Infinera Technology

Bandwidth Virtualization is an architecture that transforms the flexibility and responsiveness of the optical network by decoupling the underlying physics of the optical layer from the practical need to deliver capacity between two or more locations. This gives the advantage of quickly delivering differentiated services to any point in the network.

The key benefits of Bandwidth Virtualization are:

• Flexibility for new service offerings: the service provider can offer services of different speeds, from 1Gb/s to 100Gb/s, with different protocols, along with value-added features such as digital protection, restoration and multicast without complex network re-engineering or re-deployments.
• Speed of service delivery: service providers can quickly provision new bandwidth requests from end-users over a common pool of WDM bandwidth and with minimal operational or engineering complexity.
• Capital and operational efficiency: Using end-to-end software intelligence to provision new services, operators can avoid the costly, complex and time-consuming "truck rolls", re-engineering and overbuild activities often required with conventional WDM networks.

Limitations of Conventional Optical Networks

In a conventional optical network capacity is added using analog optical transponders, or muxponders for sub-wavelength services. The lead times on these components can be surprisingly long - usually measured in weeks or even months. But even if these components were held in stock by the service provider, the design of the optical path from ingress to egress is time consuming and requires very detailed understanding of the physics of the optical domain.

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Moreover the lack of sub-wavelength grooming implies that muxponders will not be filled up efficiently, leading to higher costs per wavelength.

Finally the support for new services, such as 40G SONET/SDH, 40G Ethernet or 100G Ethernet may require a complete overhaul of the optical layer, and replacement of significant amounts of equipment.

The result for the service provider is that services are tightly coupled to the underlying wavelength in the optical network. For example a given Gigabit Ethernet or 2.5Gbit/s service is "locked inside" the 10Gbit/s wavelength that carries it. A 40Gbit/s service is "locked" to the wavelength path that has been fitted with the appropriate regeneration or PMD compensation to ensure that the service runs reliably.

This leads to higher costs, delayed revenue, and an overall increase in the risk associated with their business.

Benefits of Bandwidth Virtualization

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In a Digital Optical Network with Bandwidth Virtualization, new services are added digitally. The new service wavelength is provisioned from a virtual pool of service ready capacity that is already working and tested in the core of the network. In this way services are decoupled from the underlying optical wavelengths.

Instead of waiting for transponders that have delivery times of weeks or months, the Digital Optical Network uses Tributary Adapter Modules (TAMs) that are delivered in just 10 days. The path design process is also highly simplified because the optical signal can be switched or groomed at each digital ROADM hop. So if the necessary capacity exists between the ingress and egress point of the service, then it's certain to be provisioned successfully. This deterministic provisioning behavior means that GMPLS can now be allowed to do its job without manual intervention, and to provision service paths automatically across the backbone.

The result is that virtually any service can be turned up in minutes or days, not weeks or months, and without re-engineering the optical infrastructure.