3GPP TSG-RAN WG1 Meeting #121	R1-2503259
St Julian’s, Malta, May 19th – 23rd, 2025

Agenda Item:	9.9.1
Source:	Huawei, HiSilicon
Title:	Measurements related enhancements for LTM
Document for:	Discussion and Decision

Summary and conclusion
In this contribution, we have following proposals: 
Proposal 1: When SPCellInclusion is configured for CSI-RS based measurements, support Option 1 to determine the CSI-RSs from the current SpCell:
Option 1: NZP-CSI-RS resources in [ltm-CSI-NZP-CSI-RS-ResourceList] associated with the current SpCell are the entries where PCI (given by ltm-CandidatePCI) and frequency information (given by ssb-Frequency for the SSBs QCLed with NZP-CSI-RSs) of the candidate cell associated with the LTM-CandidateId (given by the corresponding entry in ltm-CandidateIdList) is equal to the PCI and center frequency of cell-defining SSB of the current SpCell.
Proposal 2: The activated semi-persistent CSI-RS resource(s) of cells other than the target cell are deactivated automatically after CSC. 
Proposal 3: Semi-persistent CSI-RS measurement after CSC can be automatically activated by CSC.
The indicated TCI state in CSC can be applied to receive semi-persistent CSI-RSs.
Proposal 4: The subset selection of CSI-RS resources for CSI acquisition before CSC can be discussed in R20 together with L1 measurement procedure for LTM.
Proposal 5: CSI report configuration for CSI acquisition is implicitly determined from the field of Target Configuration ID in CSC.
Proposal 6: For CSI measurement after CSC, UE only measures CSI-RS resource configured/indicated with the TCI state same as the LTM TCI state indicated in CSC.
Proposal 7: For CFRA based LTM cell switch, CSI report can be reported on PUSCH scheduled by RAR UL grant or PUSCH of MsgA to target cell. 
Proposal 8: For CBRA based LTM cell switch, CSI reporting is carried in the first UL channel after RA procedure is successfully completed to target cell.
Proposal 9: For RACH-less LTM cell switch, CSI reporting is carried in the first UL channel (either CG-based or DG-based PUSCH).
Proposal 10: Legacy UCI multiplexing on PUSCH can be reused for CSI reporting on target cell.
Proposal 11: UE will report lowest CQI index if the PUSCH for CSI report starts earlier than at symbol Z'ref, where Z'ref is the next uplink symbol with its CP starting  after the end of the last symbol in time of the measured CSI-RS resource for CSI acquisition.
, when only one CSI-RS resource and at most 4 CSI-RS ports are configured. 
, when more than 32 CSI-RS ports are configured for a UE with capability 2
, otherwise. 
Proposal 12: If the lowest CQI index is reported, CSI-RS resource associated with LTM CSI report should still be effective and UE can keep measurement.
Proposal 13: If the lowest CQI index is reported, gNB can reschedule a PUSCH by DCI for valid CSI report.
The rescheduling of a PUSCH carrying valid CSI report should be within a time window after the lowest CQI index is reported.
The valid CSI report can be carried in the UL resource scheduled by DCI with non-zero CSI request field if DCI is received within the time window.
Proposal 14: Support UCI format defined in Table 6.3.1.1.2-7 in TS38.212 can be reused for CSI reporting on target cell.
Proposal 15: Support to define CPU of LTM CSI report for CSI acquisition.
Proposal 16: For CSI measurement before CSC, the start of CPU occupancy time of CSI report associated with semi-persistent CSI-RS can be from the first symbol after 3 msec of the last symbol of HARQ-ACK information for the semi-persistent CSI-RS activation MAC CE.
Proposal 17: For CSI measurement before CSC, the start of CPU occupancy time of CSI report associated with periodic CSI-RS can be from the first symbol of earliest CSI-RS resource after RRC configuration.
Proposal 18: For CSI measurement before CSC, the end of CPU occupancy time depends on whether CSI report is associated with CSI-RS resource from target cell.
If a CSI report is associated with CSI-RS resource from target cell, the end of CPU occupancy time can be the last symbol of the UL resource carrying the report.
If a CSI report is associated with CSI-RS resource from non-target cell, the end of CPU occupancy time can be the last symbol of HARQ-ACK corresponding to LTM CSC MAC CE.
Proposal 19: For CSI measurement after CSC, the occupied CPU can be from the first symbol of earliest CSI-RS resource after 3 msec of the last symbol of HARQ-ACK information for the LTM CSC MAC CE until the last symbol of the UL resource carrying the report.
Proposal 20: To support CSI-RS based measurement and report for R19 LTM, at least the RRC parameters in Table 1 should be further introduced.

3GPP TSG RAN WG1 #121	R1-2503376
St Julian’s, Malta, May 19th – 23th, 2025

Source:	vivo
Title:	Remaining issues on measurements related enhancements for LTM
Agenda Item:	9.9.1
Document for:	Discussion and Decision

Conclusion
For measurements related enhancement(s) for LTM, we have the following observations and proposals:
If semi-persistent CSI-RS resources are used for beam management and CSI acquisition on candidate cell(s), besides the legacy activation/deactivation mechanism by MAC CE, the active semi-persistent CSI-RS resources associated with candidate cell(s) other than the target cell should be deactivated after the reception of LTM cell switch command.

If CSI measurement before the reception of cell switch command is supported, UE only measures CSI-RS resources on candidate cell(s) associated with activated Candidate TCI state(s) before the cell switch command is received;  
If CSI measurement before the reception of cell switch command is not supported or after the reception of the cell switch command, UE only measures the CSI-RS resource(s) associated with the TCI state indicated in the cell switch command;
The above CSI-RS resources that UE measures are the CSI-RS resources that are QCLed with the reference signal in the indicated/activated Candidate TCI state within the multiple CSI-RS resources with the CSI report configuration.
UE only reports CSI measurement result acquired by the CSI-RS resource(s) associated with the indicated Candidate TCI state in the cell switch command to the target cell.
If the number of CSI-RS resources associated with the indicated TCI state in the CSC is larger than 1, CRI is reported; Otherwise, CRI is not reported.
The definition of valid CSI for LTM is listed below.
Support Option-3’ for CG-based rach-less LTM, i.e., the CG-PUSCH configured for the first UL message is shared with the initial CSI report, and only when the initial CSI report and the first UL message are transmitted, the CG-PUSCH configuration is released.
The occupied CPU of the initial CSI report starts from the first symbol after the PDSCH carrying the LTM CSC MAC CE, and ends up with the last symbol of the uplink resource carrying the initial CSI report.
Do not support CSI measurement on candidate cells performed outside the active BWP of the serving cell.
Support to define a new UE capability on the maximum number of CSI-RS for CSI across candidate cells that UE can measure before cell switch.
Activated Candidate TCI state(s), other than the TCI state associated with the triggered beam, should be deactivated upon CLTM procedure being triggered.

3GPP TSG RAN WG1 #121	R1-2503419
St Julian’s, Malta, May 19th – 23th, 2025

Agenda item:	9.9.1
Source:	NEC
Title:              	Discussion on measurements related enhancements for LTM
Document for:	Discussion and Decision

Conclusion
In this contribution, we provided our views on measurements related enhancements for LTM. Specifically, we have the following proposals:
Proposal 1: Support simultaneous configuration of both UE event triggered report and any of NW triggered periodic/semi-persistent/aperiodic report.
Proposal 2: Specify measurement value thresholds for the start or stop of event triggered L1 measurement reporting.
Proposal 3: Support event triggered measurement reporting with optional TCI state indication.
Proposal 4: Support event triggered measurement reporting with optional CFRA resource indication and UL access resource selection.
Proposal 5: UE can determine the CSI report configuration for the target cell based on the Target Configuration ID indicated by the LTM CSC MAC CE.
Proposal 6: UE can determine the CSI-RS resource for CMR for the target cell based on the TCI state ID indicated by the LTM CSC.
Proposal 7: Support gNB to configure appropriate measurement reporting resources for UCI-based CSI feedback for LTM early CSI acquisition.

