To improve the energy efficiency of small-cell networks, in this paper, we analyze the operating procedure of home base stations, i.e., Home evolved Node B (HeNB), in femtocells, by introducing an MAP/PH/1/k queueing model. In this analytical model, the HeNB's power on/off is represented as the alternative service and vacation periods. In addition, the hybrid-access mode defined in Third-Generation Partnership Project (3GPP) Release 9 is considered, which involves both high-priority and low-priority users. Based on the analytical results, an adaptive service rate and vacation length (ASV) method is proposed to maximize the HeNB's energy efficiency while satisfying its quality-of-service (QoS) requirements, such as blocking probability and user waiting time. Simulation results demonstrate that the proposed ASV method is more effective in improving energy efficiency compared with its counterpart.
['Hong Zhang', 'Jun Cai', 'Xiaolong Li', 'Shiwei Huang']
Adaptive Service Rate and Vacation Length for Energy-Efficient HeNB Based on Queueing Analysis