15.4.2.8 On-demand SSB SCell

On-demand SSB-based SCell operations are supported for UEs in RRC_CONNECTED configured with carrier aggregation (CA), applicable to both intra-band and inter-band CA configurations for FR1 and FR2 in non-shared spectrum. The OD-SSB transmission activation command can only be transmitted to a UE configured with an SCell prior to or when receiving the SCell activation command. Both RRC and MAC-CE can be used for signalling the activation/deactivation state of OD-SSB transmissions. Additionally, the same MAC-CE can also update the transmission parameter of an activated OD-SSB after the SCell activation completion. The OD-SSB transmission deactivation can also be achieved implicitly based on the number of OD-SSB bursts to be transmitted configured by RRC. When there is no SSB on the SCell, the OD-SSB transmission is maintained while the SCell is activated. When SSB and OD-SSB have different centre frequencies in the SCell, only a single OD-SSB on a different centre frequency is supported. L3 measurement on OD-SSB is supported as specified in TS 38.331 [12].