Traffic-aware two-dimensional dynamic network provisioning for energy-efficient cellular systems

Abstract

Conventional peak-traffic-based provisioning of cellular mobile networks leads to a significant wastage of electrical energy. Therefore, we propose a novel traffic-aware two-dimensional dynamic network provisioning mechanism for enhancing the energy efficiency in orthogonal frequency division multiple access (OFDMA)-based cellular systems. Proposed scheme, named as joint dynamic sectorisation and switching of base station (BS), adaptively provisions cellular access networks by switching the redundant BSs as well as sectors into sleep mode. Quality of service, namely, user data rate, service continuity and network coverage, is also maintained. Because of the high complexity of the formulated generalised energy optimisation problem, the two dimensions (i.e. sector switching and BS switching) are decoupled in time-domain into two sub-problems, each executing its own heuristically guided algorithm. Moreover, a novel exponentially weighted moving average (EWMA)-based load factor estimator is employed for reducing the occurrence of network provisioning. System performance is evaluated using extensive simulations demonstrating substantial energy savings. In addition, impact on the spectral efficiency and resource utilisation is presented. Effectiveness of joint dynamic sectorisation and switching of BS is further validated by comparing with the individual application of sectorisation and BS switching. Furthermore, for realistic traffic patterns, use of EWMA estimator achieves over 40% reduction in network provisioning events without compromising energy-saving performance.