5.7 Other

38.3313GPPNRProtocol specificationRadio Resource Control (RRC)Release 15TS

5.7.1 DL information transfer

5.7.1.1 General

Figure 5.7.1.1-1: DL information transfer

The purpose of this procedure is to transfer NAS dedicated information from NG-RAN to a UE in RRC_CONNECTED.

5.7.1.2 Initiation

The network initiates the DL information transfer procedure whenever there is a need to transfer NAS dedicated information. The network initiates the DL information transfer procedure by sending the DLInformationTransfer message.

5.7.1.3 Reception of the DLInformationTransfer by the UE

Upon receiving DLInformationTransfer message, the UE shall:

1> if dedicatedNAS-Message is included:

2> forward dedicatedNAS-Message to upper layers.

5.7.2 UL information transfer

5.7.2.1 General

Figure 5.7.2.1-1: UL information transfer

The purpose of this procedure is to transfer NAS dedicated information from the UE to the network.

5.7.2.2 Initiation

A UE in RRC_CONNECTED initiates the UL information transfer procedure whenever there is a need to transfer NAS dedicated information. The UE initiates the UL information transfer procedure by sending the ULInformationTransfer message.

5.7.2.3 Actions related to transmission of ULInformationTransfer message

The UE shall set the contents of the ULInformationTransfer message as follows:

1> if the upper layer provides NAS PDU:

2> set the dedicatedNAS-Message to include the information received from upper layers

1> submit the ULInformationTransfer message to lower layers for transmission, upon which the procedure ends.

5.7.2.4 Failure to deliver ULInformationTransfer message

The UE shall:

1> if AS security is not started and radio link failure occurs before the successful delivery of ULInformationTransfer messages has been confirmed by lower layers; or

1> if PDCP re-establishment or release/addition (e.g due to key refresh upon PCell or PSCell change, or RRC connection re-establishment) occurs on an SRB on which ULInformationTransfer messages were submitted for transmission but successful delivery of these messages was not confirmed by lower layers:

2> inform upper layers about the possible failure to deliver the information contained in the concerned ULInformationTransfer messages.

5.7.2a UL information transfer for MR-DC

5.7.2a.1 General

Figure 5.7.2a.1-1: UL information transfer MR-DC

The purpose of this procedure is to transfer MR-DC dedicated information from the UE to the network e.g. the NR or E-UTRA RRC MeasurementReport and FailureInformation message.

5.7.2a.2 Initiation

A UE in RRC_CONNECTED initiates the UL information transfer for MR-DC procedure whenever there is a need to transfer MR-DC dedicated information. I.e. the procedure is not used during an RRC connection reconfiguration involving NR or E-UTRA connection reconfiguration, in which case the MR DC information is piggybacked to the RRCReconfigurationComplete message.

5.7.2a.3 Actions related to transmission of ULInformationTransferMRDC message

The UE shall set the contents of the ULInformationTransferMRDC message as follows:

1> if there is a need to transfer MR-DC dedicated information related to NR:

2> set the ul-DCCH-MessageNR to include the NR MR-DC dedicated information to be transferred (e.g., NR RRC MeasurementReport and FailureInformation message);

1> else if there is a need to tranfer MR-DC dedicated information related to E-UTRA:

2> set the ul-DCCH-MessageEUTRA to include the E-UTRA MR-DC dedicated information to be transferred (e.g., E-UTRA RRC MeasurementReport);

1> submit the ULInformationTransferMRDC message to lower layers for transmission, upon which the procedure ends;

5.7.3 SCG failure information

5.7.3.1 General

Figure 5.7.3.1-1: SCG failure information

The purpose of this procedure is to inform E-UTRAN or NR MN about an SCG failure the UE has experienced i.e. SCG radio link failure, failure of SCG reconfiguration with sync, SCG configuration failure for RRC message on SRB3 and SCG integrity check failure.

5.7.3.2 Initiation

A UE initiates the procedure to report SCG failures when SCG transmission is not suspended and when one of the following conditions is met:

1> upon detecting radio link failure for the SCG, in accordance with subclause 5.3.10.3;

1> upon reconfiguration with sync failure of the SCG, in accordance with subclause 5.3.5.8.3;

1> upon SCG configuration failure, in accordance with subclause 5.3.5.8.2;

1> upon integrity check failure indication from SCG lower layers concerning SRB3.

Upon initiating the procedure, the UE shall:

1> suspend SCG transmission for all SRBs and DRBs;

1> reset SCG MAC;

1> stop T304 for the SCG, if running;

1> if the UE is in (NG)EN-DC:

2> initiate transmission of the SCGFailureInformationNR message as specified in TS 36.331 [10], clause 5.6.13a.