3GPP TSG RAN WG1 #121	R1- 2503422
Malta, MT, 19 - 23 May 2025

Agenda item: 		9.9.1
Source:	Nokia
Title:	Measurement related enhancements for LTM
Document for:		Discussion and Decision

Conclusion
In this contribution, the following observations and proposal have been made:
For CSI-RS-based measurements, multiple CSI-RSs may be configured in a cell, and different sets of UE-specific CSI-RSs may be assigned to different UEs. Also, there is no specific frequency parameter for a CSI-RS
When SPCellInclusion is configured, it needs to be clarified that which frequency information should be used to determine which CSI-RSs from a measurement RS set belong to the current SpCell.
According to the latest draft version of the RAN2 MAC running CR [2], when the CandidateTCI-State or CandidateTCI-UL-State is linked to a CSI-RS, clarification from RAN1 is needed on whether the UE should select a configured grant tied to that specific CSI-RS.
For CSI-RS-based TCI states and RACH-less configured grant-based cell switch, allocating separate configured grants for each CSI-RS may increase network overhead.
Reporting for early CSI acquisition is performed toward the candidate cell itself, therefore it is not logical to provide the report configuration in the current serving cell.
From the UE’s perspective, rules similar to those used for aperiodic CSI reporting can be applied to determine when valid CSI can be available.
If the UE performs CSI measurements for a candidate cell before receiving the cell switch command, the CPU usage should be clearly defined for both the serving and target cells. However, for baseline UEs, it only needs to be defined for the target cell.
If the UE performs CSI measurements for a candidate cell before receiving the cell switch command, the duration for active CSI-RS ports/resources should be clearly defined for both the serving and target cells. However, for baseline UEs, it only needs to be defined for the target cell.
In Rel-18 LTM for L1-RSRP based measurements, after a candidate TCI activation command, L1 measurement requirements stop applying for candidate cells without active TCI states [Sections 9.14 and 9.15, 38.133].
Since the cell switch command provides a TCI state for accessing the target cell, measuring CSI-RSs not associated with this TCI state is unnecessary.
Measuring candidate CSI-RSs outside the active BWP may add significant complexity at the UE and would require considerable effort in RAN4.

When SpCellInclusion is configured, one of the following options can be used to determine the CSI-RSs from the current SpCell:
Option 1: NZP-CSI-RS resources in [ltm- NZP-CSI-RS-ResourceList] associated with the current SpCell are the entries where PCI (given by ltm-CandidatePCI) and frequency information (given by ssb-Frequency for the SSBs QCLed with NZP-CSI-RSs) of the candidate cell associated with the LTM-CandidateId (given by the corresponding entry in ltm-CandidateIdList) is equal to the PCI and center frequency of cell-defining SSB of the current SpCell.
Option 2: NZP-CSI-RS resources in [ltm -NZp-CSI-RS-ResourceList] associated with the current SpCell are the entries where PCI (given by ltm-CandidatePCI) and frequency information (absoluteFrequencyPointA) of the candidate cell associated with the LTM-CandidateId (given by the corresponding entry in ltm-CandidateIdList) is equal to the PCI and frequency associated with point A of the current SpCell.
For RACH-less configured grant-based cell switch, when the CandidateTCI-State or CandidateTCI-UL-State indicated by the Cell Switch Command is associated with a CSI-RS, the UE determines the configured grant based on the SS/PBCH block that is QCLed with the CSI-RS, following the same approach as in Rel-18.
For early CSI acquisition for a candidate cell, the report configuration is provided in the candidate cell’s LTM-Candidate IE (but outside of the ltm-CandidateConfig). 
For early CSI acquisition of a candidate cell, the CSI-RS resource information can be provided using an NZP-CSI-RS-ResourceSet given under LTM-Candidate IE.
After receiving the cell switch command, the UE transmits a CSI report to the target cell using:
For RACH-less cell switch: the PUSCH sent via either the configured grant (CG) or dynamic grant (DG).
For CFRA-based cell switch: the PUSCH scheduled by the RAR UL grant or the PUSCH of MsgA to the target cell.
For CBRA-based cell switch: the first PUSCH after the completion of the RACH procedure.
The rules for UE to determine when a valid CSI is available can be defined using one of the options below:
Option 1 – Use existing time constraints defined for DCI-triggered aperiodic CSI reporting by introducing a CSI reference resource associated with the report. FFS: Define CSI reference resource.
Option 2 – If there is at least one measurement RS occasion associated with the CSI reporting configuration after the measurement triggering point (i.e., application of the RRC configuration for early measurement or application of the cell switch command for baseline UE) such that the time gap between the RS occasion and the reporting slot is greater than a predefined duration (e.g., Z’).
FFS: An additional timeline requirement for the minimum duration between the triggering command and the reporting slot.
After sending a UCI report in the first PUSCH indicating that a valid CSI is not available, the UE can monitor for a DCI providing a dynamic grant to send the CSI report. 
DCI providing a dynamic grant to send the CSI report indicates that the requested CSI report corresponds to an LTM CSI report.
RAN1 to clarify whether early CSI measurements should count toward the UE’s existing simultaneous CSI processing limit, or if a separate limit should apply.
For UEs that can start measurements before the reception of the cell switch command, a CSI report for a candidate cell should occupy CPU(s) on one or more symbols starting from the last symbol of the uplink slot carrying the acknowledgment for the LTM configuration to the last symbol of the downlink slot carrying the cell switch command or the last symbol of the uplink slot carrying the acknowledgment for the cell switch command. 
FFS: if additional triggering mechanism is used to trigger the measurements before the cell switch command. 
After the cell switch, in the target cell, a CSI report carrying the CSI performed before or during the cell switch procedure should occupy CPU(s) until the last symbol of the uplink slot carrying the report. FFS: whether the starting time needs to be defined. 
For UEs that support measurements before receiving the cell switch command, in the serving cell:
A periodic CSI-RS for a candidate cell should be considered active from the time it is configured by the LTM configuration until the cell switch command is received.
A SP CSI-RS for a candidate cell should be considered active from its activation command until either the cell switch command or a deactivation command is received, whichever comes first.
After the cell switch, in the target cell, a periodic or SP CSI-RS resource should be considered active during a time duration starting when the cell switch command is applied, and ending at the end of the uplink slot containing the report associated with the RS.
RAN1 to clarify whether early CSI measurement ports/resources (in both serving and target cells) should count toward the existing UE limit for active CSI-RS ports/resources or be considered separately. 
Ater a candidate TCI state activation, the UE continues/initiates the measurements for early CSI acquisition only for cells/RSs associated with active TCI states. FFS: whether PDCCH order used for early RACH can be used.
After receiving the cell switch command, the UE performs CSI acquisition only for the target cell and only for CSI-RSs associated with the indicated TCI state.  
Send an LS to RAN4 to clarify whether it would be beneficial to limit CSI acquisition measurements to the following scenarios:
Before cell switch: CSI-RS measurements should be performed only using CSI-RSs within the serving cell’s active BWP.
During cell switch: CSI-RS measurements should be performed using CSI-RSs within the source cell’s active BWP or within the target cell’s initial BWP.
Send an LS to RAN4 to ask whether CSI measurements during cell switch impact cell switch delay.
In case the CSI measurements during the cell switch impact the cell switch delay, RAN1 to discuss whether the cell switch command may include an indication to specify whether the UE can perform CSI measurements (and reporting) as part of the cell switch operation.

3GPP TSG RAN WG1 #121			R1-2503428
St Julian’s, Malta, May 19th – 23th, 2025

Agenda Item:	9.9.1
Source: 	LG Electronics
Title: 	Discussion on measurements related enhancements for LTM
Document for:	Discussion and decision

Summary
In this contribution, we have discussed on potential enhancements on mobility enhancement phase 4. From the discussion, we obtained following proposals and observations;

Observation 1. The main purpose of the CSI-RS based measurement is to inform network which of the beams are desirable after UE receiving cell switch command, rather than which of the candidate cells are desirable for hand-over.

Proposal 1. Only the NZP-CSI-RS resources associated to the candidate cells with activated TCI states are valid for the measurement when UE received TCI activation before CSC.

Proposal 2. LTM CSI resources should be counted for the active CSI-RS ports or resources. Down-select from the following options:
Option 1: it is counted as conventional active CSI-RS ports or resource in active BWP
Option 2: it is newly introduced active CSI-RS ports or resources for LTM

Proposal 3. It is sufficient to reuse rule based on the existing CPU occupancy rule for event triggered reporting in Rel-19 LTM.
, for a CSI report with LTM-CSI-ReportConfig.
The CPU(s) are occupied for a number of OFDM symbols
from the first symbol of the earliest one of each CSI-RS resource triggered TTT.
until the last symbol of the configured PUSCH carrying the MAC-CE report.

Proposal 4. The aperiodic CSI report triggered by DCI is supported for CSI acquisition on candidate cell.

Proposal 5. CPU rules for CSI acquisition don’t need to be defined.

Proposal 6. Discuss CSI reference resource and UE assumption for CQI/PMI/RI calculation to enable CSI acquisition for LTM.

3GPP TSG-RAN WG1 Meeting #RAN 121	R1-2503447
Malta, Malta, May 17 – 21, 2025

Agenda Item:	9.9.1	
Source:	TCL
Title:	Discussion on measurements related enhancements for LTM
Document for:	Discussion and Decision 

Conclusions
This contribution presents our views on CSI-RS measurements for LTM procedures and CSI acquisition before or during the LTM cell switch. We have following proposals.
 : Support aperiodic CSI measurement and reporting for the target cell triggered by the CSC MAC CE.
 : For periodic or semi-persistent CSI-RS configuration, support aperiodic CSI reporting for the target cell triggered by the CSC MAC CE.
 : For CSI reports for the target cell, when periodic CSI-RS resource is configured, the UE only requires to measure CSI for these candidate cells with higher probability to be target cells, which depends on the UE’s reporting of L1 measure results based on the event-triggered L1 measure reporting or gNB-scheduled L1 measure reporting. 
 : For CSI reports for the target cell, when periodic CSI-RS resource is configured, the UE measures CSI for these candidate cells with higher probability to be target cells not earlier than the slot when the UE reports L1 measurement results based on the event-triggered L1 measure reporting or gNB-schedule L1 measure reporting. 

