fisheries & resource management, iceberg tracking and navigation, coastal defense and infrastructure protection such as for submarine cables). Depending on the mission parameters and type of AUV, the range is between up to 100 kilometers (e.g., REMUS100) to thousands of kilometers (e.g., SeaBed2030) and an operational time (endurance) from max. 24 hours (e.g., REMUS100, Bluefin-21), to multiple days (e.g., Boing Echo Voyager), to several months (SeaBed2030). A subset of this kind of underwater solution would be swarm-like AUV constellations. See Figure 17 below for an illustration.
  • Increase RD&T (Research, Development & Trials) on Arctic Internet of Things (A-IOT) (note: require some level of coverage, minimum satellite) for civil, defense/military (e.g., Military IOT nor M-IOT) and dual-use applications, such as surveillance & reconnaissance, environmental monitoring, infrastructure security, etc… (note: IOTs are not only for terrestrial use cases but also highly interesting for aquatic applications in combination with AUV/UUVs). Military IoT refers to integrating IoT technologies tailored explicitly for military applications. These devices enhance operational efficiency, improve situational awareness, and support decision-making processes in various military contexts. Military IoT encompasses various connected devices, sensors, and systems that collect, transmit, and analyze data to support defense and security operations. In the vast and remote regions of Greenland and the Arctic, military IoT devices can be deployed for continuous surveillance and reconnaissance. This includes using drones, such as advanced HAPS, equipped with cameras and sensors to monitor borders, track the movements of ships and aircraft, and detect any unauthorized activities. Military IoT sensors can also monitor Arctic environmental conditions, tracking ice thickness changes, weather patterns, and sea levels. Such data is crucial for planning and executing military operations in the challenging Arctic environment but is also of tremendous value for the Greenlandic society. The importance of dual-use cases, civil and defense, cannot be understated; here are some examples:
    Infrastructure Monitoring and Maintenance: (Military Use Case) IoT sensors can be deployed to monitor the structural integrity of military installations, such as bases and airstrips, ensuring they remain operational and safe for use. These sensors can detect stress, wear, and potential damage due to extreme weather conditions. These IoT devices and networks can also be deployed for perimeter defense and monitoring. (Civil Use Case) The same technology can be applied to civilian infrastructure, including roads, bridges, and public buildings. Continuous monitoring can help maintain these civil infrastructures by providing early warnings about potential failures, thus preventing accidents and ensuring public safety.
    Secure Communication NetworksMilitary Use Case: Military IoT devices can establish secure communication networks in remote areas, ensuring that military units can maintain reliable and secure communications even in the Arctic’s harsh conditions. This is critical for coordinating operations and responding to threats. Civil Use Case: In civilian contexts, these communication networks can enhance connectivity in remote Greenlandic communities, providing essential services such as emergency communications, internet access, and telemedicine. This helps bridge the digital divide and improve residents’ quality of life.
    Environmental Monitoring and Maritime SafetyMilitary Use Case: Military IoT devices, such as underwater sensor networks and buoys, can be deployed to monitor sea conditions, ice movements, and potential maritime threats. These devices can provide real-time data critical for naval operations, ensuring safe navigation and strategic planning. Civil Use Case: The same sensors and buoys can be used for civilian purposes, such as ensuring the safety of commercial shipping lanes, fishing operations, and maritime travel. Real-time monitoring of sea conditions and icebergs can prevent maritime accidents and enhance the safety of maritime activities.
