QoS aware green routing and wavelength assignment in core WDM networks

In order to reduce the power consumption of data centers, green routing has been touched upon and noticed by research community. From optical WDM network layer point of view, energy aware routing and wavelength assignment refers to establish connections on a subset of network topology while maintaining connectivity and QoS. Idle network elements can be put to sleep or hibernate mode in order to save energy. In this paper, a multi-objective ILP formulation for RWA problem is developed. Then, five novel energy aware routing approaches are proposed in which we aim at simultaneously minimizing energy consumption in WDM network as well as the number of transitions from sleep to active mode while guaranteeing a QoS constraint. By applying the proposed algorithms, noticeable and significant reduction in total number of state transitions from sleep to active mode is experienced. Besides, energy efficiency and blocking rate as two main QoS parameters can be flexibly traded off by adjusting proper values for input parameters of the proposed algorithms.