The cell zooming algorithm for energy efficiency optimization in heterogeneous cellular network

The future 5G communication will bring about the surge of traffic. The traffic of cellular network has great non-uniformity and volatility in space and time, which brings opportunities and challenges to the planning and management of cellular network. The energy consumption on base station (BS) accounts for more than 50% of the total energy consumption of the cellular network. Due to the space-time characteristics of the traffic, the BS can not allocate resources reasonably, which results in wasting energy consumption and low energy efficiency (EE). In this paper, based on the heterogeneous cellular network, we propose LB algorithm which based on load balancing and improve LC algorithm which based on load concentration to reduce energy consumption and improve EE. The two algorithm are both based on cell zooming. The process of LB algorithm is to balance the load of small base station (SBS) by adjusting the transmission power of SBSs with heavy load, and dispersing the traffic to the neighboring SBSs with light load. The process of LC algorithm is to close the SBSs of which the load are less than the threshold and the surrounding SBSs absorb the users. The simulation results show that both LB algorithm and LC algorithm can reduce the energy consumption and improve the EE of heterogeneous cellular network compared with no cell zooming. When the traffic level of heterogeneous cellular network is high, the LB algorithm can make the EE of the heterogeneous cellular network better. When the traffic level of heterogeneous cellular network is low, the LC algorithm can make the EE of the heterogeneous cellular network better. What is more, LB algorithm has better effect than LC algorithm in reducing the outage probability.