Control plane issues in cross-layer optimized dynamic optical networks

In transparent optical networks, physical layer impairments (PLIs) incurred by non-ideal optical transmission media accumulate along an optical path, and the overall effect determines the feasibility of the lightpaths. If the received signal quality is not within the receiver sensitivity threshold, the receiver may not be able to correctly detect the optical signal. Hence it is important to understand the techniques that provide PLI information to the control plane protocols and that use this information efficiently to compute feasible routes and wavelengths. In this paper, we briefly describe and compare various control plane approaches, namely, signalling-based approach, routing-based approach, hybrid approach, and PCE-based approach. Furthermore, preliminary results for signalling-based and hybrid approaches from EU funded DICONET project are presented.