To address the need of coverage enhancement in the fifth generation (5G) of wireless cellular telecommunications, while taking into account possible bottlenecks related to deploying fiber based backhaul (e.g., required cost and time), the 3rd generation partnership project (3GPP) proposed in Release 18 the concept of network-controlled repeaters (NCRs). NCRs enhance previous radio frequency (RF) repeaters by exploring beamforming transmissions controlled by the network through side control information. In this context, this paper introduces the concept of NCR. Furthermore, we present a system level model that allows the performance evaluation of an NCR-assisted network. Finally, we evaluate the network deployment impact on the performance of NCR-assisted networks. As we show, with proper network planning, NCRs can boost the signal to interference-plus-noise ratio (SINR) of the user equipments (UEs) in a poor coverage of a macro base station. Furthermore, celledge UEs and uplink (UL) communications are the ones that benefit the most from the presence of NCRs.

翻译：为满足第五代（5G）无线蜂窝通信的覆盖增强需求，同时考虑到部署光纤回程可能存在的瓶颈（如所需成本和时间），第三代合作伙伴计划（3GPP）在第18版标准中提出了网络控制中继器（NCR）的概念。NCR通过探索由网络通过侧链路控制信息控制的波束赋形传输，对先前的射频（RF）中继器进行了增强。在此背景下，本文介绍了NCR的概念。此外，我们提出了一个系统级模型，可用于评估NCR辅助网络的性能。最后，我们评估了网络部署对NCR辅助网络性能的影响。如我们所示，通过适当的网络规划，NCR能够提升宏基站弱覆盖区域内用户设备（UE）的信号与干扰加噪声比（SINR）。此外，小区边缘UE和上行链路（UL）通信是NCR存在受益最显著的部分。