Delay-SRLG constrained, backup-shared path protection in WDM networks with sleep scheduling

This paper addresses the Delay-Shared Risk Link Groups (SRLG) constrained path protection problem in green WDM networks with sleep scheduling, and presents a Green Delay-SRLG Constrained Protection (GDSCP) approach. In order to balance the QoS (delay, SRLG reliability, etc.) and energy consumption, the path search algorithm in GDSCP adopts different principles in the search of the primary and backup paths. The choice of the primary path is optimal for the end-to-end delay while minimizing the node awaking to save energy. When necessary, the rarely used backup paths are allowed to go through more sleeping nodes that lead to potential node awaking to ensure the disjoint degree, and thus increase the SRLG reliability of the combined path. Besides the traditional wavelength sharing between backup paths, our approach further encourages paths of different connections to wake up common sleeping nodes to increase the utilization of the reserved node awaking and thus reduce the demand for the new node-state switching in the network. Comparing to the traditional energy-aware schemes, simulations show promising results that GDSCP can obtain significant improvement in terms of increasing the sleeping percentage of the network and reducing the number of node-state switching without sacrificing the performance of blocking rate.