3GPP TSG-RAN WG1 Meeting #121                                                                                         	   R1-2503256
St Julian’s, Malta, May 19-23, 2025

Agenda Item:	9.8.1
Source:	Huawei, HiSilicon
Title:	Considerations on the 7-24GHz channel model validation 
Document for:	Discussion and Decision

Conclusions
In this contribution, we introduce our parameters validation and update, calibration settings and results and an important scenario. Following observations and proposals are given:
Observation 1: Based on companies’ measurements, the measured number of clusters under InH, UMi and UMa scenarios is smaller than that in TR 38.901.
Observation 2: The median intra-cluster power ratios are -1.1 dB and -2.5 dB for UMi LOS and NLOS scenarios, respectively, which means the power of the strongest ray in a cluster is not as dominant as the LOS path.
Observation 3: At least some fast fading parameters of low-altitude airspace scenario are altitude-dependent.
Observation 4: The fast fading parameters of low-altitude airspace scenario differ from that of UMa in TR 38.901/UMa-AV in TR 36.777.
Proposal 1: Support to update the number of clusters under InH, UMi and UMa scenarios according to Table 2.
Proposal 2: Support Config C as a candidate UT antenna configuration for adequate calibration purpose.
Proposal 3: Support to introduce low-altitude airspace scenario with:
Aerial UTs vertically ranging from 0 to 600 m.
Altitude-dependent fast fading parameters.

3GPP TSG RAN WG1 #121                                                            R1-2503374
St Julian, Malta, May 19th – 23rd, 2025

Source:	vivo, BUPT
Title:	Views on channel model validation of TR38.901 for 7-24GHz
Agenda Item:	9.8.1
Document for:	Discussion and Decision

Conclusions
In this contribution, we have expressed our views on the channel model validation of TR38.901 using measurements at least for 7-24 GHz. The proposals are summarized as follows.
Proposal 1: RAN1 studies the impact of channel sparsity on the existing channel model based on the experiment result.
Proposal 2: The working assumption for the rotation of handheld UE can be confirmed with some modification, i.e., the three figures in reference orientation of handheld UE and the two figures of different morphology for handheld UE shown by example should be modified by Figure 1 to Figure 5. 

3GPP TSG RAN WG1 #121											                        R1-2503439 
Malta, MT, May 19th – 23rd, 2025

Agenda Item:		9.8.1	
Source:				InterDigital, Inc.
Title:						Remaining Details of Evaluation of FR3 Channel Modeling
Document for:		Discussion and Decision

Conclusions
In this contribution, we shared and discussed our views for Rel-19 FR3 NF channel modeling. Based on presented discussions, the following observations and proposals are made,

Observation 1: An immediate outcome of the polarization leakage is a potential reduction of the rank of the wireless channel which negatively impact system capacity and throughput.

Proposal 1: RAN1 should take the opportunity to enhance the existing channel model by introducing random power variability in each polarization to be able to study and develop new CSI feedback procedures and MIMO precoders/codebook for 6G.

Observation 2: Based on the conducted measurements in [3]-[4] and analysis [5], the level of cross-polarization interference can vary according to the UE location and channel delay profile of a channel. 

Proposal 2: Support consideration of the proposed modeling of random power variability in each polarization.


Observation 3: The total aggregated amount of phase polarization rotation depends on the number of reflections. For example, it is expected to observe more rotation in a UMa/UMi environment than in a suburban area.

Proposal 3: Power scaling parameters should be described by a distribution, where the related parameters are defined by the deployment scenario.

Calibration
	In the accompanying Excel sheet, we have shared our initial evaluation results based on the agreed available parameters and definitions for the following cases, 
Large scale – UMI-6, Imu-7, UMa-6, UMa-7,
Full – UMi-6-Config1, UMi-6-Config2, UMi-7-Config3B-20MHz, UMa-6-Config1, UMa-6-Config2, UMa-7-Config3B-20MHz
We will further update our results according to the outcome of this meeting.

3GPP TSG-RAN WG1 Meeting #121		R1-2503578
St Julian’s, Malta, May 19th – 23th, 2025

Agenda item:	9.8.1 
Title:	Discussion on channel model validation of TR38.901 for 7-24 GHz 
Source:	Samsung
Document for:	Discussion and Decision

Conclusion
Upon plotting the pathloss across distance per frequency bands utilizing these equations, it was observed that beyond a particular distance (i.e., breakpoint), the values tend to converge 
In the case of a UE located at ground level, (effective environment height) is set to 1 m. As a result, the breakpoint distance becomes a dominant parameter for frequency rather than the height of the UE. In other words, as the frequency increases,  also increase, and at the same time, the correction term for  in UMa increases, so the absolute value change of  decreases
Pathloss comparison with long distance will mainly be used for link budget calculation or coverage analysis over frequency band rather than system-level simulation.
One alternative is to set the  (effective environment height) to 0 m. The meaning of  being 0 m is to assume reflection at a completely flat ground level and another alternative is to consider using only , which does not take into account the breakpoint
RAN1 decide the way among option 2 or option 3 to address pathloss convergence issue after breakpoint 
The currently defined tables align the number of clusters and scaling factor values for NLOS and O2I (Outdoor-to-Indoor) conditions in scenarios such as UMa, UMi, and RMa. However, in Rel-19, it has been agreed that the number of clusters for O2I conditions in the SMa scenario is 14, and the zenith angle scaling factor is not supported
RAN1 discuss to either define separate values for the SMa scenario or reconsider the number of SMa O2I clusters.
Some readers of channel model might want to know the difference in performance between having the FR1 antenna at the edge versus the corner, which could also apply to the FR2 antenna array. Additionally, whether antenna for new frequency band become antenna elements or arrays remains unknown.
RAN1 do not consider the detailed guidelines for how antenna elements and antenna modules are mapped to antenna location candidates
UE antenna modelling in existing channel model sets a bearing angle for the rotation of the UE. It is necessary to confirm that each antenna elements for the UE applies the same bearing angle
RAN1 confirm that maximal gain directivity of the antenna radiation pattern to be aligned with direction of the antenna candidate location
RAN1 consider that same bearing angle is applied to all antenna element candidates
RAN1 consider that the orientation for each antenna element's radiation pattern can then be determined according to this z-axis-based vector

Appendix. Simulation assumptions for calibration
UMa/UMi at 6 GHz 

UMa/UMi/SMa at 7 GHz 

3GPP TSG RAN WG1 Meeting #121	R1-2503606
St Julian’s, Malta, May 19th – 23rd, 2025

Source:	Intel Corporation
Title:	Discussion on channel modeling verification for 7-24 GHz
Agenda item:	9.8.1
Document for:	Discussion

Conclusions
In this contribution, we discussed the potential aspects that may require channel modeling validation effort for frequencies from 7 to 24 GHz. The following is a summary of proposals and observations made in this contribution.
Proposal #1:
Suggested Conclusion:
No consensus to change channel InF angular spread modeling parameters due to lack of data inputs.

Proposal #2:
If no inputs on UMa cluster AoD and O2I AoD parameters, then confirm working assumption for the changes.

Proposal #3:
Do not add antenna Config C for UT as part of full calibration assumption

Proposal #4:
Agree to optional BS antenna configuration for 15 GHz and remove the FFS from calibration assumptions.

Proposal #5:
Confirm working assumption for channel bandwidth for large scale and full calibration and remove brackets.

Proposal #6:
Unless there are additional inputs for SMa physical blocker modeling, we suggest closing the open FFS for modeling of physical block region parameters for SMa scenario.

Proposal #7:
Unless there are additional inputs for SMa modeling, we suggest confirm the working assumption for clutter heights for ZSD and absolute delay parameters for SMa scenario.

Proposal #8:
For UMi and Uma pathloss model, add a disclaimer note that state “pathloss model may not be accurate beyond the breakpoint distances when utilizing the pathloss model beyond system level evaluations, such as for link budget analysis.” 

Proposal #9:
Capture the UE device orientation description under Clause 7.3 of the TR.

Proposal #10:
Adopt the following updates to LSP correlation values for SMa LOS scenario:

Proposal #11:
Clarify outdoor UT for SMa are car deployment and subject to car O2I penetration loss.

Proposal #12:
Use 0% vegetation for SMa calibration purposes.

Proposal #13:
Update the SMa pathloss equation as follows:


Proposal #14:
 is minimum of two independently generated uniformly distributed variables between 0 and 25 m for UT considered to be inside commercial building in SMa, and between 0 and 10 m for for UT considered to be inside residential building in SMa.

Proposal #15:
Update the d2D to d2D-out for LOS probability determination for SMa scenario

Proposal #16:
RAN1 to instruct the rapporteurs to capture the RAN1 observations and conclusions related to channel modeling parameters including those that resulted in updates to the channel model and those that did not result in updates to the channel model.

3GPP TSG-RAN WG1 Meeting #121	Tdoc R1-2503620
St Julian’s, Malta, May 19th – 23rd, 2025
Agenda Item:	9.8.1
Source:	Ericsson
Title:	Discussion on validation of channel model
Document for:	Discussion

Conclusion
In the previous sections we made the following observations: 
Observation 1	The UMa and UMi scenarios in TR 38.901 clause 7.2 do not specify any particular ratio of low-loss and high-loss buildings, leaving such considerations for future decisions depending on study needs.
Observation 2	The indoor distance need to be defined for the SMa scenario
Observation 3	In the TR 38.901 model, the two co-polar components in the channel always have exactly equal power, and the two cross-polar components are equally attenuated according to a stochastic XPR.
Observation 4	Measurements and ray tracing experiments show a slow variability around the mean co-polar and cross-polar power that is independent between different components.
Observation 5	The potential rank reduction of the channel due to polarization power variability is independent on whether the Tx or Rx uses V/H-polarized or ±45° polarized antennas. It manifests as a power imbalance in the former case and a correlation between fading in the latter case.
Observation 6	More paths can be detected in measurements than in comparable channels generated by the UMa model.