    Fisheries Management and SurveillanceMilitary Use Case: IoT devices can monitor and patrol Greenlandic waters for illegal fishing activities and unauthorized maritime incursions. Drones and underwater sensors can track vessel movements, ensuring that military forces can respond to potential security threats. Civil Use Case: These monitoring systems can support fisheries management by tracking fish populations and movements, helping to enforce sustainable fishing practices and prevent overfishing. This data is important for the local economy, which heavily relies on fishing.
  • Implement Distributed Acoustic Sensing (DAS) on submarine cables. DAS utilizes existing fiber-optic cables, such as those used for telecommunications, to detect and monitor acoustic signals in the underwater environment. This innovative technology leverages the sensitivity of fiber-optic cables to vibrations and sound waves, allowing for the detection of various underwater activities. This could also be integrated with the AUV and A-IOTs-based sensor systems. It should be noted that jamming a DAS system is considerably more complex than jamming traditional radio-frequency (RF) or wireless communication systems. DAS’s significant security and defense advantages might justify deploying more submarine cables around Greenland. This investment is compelling because of enhanced surveillance and security, improved connectivity, and strategic and economic benefits. By leveraging DAS technology, Greenland could strengthen its national security, support economic development, and maintain its strategic importance in the Arctic region.
  • Greenland should widely embrace autonomous systems deployment and technologies based on artificial intelligence (AI). AI is a technology that could compensate for the challenges of having a vast geography, a hostile climate, and a small population. This may, by far, be one of the most critical components of a practical security strategy for Greenland. Getting experience with autonomous systems in a Greenlandic and Arctic setting should be prioritized. Collaboration & knowledge exchange with Canadian and American universities should be structurally explored, as well as other larger (friendly) countries with Arctic interests (e.g., Norway, Iceland, …).
  • Last but not least, cybersecurity is an essential, even foundational, component of the securitization of Greenland and the wider Arctic, addressing the protection of critical infrastructure, the integrity of surveillance and monitoring systems, and the defense against geopolitical cyber threats. The present state and level of maturity of cybersecurity and defense (against cyber threats) related to Greenland’s critical infrastructure has to improve substantially. Prioritizing cybersecurity may have to be at the expense of other critical activities due to limited resources with relevant expertise available to businesses in Greenland). Today, international collaboration is essential for Greenland to develop strong cyber defense capabilities, ensure secure communication networks, and implement effective incident response plans. However, it is essential for Greenland’s security that a cybersecurity architecture is tailor-made to the particularities of Greenland and allows Greenland to operate independently should friendly actors and allies not be in a position to provide assistance.
Figure 17 Above illustrates an Unmanned Underwater Vehicle (UUV) near the coast of Greenland inspecting a submarine cable. The UUV is a robotic device that operates underwater without a human onboard, controlled either autonomously or remotely. In and around Greenland’s coastline, UUVs may serve both defense and civilian purposes. For defense, they can patrol for submarines, monitor underwater traffic, and detect potential threats, enhancing maritime security. Civilian applications include search & rescue missions, scientific research, where UUVs map the seabed, study marine life, and monitor environmental changes, crucial for understanding climate change impacts. Additionally, they inspect underwater infrastructure like submarine cables, ensuring their integrity and functionality. UUVs’ versatility makes them invaluable for comprehensive underwater exploration and security along Greenland’s long coast line. Integrated defense architectures may combine the UUV, Distributed Acoustic Sensor (DAS) networks deployed at submarine cables, and cognitive AI-based closed-loop security solutions (e.g., autonomous operation). Courtesy: DALL-E.

