Energy-efficient design for IP over WDM networks with clock frequency adaptive router cards

Because a router card consumes less energy at a lower clock frequency, we can minimize the energy consumption of an IP over WDM network by adaptively adjusting the clock frequencies of a router card according to its actual carried traffic demand. We develop a mixed integer linear programming (MILP) model and an efficient heuristic algorithm to adjust the clock frequency of a router card in different time slots. Results show that the clock frequency adaptation strategy can significantly reduce the energy consumption of an IP over WDM network compared to the non-adaptive case, and the heuristic algorithm is efficient to perform as close as the MILP model.