Energy Efficient Radio Resource Management for Future Mobile Cellular Radio Access Networks

Historically mobile Radio Access Networks (RANs) were optimised initially to maximise coverage and subsequently to improve capacity, user data rates and quality of service. However, the recent exponential growth in the volume of transmitted data coupled with the ever increasing energy costs has highlighted the need to optimise futuristic RANs from an energy efficiency perspective. This research study postulated the utilisation of radio resource management approaches to improve the energy efficiency of modern RANs, with a particular emphasis on the radio frequency energy performance. The research study yielded the following major outcomes. First, there was notable positive correlation between user channel quality improvements and the energy efficiency of RANs. Second, channel quality aware packet schedulers were more energy efficient than channel quality ignorant packet schedulers. Third, energy aware scheduling metrics coupled with power control algorithms can be utilised to optimise and refine the energy efficiency performance of the rate adaptive frequency domain packet scheduling. Fourth, the dynamic temporal and spatial traffic load characteristics, in the radio access network, present energy saving opportunities through collaborative and cooperative Inter-Cell Interference (ICI) management among neighbouring base stations. While the results presented in this thesis pertain to radio frequency and/or radio head energy consumption, the improved energy efficiency could be leveraged by increasing the inter site distance between base stations subsequently reducing the density of base stations in any given geographical area thus reducing the energy consumption of the RANs as a whole. The benefits of energy efficient RANs are twofold, i.e. reduction in the amount of CO 2 emission and lower operating expenditure (OPEX).