Power-Aware Multi-Rate WDM Network Design under Static/Dynamic Traffic

Power-awareness in carriers' networks has become a major concern in the past few years due to the increasing power consumption required by high speed electronics. Today, the scalability of the Internet is not only limited by communication technology but also by operational expenditure induced by electrical power needed to feed and cool switching/routing and transmission equipment. Designing low power network equipment is certainly the most effective solution to reduce unnecessary power dissipation due to the Joule effect. In the short-term, alternative solutions targeting the existing infrastructures must be provided until the emergence of green-networking technologies. Recently, innovative approaches based on traffic rerouting and grooming have been proposed in the literature for core WDM networks. Transceivers used at the optical switching nodes for add-drop and grooming purposes are the key elements conditioning power consumption. In current networks, transceivers are powered-on permanently, whatever the activity of the data sources at the electrical layer. In this paper, we aim to minimize network's power consumption assuming transceivers with fixed data rates. In this context, we propose an optimal mapping of a set of scheduled traffic demands at the electrical layer onto the optical network. The number of optical channels per optical fiber being upper-bounded, this mapping also minimizes connections' rejection. This optimization problem is formulated as an Integer Linear Program.