3GPP TSG RAN WG1#121	                                       	 R1-2503526
St Julian’s, Malta, May 19th – 23th, 2025

Agenda Item:     9.9.1
Source:	Spreadtrum, UNISOC
Title:	             Discussion on measurements related enhancements for LTM
Document for:	Discussion and decision

Conclusion 
In this contribution, we provide our proposals on Rel-19 NR mobility enhancements Phase 4:
Proposal 1:
For UE supporting CSI measurement before the reception of LTM CSC, 
before the reception of LTM CSC, the UE shall perform CSI measurements on each candidate cells;
after the reception of LTM CSC, the UE only performs CSI measurement on the target cell indicated by LTM CSC,
the CSI measurement on the target cell can be stopped when the CSI report is transmitted on target cell.
Proposal 2:
For UE only supporting CSI measurement after the reception of LTM CSC, when the PDSCH carrying the LTM CSC is received or the PUCCH with HARQ-ACK corresponding to the PDSCH carrying the LTM CSC is transmitted, the UE starts measuring the CSI-RS resource of the target cell.
Proposal 3:
In addition to P-CSI-RS and SP-CSI-RS, support AP-CSI-RS for UE only supporting CSI measurement after the reception of LTM CSC, where the AP-CSI-RS is associated with the CSI report.
Proposal 4:
After the reception of LTM CSC, only the CSI-RS QCLed with the QCL RS in the TCI state indicated by LTM CSC needs to be measured, or the QCL RS of the CSI-RS is updated based on the indicated TCI state.
Proposal 5:
Support triggering CSI reporting by LTM CSC MAC CE and the reported measurement results are derived based on the CSI-RS resource from the target cell in the resource set under the CSI report configuration.
Proposal 6:
The CSI report can be included on the Msg3 for RACH-based LTM or the first UL channel for RACH-less LTM.
Proposal 7:
For further UE complexity reduction and power saving, the number of candidate cells to be measured not exceeds N for CSI-RS measurement before the reception of LTM CSC MAC CE.
The supported N value is up to separate UE capability.
Proposal 8:
For LTM CSI acquisition, the CSI-RS resource is active in a duration of time defined as follows:
for UE supporting CSI measurement before the reception of LTM CSC: 
reuse the starting time as legacy definition for P-/SP-CSI-RS,
the ending time for target cell is: at the end of the uplink channel resource containing the CSI report,
the ending time for the candidate cell other than target cell is: when the PDSCH carrying the LTM CSC is received or the PUCCH with HARQ-ACK corresponding to the PDSCH carrying the LTM CSC is transmitted,
for UE only supporting CSI measurement after the reception of LTM CSC: 
the starting time is: the end of the PDSCH carrying the LTM CSC or the end of the PUCCH with HARQ-ACK corresponding to the PDSCH carrying the LTM CSC,
the ending time is: at the end of the uplink channel resource containing the CSI report.
Proposal 9:
Define the CSI computation time for LTM CSI acquisition as follows:
the LTM CSI report occupies CPU(s) from the first symbol after the trigger signaling of the report, e.g. LTM CSC MAC CE, until the last symbol of the uplink channel resource carrying the report in target cell.

3GPP TSG RAN WG1 #121	        		             R1-2503580
St. Julian’s, Malta, May 19th – 23rd, 2025
Agenda item:	9.9.1
Source: 	Samsung
Title: 	Views on Rel-19 measurement related enhancements for LTM
Document for:	Discussion and Decision

Conclusions 
In this contribution, we provide our views on various design aspects related to Rel-19 LTM operations, focusing on necessary components to support CSI-RS for LTM measurement/reporting, event triggered L1 measurement reporting and CSI acquisition on candidate cell(s). In particular, we present the following proposals and observations focusing on various design aspects related to the Rel-19 LTM enhancements:

Proposal 1: For associating between the configured CSI-RS resources and candidate cells for L1 measurement(s), further support
(implicit association): association between the configured CSI-RS resource(s) and the candidate cell(s) is based on association between the SSBs (QCL’ed with the configured CSI-RS resource(s)) and the candidate cells

Proposal 2: For gNB scheduled reporting and event triggered reporting, support shared CSI-RS resource for both LTM and L3 mobility, e.g., the CSI-RS introduced for LTM measurement can be configured for L3 mobility as well.

Proposal 3: For CSI acquisition, 
a UE can be provided by the network whether a candidate cell is enabled or not for CSI acquisition, and
for CSI measurement before CSC MAC CE, study mechanism for limiting total CSI acquisition for candidate cell(s) by the same UE before cell switching command. e.g. based on the RS(s) in the TCI state(s) activated for the corresponding candidate cell(s) and UE capabilities.
Proposal 4: For CSI acquisition for candidate cell during LTM, the UE only needs to keep/store CSI for a limited number of candidate cell(s) before cell switching command, subject to corresponding UE’s capabilities.

Proposal 5: For CSI measurement after CSC MAC CE for CSI acquisition, do not support further selecting a subset of the configured CSI-RS(s) for the target cell via either sub-selection by the UE or indication by the gNB.

Proposal 6: For CSI acquisition, 
support the UE to send the CSI report at least a time gap after reception of the LTM CSC,
for both RACH-less and RACH-based LTM procedures, support the first CG/DG PUSCH that carries the RRC completion message to carry the CSI report 

3GPP TSG RAN WG1 #121                                         R1-2503672 
St Julian’s, Malta, May 19th – 23rd, 2025

Source:	ZTE Corporation, Sanechips
Title:	Discussion on measurements related enhancements for LTM
Agenda Item:	9.9.1
Document for:	Discussion and Decision

Conclusion
In this contribution, we share our views on the remaining open issues of measurement related enhancements for Rel-19 LTM, and then proposals are provided as below:
Proposal 1: The following configuration framework should be supported for CSI-RS based early CSI acquisition:
CSI-RS resource/set configuration
A list of NZP CSI-RS resources (e.g., ltm-nzp-CSI-RS-ResourceToAddModList-r18) and a list of NZP CSI-RS resource sets (e.g., ltm-nzp-CSI-RS-ResourceSetToAddModList-r18) are provided by LTM-TCI-Info-r18 in LTM-Candidate-r18, where NZP-CSI-RS-ResourceSet is configured without the higher layer parameters ‘repetition’ and ‘trs-Info’.
CSI-RS measurement configuration
A list of CSI resource configurations (e.g., ltm-csi-ResourceConfigToAddModList-r19) is configured in LTM-Candidate-r18, where one CSI resource configuration (e.g., ltm-CSI-ResourceConfig-r19) provides one or more NZP CSI-RS resource sets and each NZP CSI-RS resource set includes multiple CSI-RS resources for CSI measurement.
CSI reporting configuration
One LTM CSI Reporting configuration (i.e., LTM-CSI-ReportConfig-r19) is configured in LTM-Candidate-r18. 
Proposal 2: Regardless of CSI-RS measurement before or after LTM CSC MAC CE for early CSI acquisition, SP CSI-RS activation operation should be performed before reception of LTM Cell Switch Command MAC CE.
Proposal 3: The activated SP CSI-RS resources for candidate cell or target cell are deactivated after a MAC CE signaling for SP CSI-RS deactivation is applied.
Proposal 4: For CSI-RS measurement operation before LTM Cell Switch Command MAC CE, CSI-RS measurement resources per candidate cell are determined by RRC configuration (e.g., ltm-CSI-ResourceConfig-r19).
Proposal 5: For CSI-RS measurement operation before LTM Cell Switch Command MAC CE, CSI-RS measurement resources are determined based on one of the following alternatives in order to avoid large measurement overhead at UE side:
Alt-1: Candidate TCI state activation or deactivation MAC CE.
CSI-RS measurement resource is same as or associated with RS in the activated candidate TCI state.
Alt-2: A new MAC CE for selecting CSI-RS resources from the configured CSI-RS resources.
Whether to support reduction of measurement overhead is up to UE capability. 
Proposal 6: For CSI-RS measurement operation after LTM Cell Switch Command MAC CE,
CSI-RS measurement resources are determined by the associated CSI reporting configuration, where the candidate cell of associated CSI reporting is determined based on target cell ID provided by Target Configuration ID field in LTM Cell Switch Command MAC CE.
Proposal 7: For CSI-RS measurement after reception of LTM Cell Switch Command MAC CE, UE can start CSI measurement on the CSI-RS resource after a time interval relative to HARQ-ACK transmission corresponding to LTM Cell Switch Command MAC CE.
 The minimum value of the time interval can be 0.
Proposal 8: For CSI-RS measurement before reception of LTM Cell Switch Command MAC CE,
If CSI-RS measurement starts to be performed before receiving LTM Cell Switch Command MAC CE, CSI-RS resources associated with LTM CSI reporting configurations across candidate cells should be counted as active CSI-RS resource(s). 
After receiving LTM CSC MAC CE, CSI-RS resources associated with LTM CSI reporting configuration for candidate cell that is same as target cell ID provided by Target Configuration ID field in LTM CSC MAC CE should be counted as active CSI-RS resource(s).
Proposal 9: For CSI-RS measurement after reception of LTM Cell Switch Command MAC CE,
Before receiving LTM Cell Switch Command MAC CE, CSI-RS resources associated with LTM CSI reporting configurations across candidate cells should NOT be counted as active CSI-RS resource(s) even if CSI-RS resources have been obtained or activated before receiving LTM CSC MAC CE. 
After receiving LTM Cell Switch Command MAC CE, CSI-RS resources associated with LTM CSI reporting configuration for a candidate cell for cell switch should be counted as active CSI-RS resource(s). 
Proposal 10: A CSI measured on a CSI-RS resource is considered to be valid only if the following conditions are met:
The time gap between the CSI-RS resource for CSI calculation and CSI reporting is no less than X symbols, where the value of X is based on UE capability.
There is at least one CSI-RS resource after a time interval relative to HARQ-ACK transmission corresponding to LTM CSC MAC CE for the case of CSI-RS measurement after LTM CSC MAC CE.
Proposal 11: When a valid CSI is not available, a CSI reporting only contains CSI part 1 with fixed size, e.g., CQI, RI and/or CRI.
Proposal 12: Report quantity of 'cri-RI-CQI' should be introduced to accommodate the case that a valid CSI is not available.
Proposal 13: In order to achieve link adaptation as early as possible after completion of cell switch, a valid CSI on a CSI-RS resource associated with LTM CSI reporting configuration should be transmitted on a UL channel that is after the UL channel where an invalid CSI is transmitted.
Note that the LTM CSI reporting configuration is determined based on LTM CSC MAC CE.
Proposal 14: The LTM-CSI report should be transmitted on PUSCH in which RRC reconfiguration is transmitted regardless of RACH-less LTM cell switch or RACH-based LTM cell switch.
Proposal 15: For gNB-triggered reporting, if spCellInclusion is configured,
For CSI-RS resources in [ltm-CSI-NZP-CSI-RS-ResourceList] associated with the current SpCell, their PCI (given by ltm-CandidatePCI) and frequency information (given by refFreqCSI-RS) of the candidate cell associated with the LTM-CandidateId (given by the corresponding entry in ltm-CandidateIdList) is determined according to the PCI and center frequency of CSI-RS of the current SpCell.

