3GPP TSG-RAN WG1 Meeting #121                                                                                         	   R1-2503257
St Julian’s, Malta, May 19-23, 2025

Agenda Item:	9.8.2
Source:	Huawei, HiSilicon 
Title:	Considerations on the 7-24GHz channel model extension 
Document for:	Discussion and Decision

Conclusions
In this contribution, we provide our views on the near-field and non-stationary channel modelling. Following observation and proposals are given:
Observation 1: Incomplete reflection, diffraction and scattering can result in spatial non-stationary effect. 
Proposal 1: Support to set the ratio of non-direct path with spherical-wavefront phenomenon to one.
Proposal 2: For modelling spatial non-stationarity by stochastic visibility-based model, support to calculate the visible probability according to the parameters in Table 1.
Proposal 3: For modelling spatial non-stationarity by stochastic visibility-based model, the location of visibility region follows uniform distribution, i.e., the visibility region is located at either upper or lower part of antenna array with equal probability of 0.5.
Proposal 4: For calibration of BS-side spatial non-stationarity, support to determine the UT attachment based on the average RSRP from all BS port.

3GPP TSG RAN WG1 #121                                                            R1-2503375
St Julian, Malta, May 19th – 23rd, 2025

Source:	vivo, BUTP
Title:	Views on channel model adaptation/extension of TR38.901 for 7-24GHz
Agenda Item:	9.8.2
Document for:	Discussion and Decision

Conclusions
In this contribution, we have elaborated the realization of near-filed channel modeling in consideration of the antenna element-wise channel parameters associated with indirect paths. Then, two models for spatial non-stationarity modeling at BS side are compared. The observations and proposals are summarized as follows.
Proposal 1: The distance  is generated independently for different sub-clusters in the same cluster, using the formula for the sub-cluster  as . 
Proposal 2: The stochastic-based model is the more appropriate to model the spatial non-stationarity phenomenon at BS side.

3GPP TSG RAN WG1 #121	                                                           R1-2503427
St Julian’s, Malta, May 19th – 23st, 2025


Agenda Item:	9.8.2
Source: 	LG Electronics
Title: 	Discussion on channel modelling adaptation/extension for 7-24GHz
Document for:	Discussion and decision

Conclusion
Based on the above discussion, the following proposals are provided.

Proposal 1: Support to adopt both the stochastic-based and the physical blocker-based approaches as optional models for modelling spatial non-stationarities at the BS side.

Proposal 2: Support to adopt the stochastic-based approach as the baseline among the optional models for modelling spatial non-stationarities at the BS side, in case a down-selection is required.

3GPP TSG RAN WG1 Meeting #121													R1-2503440
Malta, MT, May 19th – 23rd, 2025

Agenda Item:		9.8.2	
Source:				InterDigital, Inc.
Title:						Remaining Details of Extension 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: More clusters are impacted by SnS in indoor office and UMi than UMa and the distribution of the cluster visibility probability is higher than UMa. 

Proposal 1: for the Step 1, the distribution of cluster visibility probability  is determined as ,  and ,   for indoor office and UMi, respectively. 

Observation 2: The visibility region tends to increase from indoor office to UMi, and UMa scenarios. 

Proposal 2: For the Step 2, for the modelling of spatial non-stationarity, if the unified visibility region based approach is adopted then A, B,  and  parameters can be referred by following Table 3 where A = 0.08, B =0.35,  for indoor office, and A = 0.13, B =0.40, ,  for UMI, respectively. 

Observation 3: From the ray tracing simulation, the location of cluster VR from the top right, top left, bottom right and bottom left of the full array shows almost same probability.

Proposal 3: For Step 2, the located VR with width (a) and height (b) can be randomly selected from the four corners of the full array with an equal probability, i.e., 0.25 for the -th cluster.

3GPP TSG-RAN WG1 Meeting #121		R1-2503579
St Julian’s, Malta, May 19th – 23th, 2025

Agenda item:	9.8.2 
Title:	Discussion on channel model adaptation/extension of TR38.901 for 7-24GHz
Source:	Samsung 
Document for:	Discussion and Decision 

