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. So, utilizing a solution like Ciena’s GeoMesh Extreme enables submarine providers to get more out of their existing infrastructure. GeoMesh Extreme helps providers overcome the challenges of submarine networks with four categories of available building blocks—all of which can be mixed and matched to address specific business needs.

• Optical: Submarine WaveLogic Ai, Liquid Spectrum™, WaveLogic Photonics, C+L-band support, and Integrated Test Capabilities
• Switching: 5430 Packet-Optical Platform, 6500 Packet-Optical Platform, 8700 Packetwave® Platform, and OneConnect intelligent control plane
• Management: OneControl Unified Management System, Blue Planet V-WAN for agile connectivity, Blue Planet Manage, Control and Plan (MCP), Blue Planet Multi-Domain Service Orchestration (MDSO), and Blue Planet Analytics
• Services: Cloud-based SLA Portal, PinPoint Coherent Optical Time Domain Reflectometer (C-OTDR), Managed NOC, Network Health Predictor, Topology Discovery, and Alarm Correlation

How GeoMesh Extreme is being used and rolled out

Looking to utilize Spectrum Sharing on C-band and L-band, submarine cable operators have turned to GeoMesh Extreme for its unique architecture that leverages both submarine and terrestrial technologies. In addition, GeoMesh Extreme provides a wealth of other benefits to submarine networks, such as the analytics and machine learning capabilities that come with a Software-Defined Network (SDN).

Other GeoMesh Extreme features and services include:

• SLA Portal, which dramatically improves customer satisfaction and retention by providing transparent visualization of service performance. Customers can self-diagnose network service health and verify SLA performance assurance.
• PinPoint C-OTDR, which provides visibility into the performance of multiple segments and systems of submerged plant. It also enables remote access to C-OTDRs in various sites from a centralized Network Operations Center (NOC)/data center.
• Ciena’s Managed NOC services, which extend your customers’ business with the networking skills and experience required to manage their network infrastructure, provision bandwidth growth, and minimize network downtime that impacts critical business processes.
• Network Health Predictor, which utilizes big data analytics to enable you to proactively identify and address areas where network issues and faults might occur
• Topology Discovery, which ensures you can utilize the network to maximum capacity by revealing actual network connectivity, stitching circuits, and identifying stranded bandwidth.

Alarm Correlation, which groups events to reduce the number of issues you need to investigate. Because it identifies related alarms and targets them simultaneously, you don’t spend as much time troubleshooting.