3GPP TSG RAN WG1 #121		R1-2503713
St Julian’s, Malta, May 19th – 23th, 2025

Agenda Item:	9.9.1
Source:	Lekha Wireless
Title:	Discussion on measurements related enhancements for LTM
Document for: 	Discussion

Conclusion
According to the above discussion(s), we have the following observation(s) and/or proposal(s) for CSI-RS measurement for LTM procedure. 
Proposal 1:  In the context of LTM CSI reporting for mobility enhancements we define valid CSI. 

Proposal 2: Option 1-1-2 as a solution to avoid blind detection at gNB and additionally to indicate from a UE that valid CSI is not available.

Proposal 3: Option 1-1 with a mobility class–dependent indication mechanism.

3GPP TSG RAN WG1 #121		                                             R1-2503809
St Julian’s, Malta, May 19th – 23rd, 2025

Source:	CATT
Title:	Remaining issues on measurements related enhancements for LTM
Agenda Item:	9.9.1
Document for:	Discussion and Decision

Conclusions
In this contribution, we provide our views on the support of event triggered L1 measurement reporting, CSI acquisition and conditional LTM. We have the following proposals:
Proposal 1: No need to define CSI reference resource for LTM event-triggered reporting. 
Proposal 2: For the definition of CPU occupancy timeline, support Alt 2. i.e., the CPU occupancy time starts from the first OFDM symbol of the earliest transmission occasion of periodic CSI-RS/SSB resource of all the candidate cells for L1-RSRP measurements, until   symbols after the last symbol of the latest CSI-RS/SSB resource of all the candidate cells for L1-RSRP measurements in each transmission occasion.
Proposal 3: From RAN1 perspective, there is no restriction with regards to the frequency location of CSI-RS used for CSI acquisition.
Proposal 4: For RACH-less based LTM, CSI is carried by either DG-PUSCH or CG-PUSCH where RRC reconfiguration complete message is transmitted. For RACH-based LTM, Msg3 could be used.
Proposal 5: If valid CSI is not available at the predefined PUSCH, another candidate PUSCH could be used instead. For example, CG-PUSCH could be reserved until valid CSI is ready to be  reported, or Msg5 is used for RACH-based LTM.
Proposal 6: For the baseline case, the CSI-RS resources to be measured are defined as those CSI-RS resources, which are associated with the CSI report configured under the target cell and QCLed with the target TCI state.
Proposal 7: For the subset selection of the measurement CSI-RS resource(s) from the configured CSI-RS resources before CSC, specify a mechanism to indicate the subset of CSI-RS resources for CSI measurement (Option 1-1).
Proposal 8: For the subset selection of the measurement CSI-RS resource(s) from the configured CSI-RS resources before CSC, either Option 2 or Option 3 could be supported:
Option 2: The subset is indicated by PDCCH order 
Option 3: The subset is implicitly indicated by the Candidate cell TCI state activation/deactivation MAC CE
Proposal 9: No need to define beam application time for NR Rel-19 RACH-less C-LTM.

3GPP TSG RAN WG1 #121			R1-2503843
St Julian's, Malta, 19 - 23 May, 2025


Agenda item:	9.9.1
Title:	Discussion on measurements related enhancements for LTM
Source:	CMCC
Document for:	Discussion and Decision

1. 

Conclusion
Based on the above discussions, the proposals are as follows:
Proposal 1: SpCellInclusion can be reused to indicate whether the UE shall include a L1 measurement report associated to the current SpCell for CSI-RS based gNB scheduled LTM reporting.
Proposal 2: From RAN1 perspective, there is no restriction with regards to the frequency location of CSI-RS used for CSI acquisition.
Proposal 3: The Candidate Cell ID in the CSC MAC CE can be reused to activate the CSI report for CSI acquisition.
Proposal 4: The CSI report is carried on UCI and transmitted on the first PUSCH carrying RRC reconfiguration complete message.

5. 

TDoc file not a doc/docx file

3GPP TSG RAN WG1 Meeting #121	R1-2503863
St Julian’s, Malta, May 19th – 23rd, 2025

Source:		Moderator (Fujitsu)
Title:	FL summary 1 of Measurements related enhancements for LTM
Agenda Item:	9.9.1
Document for:	Information

Conclusion]
The discussion of this section is closed without FL proposal. 

Conditional intra-CU LTM
[Closed] RAN1 spec impact of Conditional intra-CU LTM
[Agreements in the previous meetings]
None

[Summary of contributions]
Vivo
Activated Candidate TCI state(s), other than the TCI state associated with the triggered beam, should be deactivated upon CLTM procedure being triggered
CATT
No need to define beam application time for NR Rel-19 RACH-less C-LTM
Sharp
How to determine the subcarrier spacing for an amount of time alignment,, may require further discussion in the case that the timing advance command is received in  the LTM Candidate Timing Advance Command MAC CE for conditional LTM. 
For example,  is relative to the SCS of the first uplink transmission from the UE after the UE switches to the target cell during CLTM.

[FL observation]
Based on the contribution from companies, FL identifies no issue to immediately resolve in this meeting. With this, the discussion of this section is closed without any FL proposal. 

[Comments if any]

3GPP TSG RAN WG1 Meeting #121	R1-2503864
St Julian’s, Malta, May 19th – 23rd, 2025

Source:		Moderator (Fujitsu)
Title:	FL summary 2 of Measurements related enhancements for LTM
Agenda Item:	9.9.1
Document for:	Information

Conclusion]
The discussion of this section is closed without FL proposal. 

Conditional intra-CU LTM
[Closed] RAN1 spec impact of Conditional intra-CU LTM
[Agreements in the previous meetings]
None

[Summary of contributions]
Vivo
Activated Candidate TCI state(s), other than the TCI state associated with the triggered beam, should be deactivated upon CLTM procedure being triggered
CATT
No need to define beam application time for NR Rel-19 RACH-less C-LTM
Sharp
How to determine the subcarrier spacing for an amount of time alignment,, may require further discussion in the case that the timing advance command is received in  the LTM Candidate Timing Advance Command MAC CE for conditional LTM. 
For example,  is relative to the SCS of the first uplink transmission from the UE after the UE switches to the target cell during CLTM.

[FL observation]
Based on the contribution from companies, FL identifies no issue to immediately resolve in this meeting. With this, the discussion of this section is closed without any FL proposal. 

