Is It Possible to Simultaneously Achieve Zero Handover Failure Rate and Ping-Pong Rate?

TL;DR

This paper introduces ZEUS HO, a novel handover scheme that theoretically achieves zero failure and ping-pong rates in dense 5G small cell networks by optimizing handover timing and conditions.

Contribution

The paper proposes ZEUS HO, a new handover method that guarantees zero failure rate without increasing ping-pong rate, addressing a key challenge in 5G mobility management.

Findings

ZEUS HO achieves zero handover failure rate.

ZEUS HO maintains low ping-pong rate.

Zero failure and ping-pong rates are simultaneously possible.

Abstract

Network densification through the deployment of large number of small cells has been considered as the dominant driver for wireless evolution into 5G. However, it has increased the complexity of mobility management, and operators have been facing the technical challenges in handover (HO) parameter optimization. The trade-off between the HO failure (HOF) rate and the ping-pong (PP) rate has further complicated the challenges. In this article, we proposed ZEro handover failure with Unforced and automatic time-to-execute Scaling (ZEUS) HO. ZEUS HO assures HO signaling when a user equipment (UE) is in a good radio link condition and executes the HO at an optimal time. We analyzed the HO performance of Long-Term Evolution (LTE) and ZEUS theoretically using a geometry-based model, considering the most important HO parameter, i.e., HO margin (HOM). We derived the probabilities of HOF and PP from the analysis. The numerical results demonstrated that ZEUS HO can achieve zero HOF rate without increasing the PP rate, solving the trade-off. Furthermore, we showed that the ZEUS HO can accomplish zero HOF rate and zero PP rate simultaneously with an extension of keeping fast moving users out of small cells.