Abstract-In this paper, we investigate the joint optimization of power, electricity cost and propagation delay in IP over WDM networks employing renewable energy. We develop a mixed integer linear programming (MILP) model to jointly minimize the three parameters and compare its results to the results of optimizing these parameters individually. The models results show that the joint optimization maintains the power consumption and electricity cost savings obtained by the non-renewable powerminimized and the electricity cost-minimized models while hardly affecting the propagation delay. Compared to the delay-minimized model, the joint optimization model achieves power consumption and electricity cost savings of 73% and 74%, respectively under the non-bypass approach considering a unicasting traffic profile. The power and cost savings under an anycasting traffic profile increases to 82%. I. INTRODUCTION The energy consumption and CO 2 emissions associated with information and communication technology (ICT) networks are increasing rapidly as a result of the network expansion in bandwidth and reach. Today the energy consumption of networks is a significant contributor to the total energy demand in many developed countries; for example, in 2005 the energy consumption of the Telecom Italia network was more than 2TWh which is about 1% of the total Italian energy demand [1] . In the winter of 2007, British Telecom became the largest single power consumer in the UK accounting for 0.7% of the total UK's energy consumption [2] . Given the ecological and economic drivers, significant research efforts are increasingly being focused on reducing the energy consumption of ICT networks. A significant literature body exists on power-awareness in mobile ad-hoc and wireless networks [3] , and computer architecture [4] . However, many challenges need to be addressed to develop and deploy energy efficient wired networks. In 2003 Gupta et al. [5] introduced the concept of "greening the internet". In our previous work, we have studied different energy efficiency approaches in optical networks. In [6], we have investigated reducing the CO 2 emission of backbone IP over WDM networks by introducing renewable energy sources. In [7] , we have studied the power consumption of IP over WDM networks with data centres and have investigated the problem of whether to locate data centres next to renewable energy or to transmit renewable energy to data centres. In [8], we have investigated energy-efficient physical topologies in IP over WDM networks considering different IP over WDM approaches, nodal degree constraints, traffic symmetry and renewable energy availability. We have also reconsidered the physical topology design optimization
The joint optimization of power, EC, and delay in IP-over-WDM networks is studied in REF .
Joint optimization of power, electricity cost and delay in IP over WDM networks
2013 IEEE International Conference on Communications (ICC)
2013 IEEE International Conference on Communications (ICC)
Computer Science