[Comments if any]

3GPP TSG RAN WG1 Meeting #121	R1-2503865
St Julian’s, Malta, May 19th – 23rd, 2025

Source:		Moderator (Fujitsu)
Title:	FL summary 3 of Measurements related enhancements for LTM
Agenda Item:	9.9.1
Document for:	Information

Conclusion]
The discussion of this section is closed without FL proposal. 

Conditional intra-CU LTM
[Closed] RAN1 spec impact of Conditional intra-CU LTM
[Agreements in the previous meetings]
None

[Summary of contributions]
Vivo
Activated Candidate TCI state(s), other than the TCI state associated with the triggered beam, should be deactivated upon CLTM procedure being triggered
CATT
No need to define beam application time for NR Rel-19 RACH-less C-LTM
Sharp
How to determine the subcarrier spacing for an amount of time alignment,, may require further discussion in the case that the timing advance command is received in  the LTM Candidate Timing Advance Command MAC CE for conditional LTM. 
For example,  is relative to the SCS of the first uplink transmission from the UE after the UE switches to the target cell during CLTM.

[FL observation]
Based on the contribution from companies, FL identifies no issue to immediately resolve in this meeting. With this, the discussion of this section is closed without any FL proposal. 

[Comments if any]

3GPP TSG RAN WG1 Meeting #121	R1-2503866
St Julian’s, Malta, May 19th – 23rd, 2025

Source:		Moderator (Fujitsu)
Title:	Final FL summary of Measurements related enhancements for LTM
Agenda Item:	9.9.1
Document for:	Information

Conclusion]
The discussion of this section is closed without FL proposal. 

Conditional intra-CU LTM
[Closed] RAN1 spec impact of Conditional intra-CU LTM
[Agreements in the previous meetings]
None

[Summary of contributions]
Vivo
Activated Candidate TCI state(s), other than the TCI state associated with the triggered beam, should be deactivated upon CLTM procedure being triggered
CATT
No need to define beam application time for NR Rel-19 RACH-less C-LTM
Sharp
How to determine the subcarrier spacing for an amount of time alignment,, may require further discussion in the case that the timing advance command is received in  the LTM Candidate Timing Advance Command MAC CE for conditional LTM. 
For example,  is relative to the SCS of the first uplink transmission from the UE after the UE switches to the target cell during CLTM.

[FL observation]
Based on the contribution from companies, FL identifies no issue to immediately resolve in this meeting. With this, the discussion of this section is closed without any FL proposal. 

[Comments if any]

3GPP TSG RAN WG1 #121                                     	      R1-2503894
St Julian’s, Malta, May 19th – 23rd, 2025

Agenda Item:	9.9.1
Source:	Xiaomi 
Title:                     Discussion on measurements related enhancements for LTM
Document for:	Discussion and Decision

Conclusion
In this contribution, we discuss about the event-triggered measurement reporting for LTM. Based on above discusses, we provide the following proposals.
Proposal 1: UE selects the measured candidate cell and measured CSI-RS resource based on activated TCI states of candidate cells before CSC command.
Proposal 2: Support aperiodic CSI reporting triggered by LTM cell switch command MAC CE.
Proposal 3: CSI report of target cell can be reported on the PUSCH during random access procedure to target cell at least for LTM cell switch based on CFRA. 
Proposal 4: For RACH-less LTM cell switch, UE reports the CSI report on the earliest available PUSCH on target cell.

3GPP TSG RAN WG1#121                                                                  R1-2503916
St Julian’s, Malta, May 19th – 23rd, 2025

Agenda Item:	9.9.1
Source:	Lenovo
Title:	Measurement related enhancements for LTM
Document for:	Discussion

Conclusion
In this contribution, we have following proposals to support the CSI-RS based beam report for LTM:
Proposal 1: Each CSI-RS resource associated with an LTM-CSI-ReportConfig is QCLed with an SSB associated with a same LTM-Candidate-ID.
Proposal 2: If the QCLed SSB for a CSI-RS from a candidate cell is not detected by the UE, the UE shall not measure the CSI-RS.

Proposal 3: The CSI-RS resources from different candidate cells but associated with a same LTM-CSI-ReportConfig should be configured with a same bandwidth.

Proposal 4: Support group based beam report for LTM CSI report to enable the multi-TRP operation after switch to the new serving cell.

Further, we provide the following proposals on the early CSI acquisition:
Proposal 5: One or more CSI report configuration can be configured on a serving cell for early CSI acquisition for LTM, where one or more CSI-RS resource sets are associated with a CSI report configuration and each CSI-RS resource set contains CSI-RS resources associated with a candidate cell.
Proposal 6: The UE only measure CSI based on the CSI-RS resources associated with activated joint or DL TCI state for a candidate cell when at least one joint or DL TCI state is activated for the candida cell.
Proposal7: The UE only need to report the CSI corresponding to the CSI-RS resource associated with the indicated TCI state indicated in the CSC for the target cell.

Proposal 8: For RACH-based LTM is triggered, the early CSI for the target cell can be carried by Msg. 3.
Proposal 9: For RACH-less LTM is triggered, the early CSI can be carried by the first PUSCH in the target cell.

Additionally, we have the following proposals to support event triggered beam report for LTM
Proposal 10: Only one event corresponding to a LTM CSI report configuration is reported in the MR MAC CE. 
Proposal 11: Further study the CSI reference resource for MAC CE based beam report.

3GPP TSG RAN WG1 #121                         			   		R1-2503949
St Julian’s, Malta, May 19th – 23th, 2025

Agenda Item:	9.9.1
Source:	InterDigital, Inc.
Title:	Measurements related enhancements for LTM
Document for:	Discussion and Decision

Conclusion
This contribution discussed further details of CSI acquisition on candidate cell(s) before or during LTM cell switch. The following proposals are made:
Proposal 1: Configure association between each CSI-RS resource of a CSI report configuration for candidate cell and a candidate TCI state.
Proposal 2: UE is not expected to provide valid CSI if CSI-RS resource of the CSI report configuration is not associated to activated candidate TCI state.
Proposal 3: UE reports CSI of target cell in first PUSCH transmission in target cell.
Proposal 4: For UE triggering CSI measurement after cell switch, CSI is valid based on 38.214 (5.4) where Zref is defined with reference to the MAC CE containing cell switch command.
Proposal 5: For UE triggering CSI measurement before cell switch, CSI is valid based on 38.214 (5.4) where Zref is defined with reference to the MAC CE activating candidate TCI state associated with CSI-RS resource.
Proposal 6: Support triggering of CSI of target cell by DCI indicating a PUSCH.

3GPP TSG RAN WG1 Meeting #121		 R1-2504004
St Julian’s, Malta, May 19th – 23rd, 2025	
Source:	Fujitsu
Title:	Discussion on measurement related enhancements for LTM
Agenda Item:	9.9.1
Document for:	Discussion

Conclusion
In this contribution, we provide our views as below.

Proposal 1: The legacy CPU definition can be reused to the gNB scheduled reporting in the Rel-19 LTM for CSI-RS based RSRP reporting.
The number of CPUs is provided by separate UE capability from that of the legacy.

Proposal 2: For CPU occupation duration for the event triggered reporting, the CPU occupation duration starts from the earliest one of each transmission occasion of periodic CSI-RS/SSB resource until symbols after the transmission occasion.

Proposal 3: The active CSI-RS resources / ports are not counted for the event triggered reporting.

Proposal 4: Introduce timeRestrictionForChannelMeasurements for L1-RSRP calculation in the event triggered reporting without defining the CSI reference resource.
If this parameter is configured, only a single sample can be used
Otherwise, multiple samples can be used, and the detail is up to RAN4

Observation 1: 
The indication of the subset selection of CSI-RS resources before CSC is needed to reduce the measurement overhead.
UE cannot receive the CSI-RS if there is no corresponding TCI state activation.

Proposal 5: Introduce a new MAC CE to indicate subset of CSI-RS resources for CSI acquisition before reception of CSC.

Proposal 6: UE shall measure the CSI after reception of the indication of the subset selection for CSI acquisition before CSC.
UE is not expected to measure the configured CSI-RS resources not indicated by the new MAC CE.
UE does not have to measure the CSI if the UE does not receive the indication.

Proposal 7: Introduce the CRI in the cell switch command to indicate the CSI-RS resource for CSI acquisition after reception of CSC.

Proposal 8: CSI report configuration for each candidate cell is provided under LTM-Config.

Proposal 9: For CSI-RS resource set configuration, CSI-RS resource(s) in a single resource set can be associated with only one candidate cell.

Proposal 10: For the valid CSI, the legacy definition (Z, Z’) of the aperiodic CSI reporting can be reused with with the following enhancement.
Z starts from the last symbol of a PUCCH or PUSCH with HARQ-ACK information for the PDSCH carrying CSC
Z’ starts from the end of the last symbol of corresponding CSI-RS, which is the first CSI-RS starting from the end of Beam application time

Proposal 11: For CSI retransmission of CSI acquisition, introduce the repetitive transmission of CSI on the CG-/DG-PUSCH.
The number of repetitions is pre-configured in RRC.
The CSI report will not be transmitted after the repetition period.

