3GPP TSG-RAN WG2 Meeting #130 	 R2-2503353
St. Julian’s, Malta, May 19th – 23rd, 2025

Agenda item:	8.8.4
Source:	vivo
Title:	Remaining Issues on MBS Broadcast Provision in NTN
Document for:	Discussion and Decision

Conclusion
In this contribution, we have discussed the remaining issues on MBS broadcast in Rel-19 NTN. And we make the following observations and proposals,
Singalling details:
Proposal 1: If a broadcast session is intended for reception within the entire cell area, the network does not configure the intended area ID(s) associated with that service. 
Proposal 2: RAN2 confirms that if no intended area ID is explicitly indicated in MCCH for an MBS broadcast service the UE is interested in, the UE considers the service is allowed for reception within the entire cell area, with legacy behavior applicable.

Broadcast service continuity:
Observation 1: Multiple broadcast sessions may be established with the same FSAI on the same frequency (e.g., the network deploys 2 sessions associated with the same service area on a given frequency). 
Observation 2: The association between FSAI and ISA IDs fails to distinguish which service is associated with a specific intended service area, particularly when multiple services share the same FSAI on a given frequency.
Proposal 3: SIB21 can include a service area ID list explicitly associated with TMGI.
Proposal 4: UE no longer prioritizes the frequency that providing the MBS broadcast service when the UE is outside the service area of that interested broadcast service.
Proposal 5: No enhancement is considered for the MCCH neighbour cell list mechanism in Rel-19.
Proposal 6: RRC_CONNECTED UE may initiate the MBS Interest Indication reporting procedure when UE is entering or leaving the intended service area.
4 

3GPP TSG-RAN WG2 Meeting #130	R2-2503460
St.Julians, Malta, May 19th – 23rd, 2025

Agenda Item:	8.8.4
Source: 	CATT
Title: 	Further discussion on support of broadcast service in NR NTN
Document for: 	Discussion and Decision

Conclusion
In this contribution, support of broadcast service via NR NTN is discussed with the observations and proposals listed as follows:
Observation 1: If service areas were to be introduced specifically for FSAI in SIB21, they should be provided per FSAI and per MBS session. This brings excessively huge signalling overhead for the system information, and the signalling design is unacceptable due to the SI size limitation concern.
Observation 2: It was agreed that the intended service area for an MBS session may include geographic areas within neighbour cell(s). If the UE is still within the service area and the reselected cell is within the neighbour cell list provided in MCCH, the UE can consider the neighbour cell providing this MBS session.
Proposal 1: Do not introduce service area information specific for FSAI in SIB21.
Proposal 1a: Information in existing SIB21 and USD in the current Specs is already sufficient for the UE to determine the frequency(ies) associated with the intended service area and perform the frequency (de)prioritization operations as agreed in RAN2#129bis.
Proposal 2: Do not introduce service area per neighbour cell in MCCH.
Proposal 2a: In addition to the neighbour cell list provided in MCCH, it can be left to UE implementation whether/how the UE considers the intended service area configured in MCCH for the MBS session, when the UE determines whether the reselected cell is providing its interested MBS session at its location. RAN2 discusses whether any informative text is needed in the Spec.

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3GPP TSG-RAN WG2 Meeting #130	R2-2503748
St.Julians, Malta,  May 19th – 23rd , 2025 	
Agenda item:		8.8.4 Support of broadcast service
Title:		Remaining issues on the support of broadcast service in NTN
Source:		ETRI
Document for:		Discussion
1. 

Conclusions
Proposal 1: RAN WG2 to extend the MBS-SessionInfoList to support the mapping between TMGI and ISA ID.
Observation 1: A single MBS service can be broadcast over different carrier frequencies in NTN.
Proposal 2: RAN WG2 to confirm that the list of ISAs for neighbouring cells should be provided by the serving cell via a new SIB.
Proposal 3: RAN WG2 to agree that ISA IDs should be associated with carrier frequencies to efficiently support service continuity.
Proposal 4: RAN WG2 to confirm that a new SIB defining the ISAs should be cell-specific.
Proposal 5: For service continuity, RAN WG2 to decide to introduce intended service area information (e.g. intended service area ID(s)) associated to the current and/or neighbouring carrier frequencies in SIB21.

