Theoretical analysis of handover failure and no handover rates for heterogeneous networks

Heterogeneous Network (HetNets) could enhance the performance of 3GPP LTE-A such as system capacity and network coverage. However, it also brings complex mobility management problems like higher Handover Failure (HF) rates. The traditional method is modeling the Handover (HO) trigger locations and HF locations as co-centric circles so that HF and No Handover (NHO) rates can be calculated through geometric derivation. However, the applicability of co-centric circles model is restricted. In this paper, we revise the co-centric circle model and improve the method in theoretical analysis. As a result, HF and NHO rates can be got by using the theoretical expressions. Besides, we provide an insight into the relation of HF/NHO rates and parameters such as time-to-trigger (TTT), user equipment (UE) velocity, the coverage size of picocell. Simulation results verify the accuracy of theoretical analysis and indicate a wide applicability of the model.