On the Modeling and Analysis of Fast Conditional Handover for 5G-Advanced

TL;DR

This paper evaluates the performance of fast conditional handover (FCHO) in 5G-Advanced networks, demonstrating its ability to reduce signaling overhead and mobility failures compared to traditional CHO, especially in frequency range 2.

Contribution

It provides a comprehensive analysis of FCHO's mobility performance and compares it with CHO for different multi-panel UE schemes in 5G-Advanced.

Findings

FCHO significantly reduces signaling overhead.

FCHO decreases mobility failures due to faster handover triggering.

Performance improvements are notable in frequency range 2.

Abstract

Conditional handover (CHO) is a state-of-the-art 3GPP handover mechanism used in 5G networks. Although it improves mobility robustness by reducing mobility failures, the decoupling of the handover preparation and execution phases in CHO significantly increases the signaling overhead. For 5G-Advanced networks, fast CHO (FCHO) is a recent 3GPP proposal that offers a practical solution whereby the user equipment (UE) can reuse earlier target cell preparations after each handover to autonomously execute subsequent handovers. This saves the signaling overhead associated with the reconfiguration and repreparation of target cells after each handover. In this paper, a comprehensive study on the mobility performance of FCHO with respect to mobility failures and signaling overhead in frequency range 2 (FR2) is carried out. In particular, the performance of FCHO is compared with CHO for two different multi-panel UE (MPUE) schemes. Results show that FCHO substantially reduces the signaling overhead of CHO, while at the same time it also reduces mobility failures due to faster triggering of the handover that is achieved by saving the preparation delay.