Section: 5.10.1.2 Multicast MCCH scheduling
Content: The multicast MCCH information (i.e. information transmitted in messages sent over multicast MCCH) is transmitted periodically, using a configurable repetition period and within a configured transmission window. MCCH transmissions (and the associated radio resources and MCS) are indicated via the PDCCH addressed to Multicast MCCH-RNTI. PDCCH monitoring occasion(s) for the multicast MCCH transmission are determined according to the common search space indicated by searchspaceMulticastMCCH. If searchspaceMulticastMCCH is set to zero, PDCCH monitoring occasions for the multicast MCCH message reception in the multicast MCCH transmission window are the same as PDCCH monitoring occasions for SIB1 where the mapping between PDCCH monitoring occasions and SSBs is specified in TS 38.213[ NR; Physical layer procedures for control ]  [13]. If searchspaceMulticastMCCH is not set to zero, PDCCH monitoring occasions for the multicast MCCH message are determined based on search space indicated by searchspaceMulticastMCCH. PDCCH monitoring occasions for the multicast MCCH message which are not overlapping with UL symbols (determined according to tdd-UL-DL-ConfigurationCommon) are sequentially numbered from one in the multicast MCCH transmission window. The [x×N+K]th PDCCH monitoring occasion for the multicast MCCH message in the multicast MCCH transmission window corresponds to the Kth transmitted SSB, where x = 0, 1, ...X-1, K = 1, 2, …N, N is the number of actual transmitted SSBs determined according to ssb-PositionsInBurst in SIB1 and X is equal to CEIL(number of PDCCH monitoring occasions in multicast MCCH transmission window/N). The actual transmitted SSBs are sequentially numbered from one in ascending order of their SSB indexes. The UE assumes that, in the multicast MCCH transmission window, PDCCH for a multicast MCCH message is transmitted in at least one PDCCH monitoring occasion corresponding to each transmitted SSB and thus the selection of SSB for the reception multicast MCCH messages is up to UE implementation.