Understanding Google's Undersea Cable Design with 32 Strands

The question of why Google's new undersea cable comprises only 32 strands is a matter of careful cost optimization and strategic planning in the realm of data communication infrastructure. Let's break down the reasoning behind this choice.

Understanding Fiber Strand Usage

The assertion that the cable only has 32 strands might be misleading. It is highly likely that Google contracts for 32 active strands, with the remaining strands serving as spares to ensure uninterrupted service in case an active strand fails. This approach is common in undersea cable systems, where redundancy is crucial for maintaining communication reliability.

Redundancy and Future Upgrades

Having spare strands allows Google to upgrade the capacity of the cable in the future without the need to lay an additional cable. By simply activating additional strands, Google can significantly increase its data transmission capacity without incurring the substantial costs of laying and operating a new cable. This strategy is both cost-effective and future-proof.

Optimization of Repeaters and System Nodes

Each cable requires repeaters at regular intervals to boost the signal. If a cable has 32 strands, it would need 32 repeaters. Due to the physical constraints of the cable and the need for efficient power usage, it is often not cost-effective or power-efficient to stuff more than 32 strands into a single repeater node. This is a trade-off between cost, maximum bandwidth, and the number of repeaters required.

Bandwidth and Data Transmission Capacity

The cable is designed to transport 340-350 terabytes of data per second, which equates to 17.5 million people simultaneously streaming 4K videos. The high bandwidth capacity of the fiber used in this cable ensures that it can handle this immense amount of data without significant degradation in performance.

The Role of DWDM Technology

The choice to use a lower number of strands is also influenced by the use of Dense Wavelength Division Multiplexing (DWDM) technology. DWDM allows multiple channels to be amplified simultaneously over a single fiber, making it more cost-effective to add capacity to the cable. Light amplification works more efficiently with closely spaced channels or a single channel, which means that adding more capacity to the fiber is cheaper than adding more individual strands. This is an important consideration in the economics of undersea cable deployment.

Future Expandability

The cable is designed to handle the needs of the foreseeable future. While a million strands might seem ideal from a capacity perspective, the practical constraints of cable diameter, shipping logistics, and operational costs make this approach less viable. The current configuration of 32 strands strikes a balance between initial investment and future expandability. It is likely that 24 strands are currently in use, with 8 strands set aside as spares.

Conclusion: Balancing Cost and Capacity

In summary, the design of Google's undersea cable with 32 strands is a product of strategic cost optimization and technical considerations. While the idea of a cable with a million strands might seem ideal, the practicalities of cable laying, operation, and logistics ensure that a more restrained approach is more cost-effective and efficient. The current design is a testament to the careful balancing of cost, capacity, and future scalability in the ever-evolving world of data communication technology.

Understanding the rationale behind such design choices is crucial for anyone involved in the field of telecommunications, as it provides insights into the complex trade-offs made in the pursuit of efficient and reliable data transmission systems.