Systems, methods, and instrumentalities are described herein associated with relay usage (e.g., new radio (NR) relays used as an example herein) where handovers between sidelink (SL) and direct link and/or between sidelinks may be based on consideration of end-to-end radio and/or load conditions. Handover decisions may be determined, for example, based on measurements of direct connections, sidelink connections, and/or backhaul connections. Handover decisions may be optimized, for example, based on measurement reporting behavior. A remote wireless transmit/receive unit (WTRU) (e.g., a WTRU that may be configured to connect to a network, for example, using a relay WTRU) in sidelink relay operation with a relay WTRU may determine measurement reporting behavior (e.g., associated with performed measurements of the direct connections, sideline connections, and/or backhaul connections), for example, while considering the sidelink quality associated with the relay WTRU.