Section: 5.2.2.2.2 SI change indication and PWS notification
Content: A modification period is used, i.e. updated SI message (other than SI message for ETWS, CMAS, positioning assistance data, and some NTN-specific information as specified in the field descriptions ) is broadcasted in the modification period following the one where SI change indication is transmitted. The modification period boundaries are defined by SFN values for which SFN mod m = 0, where m is the number of radio frames comprising the modification period. The modification period is configured by system information. If H-SFN is provided in SIB1, and UE is configured with eDRX, modification period boundaries are defined by SFN values for which (H-SFN * 1024 + SFN) mod m = 0. For UEs in RRC_IDLE or RRC_INACTIVE configured to use an IDLE eDRX cycle longer than the modification period, an eDRX acquisition period is defined. The boundaries of the eDRX acquisition period are determined by H-SFN values for which H-SFN mod 1024 = 0. The UE receives indications about SI modifications and/or PWS notifications using Short Message transmitted with P-RNTI over DCI (see clause 6.5). Repetitions of SI change indication may occur within preceding modification period or within preceding eDRX acquisition period. SI change indication is not applicable for SI messages containing posSIBs. UEs in RRC_IDLE or in RRC_INACTIVE while SDT procedure is not ongoing shall monitor for SI change indication in its own paging occasion(s) that the UE monitors as specified in TS 38.304[ NR; User Equipment (UE) procedures in Idle mode and in RRC Inactive state ]  [20]. UEs in RRC_CONNECTED shall monitor for SI change indication in any paging occasion at least once per modification period if the UE is provided with common search space, including pagingSearchSpace, searchSpaceSIB1 and searchSpaceOtherSystemInformation, on the active BWP to monitor paging, as specified in TS 38.213[ NR; Physical layer procedures for control ]  [13], clause 13. UEs in RRC_INACTIVE while SDT procedure is ongoing shall monitor for SI change indication in any paging occasion at least once per modification period, if the initial downlink BWP on which the SDT procedure is ongoing is associated with a CD-SSB. During a modification period where ETWS or CMAS transmission is started or stopped, the SI messages carrying the posSIBs scheduled in posSchedulingInfoList may change, so the UE might not be able to successfully receive those posSIBs in the remainder of the current modification period and next modification period according to the scheduling information received prior to the change. ETWS or CMAS capable UEs in RRC_IDLE or in RRC_INACTIVE while SDT procedure is not ongoing shall monitor for indications about PWS notification in its own paging occasion(s) that the UE monitors as specified in TS 38.304[ NR; User Equipment (UE) procedures in Idle mode and in RRC Inactive state ]  [20]. ETWS or CMAS capable UEs in RRC_CONNECTED shall monitor for indication about PWS notification in any paging occasion at least once every defaultPagingCycle if the UE is provided with common search space, including pagingSearchSpace, searchSpaceSIB1 and searchSpaceOtherSystemInformation, on the active BWP to monitor paging. ETWS or CMAS capable UEs in RRC_INACTIVE while SDT procedure is ongoing shall monitor for indication about PWS notification in any paging occasion at least once every defaultPagingCycle, if the initial downlink BWP on which the SDT procedure is ongoing is associated with a CD-SSB. For Short Message reception in a paging occasion, the UE monitors the PDCCH monitoring occasion(s) for paging as specified in TS 38.304[ NR; User Equipment (UE) procedures in Idle mode and in RRC Inactive state ]  [20] and TS 38.213[ NR; Physical layer procedures for control ]  [13]. A L2 U2N Remote UE is not required to monitor paging occasion for SI modifications and/or PWS notifications. It obtains the updated system information and SIB6/7/8 from the connected L2 U2N Relay UE as defined in clause 5.8.9.9.3. If the UE receives a Short Message, the UE shall: 1> if the UE is ETWS capable or CMAS capable, the etwsAndCmasIndication bit of Short Message is set, and the UE is provided with searchSpaceSIB1 and searchSpaceOtherSystemInformation on the active BWP or the initial BWP: 2> immediately re-acquire the SIB1; 2> if the UE is ETWS capable and si-SchedulingInfo includes scheduling information for SIB6: 3> acquire SIB6, as specified in clause 5.2.2.3.2, immediately; 2> if the UE is ETWS capable and si-SchedulingInfo includes scheduling information for SIB7: 3> acquire SIB7, as specified in clause 5.2.2.3.2, immediately; 2> if the UE is CMAS capable and si-SchedulingInfo includes scheduling information for SIB8: 3> acquire SIB8, as specified in clause 5.2.2.3.2, immediately; NOTE: In case SIB6, SIB7, or SIB8 overlap with a measurement gap it is left to UE implementation how to immediately acquire SIB6, SIB7, or SIB8. 1> if the UE does not operate an IDLE eDRX cycle longer than the modification period and the systemInfoModification bit of Short Message is set: 2> apply the SI acquisition procedure as defined in clause 5.2.2.3 from the start of the next modification period; 1> if the UE operates an IDLE eDRX cycle longer than the modification period and the systemInfoModification-eDRX bit of Short Message is set: 2> apply the SI acquisition procedure as defined in clause 5.2.2.3 from the start of the next eDRX acquisition period boundary.