QoT-aware grooming, routing, and wavelength assignment (GRWA) for Mixed-Line-Rate translucent optical networks

A Mixed Line Rate optical network is a good candidate for a core backbone network because of its ability to provide diverse line rates to effectively accommodate traffic demands with heterogeneous bandwidth requirements. 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. Thus there is a maximum transmission reach for optical signals before they have to be regenerated. Being expensive devices, regenerators are expected to be sparsely located and used in such a network, called a translucent optical network. In this paper, we consider the grooming, routing, and wavelength assignment (GRWA) 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 to effectively allocate the sparse regenerators are developed, and extensive simulation results are presented to demonstrate their effectiveness.