A next-generation node B (gNB) configured for operation in a fifth-generation system (5GS) encode signalling for transmission to a user equipment (UE) indicating a Transmission Configuration Indication (TCI) state change to activate a new TCI state. A physical downlink control channel (PDCCH) is encoded in accordance with a highest aggregation level if the signalling indicating the TCI state change indicates activation of a new TCI state for the PDCCH. A physical downlink shared channel (PDSCH) is encoded in accordance with a lowest modulation and coding scheme (MCS) level if the signalling indicating the TCI state change indicates activation of a new TCI state for the PDSCH. After the TCI state change, reference signals (RS) are transmitted with a different spatial filter or different antenna ports demodulation of the PDCCH and PDSCH by the UE.