A Flexible WDM Ring Network Design and Dimensioning Methodology

Abstract

Designing arbitrary topologies based on Wavelength Division Multiplexing (WDM) rings yields a number of advantages, including fast restoration mechanisms, simple network management and control. The optimal design of such networks is however a rather complex task, with multiple objectives being optimized that can often be in conflict one with another. The paper presents a modular methodology that encompasses three fundamental steps in designing an arbitrary topology organized as a set of interconnected WDM rings. These are the selection of the Ring Cover, the Routing of the inter-ring traffic and the Traffic Balancing with Wavelength Assignment (TBWA) of the traffic locally on individual rings. After a description of the overall methodology, a detailed formulation of the TBWA problem in presence of both symmetric and asymmetric traffic demands is given. An efficient algorithm that yields sub-optimal solution of the TBWA problem is then proposed. Numerical results show that the algorithm finds an optimum solution in a number of experiments.