The Study Of Energy Saving Algorithms In IP Over WDM Networks

In recent years, green communication has been a hot research topic. IP over WDM network is a typical structure in the backbone network, the study of its energy saving problem is important. Traditionally researches mostly focus on the cases in which network capacity is more than traffic load or even infinite. But with the development of the Internet of Things, LTE, cloud computing, and big data technology, traffic load increase faster than the network capacity. In the bandwidth constrained IP over WDM network, energy consumption research is more practical.In this work, we have four contributions. Firstly, a path based Integer Linear Programming (ILP) method is proposed to optimize the network energy consumption under the bandwidth constrained transparent IP over WDM network model. It maximizes the throughput for a given network, and then minimizes energy consumption under the constraints of maximum throughput in the first step. The results show that the new method can significantly save energy without sacrificing the network capacity.Secondly, this paper compared the path-based and link-based ILP methods. For the limit of optical signal transmission distance, the freedom of path selection is limited in the latter method. The simulation results show the path-based ILP method can achieve lower energy consumption.Thirdly, we propose blocking connection requests for further saving network energy. If the amount of energy consumed by a connection request exceeds the predetermined boundaries, networks can choose to deny the service. Simulation results show that the network can save large amount of energy by blocking only a few connection requests.Finally, the translucent IP over WDM network model is studied. Compared with the transparent IP over WDM network in which the optical signal regeneration only be accomplished by using IP routers in the intermediate node, the translucent networks can use 3R regenerator to do it. In this paper, we model the translucent IP over WDM networks. The simulation results show that translucent IP over WDM networks consumes less energy than the transparent IP over WDM networks.