When AI meets line systems: scaling faster with multi-rail OLS

AI is changing the rules of networking and optical infrastructure is an important part of this transformation. As AI workloads grow larger and more distributed, data centers must exchange massive volumes of data, quickly, reliably and predictably. That means more bandwidth and more fiber pairs, otherwise known as rails, than ever before. 

The challenge? Space, power and operational complexity. Traditional optical amplification models were not designed for this level of scale. The Nokia 1830 GX Multi-rail Open Line System (OLS) changes that equation, making it easier and far more efficient to scale optical connectivity in the AI era.

The AI Supercycle is real, and it’s hungry for bandwidth

Modern AI training and AI-cluster backend connectivity don’t take place in a single data center. Instead, space and electrical power limitations force expansion into other locations, often thousands of kilometers apart. AI and cloud providers frequently deploy dozens, even hundreds of rails between these data centers, consuming the full C+L band spectrum multiple times. This AI cluster backend inter-data center-connectivity is referred to as scale-across. 

In addition, service providers, wholesalers, and neo clouds are looking for ways to grow more effectively in the shadow of the Shannon limit. As we start to hit the physical limits of how much capacity we can transport over fibers, deploying multi-rail solutions in traditional data center interconnect and in managed optical fiber network (MOFN) applications now becomes a necessity.

But increased rail counts quickly give rise to bottlenecks. In-line amplifier (ILA) sites hit their limits first, constrained by rack space, power availability and the sheer number of modules to manage. This is where multi-rail amplification becomes essential.

One module, four rails: density that changes the game

The multi-rail architecture is built around a simple idea: do more with less in smaller footprint. With Nokia’s 1830 GX multi-rail amplifier, four fiber rails are supported in 1RU. That translates to a deployment of up to 160 rails in a standard 40RU rack. This is a dramatic shift from traditional designs that required 12RU or more. The result is:

• Far fewer shelves and modules
• Far less intra-system cabling
• Faster deployment and turn up

This is both a technical and practical improvement for AI and cloud providers. Scaling no longer requires finding more space at every ILA site because infrastructure can now scale at the same pace as demand.

Power savings that add up fast

Density alone is not enough. Power is often the real bottleneck, especially at remote or space-constrained amplifier locations.

Here again, the multi-rail design delivers clear benefits, reducing power per fiber rail by more than 60% through the integration of multiple amplifiers into a single module. Multiply those savings across hundreds of rails, and the impact on operational cost and sustainability becomes impossible to ignore.

Less hardware, less complexity and better operations

As networks grow, operational complexity can quietly become the biggest cost driver. More modules mean more cabling, more patch fibers, more points of failure and more time spent managing infrastructure.

The 1830 GX multi-rail solution simplifies operations by design, with:

• Fewer modules and shelves
• Shared integrated dynamic gain equalization (DGE), optical channel monitoring (OCM), optical supervisory channel (OSC), and optical time-domain reflectometry (OTDR) across multiple rails
• Reduced weight, cabling and installation effort
• Management options with “blade as a network element” 

The payoff is faster deployment, easier scaling and smoother day-to-day operations: exactly what AI-driven environments demand.

Built for full C+L band scaling

The platform is optimized for full C+L band operation, enabling 9.6 THz of spectrum per fiber. This offers 51.2 Tb/s of fiber capacity with 800G coherent transceivers or 76.4 Tb/s with 1.2 Tb/s embedded engines. Integrated capabilities include:

• Integrated C+L band Erbium-doped fiber amplifier (EDFA) pre-amp and booster amplifiers
• Integrated OTDR, DGE, and optical channel monitoring (OCM)

Optional Raman amplification provides even more flexibility, allowing operators to tailor performance for long-haul or ultra-high-capacity scenarios with short or longer spans. Whether the goal is maximum reach or maximum throughput, the system adapts.

End-to-end efficiency with hyperscale OLS

The multi-rail ILA is not a stand-alone product. It is a key building block for the Nokia hyperscale OLS solution, designed to simplify the entire optical path. Our GX hyperscale OLS delivers:

• High-density, low-power terminals at data center nodes
  • C+L band amplifiers, C+L 66 port wavelength selective switches (WSS), amplified spontaneous emission (ASE) and OTDR all integrated into a single 2RU module   
• High-density, low-power amplification at ILA sites
  • Four C+L band amplifications east+west, DGE, and OTDR all highly integrated into a single 1RU module
• Fewer modules, shelves and patch fibers end to end
• Automated optical power management and operations

Cost-effective fixed DWDM configurations

The multi-rail sled can also be configured flexibly for terminal operation, functioning as a multi-fiber pre-amplifier and booster amplifier. Combined with a C+L band fixed dense wavelength-division multiplexing (DWDM) mux/demux, it forms a cost-effective fixed DWDM open line system for short- and medium-sized links where ultra-high capacity is required.

The bottom line

AI is driving unprecedented demand for optical connectivity, and traditional amplification models cannot keep up. The Nokia 1830 GX hyperscale and multi-rail solution removes the barriers to scaling capacity. It’s a smarter way for cloud and AI providers, telecommunication providers, neo clouds and wholesale providers to build efficient, high-capacity multi-rail optical networks faster and more economically in the era of skyrocketing demand driven by AI.