Based on the discussion in the previous sections we propose the following:
Proposal 1	For the Suburban Macro scenario definition, align with the principle of UMa and UMi by not specifying any particular low-loss/high-loss ratio of buildings.
Proposal 2	For calibrations involving the Suburban Macro scenario, use 100% low-loss A for both residential and commercial builings Note that this should not be seen as restricting the use of other ratios or models for future evaluations.
Proposal 3	For the SMa scenario set the indoor distance  to the minimum of two independently generated uniformly distributed variables between 0 and 25 m for commercial builings and between 0 and 10 m for residential buildings.
Proposal 4	Extend the lower range of the SMa scenario down to 0.5 GHz.
Proposal 5	Introduce a random variability of the co- and cross polar powers in the TR 38.901 model, such as an i.i.d zero-mean Gaussian with 2-3 dB standard deviation, via the following changes to step 9 and eqs (7.5-22) and (7.5-28) in clause 7.5 in TR 38.901.
Proposal 6	Encourage companies to perform measurements to further study whether the existing mechanisms for generating clusters and rays are inaccurate when simulating large antenna arrays.
Proposal 7	While measurements support increasing the number of clusters in the UMa channel, for complexity reasons it may be better to keep this number unchanged, i.e. support Alt 2) in the RAN1#120 agreement.

3GPP TSG RAN WG1 #121	R1-2503633
St Julian’s, Malta, May 19th – 23th, 2025

Title 	:  Discussion on the channel model validation for 7-24 GHz
Source 	:  ZTE Corporation, Sanechips
Agenda item	:  9.8.1
Document for:  Discussion
 

Conclusion
In this contribution, we provide our analysis and proposals for Channel model validation of TR38.901 for 7-24 GHz.
Observation 1: For SMa scenario, considering the higher BS height and lower building height compared to UMa scenario, the ZSA in SMa scenario should be much smaller than ZSA in UMa scenario.
Observation 2: For SMa scenario, considering the BS height, large ISD, and sparse building density, the scatterers generating multi-paths are more dominant in horizontal dimension than in vertical dimension, thus ZSA should be much smaller than ASA.
Observation 3: For SMa scenario, if the ZSA is unexpectedly comparable to ASA, the base station has to deploy more antenna elements in the vertical dimension to utilize more resolvable spatial channels in vertical dimension.
Observation 4: The power imbalance of co-polarization and cross-polarization will be eliminated under  polarization slant assumption.
Observation 5: The polarization variability powers, if needed, should be normalized to avoid increasing cluster power.
Observation 6: Similar RANK can be achieved with and without adding polarization power variability for both H-V and  polarization with the updated approach.
Observation 7: If the number of clusters is significantly reduced to a fixed value, after removal of -25dB power offset, there will be very few NLOS clusters remained in simulation for a large portion of UEs.
Observation 8: If the direction of the LOS ray remain unchanged, the mean angle cannot be adjusted simultaneously.
Proposal 1: For SMa scenario, the ZOA spread should be further validated, e.g., via the comparison with other scenarios and other SMa parameters such as AOA spread..
Proposal 2: For SMa scenario, the validation of the K-factor should be further considered, e.g., whether/how to reduce the standard deviation of K factor.
Proposal 3: For SMa scenario, RAN1 to discuss how to update the cross correlations for LOS UE.
Proposal 4: For SMa scenario, O2I car penetration loss with μ = 9, and σP = 5 should be used for SMa outdoor UEs.
Proposal 5: For SMa scenario, d2D in the LOS probability formula should be changed to d2D-out.
Proposal 6: For SMa scenario, the 2D indoor distance can be generated using the same method of UMa scenario, i.e. d2D-in is minimum of two independently generated uniformly distributed variables between 0 and 25 m.
Proposal 7: For the absolute time of arrival,  is not applicable for LOS case, the impulse response in LOS is determined using equation (7.6-44) instead of (7.5-30),
.	(7.6-44)
where 
Proposal 8:  Confirm the following working assumption
Proposal 9: No need to change the polarization matrix in the channel realization formula in TR 38.901.
Proposal 10: For LOS UE, the -25dB power offset removal should be based on the cluster power in equation 7.5-8.
Proposal 11: If it’s necessary to reduce the number of clusters according to the measurement results, reduction of number of clusters can be achieved via the introduction of frequency-selective approach or a distribution.
Proposal 12: If the direction of the LOS ray in CDL-D and CDL-E needs to remain unchanged before and after the scaling of angles, the following formulas can be considered:
,

3GPP TSG RAN WG1 Meeting #121                                                       	R1-2503653
St Julian, Malta, 19 May – 23 May, 2025
Source:           BUPT
Title:              Discussion on channel model validation of TR38.901 for 7-24 GHz
Agenda item:    	9.8.1
Document for:  	Discussion and Decision

Conclusion
In this contribution, we provide our views on the validation and the details for Rel-19 channel modeling enhancements for 7-24 GHz. Key consideration is the modification of the cluster structure. The observation and proposals are as follows:
Observation 1: The values of  for 6-24 GHz are consistently below 20, causing all clusters in these frequency bands to adopt 20 rays. Consequently, the frequency parameter in the equation becomes functionally irrelevant, unable to reflect the frequency-dependent characteristics of the channel. 
Observation 2: The number of rays per cluster is less than 20 based on the measurements.
Observation 3: The measured cluster number is smaller than the 3GPP model, and there is still a gap after interception using the threshold of -25 dB.

Proposal 1: It is proposed that Equation (7.6-8) 

in Section 7.6.2.2 be modified to 

 is the lower limit of  and can be selected by the user of the channel model. The default value of  is 20.
 can be selected as the mean number of dominant rays within clusters obtained from measurements. The number of dominant rays is defined as the number of rays in which the cumulative power exceeds 95% of the cluster power for the first time.

Proposal 2: It is proposed to add a paragraph at the end of section 7.6.2:
“It is well known that as frequency increases, the multipath channel becomes sparse compared to microwave channels. There are dominant path(s) that reduce the channel rank [3]. However, in 38901, the equal powers per ray in a cluster, the number of rays per cluster, and the number of clusters remain constant across all frequency bands, the impulse response remains the same for all bands. Consequently, it exhibits no frequency sensitivity.
Proposal 3: The number of clusters in TR 389.01 needs modification. The mean number of clusters to correct the previously mentioned UMa NLOS scenario is 10.
The above procedure can provide a framework to vary the numbers of rays per cluster and ray powers within a cluster as a function of frequency and could therefore enable the simulation of a sparse channel.”

3GPP TSG RAN WG1 #121			R1-2503762
St Julian’s, Malta, May 19th – 23th, 2025

Agenda item:	9.8.1 
Title:	Discussion on Channel model validation of TR38.901 for 7-24GHz
Source:	SK Telecom
Document for:	Discussion and Decision
1. 

Conclusion
For the UMa scenario, path loss validation should be closely linked to 6G usage scenarios and coverage considerations.
We emphasize the need for continued and rigorous validation of the FR3 channel model based on measured, physically grounded characteristics.

3GPP TSG RAN WG1 #121		                                                      R1-2503805
St Julian’s, Malta, May 19th – 23rd, 2025

Source:	CATT
Title:	Views on channel model validation for 7-24GHz
Agenda Item:	9.8.1
Document for:	Discussion and Decision

Conclusions
In this contribution, remaining aspects of channel model involved in the validation for 7-24GHz are discussed. Based on the discussion, the following proposals are made:
Proposal 1: If pathloss convergence needs to be resolved, Option 3 is supported.
Option 3) Add note that provide information on pathloss convergence phenomena beyond the breakpoint distance across different frequencies.
Proposal 2: Update the number of clusters for 7-24 GHz.
Proposal 3: Do not introduce intra-cluster power profile for 7-24 GHz.

3GPP TSG RAN WG1 #121                                         R1-2503962 

Malta, Europe, May 19th – 23rd, 2025

Source:	Sharp
Title:	Views on Channel Model Validation 
Agenda Item:	9.8.1
Document for:	Discussion and Decision

Conclusion
Observation 1: Please be advised that the final updated values for the channel parameters are subject to revision if new measurements are made available for any of the channel parameters in RAN1#121. 

Observation 2: O2I parameters values are same as SMa NLOS values, unless new measurements are provided in RAN1#121. 

Observation 3: The current wording in the draft CR i.e., “The low-loss A model is applicable to SMa in the draft CR” lacks clarity regarding the applicability of the other models i.e., low-loss, high-loss model to SMa. It is uncertain whether the existing low-loss and high-loss model in TR 38.901 are also applicable to the SMa scenario in addition to the low-loss A model. Therefore, we strongly advise making this statement clear to eliminate any potential ambiguities that may emerge.
Observation 4: There is substantial evidence in the literature showing that received power varies not only between co-polarized and cross-polarized antenna configurations, but also within each polarization group. Specifically, the power levels for V-V and H-H (co-polarized), as well as for V-H and H-V (cross-polarized), are often not equal in practice. Despite this, the TR 38.901 channel model assumes equal power between V-V and H-H, and likewise between V-H and H-V. The model only accounts for polarization effects by introducing the Cross-Polarization Power Ratio (XPR), which captures the power difference between co-polarized and cross-polarized components using a log-normal distribution characterized by a mean (κ) and standard deviation. This simplification overlooks the asymmetries observed among different polarizations in real-world measurements.
Observation 5: Therefore, based on findings in [5, 6, 7, 8], it is reasonable to conclude that real-world scenarios include a variety of cluster structures some with a single dominant ray, others with multiple or none. Section 7.6.2 of TR 38.901, which describes the intra-cluster power distribution, is flexible and general enough to accommodate this variability. With appropriate refinements, it can realistically model clusters with a single dominant ray, more than one dominant ray, or no dominant ray at all, consistent with observed measurement data.
Observation 6: For the UMi, UMa, and InH scenarios, the average number of clusters derived from various measurement sources in LOS is similar to the number of clusters specified in TR 38.901 when a 25 dB power threshold is applied. 
Observation 7: For the UMi, UMa, and InH scenarios, the average number of clusters obtained from various measurement sources in NLOS differs significantly from the number specified in TR 38.901 when a 25 dB power threshold is applied.