Conclusion
Config 1B (4 ports on a handheld antenna model) at a distance of 10m with phase term updates on both LOS and NLOS ray shows better orthogonality in the near-field model compared to the far-field model
Becoming the distance is increased, the non-planar wave characteristics of the near-field do not show significant differences from the planar wave characteristics of the far-field
Although near-field effects can have positive potentials compared to far-field environment, whether such calibration assumptions can be applied to real-life scenarios requires detailed review.
For same implementation method, the consistency makes that the model can be universally applied without the need for transition points. However, this comes at the complexity for computation. Non-planar wavefronts are significant in near-field conditions, while far-field condition is adequately modelled using plane wavefront. So, by using a more complex equation across all field condition, the model may introduce unnecessary computational overhead in far-field conditions
For different implementation method, it enhances computational efficiency by applying the appropriate model to each region. However, it introduces challenges in managing the transition between near- and far-field regions
RAN1 discuss same/different implementation method taking into account channel consistency and computational complexity
RAN1 consider the updates of channel parameter with weighting vector for antenna array  
Spatial non-stationarity occurs when a large-scale antenna array in BS is introduced or the UE is very close to the BS. 
RAN1 discuss the condition of occurrence for spatial non-stationarity
Considering the presence of geographical blockers between the BS and UE, it is crucial to examine power attenuation per antenna element within the BS
RAN1 consider the blockage model B of blocker-based approach for the modelling of spatial non-stationarity

Appendix. Simulation assumptions for calibration

3GPP TSG-RAN WG1 Meeting #121	Tdoc R1-2503621
St Julien’s, Malta, May 19th – 23rd, 2025
Agenda Item:	9.8.2
Source:	Ericsson
Title:	Discussion on adaptation and extension of channel model
Document for:	Discussion

Conclusion
In the previous sections we made the following observations: 
Observation 1	Existing CDL models already support blockage in NLOS conditions and can support blockage also for the LOS path if the geometric Tx-Rx distance  is specified. This means that element-based blockage as introduced in this SI should be easy to apply to existing CDL models.

Based on the discussion in the previous sections we propose the following:
Proposal 1	To enhance the existing CDL models for optional use with spherical wavefront modeling, generate and tabulate  and  values for each cluster. Then calculate  where  is the speed of light,  is the relative cluster delay, and  is a user-supplied distance. Similarly, .
Proposal 2	Specify the procedure for spatial non-stationary based on Blockage model B for link-level simulations.
Proposal 3	Capture the agreements on spatial non-stationarity based on Blockage model B in the existing clauses 7.6.4 and 7.6.4.2 in TR 38.901, e.g. by adding the sentence “Model B can also be used to model spatial non-stationarity due to partial blocking across an antenna array.” at the end of clause 7.6.4 and the updated types of blockers and equations in clause 7.6.4.2.
 

3GPP TSG RAN WG1 #121	R1-2503634
St Julian’s, Malta, May 19th – 23th, 2025

Source:	 ZTE Corporation, Sanechips
Title:	 Discussion on channel model adaptation and extension
Agenda Item:	 9.8.2
Document for:  Discussion

Conclusion
In this contribution, we provide our analysis and proposals for the channel model adaptation/extension of TR38.901 at least for 7-24GHz.
Observation 1: For visible probability and visibility region based approach, the followings can be observed:
Visible probability and visibility region based approach cannot guarantee the consistency across clusters with similar departure directions.
In the visible probability and visibility region based approach, the attenuation of each ray is assumed to be completely consistent, leading to a lack of precision in channel modeling.
The visible probability and visibility region based approach cannot reflect variations in SNS probability caused by different BS apertures, blocker types, blocker numbers, and blocker position regions.
Proposal 1: The following issues should be discussed and clarified for the visible probability and visibility region based approach:
The definition of  to accurately calculate the attenuation within the visible region .
The definition of Pn in the visible probability formula
Proposal 2: Visible probability and visibility region based approach cannot reflect the consistency impact of partial blockage.

3GPP TSG RAN WG1 Meeting #121	R1-2503647
St Julian’s, Malta, May 19th – 23rd, 2025

Source:	Intel Corporation
Title:	Discussion on channel model adaptation/extension
Agenda item:	9.8.2
Document for:	Discussion

Conclusions
In this contribution, we discussed near-field communications and other channel model adaptations/extensions. The following is a summary of proposals and observations made.
Proposal #1: Add a text in the TR to recommend using physical blocker based model for InH and InF scenarios, and stochastic block model for UMi, UMa, and SMa scenarios.

