Energy Consumption and Quality of Service in Computer Systems and Networks

Over the last decade, the increased automation in the management of computer systems and networks, the rising costs of energy, and the sensitivity about the environmental impact of energy consumption, has resulted in an increase of the importance of energy in the overall running of ICT (Information and Communication) Systems. The deregulation in telecommunication services has also had an impact in this direction because of the increased duplication in telecommunication infrastructures. Furthermore, most cyberattacks, also increase the energy consumption of ICT systems. Thus, today the overall electricity consumed by ICT worldwide is comparable to the total electricity consumption of two major industrial powers: Japan plus Germany. Clearly, of one wishes to save energy in ICT, this may come at the expense of a reduction in the measured Quality of Service (QoS) of ICT systems. Thus we will survey a number of our own research results, covering wireless communications, compute servers and network routing, to offer optimal trade-offs between energy consumption and QoS. The Energy Packet Network (EPN) that we have introduced to optimise the Energy-QoS trade-offs will be described and applied to a number of examples. We will also describe some results on the potential and limitations for communicating and computing with particle spins as a means to achieve energy savings.