How do we frame some of the above recommendations into a context of securitization in the academic sense of the word aligned with the Copenhagen School (as I understand it)? I will structure this as the “Securitizing Actor(s),” “Extraordinary Measures Required,” and the “Geopolitical Implications”:

Example 1: Improving Communications networks as a security priority.

Securitizing Actor(s): Greenland’s government, possibly supported by Denmark and international allies (e.g., The USA’s Pituffik Space Base on Greenland), frames the lack of higher availability and reliable communication networks as an existential threat to national security, economic development, and stability, including the ability to defend Greenland effectively during a global threat or crisis.

Extraordinary Measures Required: Greenland can invest in advanced digital communication technologies to address the threat. This includes upgrading infrastructure such as fiber-optic cables, satellite communication systems, stratospheric high-altitude platform (HAP) with IMINT, SIGINT, and broadband communications payload, and 5G wireless networks to ensure they are reliable and can handle increased data traffic. Implementing advanced cybersecurity measures to protect these networks from cyber threats is also crucial. Additionally, investments in broadband expansion to remote areas ensure comprehensive coverage and connectivity.

Geopolitical Implications: By framing the reliability and availability of digital communications networks as a national security issue, Greenland ensures that significant resources are allocated to upgrade and maintain these critical infrastructures. Greenland may also attract European Union investments to leapfrogging the critical communications infrastructure. This improves Greenland’s day-to-day communication and economic activities and enhances its strategic importance by ensuring secure and efficient information flow. Reliable digital networks are essential for attracting international investments, supporting digital economies, and maintaining social cohesion.

Example 2: Geopolitical Competition in the Arctic

Securitizing Actor(s): The Greenland government, aligned with Danish and international allies’ interests, views the increasing presence of Russian and Chinese activities in the Arctic as a direct threat to Greenland’s sovereignty and security.

Extraordinary Measures Required: In response, Greenland can adopt advanced surveillance and defense technologies, such as Distributed Acoustic Sensing (DAS) systems to monitor underwater activities and Unmanned Aerial & Underwater Vehicles (UAVs & UUVs) for continuous aerial surveillance. Additionally, deploying advanced communication networks, including satellite-based systems, ensures secure and reliable information flow.

Geopolitical Implications: By framing foreign powers’ increased activities as a security threat (e.g., Russia and China), Greenland can attract NATO and European Union investments and support for deploying cutting-edge surveillance and defense technologies. This enhances Greenland’s security infrastructure, deters potential adversaries, and solidifies its strategic importance within the alliance.

Example 3: Cybersecurity as a National Security Priority.

Securitizing Actor(s): Greenland, aligned with its allies, frames the potential for cyber-attacks on critical infrastructure (such as power grids, communication networks, and military installations) as an existential threat to national security.

Extraordinary Measures Required: To address this threat, Greenland can invest in state-of-the-art cybersecurity technologies, including artificial intelligence-driven threat detection systems, encrypted communication channels, and comprehensive incident response frameworks. Establishing partnerships with global cybersecurity firms and participating in international cybersecurity exercises can also be part of the strategy.

Geopolitical Implications: By securitizing cybersecurity, Greenland ensures that significant resources are allocated to protect its digital infrastructure. This safeguards its critical systems and enhances its attractiveness as a secure location for international investments, reinforcing its geopolitical stability and economic growth.

Example 4: Arctic IoT and Dual-Use Military IoT Networks as a Security Priority.

Securitizing Actor(s): Greenland’s government, supported by Denmark and international allies, frames the lack of Arctic IoT and dual-use military IoT networks as an existential threat to national security, economic development, and environmental monitoring.

Extraordinary Measures Required: Greenland can invest in deploying Arctic IoT and dual-use military IoT networks to address the threat. These networks involve a comprehensive system of interconnected sensors, devices, and communication technologies designed to operate in the harsh Arctic environment. This includes deploying sensors for environmental monitoring, enhancing surveillance capabilities, and improving communication and data-sharing across military and civilian applications.

Geopolitical Implications: By framing the lack of Arctic IoT and dual-use military IoT networks as a national security issue, Greenland ensures that significant resources are allocated to develop and maintain these advanced technological infrastructures. This improves situational awareness and operational efficiency and enhances Greenland’s strategic importance by providing real-time data and robust monitoring capabilities. Reliable IoT networks are essential for protecting critical infrastructure, supporting economic activities, and maintaining environmental and national security.

THE DANISH DEFENSE & SECURITY AGREEMENT COVERING THE PERIOD 2024 TO 2033.