3GPP TSG RAN WG1 #121                               R1-2503654
Malta, MT, May 19th – 23th, 2025

Source:	BUPT, CMCC, X-NET
Title:	Discussion on near-field propagation and spatial non-stationary
Agenda Item:	9.8.2
Document for:	Discussion and Decision

Conclusions
Proposal 1: For the modelling of spatial non-stationarity, if the unified visible probability and visibility region based approach is adopted, for the Step 1 (whether a cluster is impacted by SNS):
In UMi, the distribution of  is determined as: ;
In InH, the distribution of  is determined as: ;

3GPP TSG- RAN WG1 #121 Meeting 	                                                                      R1- 2503714
Malta, MT, May 19th – 23rd, 2025

Agenda item:	9.8.2
Title:	Discussions on FR3 Channel Modelling
Source:	Lekha Wireless Solutions
Document for:	Discussion/ Decision


 

Conclusion
In this proposal, we discussed and provide our views on delays for direct and non-direct paths for FR3 near-field channels with following proposals:

Proposal 1: From the options shortlisted for delay of direct path, it is more credible to go with Option 2, as the delays must be relative to the distance of direct path between antenna elements at TRP and UE side.
Proposal 2: Considering the points mentioned above, we believe that the current presumptions available in TR 38.901 for non-direct paths are not sufficient for the delay modelling in near-field setup, hence, it is more suitable to go with Option 1 mentioned in observation 1.
Proposal 3: The entire channel realization process to capture the near-field propagation is shown as following,

Proposal 4: The 3D distance between the TRP and UE mentioned in the proposal above is fine for us. However, for the lower range, considering a non-zero z-coordinate value, the distance must be slightly greater than Dmin.
Hence, we propose the range to be (. We agree to the second proposal that the antenna element-wise channel parameters for the link level evaluation can be obtained following the same procedures of non-direct path and direct-path for the system-level simulation.
4. 

3GPP TSG RAN WG1 #121		                               R1-2503806
St Julian’s, Malta, May 19th – 23rd, 2025

Source:	CATT
Title:	Views on channel model adaptation/extension for 7-24GHz
Agenda Item:	9.8.2
Document for:	Discussion and Decision

Conclusions
In this contribution, we provided our views on modelling methodology for 7-24GHz. We also provided our simulation results on near-field and spatial non-stationarity.
Proposal 1:  For the modelling of spatial non-stationarity at BS side, both unified VP and VR method and physical blocker based approach should be adopted as the modelling methodologies.
Proposal 2: In the near-field propagation, by default, the near-field and far-field adopt the same implementation.
Proposal 3: CDL models are more suitable for link level simulation.
Proposal 4: To model near field in link level simulation, the followings are adopted for link level simulation:
The antenna element-wise phase modeling can be reflected in the step of ‘Generate channel coefficient’. 
Proposal 5: To model spatial non-stationarity in link level simulation, the followings are adopted for link level simulation:
The effect of power attenuation factor can be reflected in the step of ‘Generate channel coefficient’. 

3GPP TSG-RAN WG1 Meeting #121	R1- 2503994
St Julian’s, Malta, May 19th – 23rd, 2025

Agenda Item:	9.8.2
Source:	NVIDIA
Title:	Channel model adaptation of TR 38.901 for 7-24 GHz
Document for:	Discussion
1	

Conclusion
For near-field channel, to generate the  for  non-direct paths:
No additional lower bound (i.e., ) of  is defined.
Agreement
In the Indoor office scenario for near-field channel, = 4.
Agreement
In the Indoor factory scenarios, to generate the  non-direct path for the near-field channel model:
= 4;
For the  non-direct paths, the distribution of scaling factor  is a Beta distribution with 

Agreement
For the modelling of spatial non-stationarity, if the unified visible probability and visibility region based approach is adopted, to generate the power attenuation factor  for clusters with SNS, the value of C (i.e., the roll-off factor between the visible and invisible regions) is: 
C= 13 for UMa.
Agreement
For the modelling of spatial non-stationarity, the visibility region, i.e., a rectangle, is randomly located at a corner of the antenna array by following approach:
The location of the VR is jointly determined by following conditions:
The VR is located at either left or right part in horizontal domain of antenna array with equal probability of 1/2.
The probability of VR at the upper part of antenna array is [0.8] and the probability of VR at the lower part of antenna array is [0.2]; 
Agreement
For the calibration parameters for the near-field channel, 

Agreement
The following assumption is used for UE side SNS calibration:

Agreement
The following assumption is used for BS side SNS calibration:

3GPP TSG RAN WG1 #121		R1-2504222
St Julian’s, Malta, May 19th – 23rd, 2025
	

Source:	OPPO
Title:	Channel model adaptation and extension for 7-24GHz
Agenda Item:	9.8.2
Document for:	Discussion and Decision

