Energy Efficient Handover for Heterogeneous Networks: A Non-Cooperative Game Theoretic Approach

The small cell technology is considered as a key technology for 5G networks. The capacity expansion and coverage extension are both achieved through this deployment. However, the ultra-dense small cells deployment can cause a severe interference, a high number of frequent unnecessary handovers and/or handover failure and hence, high power consumption is expected due to the signalling overhead. Placing some small cells into idle mode, without causing degradation to the quality of service, is a good strategy to enhance the energy efficiency in the network. In this paper, we propose an energy efficient game theoretical method to reduce the energy consumption in dense small cells network. The proposed method enables the small cells to adjust their transmitting power while considering to balance the load among themselves. A non-cooperative game is formulated among the cells in the network to solve the cost function which considers both the power mode and its load. The game is solved using the regret matching-based learning distribution approach in which each cell chooses its optimal transmit power strategy to reach the equilibrium. The cell selection for handover is then made using a multiple attribute TOPSIS technique. Results show that the proposed method significantly reduces the power consumption and unnecessary handovers, in addition to improving the average small cell throughput compared to the conventional method.