Recently, Denmark approved its new defense and security agreement for the period 2024-2033. This strongly emphasizes Denmark’s strategic reorientation in response to the new geopolitical realities. A key element in the Danish commitment to NATO’s goals includes a spending level approaching and possibly superseding the 2% of GDP on defense by 2030. It is not 2% for the sake of 2%. There really is a lot to be done, and as soon as possible. The agreement entails significant financial investments totaling approximately 190 billion DKK (or ca. 25+ billion euros) over the next ten years to quantum leap defense capabilities and critical infrastructure.

The defense agreement emphasizes the importance of enhancing security in the Arctic region, including, of course, Greenland. Thus, Greenland’s strategic significance in the current geopolitical landscape is recognized, particularly in light of Russian activities and Chinese expressed intentions (e.g., re: the “Polar Silk Road”). The agreement aims to strengthen surveillance, sovereignty enforcement, and collaboration with NATO in the Arctic. As such, we should expect investments to improve surveillance capabilities that would strengthen the enforcement of Greenland’s sovereignty. Ensuring that Greenland and Denmark can effectively monitor and protect its Arctic territories (together with its allies). The defense agreement stresses the importance of supporting NATO’s mission in the Arctic region, contributing to collective defense and deterrence efforts.

What I very much like in the new defense agreement is the expressed focus on dual-use infrastructure investments that benefit Greenland’s defense (& military) and civilian sectors. This includes upgrading existing facilities and enhancing operational capabilities in the Arctic that allow a rapid response to security threats. The agreement ensures that defense investments also bring economic and social benefits to Greenlandic society, consistent with a dual-use philosophy. In order for this to become a reality, it will involve a close collaboration with local authorities, businesses, and research institutions to support the local economy and create new job opportunities (as well as ensure that there is a local emphasis on relevant education to ensure that such investments are locally sustainable and not relying on an “army” of Danes and others of non-Greenlandic origin).

The defense agreement unsurprisingly expresses a strong commitment to enhancing cybersecurity measures as well as addressing hybrid threats in Greenland. This reflects the broader security challenges of the new technology introduction required, the present cyber-maturity level, and, of course, the current (and future expected) geopolitical tensions. The architects behind the agreement have also realized that there is a big need to improve recruitment, retention, and appropriate training within the defense forces, ensuring that personnel are well-prepared to operate in the Arctic environment in general and in Greenland in particular.

It is great to see that the Danish “Defense and Security Agreement” for 2024-2033 reflects the principles of securitization by framing Greenland’s security as an existential threat and justifying substantial investments and strategic initiatives in response. The focus of the agreement is on enhancing critical infrastructure, surveillance platforms, and international cooperation while ensuring that the benefits of the local economy align with the concept of securitization. That is to ensure that Greenland is well-prepared to address current and future security challenges and anticipated threats in the Arctic region.

The agreement underscores the importance of advanced surveillance systems, such as, for example, satellite-based monitoring and sophisticated radar systems as mentioned in the agreement. These technologies are deemed important for maintaining situational awareness and ensuring the security of Denmark’s territories, including Greenland and the Arctic region in general. In order to improve response times as well as effectiveness, enhanced surveillance capabilities are essential for detecting and tracking potential threats. Moreover, such capabilities are also important for search and rescue, and many other civilian use cases are consistent with the intention to ensure that applied technologies for defense purposes have dual-use capabilities and can also be used for civilian purposes.

There are more cyber threats than ever before. These threats are getting increasingly sophisticated with the advance of AI and digitization in general. So, it is not surprising that cybersecurity technologies are also an important topic in the agreement. The increasing threat of cyber attacks, particularly against critical infrastructure and often initiated by hostile state actors, necessitates a robust cybersecurity defense in order to protect our critical infrastructure and the sensitive information it typically contains. This includes implementing advanced encryption, intrusion detection systems, and secure communication networks to safeguard against cyber threats.

