Cross-layer RWA in translucent optical networks

Wavelength Division Multiplexing (WDM)-based optical networks are ideal candidates for core backbone networks because of their ability to carry large amounts of traffic. Optical amplification has increased the reach of long-haul optical links. Nevertheless, it is impossible today to construct a truly optical network without converting optical signals to electrical signals and regenerating them, because of the deleterious effects of physical impairments such as amplifier noise, dispersion, and non-linear effects such as four-wave mixing and cross-phase modulation. Being expensive devices, these regenerators are expected to be sparsely located and used in such a network called as a translucent optical network. In this paper, we consider the routing and wavelength assignment (RWA) problem so that the Quality of Transmission (QoT) for connections is satisfied, and the network-level performance metric of blocking probability is minimized. Cross-layer heuristics that are based on dynamic programming to effectively allocate the sparse regenerators are developed, and extensive simulation results are presented to demonstrate their effectiveness.