Energy and Cost Efficiency of Adaptive and Mixed-Line-Rate IP Over DWDM Networks

Optimization of IP over DWDM networks is studied under constraints of cost (CAPEX) and energy consumption. Realistic IP traffic mapped to the optical DWDM which is expanded by a factor of 33 and 100 for a 10-year projection. General power and cost savings are taken into account for the 2020 scenarios. The DWDM core network (Germany 50) is analyzed for mixed-line-rate and reach/bandwidth adaptive scenarios; the latter is realized by optical orthogonal frequency division multiplexing (O-OFDM). Although the adaptive scenario shows to be more hardware efficient in terms of total number of transponders, the mixed-line-rate approach has slight advantages regarding cost and power. Moreover, a hierarchical network can show benefits in cost and power consumption compared to a network without restrictions in routing at high traffic loads.