The defense agreement also highlights the importance of having access to unmanned systems or drones. There are quite a few examples of such systems as discussed in some detail above, and can be found in my more extensive article “Stratospheric Drones & Low Earth Satellites: Revolutionizing Terrestrial Rural Broadband from the Skies?“. There are two categories of drones that may be interesting. One is the unmanned version that typically is remotely controlled in an operations center at a distance from the actual unmanned platform. The other is the autonomous (or semi-autonomous) drone version that is enabled by AI and many integrated sensors to operate independently of direct human control or at least largely without real-time human intervention. Examples such as Unmanned Vehicles (UVs) and Autonomous Vehicles (AVs) are typically associated with underwater (UUV/UAV) or aerial (UAV/AAV) platforms. This kind of technology provides versatile, very flexible surveillance & reconnaissance, and defense platforms that are not reliant on a large staff of experts to operate. They are particularly valuable in the Arctic region, where harsh environmental conditions can limit the effectiveness of manned missions.

The development and deployment of dual-use technologies are also emphasized in the agreement. These technologies, which have both civilian and military applications, are necessary for maximizing the return on investment in defense infrastructure. It may also, at the moment, be easier to find funding if it is defense-related. Technology examples include advancements in satellite communications and broadband networks, enhancing military capabilities, and civilian connectivity, particularly how those various communications technologies can seamlessly integrate with one another is very important.

Furthermore, artificial intelligence (AI) has been identified as a transformative technology for defense and security. While AI is often referred to as a singular technology. However, it is actually an umbrella term that encompasses a broad spectrum of frameworks, tools, and techniques that have a common basis in models that are being trained on large (or very large) sets of data in order to offer various predictive capabilities of increasing sophistication. This leads to the expectation that, for example, AI-driven analytics and decision-making applications will enhance the operational efficiency and, not unimportantly, the quality of real-time decision-making in the field (which may or may not be correct and for sure may be somewhat optimistic expectations at least at a basic level). AI-enabled defense platforms or applications are likely to result in improved threat detection as well as being able to support strategic planning. As long as the risk of false outcomes is acceptable, such a system will enrich the defense systems and provide significant advantages in managing complex and highly dynamic security environments and time-critical threat scenarios.

Lastly, the agreement stresses the need for advanced logistics and supply chain technologies. Efficient logistics are critical for sustaining military operations and ensuring the timely delivery of equipment and supplies. Automation, real-time tracking, and predictive analytics in logistics management can significantly improve the resilience and responsiveness of defense operations.

AT THIS POINT IN MY GREENLANDIC JOURNEY.

In my career, I have designed, planned, built, and operated telecommunications networks in many places under vastly different environmental conditions (e.g., geography and climate). The more I think about building robust and highly reliable communication networks in Greenland, including all the IT & compute enablers required, the more I appreciate how challenging and different it is to do so in Greenland. Tusass has built a robust and reliable transport network connecting nearly all settlements in Greenland down to the smallest size. Tusass operates and maintains this network under some of the harshest environmental conditions in the world, with an incredible dedication to all those settlements that depend on being connected to the outside world and where a compromised connection may have dire consequences for the unconnected community.

Figure 18 Shows a coastal radio site in Greenland. It illustrates one of the frequent issues of the critical infrastructure being covered by ice as well as snow. Courtesy: Tusass A/S (Greenland),

