Online Routing and Spectrum Assignment in Flexgrid Optical Networks

In this paper we propose a novel method for online routing and spectrum assignment (RSA) in flexgrid optical networks based on the theory of Markov Decision Processes (MDP). This theory has already been successfully applied to optimum state-dependent routing in multiservice circuit switched networks. For flexgrid optical networks we introduce enhancements and extensions to existing MDP routing models so as to consider the spectrum continuity and contiguity constraints. We first present the mathematical formulation of the MDP-based optimization model, and then the proposed online RSA optimization algorithm is outlined. Finally, we provide performance evaluation results obtained from simulations of different network and load scenarios.