Proposal 1: For SMa LOS/NLOS DS (Mean, Std) consider the values listed in the Table 1.

Table 1. SMa LOS/NLOS DS (Mean, Std)


Proposal 2: For SMa LOS/NLOS ASA (Mean, Std) consider the values listed in the Table 2.

Table 2. SMa LOS/NLOS ASA (Mean, Std)


Proposal 3: For SMa LOS/NLOS ASD (Mean, Std) consider the values listed in the Table 3.

Table 3. SMa LOS/NLOS ASD (Mean, Std)


Proposal 4: For SMa LOS/NLOS ZSA (Mean, Std) consider the values listed in the Table 4.

Table 4. SMa LOS/NLOS ZSA (Mean, Std)


Proposal 5: For SMa LOS/NLOS Cluster ASD (Mean) consider the values listed in the Table 5

Table 5. SMa LOS/NLOS Cluster ASD (Mean)


Proposal 6: The working assumption for per-cluster shadowing in SMa O2I needs to be updated from 4 to 3 when copying values from SMa NLOS. The per-cluster shadowing for SMa NLOS is 3. 

Proposal 7: Use the UMa LOS/NLOS correlation matrix for all parameters for SMa LOS/NLOS.

Proposal 8: Confirm the working assumption for SMa O2I penetration loss model listed in Table 6.
Table 6. SMa O2I Building Penetration Loss Model

Proposal 9: Please use the updated text i.e., “The low-loss, high-loss, and low-loss A model, are all applicable to SMa” instead of “The low-loss A model is applicable to SMa”. 

Proposal 10: The current updates to Table 7.5-6 Part-1 in TR 38.901 reflect an inconsistent methodology - some channel parameters are updated using WLS/WM approach with both Rel-14 and Rel-19 data over the full 0.5–100 GHz range, while others remain based only on older Rel-14 data using an ordinary least squares fit over the full 0.5–100 GHz range. This inconsistency could lead to confusion and reduced traceability. To ensure methodological consistency, while still maintaining negligible impact on system performance, it is recommended to update the remaining parameters in Table 7.5-6 Part-1 using the same WLS/WM approach with both Rel-14 and Rel-19 data over the full 0.5–100 GHz range.

Proposal 11: For UMi LOS/NLOS ASD (Mean, Std) consider the values listed in the Table 7

Table 7. UMi LOS/NLOS ASD (Mean, Std)

Proposal 12: For UMi LOS/NLOS ZSA (Mean, Std) consider the values listed in the Table 8

Table 8. UMi LOS/NLOS ZSA (Mean, Std)

Proposal 13: For UMa LOS ZSA (Mean, Std) consider the values listed in the Table 9

Table 9. UMa LOS ZSA (Mean, Std)

Proposal 14: All measurement data from the Excel sheet titled “R1-2503962_consolidated_all_meas_data_rel14_rel19.xlsx”, along with any additional data to be submitted at RAN1#121, should be included in the data source Excel sheet referenced in [25] of the draft CR. This will consolidate all relevant data into a single location, ensuring traceability.

Proposal 15: Update the reference thickness of plywood to 1.75 cm instead of 1.27 cm. The thickness of the measured plywood in [2] is 1.75 cm and not 1.27 cm.

Proposal 16: RAN1 to introduce the polarization variability for each ray of cluster for NLOS component of the channel as an optional modelling component. 

Proposal 17: Modifying the number of rays per cluster in equation 7.6-8 of TR 38.901 as proposed in R1-2503653 [6] can help generate a variety of cluster profiles, including clusters with a single dominant ray, multiple dominant rays, or no dominant ray at all, in line with observed real-world measurements.

Proposal 18: RAN1 could investigate the following options to update the number of clusters.
Option 1: If RAN1 chooses to update the number of clusters in TR 38.901 based on the average number of clusters obtained from all measurement sources, the number of clusters for LOS in TR 38.901 Table 7.5-6 can remain unchanged for UMi, UMa and InH scenarios. However, for NLOS, the updated number of clusters could be as shown in Table 12.
Table 12. Comparison of the number of clusters in TR 38.901 and proposed values for different scenarios and channel conditions. 

Option 2: RAN1 could model the number of clusters as a Discrete Uniform (DU) distribution, defined as DU(Mmin, Mmax). The values for Mmin and Mmax can be determined for each scenario and channel condition based on the measurement data captured in the R1-2503962_consolidated_all_meas_data_rel14_rel19.xlsx file.

3GPP TSG-RAN WG1 Meeting #121	R1- 2503993
St Julian’s, Malta, May 19th – 23rd, 2025

Agenda Item:	9.8.1
Source:	NVIDIA
Title:	Channel model validation of TR 38.901 for 7-24 GHz
Document for:	Discussion
1	

Conclusion


Agreement



Working Assumption
SMa O2I will use the same values as SMa NLOS

Agreement
For suburban scenario, adopt the following ZSD parameters as updated working assumption:
Values in [ ] are working assumption

Working Assumption
Introduce new penetration loss outdoor-to-indoor (O2I) building penetration loss model applicable for SMa and used for calibration:


Agreement
Adopt the following absolute time of arrival parameters for SMa
Values in [ ] are working assumption


Agreement
Adopt the following changes to Clause 7.2 of TR38.901.


Adopt the following changes to Clause 6.2 of TR38.901.

Working Assumption


Agreement
For CPE devices adopt the following device dimensions for UE antenna modeling:
(x cm × y cm × z cm) = (0 cm × 20 cm × 20 cm)
Total 9 candidate antenna locations in 4 corners of the vertical square plane, 4 center of the edges of the vertical square plane, and center of the vertical square plane. The figure below captures the side view on the device.
Note: a candidate antenna location (e.g., 9) can be used for multiple antennas


Agreement
For UE antenna modeling of handheld devices, introduce optional antenna imbalance modeling as part of antenna field pattern as follows:
No imbalance is modelled by default.
If modelled, Randomized loss is applied per UE antenna port. Details of the randomized value and it’s distribution will not be specified in TR 38.901 as part of Rel-19 SI.
If modelled, Randomized loss can be applied independently for the UL and DL directions.
Agreement
Confirm the downtilt value for SMa with ISD of 1299m, and introduce downtilt value [93] for SMa with ISD of 1732m
Downtilt value for SMa with ISD of 1732m is working assumption

3GPP TSG RAN WG1 #121	R1-2504006
Malta, May 19th – 23rd, 2025

Source:	Lenovo
Title:	Channel model validation for 7-24 GHz
Agenda Item:	9.8.1
Document for:	Discussion and Decision
Discussion
In this document, we discuss further remaining aspects on channel validation for 7-24 GHz based on the agreements reached in RAN1#120bis  as well as prior RAN WG1 meetings, which are planned to be captured in an upcoming version of TR 38.901 .
One issue that has been discussed in RAN1#120bis is whether the number of clusters per model are reduced based on some field measurements pursued by companies/universities, based on a smaller number of clusters observed. In our understanding, the number of clusters associated with a channel model is not intended to capture the average number of clusters, but rather a statistical value based on a larger CDF value of the probability of number of clusters, e.g., 90%-ile of the empirical distribution of the number of clusters, or resolvable paths. Given the exponential distribution of the power delay profile assumed in the channel generation procedure of TR 38.901, the number of effective clusters is usually smaller than Nclus specified in TR 38.901. One risk with prematurely modifying the number of clusters is the detrimental impact it has on the channel scattering, and hence leading to a lower effective channel rank. Given the limited time left in the study, we do not believe a reasonable, in-depth evaluation of the issue is possible, and hence our preference is not to modify the number of clusters specified in TR 38.901. 
The number of clusters specified in TR 38.901 is not changed.

While performing the calibration evaluation for 6-24 GHz channel, it was observed that several cross-correlation values of the LSF parameters, as well as the LoS probability for SMa model are still not finalized. For these missing values, we have adopted the working assumptions, as well as reused RMa parameter values for calibration evaluation whenever applicable. Given that RAN1#121 is the final meeting of the channel model study, and that the leftover parameters were selected by each company based on their own preference, variations in results are expected. That being said, we propose that a second round of calibration results collection is pursued following RAN1#121 and is finalized in RAN1#122, after approval from the next RAN#108 plenary, so as to move the CR endorsement of TR 38.901v19 to RAN#109 plenary meeting. 
Extend the CR endorsement of TR 38.901v19 to RAN#109 plenary meeting.

