Energy Efficient Design Strategies of Translucent and Transparent IP Over WDM Networks

A surge of interest toward design and implementation of green networks are emerging in recent years. One obvious trend to reduce energy consumption of major active network components is to craft backbone network architecture that takes into consideration traffic grooming of low-rate IP traffic as well as power-aware virtual topology design schemes and RWA. Previous research efforts developed design strategies which assumed digital processing of incoming traffic flows at every node structure in the optical layer (DXCs). This architecture provides full wavelength conversion capability by the use of optical transponders (OEO convertors) thus reduces complicated RWA problem to a simple routing problem at the cost of sacrificing lightpath transparency. Moreover, introduction of transponders give rise to extra sources of power consumption which contrasts over goal. In this paper, energyminimized design of IP over WDM networks based on optical cross connects (OXCs) is investigated. Integer linear programming formulation as well as heuristics for two design strategies viz. multi-hop lightpath and direct bypass have been developed and their performance with regard to power consumption and relative bandwidth utilization are compared. Simulation results indicate superior performance of the proposed strategies with regard to previous studies.