Smart and Green Networks Using Repeaters and Reconfigurable Intelligent Surfaces

This paper provides a brief overview of a 5G-advanced amplify-and-forward repeater technology, called network-controlled repeater (NCR). A 5G base-station can utilize an NCR to extend its coverage in a cost-efficient manner. The network-controllability of NCR allows the base-station to offer a better performance using the NCR, compared to the conventional repeaters. This paper investigates repeaters from the network energy consumption point of view and shows allowing the network to also control the NCR's power can offer extra benefits from the NCR and enable further performance and energy optimizations. The performance of NCR is compared with Reconfigurable Intelligent Surface (RIS) and it is shown while the repeaters may consume more power than RIS, they may enable more energy saving opportunities at the base-station and/or the users, and hence provide an overall more energy-efficient solution for 5G-advanced and 6G networks.