Intelligent Energy-Aware Networks

Today the energy consumption of Information and Communication Technology (ICT) industry is a significant contributor to the total energy demand in many developed countries. Recent studies show that the ICT industry is responsible for about 2% of the global emission of CO2 and this percentage is predicted to increase as the Internet expands in bandwidth and reach. In this chapter we highlight different approaches for energy efficiency in communication networks. Firstly we review the techniques proposed to reduce the energy consumption of communication networks at the equipment and network levels. Secondly we investigate the use of renewable energy to reduce the CO2 emission of IP over WDM networks. Issues including how to use renewable energy (solar in this work) more effectively, how to reduce the nonrenewable energy consumption of transponders (the second most energy consuming device in a node), how to select the location of nodes using renewable energy, and load dependent energy consumption are considered. Thirdly we discuss workload migration using virtualization technologies in data centers as an approach of energy consumption minimization. Finally we consider some of the photonic systems advances which have the potential to reduce significantly the energy consumption within Ethernet switches and IP routers in the datacenter, showing how integrated photonic switch fabrics are starting to have the performance required for energy efficient high switching applications.