Virtualization has revolutionized IT operations in companies around the world. Previously hardware-based functions exist now in software,  enabling multiple end-users to share a common hardware platform, leading to  economies of scale and optimal use of assets. This provides significant flexibility and agility as needs change. The submarine cable industry is now looking to this technology to make more efficient use of cables.

Similar to the widespread Virtual Machines in use in just about every IT shop around the globe, Spectrum Sharing utilizes virtualization  to partition optical spectrum in a submarine optical fiber pair among multiple different end-users. As such, each end-user sees only its dedicated ‘virtual’ fiber pair, which is a subset of the overall spectrum of the same, shared  physical fiber. Spectrum Sharing can work on standard C-band cables, as well as newer and wider-band cables supporting both C-band and L-band on the  same cable. Virtualizing a fiber pair is more practical on newer, uncompensated submarine cables that support wider repeater bandwidth, thus yielding more  available spectrum to partition among more end-users.

The shift to Spectrum Sharing is another step in the journey of the submarine industry, which has evolved from offering sub-lambda  (electrical) services, to wavelength-based (all-optical) services, to an entire  dark fiber pair. Spectrum Sharing enables end-users to buy or lease capacities  greater than a few wavelengths, yet less than acquiring a full, and very expensive, fiber pair—something few end-users could afford or need.

In addition to enabling greater Submarine Line Terminating Equipment (SLTE) choice to end-users, a key benefit of Spectrum  Sharing is the ability to take advantage of rapid advancements in SLTE modem technology. With Spectrum Sharing, end-users can enjoy the flexibility to increase the capacity of their optical spectrum partition with upgraded SLTE  technology at any point in the future. At the same time, cable operators face  monetization opportunities and challenges because they now market upgradeable THz  rather than the fixed Tb/s they’ve been accustomed to selling for so long. This  will require a change in service provider point of view.

While providers focus on how to monetize this new  approach, they can’t lose sight of security—a critical concern for users. To  securely and reliably implement Spectrum Sharing services, the underlying SLTE  technology must incorporate effective optical power management to ensure  changes that happen on one end-user’s spectrum do not affect other end-users  sharing the same fiber pair via leased channels or spectrum. Secure isolation of multiple end-users sharing the same fiber pair must also be incorporated into the SLTE so one end-user never sees another’s data. Vendors understand these  absolute requirements and have built in the necessary safeguards to ensure  security and privacy are implemented.

Spectrum sharing is the logical partitioning of optical  spectrum on a submarine cable for
different end-users, such that each end-user has its  own ‘virtual fiber pair.’

How Ciena helps

Ciena, with deep expertise in both terrestrial and  submarine networks, provides the technology that enables Spectrum Sharing. With  solutions from Ciena, cable operators can mix and match building blocks to  create purpose-built network solutions that can utilize both C-band and  L-bands. While adding that flexibility, Ciena continues to drive change via Open Cables, so cable operators can choose best-in-breed SLTE and wet plant  technology for optimized submarine networks.

Every day, submarine cables carry more than US$10  trillion in transactions—the very definition of critical infrastructure. Bandwidth consumption will grow at more than 40 percent CAGR over the next few  years in all regions. Our submarine networking helps providers get more out of their networks with four categories of building blocks—all of which can be mixed and matched to address specific business needs.

  • Services: cloud-based services, PinPoint OTDR, managed NOC, network health, topology discovery, and alarm correlation

Looking to expand their use of C- and L-band spectrum sharing, submarine cable operators are turning to our unique architecture that uses both submarine and terrestrial technologies. Our submarine networking also provides the analytics and machine learning capabilities of software-defined networking (SDN). We simplify end-to-end connectivity for improved capacity, latency, sustainability, and management.