Proposal 12: CSI is multiplexed on the PUSCH carrying the RRCRecofigurationComplete message for both RACH-based and RACH-less LTM

Proposal 13: From RAN1 perspective, there is no restriction with regards to the frequency location of CSI-RS used for CSI acquisition.

3GPP TSG RAN WG1 #121                                       R1-2504148
St Julian’s, Malta, May 19th – 23 th, 2025
Source: 	ETRI
Title:	Discussion on measurements related enhancements for LTM
Agenda Item:	9.9.1
Document for:	Discussion/Decision

Conclusion
In this contribution, we note the following proposals.

Observation 1:L1-RSRP-based measurements for candidate cells are already supported on inter-frequency bands in Rel-18. If inter-frequency CSI acquisition is not allowed, the UE may not be able to provide CSI for a selected inter-frequency target cell, making earlier measurements meaningless and limiting LTM effectiveness.
Observation 2: In LTM procedures, transmitting the RRCReconfigurationComplete message without a UCI report may trigger blind decoding at the target cell, increasing complexity; therefore, a fixed-length UCI report containing either valid or invalid CSI should be included in every PUSCH transmission after the CSC.

Observation 3: When a target TCI state is associated with multiple CSI-RS resources, the UE is expected to include CSI for all such resources—valid or invalid—in a single UCI report to ensure consistent interpretation and avoid ambiguity at the target cell.

Observation 4: In LTM procedures, a CSI report with CQI=0 may either represent valid CSI under poor channel conditions or indicate that the UE has not completed sufficient CSI measurements. Without a clear distinction, the target cell might misinterpret CQI=0 as invalid CSI and skip LDPC decoding, potentially missing critical messages such as RRCReconfigurationComplete.

Observation 5: Before receiving the CSC, if the UE does not measure the initially configured CSI-RS resources and no subset indication is sent, the network may incorrectly assume valid CSI exists and expect immediate reporting. This mismatch can lead to scheduling failures and procedure delays in LTM.

Observation 6: After CSC reception in LTM, limiting CSI measurement to only the CSI-RS resources associated with the target TCI state can reduce UE overhead and ensure efficient, beam-specific CSI reporting without requiring additional signaling.

Proposal 1: RAN1 should support CSI acquisition for candidate cells on both intra-frequency and inter-frequency bands, within the scope of UE capability, because if inter-frequency CSI acquisition is not supported, the UE may not be able to acquire CSI for target cells operating on different frequency bands.

Proposal 2: In RACH-less procedures, the multiplexed transmission should occur on the first PUSCH that includes the valid CSI after the CSC. In RACH-based procedures, the valid CSI should be included in the first uplink transmission granted by the Random Access Response (MSG 2).

Proposal 3: The UE shall include CSI for all CSI-RS resources associated to the target TCI state in a single UCI report. If valid CSI is unavailable, invalid entries (e.g., CQI=0) should be included to maintain a fixed format. The valid CSI report should be multiplexed with the RRCReconfigurationComplete message to avoid blind decoding at the target cell.

Proposal 4: It is proposed that the specification clarify how to distinguish valid and invalid CSI when CQI=0 is reported. Specifically, if CQI=0 is accompanied by consistent combinations of RI and PMI, the report should be treated as valid. Conversely, CQI=0 with RI=0 or inconsistent combinations of RI and PMI should indicate invalid CSI. This approach avoids implementation ambiguity while requiring no changes to the existing signaling format.

Proposal 5: We propose to define "valid CSI" as a CSI report that includes a consistent set of values (e.g., CQI, RI, PMI) derived from CSI-RS measurements, where CQI=0 is still considered valid if accompanied by consistent combinations of RI and PMI. 

Proposal 6: Since there may be cases where explicit subset indication is not provided, the UE shall measure all configured CSI-RS resources within its capability before CSC. The network may send signaling messages indicating a subset of CSI-RS resource sets, in which case the UE shall measure only the indicated subset.

Proposal 7: After receiving CSC, the UE shall measure only the CSI-RS resources associated with the target TCI state, based on pre-configured QCL or mapping. This approach enables efficient and targeted CSI acquisition without the need for additional signaling after CSC.

3GPP TSG-RAN WG1 Meeting #121	Tdoc R1-2504184
St Juilan’s, Malta, May 19th – May 23rd  2025

Agenda Item:	9.9.1
Source:	Ericsson
Title:	Measurement related enhancements for LTM
Document for:	Discussion, Decision

1	

Conclusion
In the previous sections we made the following observations: 
Observation 1	The PHY layer does not need to store any measurements for event-triggered L1 measurement reporting.
Observation 2	By active CSI-RS resource counting, the network is guaranteed that the configured resources are measured as long as the UE capability is not exceeded. In Rel. 18 LTM, there is no such guarantee: the UE selects which of the configured SSB resources it measures.
Observation 3	If active CSI-RS resource counting is used for LTM and the network wants to use the same resource configuration for different UEs with different maximum number of active CSI-RS resource, then the configuration is limited by the UE with minimum capability.
Observation 4	The TCI state activation command MAC CE is used for likely LTM target cells, making it an accurate trigger for CSI measurement operations in that cell.
Observation 5	It is not relevant to consider periodic or semi-persistent CSI reporting for early CSI reporting.
Observation 6	Since the target cell does not know when the UE received the LTM CSC MAC CE was received, the target cannot determine whether the requirements Z/Z’ are met for the CSI report in the first uplink resource in the target cell. The target cell need to rely on the UE indication if the CSI is valid or not.
Observation 7	The network needs to poll the UE at most two times to be sure to receive valid CSI with minimal delay.
Observation 8	A UE configured with CSI measurements by the source cell can report the results to the target cell if the report configuration is shared between the source and target cells, just like LTM-CSI-Resource-Configuration is already shared.


Based on the discussion in the previous sections we propose the following:
Proposal 1	L1 measurements for event-triggered reporting does not occupy any CPUs for the UE.
Proposal 2	It is up to UE to decide which of the configured CSI-RSs for gNB scheduled reporting it should measure on, just as for SSBs in Rel. 18 LTM. The network does not count active CSI-RS resources for LTM.
Proposal 3	The UE measures L1-RSRP for at least a minimum number of CSI-RS resources configured for LTM beam management. This number is a component of the UE capabilities for gNB scheduled LTM based on CSI-RS.
Proposal 4	Reuse LTM-TCI-Info to configure candidate cell CSI-RS resources for beam management
Proposal 5	Periodic CSI-RS resources for CSI acquisition in an LTM candidate cell are counted as active when there is an activated TCI state for the cell and when they are associated with a CSI report configuration. Semi-persistent CSI-RS resources should additionally be ON.
Proposal 6	Upon reception of LTM CSC MAC CE targeting one of the LTM candidates, the UE unambiguously identifies the CSI reporting configuration for that candidate, performs measurement operations and prepares CSI report accordingly.
Proposal 7	When the delay requirements Z/Z’ are met, the network assumes that the UE reports valid CSI, but valid CSI can also be available earlier.
Proposal 8	For a UE with basic capability, the delay requirements Z’/Z applies as follows: - Z' is with respect to the first CSI-RS transmission occasion after LTM CSC MAC CE,  - Z is with respect to the LTM CSC MAC CE.
Proposal 9	For a UE with capability for CSI measurement operations before LTM CSC MAC CE: If measurement operations are triggered by activation of a TCI state in the target cell, the delay requirements Z’/Z applies as follows: - Z' is with respect to the first CSI-RS transmission occasion after a TCI state in the target cell is activated,  - Z is with respect to the TCI State activation MAC CE. If measurement operations are not triggered in the target cell, then the delay requirements of the basic capability applies.
Proposal 10	If CSI is not available to be reported in the first UL resource in the target cell, then the network can poll the UE for the CSI at a later time using legacy mechanisms.
Proposal 11	Measurement operations for CSI acquisition before LTM CSC MAC CE is supported regardless of the frequency location of the target cell, given UE capability.
Proposal 12	The report configuration for CSI acquisition is the same in the source cell, the target cell and the UE. The UE keeps it over cell switch execution.
Proposal 13	Adapt LTM-CSI-ReportConfig to support relevant report quantities, including cri-RI-PMI-CQI and cqi-Table for CQI reporting.
Proposal 14	To support early CSI acquisition, use LTM-CSI-ResourceConfig and LTM-NZP-CSI-Rs-ResourceSet to provide channel measurement resources. The repetition field is absent.
Proposal 15	Introduce a new RRC IE for LTM codebook configuration.