Comparing the capital spending level of Tusass in Greenland with the averages of other Western European countries, we find that Tusass does not invest significantly more of its revenue than the telco industry’s country averages of many other Western European countries. In fact, its 5-year average Capex to Revenue ratio is close to the Western European country average (19% over the period 2019 to 2023). In terms of capital investments compared to the revenue generating units (RGUs), Tusass does have the highest level of 18.7 euros per RGU per month, based on a 5-year average over the period 2019 to 2023, in comparison with the average of several Western European markets, coming out at 6.6 euros per RGU per month, as shown in the chart below. This difference is not surprising when considering the available population in Greenland compared to the populations in the countries considered in the comparison. The variation of capital investments for Tusass also shows a much larger variation than other countries due to substantially less population to bear the burden of financing big capital-intensive projects, such as the deployment of new submarine cables (e.g., typically coming out at 30 to 50 thousand euros per km), new satellite connections (normally 10+ million euros depending on the asset arrangement), RAN modernization (e.g., 5G), and so forth … For example, the average absolute capital spend was 14.0±1.5 million euros between 2019 and 2022, while 2023 was almost 40 million euros (a little less than 4% of the annual defense and security budget of Denmark) due to, according with Tusass annual report, RAN modernization (e.g., 5G), satellite (e.g., Greensat) and submarine cable investments (initial seabed investigation). All these investments bring better quality through higher reliability, integrity, and availability of Greenland’s critical communications infrastructure although there are not a large population (e.g., millions) to spread such these substantial investments over.

Figure 19 In a Western European context, Greenland does not, on average, invest substantially more in telecom infrastructure relative to its revenues and revenue-generating units (i.e., its customer service subscriptions) despite having a very low population of about 57 thousand and an area of 2.2 million square kilometers, the size of Alaska and only 33% smaller than India. The chart shows the country’s average Capex to Revenue ratio and the Capex in euros per RGU per month over the last 5 years (2019 to 2023) for Greenland (e.g., Tusass annual reports) and Western Europe (using data from New Street Research).

The capital investments required to leapfrog Greenland’s communications network availability and redundancy scores beyond 70% (versus 53% and 44%, respectively, in 2023) would be very substantial, requiring both additional microwave connections (including redesigns), submarine cables, and new satellite arrangements, and new ground stations (e.g., to or in settlements with more than a population of 1,000 inhabitants).

Those investments would serve the interests of the Greenlandic society and that of Denmark and NATO in terms of boosting the defense and security of Greenland, which is also consistent with all the relevant parties’ expressed intent of securitization of Greenland. The required capital investments related to further leapfrogging the safety, availability, and reliability, above and beyond the current plans, of the critical communications infrastructure would be far higher than previously capital spend levels by Tusass (and Greenland) and unlikely to be economically viable using conventional business financial metrics (e.g., net present value NPV > 0 and internal rate of return IRR > a given hurdle rate). The investment needs to be seen as geopolitical relevant for the security & safety of Greenland, and with a strong focus on dual-use technologies, also as beneficial to the Greenlandic society.

Even with unlimited funding and financing to enhance Greenland’s safety and security, the challenging weather conditions and limited availability of skilled resources mean that it will take considerable time to successfully complete such an extensive program. Designing, planning and building a solid defense and security architecture meaningful to Greenlandic conditions will take time. Though, I am also convinced that there are already pieces of the puzzle operational today that is important any future work.

Figure 18 An aerial view of one of Tusass’s west coast sites supporting coastal radio as well as hosting one of the many long-haul microwave sites along the west coast of Greenland. Courtesy: Tusass A/S (Greenland).

RECOMMENDATIONS.

A multifaceted approach is essential to ensure that Greenland’s strategic and infrastructure development aligns with its unique geographical and geopolitical context.

Firstly, Greenland should prioritize the development of dual-use critical infrastructure and the supporting architectures that can serve both civilian and defense (& military) purposes. For example expanding and upgrading airport facilities (e.g., as is happening with the new airport in Nuuk), enhancing broadband internet access (e.g., as Tusass is very much focusing on adding more submarine cables and satellite coverage), and developing advanced integrated communication platforms like satellite-based and unmanned aerial systems (UAS), such as payload agnostic stratospheric high altitude platforms (HAPs). Such dual-use infrastructure platforms could bolster the national security. Moreover it could support economic activities that would improve community connectivity, and enhance the quality of life for Greenland’s residents irrespective of where they live in Greenland. There is little doubt that securing funding from international allies (e.g., European Union, NATO, …) and public-private partnerships will be crucial in supporting the financing of these projects. Also ensuring that civil and defense needs are met efficiently and with the right balance.

