Comparative performance assessment of switching options

Abstract

Switching is one of the key functionalities in next generation optical networks. It might be performed by either an optical switch (optical-electrical-optical, or OEO) or a "purely" photonic switch (optical-optical-optical or OOO). Both switches are analyzed from two perspectives - as an individual network element, and as an integral part within the communication network. As an individual network element, the performance evaluation of the two switch types is based on the individual assessment of switch footprint and power dissipation, bandwidth utilization, scalability to high speed, transparency, interoperability, technology maturity and ability to manipulate data. Although both switch types have their own advantages as a network element, the full judgement of their role in next generation optical networks requires an overall network perspective. From that viewpoint, network functionalities such as grooming capabilities, scalability, traffic management, protection, line equalization and performance monitoring are those taken into account for comparative analyses to gain an understanding of the impacts of switch choice in the network. As a result of the comparative performance assessment, the merits and benefits of both switch types in actual network applications are analyzed and outlined. Although the paper evaluates some criteria for switch choice in a network, it points out potential technologies or techniques critical to next generation architectural solutions and protocols as well as the challenges to bridge the gap towards implementing flexible, cost-effective and dynamically provisioned networks of the future. Finally, the paper responds to one critical question - What is the expected role of each switch type in next generation applications and services?