How Open-Architecture Construction is Redefining the Future of Submarine Fleets

Maritime April 28, 2026

Naval communication systems are traditionally built around closed, proprietary architectures. However, growing demands for interoperability, technology insertion and through-life affordability are driving a move towards open, modular communication architectures.

For the past 20 years, SEA has been delivering open-architecture and modular communications systems, transforming how submarine communication systems are developed, integrated, maintained and upgraded over the lifetime of a platform.

Challenging operating environment

Submarines operate in one of the most unique and challenging environments in defence, with UK Royal Navy submarines capable of deploying for long periods of time.

During these deployments, communication systems are vital to the mission outcome and must deliver a secure, reliable capability while operating within strict constraints such as limited space, weight, power consumption, noise and heat generation. At the same time, submarines need to avoid detection, meaning communications equipment must have minimal acoustic and electromagnetic signatures.

The use of proprietary closed systems can dramatically increase the cost of addressing component or system obsolescence, increase through-life maintenance costs, and increase the complexity of integrating the latest technology into an existing system.

Doing more with less space

One of the defining challenges in submarine communications system design is the extremely limited space available on board. Communications rooms must accommodate a range of equipment, including radios, encryption systems and network management tools, while maintaining strict environmental controls and ensuring comfort for operators.

Advances in digitalisation and miniaturisation are helping address these constraints. Digitised baseband capabilities, such as SEA’s proprietary Network Interface Units and compact processing modules, can deliver enhanced functionality while occupying a significantly smaller footprint. This approach frees up valuable space, creating opportunities for capability insertion, and reduces the physical complexity of submarine communications suites. This technology can also help to integrate incumbent and modern systems by converting analogue signals from legacy equipment into digital formats that can be managed within a modern control architecture.

Added to this, digital management and control systems are streamlining operations by routing signals across onboard networks, replacing extensive cabling and hardware with more flexible, browser-based management and control software.

Maintaining security

Submarines operate within stricter security protocols than many surface-ship systems to remain undetected. This means minimal signals must be emitted, be that acoustic, electro-magnetic or thermal.

Modern modular systems help overcome these challenges by consolidating functions into fewer devices and isolating critical networks. Integrated management systems allow operators to control multiple communications channels through a single interface, reducing system complexity while maintaining operational security.

These technologies support rapid transmission cycles to maintain security and submarine stealth. This is achieved by minimising the time the submarine is exposed at, or near the surface, allowing crews to switch between configurations quickly, automatically prioritising communications traffic and selecting the most optimal bearer to meet the platform’s operational need.

Reducing build time and supporting longer lifecycles

Beyond operational challenges, there are broader considerations in communications system design – one being their build time and lifespan.

Submarines are typically expected to remain in service for many decades, often exceeding 30 or 40 years. However, submarine build programmes can last for decades. During this time, communications technology evolves, creating challenges for integration of the latest technology.

Modular open architecture enables incremental upgrades throughout a platform’s lifecycle. Rather than replacing an entire communications suite, Navies can update individual components as new technologies emerge. This reduces obsolescence risk and allows submarines to incorporate new capabilities more quickly.

It also enables the integration of commercially available technologies, such as off-the-shelf radio systems, which can then be adapted for military use. This is particularly important as open system frameworks provide the customer, systems designers, integrators and installers, with options to rapidly integrate new technology within the same architecture, avoiding vendor lock in, and increasing the customers buyer power.

This flexibility supports quicker platform build times, multinational programmes and improves compatibility across classes of submarines and between allied fleets. Collaborative initiatives typically place a strong emphasis on shared operational frameworks and common technological standards. This aligns with a broader “common as possible, bespoke as necessary” (CAPBAN) approach to platform design. Modular communications systems can help support these goals through shared interfaces, compatible software environments, and consistent operating principles across partner navies. This in turn reduces training requirements and can improve operational co-ordination and alignment.

Giving navies control over their communication capability

Closed architecture sees navies having to rely on a limited number of suppliers and contractors for upgrades, maintenance and replacement parts, which ultimately increases vendor lock-in, reduces options for addressing obsolescence, and makes it more difficult to introduce new capability without costly redesign or downtime.

Open-architecture systems give navy procurement teams greater flexibility. Allowing navies to leverage equipment from multiple manufacturers within a single communications solution, which boosts submarine through-life adaptability, lowers obsolescence impact, and extends submarine system lifespan.

The modern design approach ultimately widens choice and procurement options for navies and allows them to select the technologies that best meet their specific operational requirements.

A new era for submarine fleets

The unique operating conditions of a submarine means that its communications system must be flexible, upgradable and importantly, reliable through years of service.

Open, modular communication systems are designed to meet these requirements, while providing navies with greater ownership and procurement options over their capability. For programmes such as SSN-AUKUS, a trilateral security partnership between Australia, the United Kingdom, and the United States that will replace the Astute Class Submarines, ambitious build times are critical. Open architecture solutions support faster delivery as well as greater commonality across fleets that can facilitate operational alignment and cross-nation collaboration.

In an increasingly diverse and evolving underwater threat environment, the ability to incorporate the latest technologies, maintain system availability, and deliver secure, low-signature communications will be crucial. By leveraging open architecture solutions, navies will be able to secure the operational advantage today and adapt to the challenges faced by its submarines today, and into the future.

Article submitted by James Williams, Head of UK Submarine Communications at SEA