A Kind of Topology Aggregation Algorithm in Hierarchical Wavelength-Routed Optical Networks

Abstract

In large scale networks composed of several hierarchical subnetworks, topology aggregation is implemented for both scalability and security consideration. However, due to the special characteristic of optical wavelength-routed networks, existing topology aggregation algorithms cannot be applied directly for topology compression. In this paper, we propose a kind of topology aggregation algorithm suitable for hierarchical wavelength-routed optical networks, thereby considering information of residual wavelengths on network links. Basically, our topology aggregation algorithm is based on a transition matrix technique for constructing a full mesh topology and asymmetric star approach for a more compact topology. Simulations with randomly-generated networks show that topology information compression can be achieved with a little loss of its accuracy: the ratio of border node pairs with representation deviation being well below 10%. Results also indicate that the advantage of our algorithm is also behaved on reducing the amount of link-state-advertisement messages and making networks less vulnerable to propagation delay of these messages over communication links.