Link sleep mode vs. OE devices power management approach: A comparison for survivable Green Optical Networks

The power saving provided by the dynamic power management of the OE interfaces is compared to the ons provided by the link sleep approach. In dynamic traffic scenarios, the former approach reduces by 48% the power consumption achieved by the latter. Additionally, for 1:1 dedicated protection, the recovery time is experimentally evaluated. Introduction The significant increase of energy cost and the recognition of the need to reduce CO2 emissions are economical and ecological drivers for a wide range of recently started research activities[1 toward higher energy efficiency in communications networks. Research on "greening" optical networks concerns all communication layers from device technology to systems management. Various analyses on the traffic behavior in optical networks have shown its predictable variations[2 (e.g., daily, weekly); but optical networks have a quasi-static working (all network elements are powered for the peak traffic), causing an energy consumption waste that is proportional to the difference between the peak and average transported traffic. To make optical networks more energy-efficient, a first step is the adaptation of the amount of powered optical systems with the amount of transported traffic. To make it possible at the WDM layer, the sleep-mode (low power consumption mode) state for optical systems has been proposed[3. In the literature, optical systems eligible for sleepmode are opto-electronic (OE) devices[4 and amplifier sites[5 (in the literature, the latter is referred as link sleep-mode) because they represent the main contribution on the energy consumption at the WDM layer.