Hysteresis automatic configuration for outbound handover in heterogeneous small cell networks

The hysteresis of the outbound handover in heterogeneous networks (HetNets) with both a macrocell and small cells is investigated in this paper. The hysteresis has a significant effect on the handover performance in terms of the handover initiation delay and unnecessary handovers. Meanwhile, the User Equipment (UE) speed is a critical factor which has a dramatic influence on the handover performance in the mobility management. To determine the hysteresis value effectively, we propose a hysteresis automatic configuration (HAC) algorithm based on the UE speed aims to obtain an optimized hysteresis for the UE during the outbound handover process. System-level simulations are presented and the results reveal that our proposed algorithm outperforms existing approaches in terms of reducing the radio link failure rate and the call-drop rate and achieves a better utility of the outbound handover.