Reducing Energy Consumption through Adaptation of Number of Active Radio Units

Energy consumption in mobile networks, e.g. 3G networks, may be a substantial part of an operator´´s expenses. A large part of the total energy of the network is consumed by the radio access network. One promising way to reduce the energy consumption of the radio network is to deactivate radio units during periods with low load. Significant gains can be achieved using this approach since each radio unit, connected to an antenna, has relatively high energy consumption during idle periods. In this paper we evaluate an approach where the number of active radio units needed for handling the traffic is computed based on the traffic load. This approach is evaluated using traffic measurements from a 3G network in a European city during 2009 and the results show that an energy saving around 50% is achievable. This suggests that there is potential for significantly enhancing energy efficiency in mobile networks by adaptive activation of radio units.