In RAN1#119 , it was proposed to introduce unequal powers per ray within a cluster. It was also proposed to maintain an unequal angle offset among rays to maintain the power angular spectrum per cluster. Furthermore, three alternatives were proposed in RAN1#120 regarding the support of unequal ray power ratios, in addition to updating the offset angles per ray, as follows: 
Alt 1)

Alt 2)

Alt 3)

In our opinion, introducing unequal powers per ray may complicates the design, since in practice the paths can be perceived as a continuum of cluttered components of the channel, wherein the simulation assumptions adopted in TR 38.901 are intended to capture the dominant paths that resonate around a cluster angle. Given that, unless it is observed via field tests by companies that the power variation across rays is richly distributed, i.e., the rays cannot be grouped to dominant rays with equal power and negligible rays with infinitesimal power, our first preference would be to maintain the current setup of equal powers across rays per cluster. Regarding the three alternatives above, we do not support Alt2, which introduces an additional ray with no phase offset, whose implications on the channel model are unclear to us. Alt3 would break the symmetry via assigning unequal phase offset values for the strongest two rays, leading to a shift in the average cluster angle. We are open to Alt1, which includes updated ray offset values that do not deviate from the legacy considerations for ray phase offset values, and whose ray power ratio is more straightforward compared with Alt2 and Alt3.  
For the intra-cluster ray power ratios and phase offset angles, support:
First preference: Legacy design; equal ray power within a cluster and no change to the current ray offset phase values.
Second preference: Alt1 (corresponding to Example 1) with 20 rays, symmetric phase offset values across rays and cluster-common ray power ratios.
Furthermore, in case any of the three alternatives above is supported, it was discussed whether the new table would replace the current table or be added as an optional modeling component. On one hand, having multiple alternatives for the same parameter set is inefficient, and the optional parameter set usually ends up being unused in most simulation evaluations. On the other hand, we believe some alternatives (specifically Alt2 and Alt3) deviate from legacy channel modeling principles and hence if supported, the legacy parameter set for ray powers and phase offset values should still be captured. Given that, our preference would depend on the selected alternative: if Alt1 is supported, we are fine to replace the legacy ray power and angle parameter set with that in Table 1, whereas if Alt2 or Alt3 are supported, we prefer them to be optional modeling components. Therefore, we propose the following:
Regarding whether the updated ray power/phase offset values within a cluster are supported to replace legacy model or be captured as additional modeling component:
If Alt1 (corresponding to Table 1) is supported, capture as a basic modeling component that replaces legacy approach in TR 38.901.
If Alt2 or Alt3 (corresponding to Example 2 or Example 3, respectively) are supported, capture as optional modeling component along with the legacy approach in TR 38.901.
It was also discussed in RAN1#120 whether to introduce an optional modeling component for polarization variability for each cluster for NLOS component of the channel. It is not clear how the polarization variability distribution would be modeled, and whether values across different clusters would be correlated. In general, this component can be helpful for modeling impairments in UL transmission causing power imbalance across two cross-polarized ports, however the variability would then be correlated across the clusters. To summarize, we are open to consider this polarization variability as an additional modeling component, however we believe more discussion is needed on the underlying distribution, as well as the correlation of the values across the clusters.
Polarization variability is considered as an optional modeling component per NLoS cluster for 7-24 GHz channel model, with further discussion on the underlying distribution and the correlation of the values across clusters.
Conclusion
This contribution studied aspects on channel model validation for 7-24 GHz. We have the following proposals:
The number of clusters specified in TR 38.901 is not changed.
Extend the CR endorsement of TR 38.901v19 to RAN#109 plenary meeting.
For the intra-cluster ray power ratios and phase offset angles, support:
First preference: Legacy design; equal ray power within a cluster and no change to the current ray offset phase values.
Second preference: Alt1 (corresponding to Example 1) with 20 rays, symmetric phase offset values across rays and cluster-common ray power ratios.
Regarding whether the updated ray power/phase offset values within a cluster are supported to replace legacy model or be captured as additional modeling component:
If Alt1 (corresponding to Table 1) is supported, capture as a basic modeling component that replaces legacy approach in TR 38.901.
If Alt2 or Alt3 (corresponding to Example 2 or Example 3, respectively) are supported, capture as optional modeling component along with the legacy approach in TR 38.901.
Polarization variability is considered as an optional modeling component per NLoS cluster for 7-24 GHz channel model, with further discussion on the underlying distribution and the correlation of the values across clusters.
RAN1#120bis Agreements/Conclusions
The following has been agreed in RAN1#120bis for the 7-24 GHz frequency range channel model validation study:

TDoc file conclusion not found

3GPP TSG RAN WG1 #121	R1-2504147
St Julian’s, Malta, May 19th – 23th, 2025
Agenda item:	9.8.1
Source: 	ETRI
Title:	Discussion on calibration results
Document for:	Discussion/Decision

Conclusion
In this contribution, ETRI’s initial calibration results are provided by the accompanying Excel sheets and the following observations was made:
Observation 1. The following two aspects need to be clarified for calibrations on SMa scenarios
Vegetation ratio parameter  for the LOS probability of SMa scenario
Zenith angle scaling factors for SMa NLOS scenario assuming 14 clusters (in Table 7.5-4 of TR 38.901)

3GPP TSG RAN WG1 #121			R1-2504338
St Julian’s, Malta, May 19th – 23th, 2025 
 
Agenda Item:	9.8.1
Source:	Apple
Title:	Validation of Channel Model
Document for:	Discussion/Decision

Conclusion
In this contribution, we provided our views and observations on suburban scenario parameters, material penetration loss, number of clusters, as well as our calibration results. Our observation and proposals are as follows:

Proposal 1: In the low loss A model,  is minimum of two independently generated uniformly distributed variables between 0 and 25 m for SMa scenario. 

Proposal 2: In Table 7.5-6 Part-4 of “channel model parameters for SMa”, modify the shadow fading for LOS and NLOS to “See Table 7.4.1-1”. 

Proposal 3: In Table 7.5-6 Part-4 of “channel model parameters for SMa”, the number of clusters for NLOS and O2I is 15. 

Proposal 4: The reference thickness of plywood penetration loss model is 1.75 cm. 

Observation 1: For UMi NLOS scenario at 8 GHz, the number of clusters is 18 at 95% percentile. 

3GPP TSG RAN WG1 #121	             			            		                                 R1-2504368
St Julian’s, Malta, May 19th –23rd, 2025						
Agenda Item:	9.8.1
Source:	AT&T
Title:	Discussion on Validation of the Channel Model in 38901
Document for:	Discussion/Decision

Conclusion
In this contribution, we discussed the validation of the channel model for 7-24GHz in TR 38.901. We made the following proposals.

Proposal 1: Update Table 6.3-1 to capture channel measurement capabilities in Rel. 19 SI on 7-24GHz Channel modeling including newly introduced SMa scenario

Proposal 2: Include the following in the definition of SMa in Section 6.2 of TR38.901.

(8) Suburban macro (SMa) scenarios: In suburban macro-cells base stations are located above the surrounding environment to allow wide area coverage, and mobile stations are outdoors at street level and within commercial and residential buildings. Buildings are typically low residential detached houses with one or two floors, or blocks of apartments/condos or commercial buildings with a few floors. Occasional open areas such as parks or playgrounds between the houses make the environment rather open. Streets do not form urban-like regular strict grid structure. In suburban areas, vegetation is more prevalent than in urban areas with a high variability of foliage density across different suburban areas.  
Example: [Tx height: 35m, Rx height: 1.5-2.5m, ISD: 1299m, 1732m]
Proposal 3: Use the following table for evaluation parameters in SMa.
Table: Evaluation parameters for SMa 

Proposal 4 The following LSP parameters are agreed for SMa channel model
SMa O2I will use the same values as SMa NLOS



Proposal 5: r vegetation of 0% is used for PLoS for SMa, unless indicated otherwise. 

Proposal 6: For the SMa pathloss model for LoS, add the following note in the PL table.
Note: The constraint on the dBP < 5000m is only applicable for frequencies up to 5GHz.

Proposal 7: For SMa channel model calibration, consider the following base station electric antenna downtilt values:




Proposal 8: For SMa channel model full calibration, consider changing the assumptions on BS antenna configurations to allow for virtualization. 

Agenda item: 9.8.1
Source: Qualcomm Incorporated
Title: Channel model validation of TR 38.901 for 7-24GHz
Document for: Discussion/Decision

Conclusion 
We make the following observations and proposals in this document:	
On open issues for SMa scenario
Proposal 1: For SMa, the current working assumption on the correlation values of the LSPs results in a correlation matrix that is not positive semidefinite and hence not suitable for Cholesky decomposition. To fix this issue, consider one of the following options:
Recompute the correlation values
Reuse UMa scenario’s correlation parameters.
Proposal 2: For SMa scenario, outdoor UEs are assumed to have a velocity of 40 kmph. Clarify that these UEs are in cars and that in-car O2I penetration losses will be applied. 
Proposal 3: For SMa, the current working assumption assumes 14 clusters for O2I users. However, Table 7.5-4 does not provide the scaling factors for ZOA and ZOD generation when number of clusters is 14. To fix this issue, either change the number of cluster for O2I users to 15 or add a new entry to Table 7.5-4 to support 14 clusters.
Proposal 4: For SMa scenario, clarify that the LOS probability is calculated with a default assumption of 0% vegetation (i.e., no vegetation).
Proposal 5: Confirm the following working assumption on a new loss-loss penetration model for SMa:
Working Assumption
Introduce new penetration loss outdoor-to-indoor (O2I) building penetration loss model applicable for SMa and used for calibration:

On UE antenna modeling
Proposal 6: Clarify that the polarization orientation of single-Pol UE antennas is along the plane of the phone. Adopt the orientations proposed in Option (i). Set the slant angle as defined in Section 7.3.2. to 90 degrees with the assumption that the handheld device is placed along the X-Y plane.
Proposal 7: Orientation of dual-pol antennas needs further clarification. The choice of the orientation and the direction of maximum gain need to be consistent and feasible. The orientation depicted in the following figure is suggested as an option, where slant angles 0 and 90 degrees are chosen.


Proposal 8: For UEs with 2, 3, and 6 antennas, the default antenna placements are given as follows:

On polarization coupling matrix
Observation 1: Equation 7.5-22 represents the NLOS channel between a single antenna pair. A coupling matrix is used to determine how the  and components of the transmitter and receiver interact with each other. 
Observation 2: Applicability of measurements made using a dual-polarized antenna setup to a single-polarized antenna setup as described in Eq. 7.5-22 is unclear.
Observation 3: Notational differences between WINNER II and 38.901 warrant closer inspection on the appropriate structure of the coupling matrix used in 38.901. 
On PAS and Angle Sampling
Observation 4: The additional modeling component in Section 7.6.2.2 appears capable of modelling clusters that exhibit Rician fading characteristics.
On updating number of clusters
Observation 5: Current 38.901 specification provides the values for number of clusters to consider for three different UE categories: LOS outdoor UE, NLOS outdoor UE, and O2I UE (indoor). When considering any update to the number of clusters for existing deployment scenarios, it is important to consider all three UE categories with specific emphasis on O2I UEs which constitute 80% of UEs in typical system-level evaluations. It is noted that currently there are no measurement data for O2I UEs. 
Observation 6: The exact interpretation of the number of clusters assumed in 38.901 for different scenarios needs more clarity. Interpreting it as representing the mean, median or the maximum could inform us on how to interpret the measurement data and where it diverges from the existing assumption in 38.901. 
Observation 7: From a system-level evaluation perspective, reducing the number of clusters to a lower number either by reducing the nominal number of clusters or by increasing the threshold to drop weaker clusters does not seem to significantly impact the communication metrics. 
Observation 8: Changing the number of clusters for a specific frequency range will make it difficult for cross-frequency comparisons in future evaluations.
Proposal 9: Given the negligible system-level impact due to a reduction in the number of clusters a strong motivation to alter the number of clusters in 38.901 is lacking. 

