Exergy based analysis of radio access networks

Currently, the total energy consumption of the information and communication technology (ICT) sector is continuously increasing due to the fast penetration of ICT into many areas of business and society. Particularly high growth rates have been observed in the area of technologies and applications for communication networks. Over the last decade, there has been an exponential increase of both data traffic and number of devices connected to the Internet, which has led to a fast increase of network capacity. In this context, the role of the network infrastructure is becoming increasingly important because satisfying the need for high capacity generally means higher energy consumption of the network equipment. Especially mobile networks have experienced constant evolutions that have led to new technology generations and advanced radio interfaces capable of providing data rates in the order of hundreds of Mbps or even Gbps. Additionally, the number of active mobile subscribers has grown continually and rapidly. Even through the use phase is very important because of the high energy consumption and related greenhouse emissions of telecom infrastructures, it is just a part of the story. The whole life cycle, i.e., also the production and disposal phases should be considered when determining sustainability of communication networks, especially because of the relatively short life-cycle of ICT devices. In this paper, we report results of a study that apply widely used thermodynamic tools in combination with network modeling to assess sustainability of radio access networks. In particular, we utilize the concept of available energy or exergy to determine the environmental impact of the whole life cycle of radio access network infrastructure and present results of a case study of radio access network for the city of Vienna.