Understanding the 3GPP Standardization Aspects of Network-Controlled Repeaters

Investigating network coverage improvement techniques has been a key consideration in all the mobile generations, including the fifth generation (5G) as well. 5G-Advanced in Release 18 will already provide significantly improved coverage through techniques such as frequency-do-main spectral shaping for uplink transmissions, but there have also been various attempts to introduce more architectural solutions involving RF repeaters or Integrated Access and Backhaul nodes. RF repeaters have particular limitations in millimeter wave frequencies where beamforming is critical, and therefore 3rd Generation Partner-ship Project is now providing the option of Net-work-Controlled Repeaters (NCRs) which may mitigate some of these limitations. In this article we describe the basic functionalities supported by NCRs and the network-configured control information required to perform these functions. We also provide numerical evaluations done via system level simulations to show the benefits of using side control information to manage and configure NCRs.