Dynamic lightpath routing and wavelength assignment based on wavelength reservation

Abstract

In this paper, we propose a new wavelength-reservation-based dynamic routing and wavelength assignment algorithm (RWA) to improve the fairness of previous RWA algorithms in wavelength-routed WDM networks. In the algorithm, RWA solutions available from static optimal virtual topology design are used to determine a set of wavelengths to be reserved on corresponding routes for each node pair. Based on the wavelength reservation, a set of dynamic wavelength allocation policies is proposed to use the reserved wavelengths efficiently by allowing the reserved wavelengths to be used by others. Simulation results based on NSFNET topology show that a modified RWA algorithm based on wavelength reservation can improve the fairness of the original RWA algorithm and can reduce the overall blocking probability when traffic load is low.