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

Conventional peak-traffic based provisioning of cellular mobile networks leads to a significant wastage of electrical energy. Therefore, we propose a novel traffic-aware twodimensional dynamic network provisioning mechanism for enhancing the energy efficiency in OFDMA-based cellular systems. Proposed scheme, named as joint dynamic sectorization and switching of base station (JDSBS), adaptively provisions cellular access networks by switching the redundant BSs as well as sectors into sleep mode. Quality of service (QoS), namely user data rate, service continuity and network coverage are also maintained. Because of the high complexity of the formulated generalized energy optimization 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 utilization is presented. Effectiveness of JDSBS is further validated by comparing with the individual application of sectorization 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.