Conclusion
In this contribution, we discuss the channel model adaptation and extension to TR38.901 for near field (7-24GHz) with the following proposals:
Proposal 1: The near-field region can be defined based on Rayleigh distance and FFS on scaling factor, which only serves as a reference criterion for considering spherical wavefront or not.
Proposal 2: For near-field channel, for link-level simulation, the 3D distance between TRP and UE is determined in the tabular form. Then, the absolute delay for each cluster is determined following the same procedure in Section 7.6.9 TR 38.901.
Proposal 3: For near-field channel, for link-level simulation, value of  can be directly assigned for each CDL model and should be applied for the k1 strongest of the clusters in the channel.
Proposal 4: For near-field channel, for link-level simulation, the scaling factors can be generated following the procedures below
1) Determine a basic moderate 3D distance value between TRP and UE.
2) Generate the scaling factors for each CDL model following the same procedure as system-level simulation.
3) Choose one set of scaling factors according to a specific metric, e.g. corresponds to 0.5 of singular value CDF curve or has the similar statistical property as the distribution.
4) Record the mean and variance for further scaling.
Proposal 5: For near-field channel, for link-level simulation, the scaling factors can scaled with the following equation

Proposal 6: For near-field channel, the following element-wise channel parameters of the link-level simulation for both direct and non-direct paths are modelled following the same method as in system-level simulation:
Phase
Angular domain parameters
Proposal 7: For near-field channel, the element-wise channel parameters of the specular path of the link-level simulation are modelled following the same method as the direct path in system-level simulation.

3GPP TSG RAN WG1 #121			R1-2504339
St Julian’s, Malta, May 19th – 23th, 2025 
 
Agenda Item:	9.8.2
Source:	Apple
Title:	Channel Model Adaptation and Extension of TR 38.901 for 7-24 GHz
Document for:	Discussion/Decision

Conclusion
In this contribution, we provided our views on the remaining issues of channel model adaptation/extension of TR 38.901 for 7-24 GHz. Our proposals are as follows:

Proposal 1: For the modelling of spatial non-stationarity with unified VP and VR, in Step 1, the mean values of  in UMi and indoor office are smaller than the mean value of  in UMa. 

Proposal 2: For the modelling of spatial non-stationarity with unified VP and VR, in Step 2, the probability of visibility region being at the upper part of antenna array is 0.7 and the probability of visibility region being at the lower part of antenna array is 0.3. 

Agenda item: 9.8.2
Source: Qualcomm Incorporated
Title: Channel model adaptation or extension of TR38.901 for 7-24GHz
Document for: Discussion/Decision

Conclusion 
We make the following proposals in this document:
On spherical wavefront modeling:
Proposal 1: For near-field channel modeling,  is is calculated as: 
,
where the  refers to the 3D distance between reference point at TRP and UE side. The  refers to the excess delay in NLOS obtained using Section 7.6.9 and  is the th cluster’s normalized delay in Step 5 of Section 7.5.
Proposal 2: Confirm that the excess delay  generated using Section 7.6.9 is only used for determining , and that the excess delay  and 3-D distance  are not used to determine channel response (i.e., Eq. 7.6-44 is not used).

3GPP TSG RAN WG1 #121	        	R1-2504630
St Julian’s, Malta, May 19th – 23rd, 2025

Agenda Item:					    9.8.2
Source:	Sony
Title:	Discussion of channel model adaptation/extension of TR38.901 for 7–24GHz 
Document for:	Discussion and decision

Conclusions
We made the following observations and proposals:
 For the modeling of spatial non-stationarities at the BS side, the stochastic-based model and the physical-blocker-based model can be captured by TR 38.901. Each model can be used in different scenarios, as per the assessment of the corresponding WI. For example, the stochastic-based model could be used for UMa, and the physical blocker-based model could be used for SMa.
 If a down-selection between the two models, i.e., the stochastic-based model and the physical blocker-based model, is enforced, our preference would be to adopt the physical-based model, as it appears to be the more stable one. Importantly, the physical-based channel model can be applied to all the scenarios within the scope of the study item, i.e., RMa, UMa, UMi, InH, InF, and SMa. 

3GPP TSG RAN WG1 #121	R1-2504632
Malta, MT, 19 - 23 May 2025

Agenda item:		9.8.3
Source:	Nokia
Title:	Discussion on Channel Model Adaptation/Extension 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 discussed open issues related to the near-filed/spherical waveform modelling. The following proposals and observation are made:

RAN1 to select a fixed transmitter-receiver distance in the link-level simulations that is below the near-filed/far-filed boundary and above the , e.g., max(), where  is the Rayleigh distance.
RAN1 needs to check whether the limitation on the transmitter-receiver distance may impact on the typical values of large-scale parameters, e.g., the angular configurations of the clusters.

