The amount of energy needed to power the Internet is increasing as a result of the growing number of connected users and the traffic volume generated. In the last 10 years, the networks energy consumption has increased with the aggregated bandwith and it has been multiplied by 10.
Energy consumption is currently dominated by the access network because of the high number of end-point devices but, with rising traffic volume, the major consumption is expected to shift from access to core networks.
Energy is now a new requirement of the Internet and, because of that, new energy-efficient, energy-awareness and energy-oriented infrastructures have to be developed.
Several energy-efficient architectures have been designed taking into account that power consumption of electronic traffic is always higher than the optical traffic. It’s recommended to use Optical Amplifiers (OA) instead of EDFA, to use multi-mode optical fibers (DSF) instead of simple single mode fiber, passive optical networks (GPON) instead of xDSL networkds and to use sleep mode per-node or per-interface in the network devices.
As we said before, optical networks consume 150 times less than electronic networks, so, in order to aware energy, 3R regeneration and Optical/Electrical/Optical conversion should be avoided as much as possible: amplificattion is always better than regeneration. Other measures of energy-awareness are: reduce the hop count, use coordinated sleep mode and use routing energy aware algorithms and protocols to minimize power consumption or C02 emissions.
All of this measures should be included in the networks in order to avoid rebound effect and mynimize GHG emissions, power consumption and costs.