Optimized network management for energy savings of wireless access networks

The energy consumption of wireless access networks is rapidly increasing and in some countries it amounts for more than 55% of the whole communication sector and for a non negligible part of the operational costs of mobile operators. The new wireless technologies with a growth of data rates by a factor of roughly 10 every 5 years and the increase in the number of users result in a doubling of the power consumption of cellular networks infrastructure every 4–5 years – to 60 TWh in 2007. In this paper we consider possible energy savings through optimized management of on/off state and transmitted power of access stations according to traffic estimates in different hours of the day or days of the week. We propose an optimization approach based on some ILP models that minimizes energy consumption while ensuring area coverage and enough capacity for guaranteeing quality of service. Proposed models capture system characteristics considering different management constraints that can be considered based on traffic requirements and application scenarios. Energy minimization problems are solved to the optimum or with a gap to the optimum of less than 2.7% on a set of synthetic instances that are randomly generated. Obtained results show that remarkable energy savings, up to more than 50%, can be obtained with the proposed management strategies.