User-centric power saving in self-organizing mobile networks

Traffic growth in mobile networks is posing challenges not only from the point of view of the capacity demands, but also from the power consumption. At the same time, mobile networks are becoming increasingly complex, with heterogeneous tiers of Base Stations (BSs) and different technologies. Autonomous and self-adapting power saving schemes that take into account a large number of network metrics have been proposed to address these aspects. However, the performances of the applications running in the user terminals can be negatively affected by schemes that aim at switching off BSs to reduce the power consumed. In this paper, a power-saving algorithm that switches off BSs is proposed. The algorithm is evaluated taking the point of view of the users in the network, by means of the number of HARQ retransmissions experienced, as this directly affects the communication channel quality perceived by the application layer. To perform this evaluation, a detailed network and protocol model has been developed. Simulation results show gains for the power consumed, while also reducing retransmissions or at most ensuring only a minor increase (5%).