An apparatus in accordance with the present application may monitor a sidelink (SL) connection. The apparatus includes processing circuitry that receives signals in a protocol stack to perform SL-radio link monitoring (SL-RLM), and determines, according to the signals, whether a SL-radio link failure (RLF) has occurred. The signals may include hybrid automatic repeat request (HARQ) feedback. In a case that the signals include a HARQ-NACK, the processing circuitry determines that the SL-RLF has occurred. The processing circuitry further receives configuration information related to the SL-RLM for the signals, the configuration information including configurations for measurement quantities of the signals and a condition for declaring SL-RLF, configures, according to the configuration information, lower layers of the protocol stack for the SL-RLM for the signals, and performs SL-RLM measurements of the measurement quantities.