Energy and cost efficient logical topology in optical mixed-line-rate networks

With the continuous growth of traffic for years, both the monetary cost and the power consumption of the Internet increase sharply at the same time. Especially, backbone networks will become the main contributor of the overall Internet cost and power consumption. Except the feature of huge total amount, the traffic in future backbone networks will also show high heterogeneity in bandwidth requirement. Based on the variety of those traffic demands, the mixed-line-rate (MLR) schemes have been proposed in recent years. The MLR schemes are considered to b e able to support flexibility for network provisioning. To utilize resources in MLR backbone networks efficiently, logical topology design is an important issue. However, previous studies about logical topology design have focused on optimizing either monetary cost or power consumption of the whole network. In this paper, we design logical topology for optical MLR backbone networks by considering both energy efficiency and cost efficiency. The network cost is defined as an integrity consisting of the monetary cost and the power consumption of the whole network. Then, a Mixed Integer Linear Programming (MILP) formulation is presented to minimize the network cost. In order to evaluate the proposed formulation, it is applied on illustrative case studies. Finally, the numerical results are analyzed and discussed.