3GPP TSG RAN WG1 #121	R1-2504512
St Julian’s, Malta, May 19th – 23th, 2025

Title 	:  Discussion on channel model validation for 7-24 GHz
Source 	:  NTT DOCOMO, INC.
Agenda item	:  9.8.1
Document for:  Discussion

Conclusion
In this contribution, we provided our views and discussions on channel model validation of TR38.901 for 7-24GHz related to UMa pathloss model. The following proposal is made:
Proposal 1: The pathloss model of UMa in TR38.901 is validated and does not need to be updated.

3GPP TSG-RAN WG1 Meeting #121	R1-2504548
St. Julian’s, Malta, May 19th – 23rd, 2025
Agenda Item:	9.8.1
Source:	Vodafone, Ericsson
Title:	Measurements of the angular spreads in urban and suburban macrocells
Document for:	Discussion

Conclusion
In the previous sections we made the following observations: 
Observation 1	The measured elevation angular spreads (ZSD) at 3.4 GHz for a very large number of communication links in an operational urban macro 5G NR network match the 38.901 UMa model.
Observation 2	The measured azimuth angular spreads (ASD) at 3.4 GHz for a very large number of communication links in an operational urban macro 5G NR network are several times lower than predicted by the 38.901 UMa model.
Observation 3	The measured UMa ZSD vs ASD correlation is similar to the model.
Observation 4	The measured ZSDs at 3.4 GHz in a suburban 5G NR macrocell are very similar to the ZSDs in urban macrocells, however at the upper percentiles there are less high outlier values.
Observation 5	The measured suburban ZSD can be well represented by a lognormal distribution with lgZSD = 0.14 and lgZSD = 0.16.
Observation 6	The measured ASDs at 3.4 GHz in a suburban 5G NR macrocell are very similar to the ASDs in urban macrocells, however at the upper percentiles there are less high outlier values.
Observation 7	The WINNER II Suburban Macro channel model overestimates the ASD by 2-3 times.
Observation 8	The measured suburban ASD can be well represented by a lognormal distribution with lgASD = 0.55 and lgASD = 0.25.
Based on the discussion in the previous sections we propose the following:
Proposal 1	Consider revisiting agreement and working assumptions for UMa LOS and NLOS AOD spread parameters from RAN#120-bis according to Table 2 to better represent measurements from live networks and additional results from new measurement campaigns.
Proposal 2	Use the ASD and ZSD parameters according to Table 4, Table 5, and Table 6 as a starting point for the Suburban Macro scenario.
Proposal 3	Further measurements of ASD and ZSD in a Suburban Macro scenario, including measurements that distinguish LOS vs NLOS vs O2I, can later be used to refine the suggested parameter values.

3GPP TSG RAN WG1 #121	        	R1-2504629 
St Julian’s, Malta, May 19th – 23rd, 2025

Agenda Item:					    9.8.1
Source:	Sony
Title:	Discussion of channel model validation of TR38.901 for 7–24GHz 
Document for:	Discussion and decision

Conclusions
We made the following observations and proposals:

Figure. The suggested update for specifying the orientation of the handheld UEs.
 Proposal 1.	 For UE antenna modeling, for specifying the reference orientation of handheld UEs, update the illustration in the working assumption according to the figure above.
 There appears to exist a disagreement between the orientations of the LCS shown in the work assumption and those obtained by applying equation (7.1-2) in TR 38.901 to the rotation angles (α,β,γ) proposed in the working assumption.
 For UE antenna modeling, for calibration of handheld UEs, consider replacing the UT angles with following ones:
For calibration with blockage:
For one-hand blockage,  deg,  deg,  deg.
For dual-hand blockage,  deg,  deg,  deg.
For hand-and-head blockage,  deg,  deg,  deg.
For all other calibration cases:
 deg,  deg,  deg.
Note: UT array orientation is defined by three angles  (UT bearing angle),  (UT downtilt angle) and  (UT slant angle).
Note: Equation (7.1-2) shall be applied to orient the LCS with respect to the GCS.
Example of  deg,  deg,  deg.
Example of  deg,  deg,  deg.
 Model-2 is widely used to determine the radiation field patterns based on a defined radiation power pattern and shall not be precluded.
 For the CR draft of TR 38.901, amend the text proposal for Sec. 7.3 as follows: “Each polarized field component of the reference radiation pattern  and  should be rotated according to the orientation of the each of UE antennae to get ,  and based on the orientation of the UE in the global coordinate system to get  and  using the method specified in Clause 7.3.2  equation (7.3-3) or equations (7.3-4) and (7.3-5) and Clause 7.1.3 equation (7.1-11).”

3GPP TSG RAN WG1 #121	R1-2504631
Malta, MT, 19 - 23 May 2025

Agenda item:		9.8.1
Source:	Nokia
Title:	Discussion on Channel Model Validation of TR38.901 for 7-24GHz
WI code:	FS_NR_7_24GHz_CHmod
Release:	Rel-19
Document for:		Discussion and Decision

Conclusion
In this paper we further elaborate about the open issues in the discussion of channel modeling for 7-24GHz frequencies.
The following proposals and observations are made:
Proposal 1: 	RAN1 not to update the angular spread parameters of the InF scenario channel model.

Observation 1: The LoS pathloss convergence phenomena deyond the breakpoint distance is observed in the UMi and UMa scenario, but the breakpoint distances are generally larger than typical ISDs of 200m and 500m, respectively. The breakpoint distance phenomena are not observed in the SMa or RMa scenarios, that can be used instead if larger ISDs are considered.
Proposal 2: For the pathloss convergence issue beyond the breakpoint distance, RAN1 to adopt the combination of Option 2 and Option 3: Add a note that provides information on pathloss convergence phenomena beyond the breakpoint distance across different frequencies and allow applying only PL1 when performing link budget analysis.

Proposal 3: There is no strong need to introduce polarization variability modelling for each rays of cluster for NLOS components of the channel.

Proposal 4: RAN1 does not need to restrict the O2I building penetration models in SMa deployments only to the new low-loss model. However, the low-loss A model should be agreed and used for indoor users for calibration of SMa scenario.

Proposal 5: RAN1 to assume that O2I car penetration loss with  is applicable to the outdoor users moving at 40 km/h speed in SMa scenario.

Proposal 6: RAN1 to assume in SMa scenario that  for indoor loss is minimum of two independently generated uniformly distributed variables between 0 and 25 m for commercial buildings and between 0 and 10 m for residential buildings, respectively, in SMa scenario.

Proposal 7: For the SMa scenario with the ISD of 1732m, BS antenna electrical downtilt can be selected in the range of [92-94] degrees.

Proposal 8: RAN1 to assume no vegetation (=0%) for the calibration of SMa scenario.

Proposal 9: RAN1 can additionally clarify that polarized filed components for each of the UE antenna u in local coordinate system (LCS) is given by the equation 

where polarized field component of the reference radiation pattern are  and , , , and the transformation  and  can be expressed by the equations (7.1-16) and (7.1-17) based on the orientation of each UE antenna .


Figure 7: Definition of the UE local Cartesian coordinate system x, y, z and the spherical angles.

Proposal 10: UE local coordinate system (LCM) is introduced so that
The origin of the LCS is in the center of the handheld UE
The surface of the UE is located in the x-y plane
Z axis is perpendicular to the surface of the device
Y axis is oriented along the longer edge of the UE
The spherical angles in a cartesian coordinate system X, Y, Z are defined so that that points to the zenith and  points to the horizon as shown in Figure 7 above.

Proposal 11: For calibration of handheld UE with directional antennas, use the following UE orientation in the GCS
For calibration with blockage:
For one-hand blockage, ΩUT,α = 0 – 360 deg, ΩUT,β = 45 deg, ΩUT,γ = 0 deg, 
For dual-hand blockage, ΩUT,α = 0 – 360 deg, ΩUT,β = 45 deg, ΩUT,γ = 90 deg, 
For hand and head blockage, ΩUT,α = 0 – 360 deg, ΩUT,β = 90 deg, ΩUT,γ = 0 deg, 
For all other calibration cases:
ΩUT,α = 0 – 360 deg, ΩUT,β = 45 deg, ΩUT,γ = 0 deg, 

3GPP TSG-RAN WG1 Meeting #121	R1-2504650
St Julian’s, Malta, May 19th – 23rd, 2025
Agenda Item:	9.8.1
Source:	BT, Ericsson
Title:	Measurements of the angular spreads in urban, suburban, and rural macrocells
Document for:	Discussion

Conclusion
In the previous sections we made the following observations: 
Observation 1	New measured elevation angular spreads (ZSD) for a very large number of communication links in an operational midband urban macro 5G NR network match the 38.901 UMa model.
Observation 2	The measured azimuth angular spreads (ASD) for a very large number of communication links in an operational midband urban macro 5G NR network are several times lower than predicted by the existing 38.901 UMa model.
Observation 3	The new UMa measurements can be well represented by the parameter values proposed in [4] as summarized in Table 2.
Observation 4	The measured suburban ZSD can be well represented by a lognormal distribution with lgZSD = -0.10 and lgZSD = 0.24.
Observation 5	The measured suburban ASD can be well represented by a lognormal distribution with lgASD = 0.55 and lgASD = 0.25.
Observation 6	New measured elevation angular spreads (ZSD) indicate a good match with the RMa model for longer distances, but at shorter distances the RMa model seems to predict higher ZSDs than what is observed in the measurements.
Observation 7	Measurements of the ZSD in rural macrocells can be fitted with a lognormal distribution with lgZSD = -0.15 and lgZSD = 0.20.
Observation 8	The measured rural ASD is several times lower than predicted by TR 38.901.
Observation 9	The measured rural ASD can be well represented by a lognormal distribution with lgASD = 0.24 and lgASD = 0.32.
Observation 10	Measurements of the RMa ASD in [6] are remarkably similar to the new measurements reported in this contribution.
Based on the discussion in the previous sections we propose the following:
Proposal 1	Take the new UMa measurements into account for updating the working assumption on UMa O2I ASD.
Proposal 2	Take the new UMa measurements into account for updating the working assumption on cluster ASD for UMa LOS/NLOS/O2I.
Proposal 3	Take the new measurement into account for updating the working assumption on the SMa ASD.
Proposal 4	Take the new measurements into account for updating the TR 38.901 model with respect to the ASD, ZSD, and cluster angular spreads in the Rural Macro scenario.
Proposal 5	Take the measurements in [6] into account for updating the TR 38.901 model with respect to the ASD in the Rural Macro scenario.