Based on the simplified analysis of the difference of the channel coefficient with and without near-field model it can be observed that significant corrections are observed not only at short Tx-Rx distance but also when Tx-Rx are far away (above 100 m).

Agenda item: 9.8.2
Source: Qualcomm Incorporated
Title: Channel model adaptation or extension of TR38.901 for 7-24GHz
Document for: Discussion/Decision

Conclusion 
We make the following proposals in this document:
On spherical wavefront modeling:
Proposal 1: For near-field channel modeling,  is is calculated as: 
,
where the  refers to the 3D distance between reference point at TRP and UE side. The  refers to the excess delay in NLOS obtained using Section 7.6.9 and  is the th cluster’s normalized delay in Step 5 of Section 7.5.
Proposal 2: Confirm that the excess delay  generated using Section 7.6.9 is only used for determining , and that the excess delay  and 3-D distance  are not used to determine channel response (i.e., Eq. 7.6-44 is not used).

3GPP TSG RAN WG1 #121                                                            R1-2504686
St Julian, Malta, May 19th – 23rd, 2025

Source:	vivo, BUTP
Title:	Views on channel model adaptation/extension of TR38.901 for 7-24GHz
Agenda Item:	9.8.2
Document for:	Discussion and Decision

Conclusions
In this contribution, we have elaborated the realization of near-filed channel modeling in consideration of the antenna element-wise channel parameters associated with indirect paths. Then, two models for spatial non-stationarity modeling at BS side are compared. The observations and proposals are summarized as follows.
Proposal 1: The distance  is generated independently for different sub-clusters in the same cluster, using the formula for the sub-cluster  as . 
Proposal 2: The stochastic-based model is the more appropriate to model the spatial non-stationarity phenomenon at BS side.

3GPP TSG RAN WG1 #121	                                                        R1-2504753
St Julian’s, Malta, May 19-23, 2025

Title 	:  Summary#1 of the channel model adaptation and extension
Source 	:  Moderator (ZTE)
Agenda item	:  9.8.2
Document for:  Discussion and Decision

Conclusion

3GPP TSG RAN WG1 #121	                                                        R1-2504754
St Julian’s, Malta, May 19-23, 2025

Title 	:  Summary#2 of the channel model adaptation and extension
Source 	:  Moderator (ZTE)
Agenda item	:  9.8.2
Document for:  Discussion and Decision

Conclusion

3GPP TSG RAN WG1 #121	                                                        R1-2504755
St Julian’s, Malta, May 19-23, 2025

Title 	:  Summary#3 of the channel model adaptation and extension
Source 	:  Moderator (ZTE)
Agenda item	:  9.8.2
Document for:  Discussion and Decision

Conclusion

3GPP TSG RAN WG1 #121	                                                        R1-2504756
St Julian’s, Malta, May 19-23, 2025

Title 	:  Summary#4 of the channel model adaptation and extension
Source 	:  Moderator (ZTE)
Agenda item	:  9.8.2
Document for:  Discussion and Decision

Conclusion
In RAN1#121 meeting, the following agreements are achieved. Additionally, based on the progress, no additional issues are foreseen in this agenda and corresponding study can be considered to be completed.

Agreement
For the following agreement made in RAN1#121, it’s to confirm that the “new blocker type/size” is only applicable for SNS.

Agreement
For the terminology used in the CR:
Keep the terminology “Near field channel model” with following updates, capturing the following TP in section 6.4:
Acknowledgments
Thanks all for your efforts and inputs! Looking fowarding to working with you again in future!
FYI: All other photos can be found and downloaded in Inbox/Photos.

3GPP TSG RAN WG1 #121		                               R1-2504814
St Julian’s, Malta, May 19th – 23rd, 2025

Source:	CATT
Title:	Views on channel model adaptation/extension for 7-24GHz
Agenda Item:	9.8.2
Document for:	Discussion and Decision

Conclusions
In this contribution, we provided our views on modelling methodology for 7-24GHz. We also provided our simulation results on spatial non-stationarity.
Proposal 1:  For the modelling of spatial non-stationarity at BS side, both unified VP and VR method and physical blocker based approach should be adopted as the modelling methodologies.
Proposal 2: In the near-field propagation, by default, the near-field and far-field adopt the same implementation.
Proposal 3: CDL models are more suitable for link level simulation.
Proposal 4: To model near field in link level simulation, the followings are adopted for link level simulation:
The antenna element-wise phase modeling can be reflected in the step of ‘Generate channel coefficient’. 
Proposal 5: To model spatial non-stationarity in link level simulation, the followings are adopted for link level simulation:
The effect of power attenuation factor can be reflected in the step of ‘Generate channel coefficient’.