Ronald Johnson

Colorless, Directionless and Contentionless multi-degree ROADM architecture for mesh optical networks

A Colorless and Directionless (C&D) ROADM architecture has empowered todays networks with the much needed flexibility and scalability to handle the unpredictable high bandwidth demands, provide any-to-any connectivity and provision new services without disrupting the existing ones. In this paper, we realize the C&D ROADM architectures using PXC and WSS at a multi-degree node. We then evaluate both the architectures based on the various advantages offered by them. We also discuss some of the drawbacks of the two architectures. Subsequently, we propose a Colorless, Directionless and Contentionless (CD&C) architecture which combines the features offered by both the C&D architectures. Finally, we discuss practical implementation issues of the proposed architecture.

Versatility of a colorless and directionless WSS based ROADM architecture

In core/metro optical networks there are multi-degree nodes providing N path interconnections and alternate paths for protection. This paper presents the optimum implementation of a colorless and directionless add/drop switching feature in a mesh network, using the WSS based ROADM. The idea of scaling, viewed as an increase in route degree and number of wavelengths handled in each direction is then addressed. Subsequently, we suggest the best ways in which specific advantages like dynamically optimizing light paths by optical bridge-and-roll, avoiding O-E-O operations and blocking specific wavelengths can be leveraged. Finally, practical implementation issues like power loss, OSNR and cost considerations are discussed.

CAPEX minimization through node degree reduction in a Colorless and Directionless ROADM architecture for flexible optical networks

Service Providers are constantly searching for means to reduce costs, generate new revenue streams and increase their competitive advantage. The migration to Colorless and Directionless mesh architecture will enable the Service Providers to realize new scalability, availability, flexibility and dynamic reconfigurability demands for optical networks. But commodification and standardization of the underlying technologies has made it very difficult to differentiate their service offerings especially in terms of price and performance. Hence, leveraging the intelligence of efficient routing algorithms, Service Providers can notably reduce the total cost of ownership of the network. This paper presents a rationalized routing algorithm for a Colorless and Directionless mesh core optical network, which enables a significant CAPEX reduction by decreasing the number of active degrees of a node.