3GPP TSG RAN WG1 #121                                                            R1-2504685
St Julian, Malta, May 19th – 23rd, 2025

Source:	vivo, BUPT
Title:	Views on channel model validation of TR38.901 for 7-24GHz
Agenda Item:	9.8.1
Document for:	Discussion and Decision

Conclusions
In this contribution, we have expressed our views on the channel model validation of TR38.901 using measurements at least for 7-24 GHz. The proposals are summarized as follows.
Proposal 1: RAN1 studies the impact of channel sparsity on the existing channel model based on the experiment result.
Proposal 2: The working assumption for the rotation of handheld UE can be confirmed with some modification, i.e., the three figures in reference orientation of handheld UE and the two figures of different morphology for handheld UE shown by example should be modified by Figure 1 to Figure 5. 

3GPP TSG RAN WG1 Meeting #121	R1-2504699
St Julian’s, Malta, May 19th – 23rd, 2025

Source: 	Moderator (Intel Corporation)
Title:	
Agenda item:	9.8.1
Document for:	Discussion

Conclusions from RAN1 #121
To be filled.

3GPP TSG RAN WG1 Meeting #121	R1-2504700
St Julian’s, Malta, May 19th – 23rd, 2025

Source:	Moderator (Intel Corporation)
Title:	
Agenda item:	9.8.1
Document for:	Discussion

Conclusions from RAN1 #121
To be filled.

3GPP TSG RAN WG1 Meeting #121	R1-2504701
St Julian’s, Malta, May 19th – 23rd, 2025

Source:	Moderator (Intel Corporation)
Title:	
Agenda item:	9.8.1
Document for:	Discussion

Conclusions from RAN1 #121
Agreement
Update the reference thickness of plywood to 1.75 cm.

Agreement
Add the following note to UMi and UMa pathloss:
UMi and UMa pathloss formula converges for different frequencies when distances beyond the breakpoint distance is applied.

Conclusion
Angular spread parameters for InF scenarios are not studied further due to lack of measurement data inputs.

Agreement
Confirm the working assumption (made in RAN1#120b) for absolute delay parameters of RMa scenario.

Agreement
Adopt the following update for scaling factor for ZOA and ZOD generation

Agreement
Update the physical blocker modeling parameters in Table 7.6.4.1-2 and 7.6.3.1-4 as follows:
Table 7.6.4.1-2: Blocking region parameters.
Table 7.6.4.1-4: Spatial correlation distance for different scenarios.

Agreement
Confirm the working assumption (made in RAN1#120b) absolute delay parameters of SMa scenario.

Agreement
Adopt the following updates to LSP correlation values for SMa LOS scenario:
Note: this is a copy of LSP correlation values for UMa LOS scenario.

Agreement
Clarify outdoor UT for SMa are in-car deployments and subject to car O2I penetration loss.
Agreement
For SMa scenario calibration, use value of 0% vegetation for LOS probability determination.

Agreement
Revise d2D to d2D-out for LOS probability equations of SMa scenario.

Agreement
Update the SMa pathloss equation as follows:

Agreement
For SMa,  is minimum of two independently generated uniformly distributed variables between 0 and 25 m for UT considered to be inside commercial buildings, and between 0 and 10 m for UT considered to be inside residential buildings.

Agreement
Low Loss, High loss, and Low Loss A penetration model are applicable for SMa.
Low Loss A penetration model is used for SMa scenario calibration purposes.

Agreement
Confirm Working Assumption (made in RAN1#120b) for penetration loss model (low loss A model) applicable for SMa.

Agreement
Update delay spread parameters for SMa scenario as follows

Agreement
Confirm the working assumption for the following SMa parameters

Agreement
Confirm working assumption (made in RAN1#120b) for channel bandwidth for large scale and full calibration and remove brackets.

3GPP TSG RAN WG1 Meeting #121	R1-2504702
St Julian’s, Malta, May 19th – 23rd, 2025

Source:	Moderator (Intel Corporation)
Title:	
Agenda item:	9.8.1
Document for:	Discussion

Conclusions from RAN1 #121
Agreement
Update the reference thickness of plywood to 1.75 cm.

Agreement
Add the following note to UMi and UMa pathloss:
UMi and UMa pathloss formula converges for different frequencies when distances beyond the breakpoint distance is applied.

Conclusion
Angular spread parameters for InF scenarios are not studied further due to lack of measurement data inputs.

Agreement
Confirm the working assumption (made in RAN1#120b) for absolute delay parameters of RMa scenario.

Agreement
Adopt the following update for scaling factor for ZOA and ZOD generation

Agreement
Update the physical blocker modeling parameters in Table 7.6.4.1-2 and 7.6.3.1-4 as follows:
Table 7.6.4.1-2: Blocking region parameters.
Table 7.6.4.1-4: Spatial correlation distance for different scenarios.

Agreement
Confirm the working assumption (made in RAN1#120b) absolute delay parameters of SMa scenario.

Agreement
Adopt the following updates to LSP correlation values for SMa LOS scenario:
Note: this is a copy of LSP correlation values for UMa LOS scenario.

Agreement
Clarify outdoor UT for SMa are in-car deployments and subject to car O2I penetration loss.
Agreement
For SMa scenario calibration, use value of 0% vegetation for LOS probability determination.

Agreement
Revise d2D to d2D-out for LOS probability equations of SMa scenario.

Agreement
Update the SMa pathloss equation as follows:

Agreement
For SMa,  is minimum of two independently generated uniformly distributed variables between 0 and 25 m for UT considered to be inside commercial buildings, and between 0 and 10 m for UT considered to be inside residential buildings.

Agreement
Low Loss, High loss, and Low Loss A penetration model are applicable for SMa.
Low Loss A penetration model is used for SMa scenario calibration purposes.

Agreement
Confirm Working Assumption (made in RAN1#120b) for penetration loss model (low loss A model) applicable for SMa.

Agreement
Update delay spread parameters for SMa scenario as follows

Agreement
Confirm the working assumption for the following SMa parameters

Agreement
Confirm working assumption (made in RAN1#120b) for channel bandwidth for large scale and full calibration and remove brackets.

Agreement
Update UMi LOS/NLOS ASD (Mean, Std) as follows


Update UMi LOS/NLOS ZSA (Mean, Std) as follows


Update UMa LOS ZSA (Mean, Std) as follows


Update UMa LOS/NLOS ASD (Mean, Std) as follows


Note: Same parameter derivation methodology as noted in RAN1 #120-bis for each parameter were re-used. For UMa ASD, the updates to previous agreement are made based on new measurement data inputs in RAN1 #121.


Agreement
Update the UMa O2I AOD spread as follows. 
Note: This would change the working assumption made in RAN1 #120-bis.
Note: No UMa O2I data was provided in Rel-14. The UMa ASD O2I values were adopted from UMi ASD O2I in TR 38.901. The UMi ASD O2I in TR 38.901 was in turn adopted from winner II channel model. In the Winner II channel model only a single measurement at 5.25 GHz for UMi O2I ASD.

Agreement
Update the UMa LOS, NLOS, and O2I Cluster AOD spread as follows. 
Note: This would change the working assumption made in RAN1 #120-bis.
Note: the update parameter was generated using all measurement and ray tracing data set from Rel-14 SI and (current) Rel-19 SI and dividing the data points into 3 groups, below 6 GHz, 6 to 24 GHz, and above 24 GHz, and weighting the data sets for each group to perform weighted least square curve fit OR compute weighted mean. If a group has fewer data points, higher weight per data point is calculated. All points within a group have the same weight. Sum of weights for all groups is equal to 1.  Each group is given equal weightage.



Agreement
Proposed Observation:
Measurement of ZSD for rural macrocell deployments from a source observed lower ZSD values compared to ZSD for RMa at shorter distances. 
Measurement of ASD for rural macrocell deployments from a source observed lower ZSD values compared to ASD for RMa.
Conclusion:
No consensus to update RMa ASD and ZSD parameters due to lack of measurement data for each of LOS, NLOS, and O2I cases. 

Agreement
Introduce an optional Mmin parameter to potentially bound the number of rays per clusters for equation (7.6-8) of intra-cluster angular and delay spreads.

Agreement
Add the following angle scaling formula for CDL-E and CDL-D that allow maintaining the LOS angle as the desired scaled LOS angle:
,



Note: This will be an additional (and alternative) formulation for CDL-D and CDL-E angle scaling.

Agreement
Update ASA and ZSA parameters for SMa scenario as follows:


Note: The updated SMa results for ZSA was based on a single source measurement data.

