Green networks: An energy-oriented model for IP over WDM optical networks

The rapid spread of the Internet has brought a significant increase in energy consumption of network equipment. Since the energy crisis and environmental protection are of increasing concern in recent years, many research efforts are in use to save energy. In this context, the present research focuses on reducing the energy consumption of an IP over WDM backbone network using the lightpath bypass strategy. Schemes based on lightpath bypass strategy were previously proposed aimed at reducing energy consumption. Although these approaches, which perform aggregation of traffic, can increase the overall power saving, they suffer from low reuse of lightpaths. To overcome the above drawback this paper proposes a new efficient heuristic called Intelligent Search Lightpath Bypass (ISLB) which will focus on energy efficiency issues related to the planning phase of a WDM optical network. This model is based on traditional traffic grooming designs and aims to increase the number of reusable lightpaths. The proposed scheme, which uses intelligent search methods to find all possible lightpaths that could be reused in the virtual topology, can significantly reduce the energy consumption of an IP over WDM network. As a result more node pairs share common lightpaths and thus less power is consumed in the network. Extensive simulation results indicate that the proposed heuristic algorithm manages to achieve a percentage of power saving, by up to 8%, compared to similar proposed techniques for energy-saving.