Additionally, it is important to invest in critical enablers like advanced monitoring and surveillance technologies for the security & safety. Greenland should in particular focus on satellite monitoring, Distributed Acoustic Sensing (DAS) on its submarine cables, and Unmanned Vehicles for Underwater and Aerial applications (e.g., UUVs & UAVs). Such systems will enable a more comprehensive monitoring of activities around and over Greenland. This would allow Greenland to secure its maritime routes, and protecting Greenland’s natural resources (among other things). Enhanced surveillance capabilities will also provide multi-dimensional real-time data for national security, environmental monitoring, and disaster response scenarios. Collaborating with NATO and other international partners should focus on sharing technology know-how, expertise in general, and intelligence that will ensure that Greenland’s surveillance capabilities are on par with global standards.

Tusass’s transport network connecting (almost) all of Greenland’s settlements is an essential and critical asset for Greenland. It should be the backbone for any dual-use enhancement serving civil as well as defense scenarios. Adding additional submarine cables and more satellite connections are important (on-going) parts of those enhancements and will substantially increase both the network availability, resilience and hardening to disruptions natural as well as man-made kinds. However, increasing the communications networks ability to fully, or even partly, function in case of network parts being cut off from a few main switching centers may be something that could be considered. With todays technologies might also be affordable to do and fit well with Tusass’s multi-dimensional connectivity strategy using terrestrial means (e.g., microwave connections), sub-marine cables and satellites.

Last but not least, considering Greenland’s limited human resources, the technologies and advanced platforms implemented must have a large degree of autonomy and self-reliance. This will likely only be achieved with solid partnerships and strong alliances with Denmark and other natural allies, including the Nordic countries in and near the Arctic Circle (e.g., Island, Faroe Island, Norway, Sweden, Finland, The USA, and Canada). In particular, Norway has had recent experience with the dual use of ad-hoc and private 5G networking for defense applications. Joint operation of UUV and UAVs integrated with DAS and satellite constellation could be operated within the Arctic Circle. Developing and implementing advanced AI-based technologies should be a priority. Such collaborations could also make these advanced technologies much more affordable than if only serving one country. These technologies can compensate for the sparse population and vast geographical challenges that Greenland and the larger Arctic Circle pose, providing efficient and effective infrastructure management, surveillance, and economic development solutions. Achieving a very high degree of autonomous operation of the multi-dimensional technology landscape required for leapfrogging the security of Greenland, the Greenlandic Society, and its critical infrastructure would be essential for Greenland to be self-reliant and less dependent on substantial external resources that may be problematic to guaranty in times of crisis.

By focusing on these recommendations, Greenland can enhance its strategic importance, improve its critical infrastructure resilience, and ensure sustainable economic growth while maintaining its unique environmental heritage.

Being a field technician in Greenland poses some occupational hazards that is unknown in most other places. Apart from the harsh weather, remoteness of many of the infrastructure locations, on many occasions field engineers have encountered hungry polar bears in the field. The polar bear is a very dangerous predator that is always on the look out for its next protein-rich meal.

FURTHER READING.