Agreement
Update ASD parameters for SMa scenario and confirm the working assumption for ZSD parameters as follows:


Agreement
Revise the Rx heigh example for UMa, UMi, and SMa in scenario description in Section 6.2 as follows:
UMi
“Example: [Tx height:10m, Rx height with reference to floor height: 1.5-2.5 m, ISD: 200m]”
UMa
“Example: [Tx height:25m, Rx height with reference to floor height: 1.5-2.5 m, ISD: 200m, 500m]”
SMa
“Example: [Tx height: 35m, Rx height with reference to floor height: 1.5-2.5m, ISD: 1299m, 1732m]”


Agreement
Confirm the working assumption for the following SMa parameters


Agreement
Update “UT array orientation” in TR 38.901 as “UT orientation”

3GPP TSG RAN WG1 Meeting #121	R1-2504703
St Julian’s, Malta, May 19th – 23rd, 2025

Source:	Moderator (Intel Corporation)
Title:	
Agenda item:	9.8.1
Document for:	Discussion

Conclusions from RAN1 #121
Agreement
Update the reference thickness of plywood to 1.75 cm.

Agreement
Add the following note to UMi and UMa pathloss:
UMi and UMa pathloss formula converges for different frequencies when distances beyond the breakpoint distance is applied.

Conclusion
Angular spread parameters for InF scenarios are not studied further due to lack of measurement data inputs.

Agreement
Confirm the working assumption (made in RAN1#120b) for absolute delay parameters of RMa scenario.

Agreement
Adopt the following update for scaling factor for ZOA and ZOD generation

Agreement
Update the physical blocker modeling parameters in Table 7.6.4.1-2 and 7.6.3.1-4 as follows:
Table 7.6.4.1-2: Blocking region parameters.
Table 7.6.4.1-4: Spatial correlation distance for different scenarios.

Agreement
Confirm the working assumption (made in RAN1#120b) absolute delay parameters of SMa scenario.

Agreement
Adopt the following updates to LSP correlation values for SMa LOS scenario:
Note: this is a copy of LSP correlation values for UMa LOS scenario.

Agreement
Clarify outdoor UT for SMa are in-car deployments and subject to car O2I penetration loss.
Agreement
For SMa scenario calibration, use value of 0% vegetation for LOS probability determination.

Agreement
Revise d2D to d2D-out for LOS probability equations of SMa scenario.

Agreement
Update the SMa pathloss equation as follows:

Agreement
For SMa,  is minimum of two independently generated uniformly distributed variables between 0 and 25 m for UT considered to be inside commercial buildings, and between 0 and 10 m for UT considered to be inside residential buildings.

Agreement
Low Loss, High loss, and Low Loss A penetration model are applicable for SMa.
Low Loss A penetration model is used for SMa scenario calibration purposes.

Agreement
Confirm Working Assumption (made in RAN1#120b) for penetration loss model (low loss A model) applicable for SMa.

Agreement
Update delay spread parameters for SMa scenario as follows

Agreement
Confirm the working assumption for the following SMa parameters

Agreement
Confirm working assumption (made in RAN1#120b) for channel bandwidth for large scale and full calibration and remove brackets.

Agreement
Update UMi LOS/NLOS ASD (Mean, Std) as follows


Update UMi LOS/NLOS ZSA (Mean, Std) as follows


Update UMa LOS ZSA (Mean, Std) as follows


Update UMa LOS/NLOS ASD (Mean, Std) as follows


Note: Same parameter derivation methodology as noted in RAN1 #120-bis for each parameter were re-used. For UMa ASD, the updates to previous agreement are made based on new measurement data inputs in RAN1 #121.


Agreement
Update the UMa O2I AOD spread as follows. 
Note: This would change the working assumption made in RAN1 #120-bis.
Note: No UMa O2I data was provided in Rel-14. The UMa ASD O2I values were adopted from UMi ASD O2I in TR 38.901. The UMi ASD O2I in TR 38.901 was in turn adopted from winner II channel model. In the Winner II channel model only a single measurement at 5.25 GHz for UMi O2I ASD.

Agreement
Update the UMa LOS, NLOS, and O2I Cluster AOD spread as follows. 
Note: This would change the working assumption made in RAN1 #120-bis.
Note: the update parameter was generated using all measurement and ray tracing data set from Rel-14 SI and (current) Rel-19 SI and dividing the data points into 3 groups, below 6 GHz, 6 to 24 GHz, and above 24 GHz, and weighting the data sets for each group to perform weighted least square curve fit OR compute weighted mean. If a group has fewer data points, higher weight per data point is calculated. All points within a group have the same weight. Sum of weights for all groups is equal to 1.  Each group is given equal weightage.



Agreement
Proposed Observation:
Measurement of ZSD for rural macrocell deployments from a source observed lower ZSD values compared to ZSD for RMa at shorter distances. 
Measurement of ASD for rural macrocell deployments from a source observed lower ZSD values compared to ASD for RMa.
Conclusion:
No consensus to update RMa ASD and ZSD parameters due to lack of measurement data for each of LOS, NLOS, and O2I cases. 

Agreement
Introduce an optional Mmin parameter to potentially bound the number of rays per clusters for equation (7.6-8) of intra-cluster angular and delay spreads.

Agreement
Add the following angle scaling formula for CDL-E and CDL-D that allow maintaining the LOS angle as the desired scaled LOS angle:
,



Note: This will be an additional (and alternative) formulation for CDL-D and CDL-E angle scaling.

Agreement
Update ASA and ZSA parameters for SMa scenario as follows:


Note: The updated SMa results for ZSA was based on a single source measurement data.

Agreement
Update ASD parameters for SMa scenario and confirm the working assumption for ZSD parameters as follows:


Agreement
Revise the Rx heigh example for UMa, UMi, and SMa in scenario description in Section 6.2 as follows:
UMi
“Example: [Tx height:10m, Rx height with reference to floor height: 1.5-2.5 m, ISD: 200m]”
UMa
“Example: [Tx height:25m, Rx height with reference to floor height: 1.5-2.5 m, ISD: 200m, 500m]”
SMa
“Example: [Tx height: 35m, Rx height with reference to floor height: 1.5-2.5m, ISD: 1299m, 1732m]”


Agreement
Confirm the working assumption for the following SMa parameters


Agreement
Update “UT array orientation” in TR 38.901 as “UT orientation”


Agreement (replaces previous agreement in RAN1 #121)
Update the SMa pathloss equation as follows:

Agreement
Update ASD parameters for SMa scenario as follows:
Note: The cluster ASD values in this agreement replaces the previous agreement in RAN1 #121.



Agreement
Add the following note to SMa description
NOTE 1: SMa scenarios with ISDs between 1200-1800m can be used for evaluations

Agreement
Clarify downtilt simulation assumption parameter for calibrations as follows:
For SMa,
downtilt refers to mechanical downtilt and no electrical downtilt applies.
Update the “Working assumption of 93 degree” to 92 degree for downtilt for SMa deployment scenario for ISD = 1732m.
For InH,
Downtilt refers to mechanical downtilt and no electrical downtilt applies
For UMa and UMi,
No mechanical downtilt applies, and downtilt values refer to electrical downtilt



Agreement
Update the reference orientation of the handheld UE as follows:

Note: The representation will be same between GCS and UE LCS for ΩUT,α = 0 deg, ΩUT,β = 0 deg, ΩUT,γ = 0 deg,
For calibration of handheld UE, use the following UE rotation based on reference UE orientation
For calibration with blockage:
For one-hand blockage, ΩUT,α = 0 – 360 deg, ΩUT,β = 45 deg, ΩUT,γ = 0 deg, 
For dual-hand blockage, ΩUT,α = 0 – 360 deg, ΩUT,β = 0 45 deg, ΩUT,γ = 4590 deg, 
For hand and head blockage, ΩUT,α = 0 – 360 deg, ΩUT,β = 90 deg, ΩUT,γ = 0 deg, 
For all other calibration cases:
ΩUT,α = 0 – 360 deg, ΩUT,β = 45 deg, ΩUT,γ = 0 deg, 
Note: UT array orientation is defined by three angles ΩUT,α (UT bearing angle), ΩUT,β (UT downtilt angle) and ΩUT,γ (UT slant angle).
Example of ΩUT,α = 0 - 360 deg, ΩUT,β = 90 deg, ΩUT,γ = 0 deg

Example of ΩUT,α = 0 - 360 deg, ΩUT,β = 0 90 deg, ΩUT,γ = 90 deg


Agreement
Reference radiation pattern of the UE antenna model is vertically polarized with all the gain in the theta field component,  and  and referred to as polarization direction along the Z’’ axis.
For cases when a candidate antenna placement location is used for one antenna field pattern (e.g., single polarization):
The polarization direction is indicated by the arrow in the following figure which is parallel with the plane of the handheld UE and perpendicular to the direction from the UE center to the candidate antenna location

For cases when a candidate antenna placement location is used for two antenna field patterns (e.g., dual polarization) (not intended for FR1):
For the first antenna field pattern, the polarization direction is indicated by the arrows in the above figure but additionally rotated 45 degrees about the direction from the UE center to the candidate antenna location (i.e. rotated using the direction from the UE center to the candidate antenna location as the rotational axis).
For the second antenna field pattern, the polarization direction is perpendicular to the polarization direction of the first filed pattern and perpendicular to the direction from the UE center to the candidate antenna location
An example for candidate antenna location (6) is given in the figure below.
	
RAN1 to perform calibration of antenna field pattern (, ) for 8 antenna handheld UE in the UE local coordinate system

Agreement
Amend the previous agreement (from RAN1 #120-bis) as follows:
Each polarized field component of the reference radiation pattern  and  should be rotated according to the orientation and polarization direction of the each of UE antennae to get ,  and based on the orientation of the UE in the global coordinate system to get  and  using the methods already specified in TR 38.901, equation (7.3-3)/(7.1-11).


