Design and optimization of energy-efficient wireless access networks powered by renewable energy sources

Currently, data traffic on Internet is growing rapidly and Wireless Access Network has a key role in this context. Communication network is in charge of providing seamless connectivity and great quality of service (QoS) to the end users, and a large amount of energy is involved to accomplish this task. Besides network performance, energy efficiency becomes an important matter. The price of energy from fossil fuel is continuously rising, the risk for depletion in the future is concrete, and the energy provisioning from hydrocarbon has an impact on global CO2 emission. In this context, carbon-low impact alternatives, like renewable energy supply, represent a possible solution. In this thesis, strategies and algorithms to manage the renewable energy accounting and to ensure good energy and network performance are investigated. The deployment tool simulates a LTE-A network, that implements energy-saving techniques and is provided of energy provisioning and storage system. Solar, wind, and geothermal contribute to the energy production and the sources are managed in a centralized manner. Two implementations of the energy management system are proposed and compared. On the one hand, regardless of the network consumption, static energy system guarantees the participation of all the available resources to the energy generation. For example, if the system is equipped with solar panels and wind turbines, the centralized management system will statically use the whole available capacity even if the network does not need large amount of energy to be fed. On the other hand, in dynamic energy system an heuristic search algorithm based on the current energy consumption of the network will choose the most suited energy provisioning system layout. The study demonstrates that the reduction of energy consumption is effective in the drop of the amount of bought energy, but the choice of the energy supply resources is fundamental to achieve the goal. The results are promising to further investigation and implementation.