Handover-based Load Balancing Algorithm for 5G and Beyond Heterogeneous Networks

Abstract

In ultra-dense networks, an enormous number of small base stations (BSs) are required to be deployed, and the number of handovers (HOs) in heterogeneous networks (HetNets) increases as a result. Mobility management with the increasing number of HOs is a critical issue that requires uninterrupted connectivity due to user mobility in HetNets. However, some BSs in the network may be more heavily loaded than their neighbors. Load balancing (LB) involves load transfer from an overloaded BS to an under-loaded neighboring BS for the more load-balanced network. HO and LB are two important issues to improve network performance. In this paper, we propose an algorithm that utilizes user speed and received signal reference power to adapt HO margin (HOM) and time to trigger (TTT). Besides, the proposed algorithm balances the loads among neighbor BSs. Additionally, the proposed algorithm aims to reduce ping-pong HOs (HOPP) and HO failure (HOF) ratios. The simulation results show that the rates of HOPP and HOF are significantly reduced by the proposed algorithm, thus improving network performance under various mobile speeds. Moreover, the results show that the proposed algorithm minimizes the standard deviation of BS loads in the network. The proposed algorithm achieves load balancing and reduces overload during user mobility in HetNets. Therefore, there is more than 60% improvement in terms of the HOF, and 63% more balanced network is achieved with the proposed algorithm in the network.