PCE-based centralized control plane for filterless networks

In this article, we present the concept of the filterless optical network from a control plane perspective, defining the network and showing to what extent a control plane could be adapted to it. Then we propose a control plane architecture and study its performance. Filterless networks act as passive broadcast and select networks, in which active switching elements, such as the wavelength selection switch, are replaced by passive optical splitters and combiners, and network agility is provided by tunable transceivers. We introduce the concept of unfiltered channels and that of backward and forward ports, and show how they impact topological performance, and, in particular, the fact that wavelength usage increases greatly as the protection ratio shrinks.