Energy efficiency approaches for radio nodes

The overall goal of the EARTH project is to identify concepts that will further improve the energy efficiency of wireless access networks. This paper elaborates on radio node level issues addressed by the project. The focus is on radio base station components and radio link concepts to adopt the potential for energy efficiency offered by holistic joint optimisations. A new class of power efficient transceivers adapt the amount of used power to the varying traffic load over a broader load range than state-of-the-art to capitalise possible energy savings in low load situations. For this a concerted scaling of the consumed energy in several components by means of dynamic power management is investigated. One approach “signal level dependent power supply” is described in more detail in this paper. It represents a power management solution controlling the power efficiency of power amplifiers, the component with the highest contribution to energy consumption, such that always optimal efficiency for the respective load situation is achieved. Further new techniques for implementing sleep modes in radio transceivers are addressed, allowing discontinuous transmission of base stations without unwanted reductions of quality of service for the end user. Key solutions introduced by this project are evaluated in a mobile network test plant of a major European operator, which allows their validation as stand-alone features or even in conjunction with other.