A Trade-off Between Unnecessary Handover and Handover Failure for Heterogeneous Networks

With fast growing traffic, high-density small cells (SC) deployment is envisioned in 5G network under the macrocell (MC) coverage area. This will improve the capacity and the cellular coverage, however, it will also introduce unnecessary handovers (UHO) and handover failures (HOF) due to user mobility and, in turn, degrades the user's quality of service (QoS). This paper aims to reduce the UHOs in a SC heterogeneous networks (HetNets) and to maintain the HOF to an acceptable level specified by the operator. Time metric is used to find a trade-off between UHO and HOF. In order to reduce the target SC list for handover, the estimated time of stay is used to avoid long neighbour list. Interference from different base stations is taken into account through the use of signal to interference plus noise ratio (SINR) metric. Simulations are performed to evaluate the performance of the proposed method. Results show that the proposed method outperformed the competitive methods presented in the literature with a lower level of UHOs and HOFs.