Observation:
The number of clusters for UMi was taken from Winner II which appears to have use the 95%-tile value from the CDF of the number of clusters assuming K-mean clustering algorithm for counting number of clusters. 
For UMa NLOS case, the 90%-tile and maximum number of cluster measurements from sources was observed to be aligned.
For UMa LOS and UMi LOS cases, the 90%-tile and maximum number of cluster measurements from sources was observed to be marginally higher than the values in current TR38.901 by 1 to 6 clusters.
For InH LOS, InH NLOS, UMi NLOS, the 90%-tile and maximum number of cluster measurements from sources was observed to be marginally lower than the values in current TR38.901 by 1 to 6 clusters.
For UMa LOS/NLOS, UMi LOS/NLOS, and InH LOS/NLOS cases, the mean number of cluster measurements were significantly lower than values in current TR38.901.

Agreement
For section 7.6, introduce an optional modeling component for number of clusters
Optional modeling components are used to evaluate a channel propagation environment with diverse cluster ranges.
Table: Number of clusters for the diverse cluster environment

Number of clusters is chosen between a closed range of [D1, D2]. The selection of the number of cluster for each link is determined by the user. This is used as the number of clusters in Table 7.5.6-Part 1 and Part 2.
Rapporteur to reference METIS channel model for this optional modeling component.
Note: D1 is the average of the mean of the number of clusters from the source data. D2 is the values from 38.901
Note: O2I values for D1 and D2 is the minimum of LOS or NLOS value


Agreement
Introduce additional cluster angle scaling factors as follows:
Table 7.5-2: Scaling factors for AOA, AOD generation

Table 7.5-4: Scaling factors for ZOA, ZOD generation



Agreement
Introduce polarization variability for each rays of cluster for NLOS component of the channel as an optional modeling component.
Generate polarization variability powers , ,  and  for each ray m of each cluster n.  is log-Normal distributed. Draw values as 
	,	(7.5-21b)
		(7.5-21c)
where  is Gaussian distributed. 
Note that  is independently drawn for each ray, cluster, and polarization component.

	(7.5-22)
Note: The model is at least applicable for model-2 antenna polarization modeling.

Agreement
Add new antenna Config C (with BS config 4) for 15 GHz for UT as optional configuration as part of full calibration assumption
(optional) Config C for 15 GHz: 16 antenna port with dual polarization based on handheld device antenna model using feasible candidate antenna locations in (1,2,3,4,5,6,7,8) as described in Clause 7.3.
Note: other UT configuration are not applicable for 15 GHz.



Agreement
Copy the following summary of observations, conclusions, and agreements to the cover sheet of the measurement data source Tdoc, intended to be captured as reference to the TR.

 

Agreement
Copy the excel sheet in R1-2504913 as additional tab sheets of the measurement data source excel file, intended to be captured as reference to the TR.
Agreement
R1-2504696 to be captured as reference for TR38.901 when endorsed.
Note: R1-2504696 contains the latest update of measurement data sources for channel model as part of the Rel-19 channel modeling enhancements for 7-24 GHz SI.

Post Email discussion for draft&final CR for TR38.901 (26th -28th, May)

Agenda item: 9.8.1
Source: Qualcomm Incorporated
Title: Channel model validation of TR 38.901 for 7-24GHz
Document for: Discussion/Decision

Conclusion 
We make the following observations and proposals in this document:	
On open issues for SMa scenario
Proposal 1: For SMa, the current working assumption on the correlation values of the LSPs results in a correlation matrix that is not positive semidefinite and hence not suitable for Cholesky decomposition. To fix this issue, consider one of the following options:
Recompute the correlation values
Reuse UMa scenario’s correlation parameters.
Proposal 2: For SMa scenario, outdoor UEs are assumed to have a velocity of 40 kmph. Clarify that these UEs are in cars and that in-car O2I penetration losses will be applied. 
Proposal 3: For SMa, the current working assumption assumes 14 clusters for O2I users. However, Table 7.5-4 does not provide the scaling factors for ZOA and ZOD generation when number of clusters is 14. To fix this issue, either change the number of cluster for O2I users to 15 or add a new entry to Table 7.5-4 to support 14 clusters.
Proposal 4: For SMa scenario, clarify that the LOS probability is calculated with a default assumption of 0% vegetation (i.e., no vegetation).
Proposal 5: Confirm the following working assumption on a new loss-loss penetration model for SMa:
Working Assumption
Introduce new penetration loss outdoor-to-indoor (O2I) building penetration loss model applicable for SMa and used for calibration:

On UE antenna modeling
Proposal 6: Clarify that the polarization orientation of single-Pol UE antennas is along the plane of the phone. Adopt the orientations proposed in Option (i). Set the slant angle as defined in Section 7.3.2. to 90 degrees with the assumption that the handheld device is placed along the X-Y plane.
Proposal 7: Orientation of dual-pol antennas needs further clarification. The choice of the orientation and the direction of maximum gain need to be consistent and feasible. The orientation depicted in the following figure is suggested as an option, where slant angles 0 and 90 degrees are chosen.


Proposal 8: For UEs with 2, 3, and 6 antennas, the default antenna placements are given as follows:

On polarization coupling matrix
Observation 1: Equation 7.5-22 represents the NLOS channel between a single antenna pair. A coupling matrix is used to determine how the  and components of the transmitter and receiver interact with each other. 
Observation 2: Applicability of measurements made using a dual-polarized antenna setup to a single-polarized antenna setup as described in Eq. 7.5-22 is unclear.
Observation 3: Notational differences between WINNER II and 38.901 warrant closer inspection on the appropriate structure of the coupling matrix used in 38.901. 
On PAS and Angle Sampling
Observation 4: The additional modeling component in Section 7.6.2.2 appears capable of modelling clusters that exhibit Rician fading characteristics.
On updating number of clusters
Observation 5: Current 38.901 specification provides the values for number of clusters to consider for three different UE categories: LOS outdoor UE, NLOS outdoor UE, and O2I UE (indoor). When considering any update to the number of clusters for existing deployment scenarios, it is important to consider all three UE categories with specific emphasis on O2I UEs which constitute 80% of UEs in typical system-level evaluations. It is noted that currently there are no measurement data for O2I UEs. 
Observation 6: The exact interpretation of the number of clusters assumed in 38.901 for different scenarios needs more clarity. Interpreting it as representing the mean, median or the maximum could inform us on how to interpret the measurement data and where it diverges from the existing assumption in 38.901. 
Observation 7: From a system-level evaluation perspective, reducing the number of clusters to a lower number either by reducing the nominal number of clusters or by increasing the threshold to drop weaker clusters does not seem to significantly impact the communication metrics. 
Observation 8: Changing the number of clusters for a specific frequency range will make it difficult for cross-frequency comparisons in future evaluations.
Proposal 9: Given the negligible system-level impact due to a reduction in the number of clusters a strong motivation to alter the number of clusters in 38.901 is lacking. 

3GPP TSG RAN WG1 Meeting #121                                                       	R1-2504721
St Julian, Malta, 19 May – 23 May, 2025
Source:           BUPT
Title:              Discussion on channel model validation of TR38.901 for 7-24 GHz
Agenda item:    	9.8.1
Document for:  	Discussion and Decision

Conclusion
In this contribution, we provide our views on the validation and the details for Rel-19 channel modeling enhancements for 7-24 GHz. Key consideration is the modification of the cluster structure. The observation and proposals are as follows:
Observation 1: The values of  for 6-24 GHz are consistently below 20, causing all clusters in these frequency bands to adopt 20 rays. Consequently, the frequency parameter in the equation becomes functionally irrelevant, unable to reflect the frequency-dependent characteristics of the channel. 
Observation 2: The number of rays per cluster is less than 20 based on the measurements.
Observation 3: The magnitude of channel coefficients still obeys Rician and Rayleigh distribution for LOS and NLOS when it uses the updated method of Section 7.6.2.2
Observation 4: The measured cluster number is smaller than the 3GPP model, and there is still a gap after interception using the threshold of -25 dB.

Proposal 1: It is proposed that Equation (7.6-8) 

in Section 7.6.2.2 be modified to 

 is the lower limit of  and can be selected by the user of the channel model based on the mean of dominant rays across all clusters. The number of dominant rays in a cluster is defined as the minimum number of rays that contain 95% of the total cluster power, when the rays in a cluster are sorted in descending order of power. The default value of  is 20.
Proposal 2: It is proposed to add a paragraph at the end of section 7.6.2:
“It is well known that as frequency increases, the multipath channel becomes sparse compared to microwave channels. There are dominant path(s) that reduce the channel rank [3]. However, in 38901, the equal powers per ray in a cluster, the number of rays per cluster, and the number of clusters remain constant across all frequency bands, the impulse response remains the same for all bands. Consequently, it exhibits no frequency sensitivity.
Proposal 3: The number of clusters in TR 389.01 needs modification. The mean number of clusters to correct the previously mentioned UMa NLOS scenario is 10.
The above procedure can provide a framework to vary the numbers of rays per cluster and ray powers within a cluster as a function of frequency and could therefore enable the simulation of a sparse channel.”

3GPP TSG RAN WG1 #121		                                                      R1-2504813
St Julian’s, Malta, May 19th – 23rd, 2025

Source:	CATT
Title:	Views on channel model validation for 7-24GHz
Agenda Item:	9.8.1
Document for:	Discussion and Decision

Conclusions
In this contribution, remaining aspects of channel model involved in the validation for 7-24GHz are discussed. Based on the discussion, the following proposals are made:
Proposal 1: If UMi/UMa pathloss convergence beyond breakpoint distance needs to be resolved, Option 3 is supported.
Option 3) Add note that provide information on pathloss convergence phenomena beyond the breakpoint distance across different frequencies.
Proposal 2: Update the number of clusters for 7-24 GHz.
Proposal 3: Do not introduce intra-cluster power profile for 7-24 GHz.

TDoc file not a doc/docx file