  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.
