An Energy Efficient Radio Base Station

Sammanfattning: The mobile telecommunication network is growing year after year and it will soon move into the high speed 5G and Internet of Things technology. These new technologies will improve the throughput and data connectivity and due to that the energy consumption in radio and digital units may increase in a Radio Base Station (RBS). There are more than 500 000 off-grid RBSs in the world which are powered by diesel generators. This results in air pollution, green house gas emission and high fuel and maintenance costs for the operators. The main objective of this thesis is to find ways to bring down the energy consumption in radio and digital units and check the viability of a solar powered site instead of a diesel powered site. This has been done for an LTE network. The current power save features developed by Ericsson has been studied and two new power save features have been implemented. The first is an innovative algorithm that optimizes the cooling in the baseband to obtain a minimal power consumption, this method was proved to work even in scenarios with large variations in ambient temperature. An Eco-mode algorithm was tried on few radio units, where the biasing of the power amplifiers was reduced in low load scenarios. This reduced the power consumption of each radio unit with up to 3.4% in the test cases described in the thesis. Finally,the design and economic analysis of a solar powered radio base station was performed, in order to recommend an energy efficient, sustainable and cost-effective option to mobile operators that would relieve the stress of regular maintenance and increased expenses. It showed that a combination of solar panels and diesel generator is the most economical and environment friendly solution.