1> else:

2> initiate transmission of the SCGFailureInformation message in accordance with 5.7.3.5.

5.7.3.3 Failure type determination for (NG)EN-DC

The UE shall set the SCG failure type as follows:

1> if the UE initiates transmission of the SCGFailureInformationNR message due to T310 expiry:

2> set the failureType as t310-Expiry;

1> else if the UE initiates transmission of the SCGFailureInformationNR message to provide reconfiguration with sync failure information for an SCG:

2> set the failureType as synchReconfigFailure-SCG;

1> else if the UE initiates transmission of the SCGFailureInformationNR message to provide random access problem indication from SCG MAC:

2> set the failureType as randomAccessProblem;

1> else if the UE initiates transmission of the SCGFailureInformationNR message to provide indication from SCG RLC that the maximum number of retransmissions has been reached:

2> set the failureType as rlc-MaxNumRetx;

1> else if the UE initiates transmission of the SCGFailureInformationNR message due to SRB3 integrity check failure:

2> set the failureType as srb3-IntegrityFailure;

1> else if the UE initiates transmission of the SCGFailureInformationNR message due to Reconfiguration failure of NR RRC reconfiguration message:

2> set the failureType as scg-reconfigFailure.

5.7.3.4 Setting the contents of MeasResultSCG-Failure

The UE shall set the contents of the MeasResultSCG-Failure as follows:

1> for each MeasObjectNR configured on NR SCG for which a measId is configured and measurement results are available:

2> include an entry in measResultPerMOList;

2> if there is a measId configured with the MeasObjectNR and a reportConfig which has rsType set to ssb:

3> set ssbFrequency to the value indicated by ssbFrequency as included in the MeasObjectNR;

2> if there is a measId configured with the MeasObjectNR and a reportConfig which has rsType set to csi-rs:

3> set refFreqCSI-RS to the value indicated by refFreqCSI-RS as included in the associated measurement object;

2> if a serving cell is associated with the MeasObjectNR:

3> set measResultServingCell to include the available quantities of the concerned cell and in accordance with the performance requirements in TS 38.133 [14];

2> set the measResultNeighCellList to include the best measured cells, ordered such that the best cell is listed first, and based on measurements collected up to the moment the UE detected the failure, and set its fields as follows;

3> ordering the cells with sorting as follows:

4> based on SS/PBCH block if SS/PBCH block measurement results are available and otherwise based on CSI-RS;

4> using RSRP if RSRP measurement results are available, otherwise using RSRQ if RSRQ measurement results are available, otherwise using SINR;

3> for each neighbour cell included:

4> include the optional fields that are available.

NOTE: The measured quantities are filtered by the L3 filter as configured in the mobility measurement configuration. The measurements are based on the time domain measurement resource restriction, if configured. Blacklisted cells are not required to be reported.

5.7.3.5 Actions related to transmission of SCGFailureInformation message

The UE shall set the contents of the SCGFailureInformation message as follows:

1> if the UE initiates transmission of the SCGFailureInformation message due to T310 expiry:

2> set the failureType as t310-Expiry;

1> else if the UE initiates transmission of the SCGFailureInformation message to provide reconfiguration with sync failure information for an SCG:

2> set the failureType as synchReconfigFailure-SCG;

1> else if the UE initiates transmission of the SCGFailureInformation message to provide random access problem indication from SCG MAC:

2> set the failureType as randomAccessProblem;

1> else if the UE initiates transmission of the SCGFailureInformation message to provide indication from SCG RLC that the maximum number of retransmissions has been reached:

2> set the failureType as rlc-MaxNumRetx;

1> else if the UE initiates transmission of the SCGFailureInformation message due to SRB3 IP check failure:

2> set the failureType as srb3-IntegrityFailure;

1> else if the UE initiates transmission of the SCGFailureInformation message due to Reconfiguration failure of NR RRC reconfiguration message:

2> set the failureType as scg-reconfigFailure.

1> include and set MeasResultSCG-Failure in accordance with 5.7.3.4;

1> for each MeasObjectNR configured by a MeasConfig associated with the MCG, and for which measurement results are available:

2> include an entry in measResultFreqList;

2> if there is a measId configured with the MeasObjectNR and a reportConfig which has rsType set to ssb:

3> set ssbFrequency in measResultFreqList to the value indicated by ssbFrequency as included in the MeasObjectNR;

2> if there is a measId configured with the MeasObjectNR and a reportConfig which has rsType set to csi-rs:

3> set refFreqCSI-RS in measResultFreqList to the value indicated by refFreqCSI-RS as included in the associated measurement object;

2> if a serving cell is associated with the MeasObjectNR:

3> set measResultServingCell in measResultFreqList to include the available quantities of the concerned cell and in accordance with the performance requirements in TS 38.133 [14];

2> set the measResultNeighCellList in measResultFreqList to include the best measured cells, ordered such that the best cell is listed first, and based on measurements collected up to the moment the UE detected the failure, and set its fields as follows;

3> ordering the cells with sorting as follows:

4> based on SS/PBCH block if SS/PBCH block measurement results are available and otherwise based on CSI-RS;

4> using RSRP if RSRP measurement results are available, otherwise using RSRQ if RSRQ measurement results are available, otherwise using SINR;

3> for each neighbour cell included:

4> include the optional fields that are available.