3GPP TSG RAN WG1 #121		R1-2504233
St Julian’s, Malta, May 19th – 23th, 2025

Source:	OPPO
Title:	Discussions on measurement enhancement for LTM
Agenda Item:	9.9.1
Document for:	Discussion and Decision

Conclusions
In this contribution, we present our views on UE-initiated beam reporting and the following proposals are made:
Proposal 1: When the serving cell is configured with mTRP and has two indicated joint/DL TCI states:
The UE derive two RSs for serving cell evaluation and each RS is from the QCL RS or the SSB that the QCL RS is QCLed to of each indicated joint/DL TCI state.
The L1-RSRP measurement of serving cell for event evaluation is the minimum value of the L1-RSRP measurement of those two RSs.
Proposal 2: UE reports one indicator to indicate which LTM event is triggered in LTM event-triggering reporting.
Proposal 3: For event LTM 2, the UE reports the L1-RSRP measurement of the RS corresponding to the indicated TCI state of serving cell.
The reported L1-RSRP measurement can be a differential L1-RSRP measurement with a reference to the corresponding threshold
Proposal 4: For event LTM 3, the UE reports:
The L1-RSRP measurement of all the beam evaluation RSs of candidate cell that satisfy the event LTM 3 trigger condition and their corresponding CRI/SSBRIs
the L1-RSRP measurement of serving cell.
The reported L1-RSRP measurement of candidate cell is differential L1-RSRP with a reference to the L1-RSRP of the serving cell.
Proposal 5: For event LTM 4, the UE reports the L1-RSRP measurement of all the beam evaluation RSs of candidate cell that satisfy the event LTM 4 trigger condition and their corresponding CRI/SSBRI
UE reports the differential L1-RSRP of each reported CRI/SSBRI with a reference to the configured L1-RSRP threshold
Proposal 6: For event LTM 5, the UE reports:
The differential L1-RSRP of each RS of candidate cell that satifies the condition of event LTM 5 with reference to the L1-RSRP threshold configured for candidate cell and the corresponding CRI/SSBRI.
The differential L1-RSRP of serving cell with reference to the L1-RSRP threshold configured for serving cell.
Proposal 7:  The definition of valid CSI report is up to UE implementation, no spec impact.
Proposal 8: If valid CSI is specified in spec, revert the support of Option 1 for avoiding blind detection and the UE does not transmit CSI when valid CSI is not available. 
Proposal 9: The NZP CSI-RS resources configured for CMR is used as IMR.
Proposal 10: For Spcell inclusion of CSI-RS L1-RSRP measurement, Option 1 is preferred.

3GPP TSG RAN WG1 #121			R1-2504300
St Julian’s, Malta, May 19th – 23th, 2025

Agenda Item:	9.9.1
Source:	Google
Title:	Discussion on measurements related enhancements for LTM
Document for: 	Discussion

Conclusion
According to the above discussion(s), we have the following observation(s) and/or proposal(s). 
Proposal 1: From RAN1 perspective, there is no restriction with regard to the frequency location of CSI-RS used for LTM CSI acquisition. 
Proposal 2: For LTM CSI acquisition, in case that RACH-less LTM is performed, the reporting medium and timing is the DG-PUSCH or CG-PUSCH for first UL transmission for completing LTM procedure. 
Proposal 3: For LTM CSI acquisition, in case that RACH-based LTM is performed, the reporting medium and timing is the first available DG-PUSCH or CG-PUSCH after completing LTM procedure. 
Proposal 4: On CSI acquisition for LTM cell switch, if periodic CSI-RS resources are configured for LTM CSI acquisition, UE starts to measure the configured periodic CSI-RS resources after the RRC configuration. 
Proposal 5: On CSI acquisition for LTM cell switch, no mechanism is introduced for selecting a subset of CSI-RS resources to measure before reception of LTM CSC MAC CE. 

3GPP TSG RAN WG1 #121		R1-2504340
St Julian’s, Malta, May 19th – 23th, 2025

Source: 	Apple Inc.
Title:                     Measurement related enhancements for LTM
Agenda item:	9.9.1
Document for:	Discussion and Decision
1 

Conclusion 
In this contribution, we have presented our views on the event-triggered L1 measurement report and CSI-RS based measurement for Rel-19 LTM. We proposed the following: 
Proposal 1: The UE reports the early CSI to target cell over UCI bits in the first PUSCH. 
Proposal 2: For each candidate cell, a separate   is configured to determine the number of REs used for early CSI report. 
Proposal 3: The first PUSCH carrying the early CSI report is determined as follows:
If RACH procedure is triggered by CSC MAC-CE, the first PUSCH is the PUSCH scheduled by Msg2 RAR; 
Otherwise, the first PUSCH is the first CG-PUSCH or DG-PUSCH after UE switchs to target cell. 
Proposal 4: Defining the following CSI reference resource for early CSI report of candidate cell for a CSI reporting in a first PUSCH in uplink slot ‘n’:
For Capability #1 UE, the CSI reference resource is defined in time domain as , where  is the smallest value greater than or equal to  and no earlier than the last symbol of CSC MAC-CE command. 
For Capability #2 UE, the CSI reference resource is defined in time domain as , where  is the smallest value greater than or equal to . 
Proposal 5: If there is no CSI reference resource corresponding to a first PUSCH occasion, a UE reports ‘invalid CSI’ by using the codepoint with the lowest CQI index; Otherwise, a valid CSI should be reported in the first PUSCH. 
Proposal 6: Define CPU occupany rule for early CSI report of candidate cell. 
Proposal 7: For early CSI report of candidate cell, the number of CPUs to process this CSI report is defined as follows:, 
For measurement performed before receiving CSC MAC-CE, ‘’ where ‘’ is the total number of CSI-RS resources in the CSI-RS resource sets across candidate cells.
For measurement performed after receiving CSC MAC-CE, ‘’ where ‘’ is the total number of CSI-RS resources in the CSI-RS resource set of the candidate cell in the CSC MAC-CE.
Proposal 8: For a early CSI report for a candidate cell, two CPU counting are applied: 
CPU counter #1: Counting for each CSI measurement occasion starting from the first symbol of the earliest one of each CSI-RS/SSB resource for channel measurement and ends at the symbol ‘’, where  is the last symbol of last CSI-RS resource.  
CPU counter #2: countering for a first PUSCH occasion. Assuming the last symbol ‘’ of first PUSCH, the CPU counter #2 starts from ‘’ symbol and ends at the last PUSCH symbol ‘’.   

3GPP TSG-RAN WG1 #121	R1-2504408
St Julian’s, Malta, May 19th – 23rd, 2025	

Agenda item:	9.9.1
Source: 	Qualcomm Incorporated
Title: 	Measurements related enhancement for LTM
Document for:	Discussion/Decision

Conclusions
In this contribution, we presented our views on measurement-related enhancement for LTM, focusing on measurement resources, event-driven measurement reporting, and candidate cell CSI acquisition. Specifically, the following observations and proposals were made:
Proposal 1: For event evaluation and measurement reporting for Events LTM2, LTM3, and LTM5, the current SpCell and its corresponding RSs should always be included in the LTM measurement resource configuration associated with the report configuration.
Proposal 2: For the determination of serving cell CSI-RS resources for LTM L1 measurement reporting, Option 1 is endorsed:
Option 1: NZP-CSI-RS resources in [ltm-CSI-NZP-CSI-RS-ResourceList] associated with the current SpCell are the entries where PCI (given by ltm-CandidatePCI) and frequency information (given by ssb-Frequency for the SSBs QCLed with NZP-CSI-RSs) of the candidate cell associated with the LTM-CandidateId (given by the corresponding entry in ltm-CandidateIdList) is equal to the PCI and center frequency of cell-defining SSB of the current SpCell.
Proposal 3: As both event evaluation and reporting for event-triggered L1 measurement reporting are managed by the MAC layer, no CPU involvement is necessary.
Proposal 4: For CSI acquisition on candidate cells, configuration of CSI-IM resources for interference measurement should be supported.
Each CSI-RS resource for CMR is resource-wise associated with a CSI-IM resource.
Proposal 5: For CSI measurement on candidate cells,
The CSI-RS measurement starts only after the TCI state activation/indication for the candidate cell.
Only a subset of CSI-RS resource(s) that are the same or QCLed with the QCL RS(s) in the activated/indicated TCI state(s) should be measured.
Proposal 6: For CSI reporting to the target cell, the determination of “valid CSI” is up to UE implementation.
Proposal 7: When the UE indicates “no valid CSI” to the target cell with the lowest CQI index, no follow-up transmission (according to the same LTM CSI report configuration) is supported.
Distinction between “no valid CSI” and “out of range” is unnecessary.
Proposal 8: CSI reporting to the target cell is multiplexed with Msg3 (RACH-based) or the first UL transmission (DG or CG) to the target cell (RACH-less).
A beta offset value for the UCI is semi-statically configured.
Proposal 9: For CSI processing for the target cell, no CPU occupancy rule is required.
Triggered by a CSC MAC CE, UE processes only a single CSI without sharing CPUs with other CSI processes.

3GPP TSG RAN WG1 #121		                            R1-2504450
St Julian’s, Malta, May 19th – 23rd, 2025
Agenda Item:	9.9.1 
Source:	KDDI Corporation
Title:	Discussion on measurements related enhancements for LTM
WID:       	NR_Mob_Ph4-Core
Tdoc Type:	Discussion
Document for: 	Discussion and decision

Conclusion
Based on the discussion in the previous sections we propose the following:
Proposal 1: Support for inter-frequency and intra-frequency for CSI acquisition.
Proposal 2: Introduce subset selection of measurement CSI-RS resource(s) from the configured CSI-RS resources before CSC. Support Option 1 (The subset is indicated by a new MAC CE) 
Proposal 3: The gNB indicates the subset of CSI-RS resources to be measured after the CSC.  

