Management of Polarization-Mode Dispersion

In this chapter, we provide a detailed description of how the transmission impairments of the optical network can be accommodated for the dynamic provisioning of lightpaths. We show how one of the most important linear phenomena of optical transmission, Polarization-Mode Dispersion (PMD), is handled in the routing and management of translucent optical networks. A constraint-based routing algorithm and a label-distribution protocol are developed. Simulation results on the Italian network topology are provided to assess the regeneration requirements. We evaluate the impact of the transmission impairments on both the routing protocol as well as the overall cost of the network. Simulation results reveal that: 1) the feasibility of the lightpath is greatly affected by the PMD factor, especially for bit-rates exceeding 5Gb/s, and 2) significant improvement (in term of cost) can be achieved through intelligent route selection schemes which take into consideration physical characteristics of fiber links. These cost savings are more apparent in networks with non-homogeneous fiber quality.