  1. Tusass Annual Reports 2023 (more reports can be found here).
  2. Naalakkersuisut / Government of Greenland Ministry for Statehood and Foreign Affairs, “Greenland in the World — Nothing about us without us: Greenland’s Foreign, Security, and Defense Policy 2024-2033 – an Arctic Strategy.” (February 2024). The Danish title of this Document (also published in Greenlandic as the first language): “Grønland i Verden — Intet om os, uden os: Grønlands udenrigs-, sikkerheds- og forsvarspolitiske strategi for 2024-2033 — en Arktisk Strategi”.
  3. Martin Brum, “Greenland’s first security strategy looks west as the Arctic heats up.” Arctic Business Journal (February 2024).
  4. Marc Jacobsen, Ole Wæver, and Ulrik Pram Gad, “Greenland in Arctic Security: (De)securitization Dynamics under Climatic Thaw and Geopolitical Freeze.” (2024), University of Michigan Press. See also the video associated with the book launch. It’s not the best quality (sound/video), but if you just listen and follow the slides offline, it is actually really interesting.
  5. Michael Paul and Göran Swistek, “Russia in the Arctic: Development Plans, Military Potential, and Conflict Prevention,” SWP (Stiftung Wissenschaft und Politik) Research Paper, (February 2022). Some great maps are provided that clearly visualize the Arctic – Russia relationships.
  6. Marc Lanteigne, “The Rise (and Fall?) of the Polar Silk Road.” The Diplomat, (August 2022).
  7. Trym Eiterjord, “What the 14th Five-Year Plan says about China’s Arctic Interests”, The Arctic Institute, (November 2023). The link also includes references to several other articles related to the China-Arctic relationship from the Arctic Institute China Series 2023.
  8. Barry Buzan, Ole Wæver, and Jaap de Wilde, “Security: A New Framework for Analysis”, (1998), Lynne Rienner Publishers Inc..
  9. Kim Kyllesbech Larsen, The Next Frontier: LEO Satellites for Internet Services. | techneconomyblog, (March 2024).
  10. Kim Kyllesbech Larsen, Stratospheric Drones & Low Earth Satellites: Revolutionizing Terrestrial Rural Broadband from the Skies? | techneconomyblog, (January 2024).
  11. Deo, Narsingh. “Graph Theory with Applications to Engineering and Computer Science,” Dover Publications. This book is a reasonably accessible starting point for learning more about graphs. If this is new to you, I recommend going for the following Geeks for Geeks ” Introduction to Graph Data Structure” (April 2024), which provides a quick intro to the world of graphs.
  12. Mike Dano, “Pentagon puts 5G at center of US military’s communications future”, Light Reading (December 2020).
  13. Juan Pedro Tomas, “Telia to develop private 5G for Norway’s Armed Forces”, RCR Wireless (June 2022).
  14. Iain Morris, “Telia is building 5G cell towers for the battlefield”, Light Reading (June 2023).
  15. Saleem Khawaja, “How military uses of the IoT for defense applications are expanding”, Army Technology (March 2023).
  16. Mary Lee, James Dimarogonas, Edward Geist, Shane Manuel, Ryan A. Schwankhart, Bryce Downing, “Opportunities and Risks of 5G Military Use in Europe”, RAND (March 2023).
  17. Mike Dano, “NATO soldiers test new 5G tech“, Light Reading (October 2023).
  18. NATO publication, “5G Technology: Nokia Meets with NATO Allied Command Transformation to Discuss Military Applications”, (May 2024).
  19. Michael Hill, “NATO tests AI’s ability to protect critical infrastructure against cyberattacks” (January 2023).
  20. Forsvarsministeriet, Danmark, “Dansk forsvar og sikkerhed 2024-2033.” (June 2023): Danish Defense & Security Agreement (Part I).
  21. Forsvarsministeriet, Denmark, “Anden delaftale under forsvarsforliget 2024-2033“, (April 2024): Danish Defense & Security Agreement (Part II).
  22. The State Council Information Office of the People’s Republic of China, “China’s Arctic Policy”, (January 2018).

ACKNOWLEDGEMENT.

I greatly acknowledge my wife, Eva Varadi, for her support, patience, and understanding during the creative process of writing this article. I am incredible thankful to Tusass for providing many great pictures used in the post that illustrates the (good weather!) conditions that Tusass field technicians are faced with in the field working tirelessly on the critical communications infrastructure throughout Greenland. While the pictures shown in this post are really beautiful and breathtaking, the weather is unforgiven frequently stranding field workers for days at some of those remote site locations. Add to this picture the additional dangers of a hungry polar bear that will go to great length getting its weekly protein intake.