3GPP TSG RAN WG1 #121			R1-2504513
St Julian’s, Malta, May 19th – 23rd, 2025

Source:	NTT DOCOMO, INC.
Title:	Discussion on measurement related enhancements for LTM
Agenda Item:	9.9.1
Document for: 	Discussion and Decision

Conclusion
In this contribution, we discussed the enhancements for Measurements related enhancements for purpose of supporting LTM. Based on the discussion, we made following observations and proposals.
gNB-scheduled beam reporting
Proposal 1
For gNB-scheduled beam reporting, active CSI-RS resource for LTM should be separately counted from serving cell.
Proposal 2
For gNB-scheduled beam reporting, to identify SpCell for CSI-RS L1-RSRP measurement, support Option-1:
Option-1: NZP-CSI-RS resources in [ltm-CSI-NZP-CSI-RS-ResourceList] associated with the current SpCell are the entries where PCI (given by ltm-CandidatePCI) and frequency information (given by ssb-Frequency for the SSBs QCLed with NZP-CSI-RSs) of the candidate cell associated with the LTM-CandidateId (given by the corresponding entry in ltm-CandidateIdList) is equal to the PCI and center frequency of cell-defining SSB of the current SpCell.

Event-triggered beam reporting
Proposal 3
For both event-triggered beam reporting and gNB-scheduled beam reporting, support to introduce configuration of time restriction for channel measurement.

Proposal 4
For CPU occupancy of event-triggered beam reporting, support Option-1.
Option-1: no CPU involvement is necessary for event triggered reporting

CSI acquisition on candidate cell(s) based on CSI-RS before or during LTM
Proposal 5
Support intra and inter-frequency CSI measurement for candidate cell before cell switch command.

Proposal 6
For the selection of CSI resource(s) for measurement and a CSI report configuration for the report after reception of cell switch command, support the following.
CSI report configuration is associated with target configuration ID in cell switch command MAC CE.
CSI-RS resource to be measured is derived from the TCI state indicated in cell switch command MAC CE.
For the optional procedure of CSI measurement before cell switch command based on UE capability,
CSI-RS resource(s) to be measured is derived from the TCI state(s) activated by the Candidate cell TCI state activation/deactivation MAC CE.

Proposal 7
Support to define the following definition of valid CSI.
Valid CSI is available when CSI calculation and preparation of CSI report for the indicated CSI-RS resource are completed.

Proposal 8
UE follows legacy serving cell operation after CSI report with the lowest CQI index is transmitted during cell switch.

Proposal 9
For CSI measurement before/after cell switch command, active CSI-RS resource for LTM should be separately counted from serving cell.

Proposal 10
For counting of active CSI-RS resource for CSI measurement before cell switch command, support Alt-2 for periodic CSI-RS and Alt-3 for semi-persistent CSI-RS.
Alt-2: A periodic CSI-RS resource for candidate cells provided by LTM-CSI-SSB-ResourceSet should be counted as active when 
it is associated with an activated TCI state in the cell and,
it is associated with an active CSI report configuration. 
Alt-3: A semi-persistent CSI-RS resource for candidate cells provided by LTM-CSI-SSB-ResourceSet should be counted as active when 
it is activated,
it is associated with an activated TCI state in the cell and,
it is associated with an active CSI report configuration.

Proposal 11
For counting of active CSI-RS resource for CSI measurement after cell switch command before CSI report to target cell,
Support Alt-2’ for periodic CSI-RS and Alt-3’ for semi-persistent CSI-RS.
Alt-2’: A periodic CSI-RS resource for target cell provided by LTM-CSI-SSB-ResourceSet should be counted as active when 
it is associated with the indicated TCI state in cell switch command and,
it is associated with an active CSI report configuration. 
Alt-3’: A semi-persistent CSI-RS resource for target cell provided by LTM-CSI-SSB-ResourceSet should be counted as active when 
it is activated,
it is associated with the indicated TCI state in cell switch command and, 
it is associated with an active CSI report configuration.

Proposal 12
For CSI reference resource for CSI measurement after cell switch command, support Alt-2.
Alt-2: Define the following CSI reference resource for early CSI report of candidate cell for a CSI reporting in a first PUSCH in uplink slot ‘n’:
For Capability #1 UE (measurement only after CSC), the CSI reference resource is defined in time domain as , where  is the smallest value greater than or equal to  and no earlier than the last symbol of CSC MAC-CE command. 
For Capability #2 UE (measurement before and after CSC) , the CSI reference resource is defined in time domain as , where  is the smallest value greater than or equal to . 

Conditional Intra-CU LTM
Proposal 13
For conditional intra-CU LTM, RAN1 should wait for determination of whole procedure design in RAN2.

3GPP TSG RAN WG1 #121	R1-2504546
St Julian’s, Malta, May 19th – 23th, 2025

Source:	Sharp
Title:	Discussion on measurements related enhancements for LTM 
Agenda item:	9.9.1
Document for: 	Discussion

Conclusions
In this contribution, we discussed the issues regarding enhancement of measurements to support LTM which includes CSI acquisition for candidate cell and Conditional intra-CU LTM. And we have proposals as follows.
Support implementing a strategy that allows the UE to measure only a subset of CSI-RS resources.
Consider one of the following methods to select a subset of CSI-RS resources
A new MAC CE to activate/deactivate a subset of CSI-RS resources
A DCI field to indicate a subset of CSI-RS resources
CSI report for CSI acquisition is carried on the first UL transmission for RACH-less procedure.
CSI report for CSI acquisition is carried on the PUSCH scheduled by RAR UL grant for RACH-based procedure.
The legacy method － where  is relative to the SCS of the first uplink transmission from the UE after the reception of the random access response or absolute timing advance command MAC CE or the cell switch command － cannot be directly applied to the case that the timing advance command is received in the LTM Candidate Timing Advance Command MAC CE.
How to determine the subcarrier spacing for an amount of time alignment,, may require further discussion in the case that the timing advance command is received in  the LTM Candidate Timing Advance Command MAC CE for conditional LTM . 
For example,  is relative to the SCS of the first uplink transmission from the UE after the UE switches to the target cell during CLTM.

3GPP TSG RAN WG1 #121			R1-2504595
St Julian’s, Malta, May 19th – 23rd, 2025

Agenda item:	9.9.1
Title:	LTM measurements related enhancements
Source:	MediaTek Inc.
Document for:	Discussion and Decision

Conclusions
We have the following observations:
Observation 1: After CSC, UE does not need to measure CSI for any candidate cell except the indicated candidate cell, hence the indication of subset of CSI-RS resources are not needed for the case where CSI is measured after CSC. 
Observation 2: Periodic CSI-RS resources are configured semi-statically by RRC. Up to UE implementation, UE can perform CSI measurements on available resources for candidate cell(s) based on available CSI-RS resources before CSC is received. This is irrespectively of whether an indication of subset of CSI-RS resources is supported or not. 
We have the following proposals:
Proposal 1: Support intra-frequency and inter-frequency for CSI acquisition.
Proposal 2: Do not support aperiodic CSI-RS for CSI acquisition
Proposal 3: Do not support indication of subset of resources before CSC. 
Proposal 4: It is up to UE implementation to determine which CSI-RS resources are measured before CSC. 
Proposal 5: It is up to UE implementation when to start measuring the CSI-RS resources. 
Proposal 6:  The UCI carrying the CSI report is sent in PUSCH where RRC reconfiguration complete message is transmitted. 

3GPP TSG RAN WG1 Meeting #121	R1-2504889
St Julian’s, Malta, May 19th – 23rd, 2025

Source:		Moderator (Fujitsu)
Title:	FL summary 4 of Measurements related enhancements for LTM
Agenda Item:	9.9.1
Document for:	Information

Conclusion]
The discussion of this section is closed without FL proposal. 

Conditional intra-CU LTM
[Closed] RAN1 spec impact of Conditional intra-CU LTM
[Agreements in the previous meetings]
None

[Summary of contributions]
Vivo
Activated Candidate TCI state(s), other than the TCI state associated with the triggered beam, should be deactivated upon CLTM procedure being triggered
CATT
No need to define beam application time for NR Rel-19 RACH-less C-LTM
Sharp
How to determine the subcarrier spacing for an amount of time alignment,, may require further discussion in the case that the timing advance command is received in  the LTM Candidate Timing Advance Command MAC CE for conditional LTM. 
For example,  is relative to the SCS of the first uplink transmission from the UE after the UE switches to the target cell during CLTM.

[FL observation]
Based on the contribution from companies, FL identifies no issue to immediately resolve in this meeting. With this, the discussion of this section is closed without any FL proposal. 

[Comments if any]