Traffic Grooming in Statistically Shared Optical Networks

We investigate the characteristics and performance of architectures that allow statistical sharing of wavelengths in the optical layer. The bandwidth of a light-wave circuit can be shared in the optical layer by multiple nodes that are along a linear path in a network through the inclusion of simple but flexible hardware overlaid with control software. We consider three types of architectures - lightpath (LP), light-trail (LT) and source based light-trail (SLT) networks. The three differ in their level of optical sharing, in their hardware and software requirements and in their performance. We study the interplay between statistical sharing at the optical layer and circuit switched sharing at the electronic layer. We develop a generic auxiliary graph model for traffic grooming in heterogeneous WDM mesh networks that can accommodate constraints related to transceivers, wavelengths, and groomers for architectures with different levels of statistical sharing and for both static and dynamic scenarios. We conclude based on our simulation results that sharing wavelength in the optical domain is beneficial and can lead to reduced blocking