NOTE 1: The measured quantities are filtered by the L3 filter as configured in the mobility measurement configuration. The measurements are based on the time domain measurement resource restriction, if configured. Blacklisted cells are not required to be reported.

NOTE 2: Field measResultSCG-Failure is used to report available results for NR frequencies the UE is configured to measure by SCG RRC signalling.

The UE shall submit the SCGFailureInformation message to lower layers for transmission.

5.7.3a EUTRA SCG failure information

5.7.3a.1 General

Figure 5.7.3a.1-1: EUTRA SCG failure information

The purpose of this procedure is to inform NR MN about an SCG failure on E-UTRA SN the UE has experienced (e.g. SCG radio link failure, SCG change failure), as specified in TS 36.331 [10] clause 5.6.13.2.

5.7.3a.2 Initiation

A UE initiates the procedure to report EUTRA SCG failures when EUTRA SCG transmission is not suspended and in accordance with TS 36.331 [10] clause 5.6.13.2. Actions the UE shall perform upon initiating the procedure, other than related to the transmission of the SCGFailureInformationEUTRA message are specified in TS 36.331 [10] clause 5.6.13.2.

5.7.3a.3 Actions related to transmission of SCGFailureInformationEUTRA message

The UE shall set the contents of the SCGFailureInformationEUTRA message as follows:

1> include failureType within failureReportSCG-EUTRA and set it to indicate the SCG failure in accordance with TS 36.331 [10] clause 5.6.13.4;

1> include and set measResultSCG-FailureMRDC in accordance with TS 36.331 [10] clause 5.6.13.5;

1> for each EUTRA frequency the UE is configured to measure by measConfig for which measurement results are available:

2> set the measResultFreqListMRDC to include the best measured cells, ordered such that the best cell is listed first using RSRP to order if RSRP measurement results are available for cells on this frequency, otherwise using RSRQ to order if RSRQ measurement results are available for cells on this frequency, otherwise using SINR to order, and based on measurements collected up to the moment the UE detected the failure, and for each cell that is included, include the optional fields that are available;

NOTE: Field measResultSCG-FailureMRDC is used to report available results for E-UTRAN frequencies the UE is configured to measure by E-UTRA RRC signalling.

The UE shall submit the SCGFailureInformationEUTRA message to lower layers for transmission.

5.7.4 UE Assistance Information

5.7.4.1 General

Figure 5.7.4.1-1: UE Assistance Information

The purpose of this procedure is to inform the network of the UE’s delay budget report carrying desired increment/decrement in the connected mode DRX cycle length, or overheating assistance information.

5.7.4.2 Initiation

A UE capable of providing delay budget report in RRC_CONNECTED may initiate the procedure in several cases, including upon being configured to provide delay budget report and upon change of delay budget preference.

A UE capable of providing overheating assistance information in RRC_CONNECTED may initiate the procedure if it was configured to do so, upon detecting internal overheating, or upon detecting that it is no longer experiencing an overheating condition.

Upon initiating the procedure, the UE shall:

1> if configured to provide delay budget report:

2> if the UE did not transmit a UEAssistanceInformation message with delayBudgetReport since it was configured to provide delay budget report; or

2> if the current delay budget is different from the one indicated in the last transmission of the UEAssistanceInformation message including delayBudgetReport and timer T342 is not running:

3> start or restart timer T342 with the timer value set to the delayBudgetReportingProhibitTimer;

3> initiate transmission of the UEAssistanceInformation message in accordance with 5.7.4.3 to provide a delay budget report;

1> if configured to provide overheating assistance information:

2> if the overheating condition has been detected and T345 is not running; or

2> if the current overheating assistance information is different from the one indicated in the last transmission of the UEAssistanceInformation message including overheatingAssistance and timer T345 is not running:

3> start timer T345 with the timer value set to the overheatingIndicationProhibitTimer;

3> initiate transmission of the UEAssistanceInformation message in accordance with 5.7.4.3 to provide overheating assistance information;

5.7.4.3 Actions related to transmission of UEAssistanceInformation message

The UE shall set the contents of the UEAssistanceInformation message as follows:

1> if transmission of the UEAssistanceInformation message is initiated to provide a delay budget report according to 5.7.4.2 or 5.3.5.3;

2> set delayBudgetReport to type1 according to a desired value;

1> if transmission of the UEAssistanceInformation message is initiated to provide overheating assistance information according to 5.7.4.2 or 5.3.5.3;

2> if the UE experiences internal overheating:

3> if the UE prefers to temporarily reduce the number of maximum secondary component carriers:

4> include reducedMaxCCs in the OverheatingAssistance IE;

4> set reducedCCsDL to the number of maximum SCells the UE prefers to be temporarily configured in downlink;

4> set reducedCCsUL to the number of maximum SCells the UE prefers to be temporarily configured in uplink;

3> if the UE prefers to temporarily reduce maximum aggregated bandwidth of FR1:

4> include reducedMaxBW-FR1 in the OverheatingAssistance IE;

4> set reducedBW-FR1-DL to the maximum aggregated bandwidth the UE prefers to be temporarily configured across all downlink carriers of FR1;

4> set reducedBW-FR1-UL to the maximum aggregated bandwidth the UE prefers to be temporarily configured across all uplink carriers of FR1;

3> if the UE prefers to temporarily reduce maximum aggregated bandwidth of FR2:

4> include reducedMaxBW-FR2 in the OverheatingAssistance IE;

4> set reducedBW-FR2-DL to the maximum aggregated bandwidth the UE prefers to be temporarily configured across all downlink carriers of FR2;

4> set reducedBW-FR2-UL to the maximum aggregated bandwidth the UE prefers to be temporarily configured across all uplink carriers of FR2;

3> if the UE prefers to temporarily reduce the number of maximum MIMO layers of each serving cell operating on FR1:

4> include reducedMaxMIMO-LayersFR1 in the OverheatingAssistance IE;

4> set reducedMIMO-LayersFR1-DL to the number of maximum MIMO layers of each serving cell operating on FR1 the UE prefers to be temporarily configured in downlink;

4> set reducedMIMO-LayersFR1-UL to the number of maximum MIMO layers of each serving cell operating on FR1 the UE prefers to be temporarily configured in uplink;

3> if the UE prefers to temporarily reduce the number of maximum MIMO layers of each serving cell operating on FR2:

4> include reducedMaxMIMO-LayersFR2 in the OverheatingAssistance IE;

4> set reducedMIMO-LayersFR2-DL to the number of maximum MIMO layers of each serving cell operating on FR2 the UE prefers to be temporarily configured in downlink;

4> set reducedMIMO-LayersFR2-UL to the number of maximum MIMO layers of each serving cell operating on FR2 the UE prefers to be temporarily configured in uplink;

2> else (if the UE no longer experiences an overheating condition):

3> do not include reducedMaxCCs, reducedMaxBW-FR1, reducedMaxBW-FR2, reducedMaxMIMO-LayersFR1 and reducedMaxMIMO-LayersFR2 in OverheatingAssistance IE;

The UE shall submit the UEAssistanceInformation message to lower layers for transmission.

5.7.5 Failure information

5.7.5.1 General

Figure 5.7.5.1-1: Failure information

The purpose of this procedure is to inform the network about a failure detected by the UE.

5.7.5.2 Initiation

A UE initiates the procedure when there is a need inform the network about a failure detected by the UE. In particular, the UE initiates the procedure when the following condition is met:

1> upon detecting failure for an RLC bearer, in accordance with 5.3.10.3;

Upon initiating the procedure, the UE shall:

1> initiate transmission of the FailureInformation message as specified in 5.7.5.3;

5.7.5.3 Actions related to transmission of FailureInformation message

The UE shall:

1> if initiated to provide RLC failure information, set FailureInfoRLC-Bearer as follows:

2> set logicalChannelIdentity to the logical channel identity of the failing RLC bearer;

2> set cellGroupId to the cell group identity of the failing RLC bearer;

2> set the failureType as rlc-failure;

1> if used to inform the network about a failure for an MCG RLC bearer:

2> submit the FailureInformation message to lower layers for transmission via SRB1;

1> else if used to inform the network about a failure for an SCG RLC bearer:

2> if SRB3 is configured;

3> submit the FailureInformation message to lower layers for transmission via SRB3;

2> else;

3> if the UE is in (NG)EN-DC:

4> submit the FailureInformation message via E-UTRA embedded in E-UTRA RRC message ULInformationTransferMRDC as specified in TS 36.331 [10].

3> else if the UE is in NR-DC:

4> submit the FailureInformation message via SRB1 embedded in NR RRC message ULInformationTransferMRDC as specified in clause 5.7.2a.3.