Advanced handover self-optimization approach for 4G/5G hetnets using weighted fuzzy logic control

The future fifth generation (5G) wireless communications support the ultra-dense networks where deployments of a large number of small cells coexist with current 4G networks. However, the dense small cell deployment is facing a technical challenge in mobility management due to the increased number of handovers (HOs), especially in heterogeneous networks (HetNets). The increasing probability of HOs may cause HO failure (HOF) or HO ping-pong (HOPP) which degrades the system performance. To solve this problem, we propose a weighted fuzzy self-optimization (WFSO) approach for the optimization of the handover control parameters (HCPs). In this approach, the HO decision relies on three considered attributes: signal-to-interference-plus-noise ratio, traffic load of serving and target base station, and user equipment's velocity. The self-optimized HCPs, namely the HO margin and time-to-trigger are adjusted according to the current status of these attributes to improve the HO performance. Simulation results indicate that the proposed WFSO approach significantly lowers the rates of HOPP, radio link failure and HOF in comparison with the other algorithms found in the literature.