Reducing Power Consumption in Wavelength Routed Networks by Selective Switch Off of Optical Links

In this paper, the power consumption of a transparent circuit-switched wavelength-division multiplexing (WDM) optical network is evaluated, considering client flow protection requirements and the daily traffic variability. Moreover, a simple heuristic algorithm is applied to the considered network scenario to reduce the power consumption of optical links. When traffic load decreases, the algorithm tries to switch off optical links according to several heuristic criteria that take into account the power consumption parameter of links, some topological consideration and the congestion of each fiber. By performing such an optimization, applying the best link-ordering criterion, it is possible to save an amount of power from 28% up to 86% of the power consumed by optical links on the basis of the traffic load. This leads to an average energy saving of 35% with respect to the energy consumed by the whole optical network. Moreover, we evaluate the impact of network design parameters on the proposed algorithm and the network power consumption. Results show that, for a 18-node network supporting an average traffic of 75 Gbits/s between each node pair, a number of wavelengths equal to 80 can drastically reduce the power consumption of optical links.