A Novel Distributed Protocol for Path Selection in Dynamic Wavelength-Routed WDM Networks

This paper solves the problem of path selection for WDM mesh networks with a special focus on the implementation in middle-sized networks, such as metropolitan-area networks (MANs). A novel routing and signaling protocol, called asynchronous criticality avoidance (ACA), is proposed to improve the network performance. With the ACA protocol, a specific set of wavelength channels are defined as critical links between a node pair according to dynamic link-state. Criticality information is defined as the critical links and the associated information, which is coordinated and disseminated by each source node to every other source node as an inter-arrival critical coordination. Routing and wavelength assignment is performed along with the criticality avoidance mechanism, in which path selection process is devised to take the criticality information into consideration. Simulation is conducted in 22- and 30-node networks to examine the proposed approach. The simulation results show that the ACA protocol significantly outperforms the fixed-path least-congested (FPLC) and adaptive dynamic routing (ADR) schemes under the fixed alternate routing architecture.