Although frequency range 2 (FR2) systems are an essential part of 5G-Advanced and future 3GPP releases, the mobility performance of multi-panel user equipment (MPUE) with hand blockage is still an area open for research and standardization. In this article, a comprehensive study on the mobility performance of MPUE with hand blockage is performed for conditional handover (CHO) and its potential enhancement denoted by fast conditional handover (FCHO). In contrast to CHO, in FCHO the MPUE can reuse earlier target cell preparations after each handover to autonomously execute subsequent handovers. This saves both the signaling overhead associated with the reconfiguration and re-preparation of target cells after each handover and reduces mobility failures. Results have shown that FCHO offers considerable mobility performance gains as compared to CHO for different hand blockage cases that are dependent on the hand position around the MPUE. For the worst-case hand blockage scenario, it is seen that mobility failures reduce by 10.5% and 19.3% for the 60 km/h and 120 km/h mobility scenarios, respectively. This gain comes at the expense of reserving the handover resources of an MPUE for a longer time given that the target cell configurations are not necessarily released after each handover. In this article, the longer resource reservation problem in FCHO is analysed and three different resource reservation optimization techniques are introduced. Results have shown that these optimization techniques not only reduce the resource reservation time but also significantly reduce the signaling overhead at the possible expense of a tolerable degradation in mobility performance.

翻译：尽管频率范围2（FR2）系统是5G-Advanced及未来3GPP版本的关键组成部分，但具有手部遮挡的多面板用户设备（MPUE）的移动性性能仍是一个待研究和标准化的领域。本文对条件切换（CHO）及其潜在增强方案——快速条件切换（FCHO）下，MPUE在手部遮挡情况下的移动性性能进行了全面研究。与CHO不同，FCHO允许MPUE在每次切换后重用先前目标小区的配置，从而自主执行后续切换。这既节省了每次切换后与目标小区重新配置和重新准备相关的信令开销，又减少了移动性故障。结果表明，对于MPUE周围不同手部位置相关的几种手部遮挡情况，FCHO相比CHO具有显著的移动性性能增益。在最坏手部遮挡场景下，60 km/h和120 km/h移动性场景中的移动性故障分别降低了10.5%和19.3%。这种增益的代价是，由于目标小区配置不一定在每次切换后释放，MPUE的切换资源会被更长时间地预留。本文分析了FCHO中较长的资源预留问题，并引入了三种不同的资源预留优化技术。结果表明，这些优化技术不仅缩短了资源预留时间，还显著降低了信令开销，但可能以移动性性能的可容忍下降为代价。