The purpose of this procedure is to resume a suspended RRC connection, including resuming SRB(s), DRB(s) and multicast MRB(s) or perform an RNA update. This procedure is also used to initiate SDT in RRC_INACTIVE.
if the frequency on which the UE is configured to transmit NR sidelink communication is included in sl-FreqInfoList within SIB12 provided by the cell on which the UE camps; and if the valid version of SIB12 does not include sl-TxPoolSelectedNormal for the concerned frequency; or
if the frequency on which the UE is configured to transmit NR sidelink discovery is included in sl-FreqInfoList within SIB12 provided by the cell on which the UE camps; and if the valid version of SIB12 does not include sl-DiscTxPoolSelected or sl-TxPoolSelectedNormal for the concerned frequency;
For L2 U2N Relay UE in RRC_INACTIVE, an RRC connection establishment is resumed in the following cases:
The UE initiates the procedure when upper layers or AS (when responding to RAN paging, upon triggering RNA updates while the UE is in RRC_INACTIVE, for NR sidelink communication/discovery/V2X sidelink communication as specified in clause 184.108.40.206a) requests the resume of a suspended RRC connection or requests the resume for initiating SDT as specified in clause 220.127.116.11b.
The UE shall ensure having valid and up to date essential system information as specified in clause 18.104.22.168 before initiating this procedure.
Upon initiation of the procedure, the UE shall:
apply the NSAG with highest NSAG priority among the NSAGs that are included in SIB1 (i.e., in FeatureCombination and in RA-PrioritizationSliceInfo), and that are associated with the S-NSSAI(s) triggering the access attempt, in the Random Access procedure (TS 38.321, clause 5.1);
restore the RRC configuration, RoHC state, the EHC context(s), the UDC state, the stored QoS flow to DRB mapping rules and the KgNB and KRRCint keys from the stored UE Inactive AS context except for the following:
derive the KgNB key based on the current KgNB key or the NH, using the nextHopChainingCount value received in the previous RRCRelease message and stored in the UE Inactive AS Context, as specified in TS 33.501;
configure lower layers to apply integrity protection for all radio bearers except SRB0 and MRBs using the configured algorithm and the KRRCint key and KUPint key derived in this clause immediately, i.e., integrity protection shall be applied to all subsequent messages received and sent by the UE;
configure lower layers to apply ciphering for all radio bearers except SRB0 and MRBs and to apply the configured ciphering algorithm, the KRRCenc key and the KUPenc key derived in this clause, i.e. the ciphering configuration shall be applied to all subsequent messages received and sent by the UE;
submit the selected message RRCResumeRequest or RRCResumeRequest1 for transmission to lower layers.
If lower layers indicate an integrity check failure while T319 is running or SDT procedure is ongoing, perform actions specified in clause 22.214.171.124.
If the UE is a RedCap UE and the RedCap-specific initial downlink BWP is not associated with CD-SSB, the UE may continue cell re-selection related measurements as well as cell re-selection evaluation, otherwise the UE shall continue cell re-selection related measurements as well as cell re-selection evaluation. If the conditions for cell re-selection are fulfilled, the UE shall perform cell re-selection as specified in clause 126.96.36.199.
if the UE has connection establishment failure or connection resume failure information available in VarConnEstFailReport or VarConnEstFailReportList and if the RPLMN is equal to plmn-Identity stored in VarConnEstFailReport or in at least one of the entries of VarConnEstFailReportList:
if the UE has radio link failure or handover failure information available in VarRLF-Report of TS 36.331 and if the UE is capable of cross-RAT RLF reporting and if the RPLMN is included in plmn-IdentityList stored in VarRLF-Report of TS 36.331:
if requestedTargetBandFilterNR is configured, for each supported NR band that is also included in requestedTargetBandFilterNR, include an entry in interFreq-needForGap and set the gap requirement information for that band; otherwise, include an entry in interFreq-needForGap and set the corresponding gap requirement information for each supported NR band;
if the UE has connection establishment failure information or connection resume failure information available in VarConnEstFailReport and if the RPLMN is equal to plmn-identity stored in VarConnEstFailReport; and
if the UE has connection establishment failure information or connection resume failure information available in VarConnEstFailReport and if the RPLMN is not equal to plmn-identity stored in VarConnEstFailReport; or
if the UE has connection establishment failure information or connection resume failure information available in VarConnEstFailReportList and if the RPLMN is not equal to plmn-identity stored in any entry of VarConnEstFailReportList:
set the measResultFailedCell to include the global cell identity, tracking area code, the cell level and SS/PBCH block level RSRP, and RSRQ, and SS/PBCH block indexes, of the failed cell based on the available SSB measurements collected up to the moment the UE detected connection resume failure;
if available, set the measResultNeighCells, in order of decreasing ranking-criterion as used for cell re-selection, to include neighbouring cell measurements for at most the following number of neighbouring cells: 6 intra-frequency and 3 inter-frequency neighbours per frequency as well as 3 inter-RAT neighbours, per frequency/ set of frequencies per RAT and according to the following:
if the lower layers indicate that cg-SDT-TimeAlignmentTimer or the configuredGrantTimer expired before receiving network response for the UL CG-SDT transmission with CCCH message while SDT procedure is ongoing; or
perform the actions upon going to RRC_IDLE as specified in clause 5.3.11 with release cause 'RRC Resume failure'.
The UE may discard the connection resume failure or connection establishment failure information, i.e. release the UE variable VarConnEstFailReport and the UE variable VarConnEstFailReportList, 48 hours after the last connection resume failure is detected.
The L2 U2N Relay UE either indicates to upper layers (to trigger PC5 unicast link release) or sends Notification message to the connected L2 U2N Remote UE(s) in accordance with clause 188.8.131.52.