3GPP TSG-RAN WG2 Meeting #130                                     R2-2503749
St.Julians, Malta,  May 19th – 23rd , 2025
Source: 			OPPO
Title: 	Discussion on providing MBS service area in NTN network
Agenda item:		8.8.4
Document for: 	Discussion and Decision

Conclusion and proposals
In this paper, following observations and proposals have been made by us:
Proposal 1: RAN2 to agree to capture the intended service area ID for the current cell in the mbs-SessionInfoList-r17 IE in MBSBroadcastConfiguration.  
Proposal 2: RAN2 to agree to capture the intended service area ID for the neighbour cells in the MBS-NeighbourCellList IE in MBSBroadcastConfiguration.
Observation 1: after the UE sends the MBS interest indication, if the network would like to provide the MBS service towards the UE no matter where the UE is, the network could just send the MBS content towards the UE via unicast. 
Proposal 3: does not introduce any additional restriction on when to initialize the MBS interest indication, on the top of the legacy UE behaviour.
Observation 2: mapping relationship between intended service area ID and the frequency can be obtained by the UE via decoding the mtch-NeighbourCell IE and MBS-NeighbourCellList IE in the mbs-SessionInfoList-r17 IE, if the intended service area ID can be agreed to be embedded in the MBS-NeighbourCellList.
Proposal 4: intended service area ID shall not be included in the SIB21.

3GPP TSG-RAN WG2 Meeting #130	R2-2503906
St. Julians, Malta, May 19th – 23rd, 2025

Agenda item:		8.8.4
Source:		Lenovo
Title:		Some remaining issues for MBS broadcast in NR NTN
Document for:		Discussion

Conclusion
In this contribution we discuss some remaining issues of MBS broadcast service continuity in NTN. It is observed that:
Observation 1: The service area information in USD is at cell level and thus cannot describe the MBS broadcast area as the new SIB does in NTN.
Observation 2: UE cannot derive the association between MBS broadcast service area and frequency in NTN only based on USD information combined with FSAI/frequency info in SIB21.
And we propose:
Proposal 1: MBS broadcast service area information or ID is included in SIB21 for service continuity.
Proposal 2: If the geographic information of a neighbour cell MBS broadcast area is included in the new SIB, its associated area ID can be included in SIB21 for service continuity (i.e. there is no need to duplicate the geographic information in SIB21).
Proposal 3: UE may report its current broadcast service area information or area ID to gNB for service continuity in RRC_CONNECTED.

3GPP TSG-RAN WG2 Meeting #130	R2-2503907
St. Julians, Malta, May 19th – 23rd, 2025                       Revision of R2-2502354

Agenda item:		8.8.4
Source:		Lenovo
Title:		Further considerations on ETWS support in NR NTN
Document for:		Discussion

Conclusion
In this contribution we discuss the signaling details of “warning area coordinates” to be introduced for ETWS in NR NTN. The following observations are given:
Observation 1: The IE warningAreaCoordinatesSegment for CMAS can describe circles and polygons.
Observation 2: The IE warningAreaCoordinatesSegment has a total number limit 10 for all circles and polygons, and a total number limit 100 for coordinates of all circles and polygons.
Observation 3: When describing circles, in the IE warningAreaCoordinatesSegment the granularity of radius is 1km and the value range is 64km.
Observation 4: The warningAreaCoordinatesSegment can be used to indicate Geo-Fencing Maximum Wait Time, which is the time a device shall allow to determine its position meeting operator policy. 
Observation 5: If the device is unable to determine its position meeting operator policy within the Geo-Fencing Maximum Wait Time, it shall present the alert to the user and discontinue further positioning determination for the alert.
Observation 6: Except for Write-Replace Warning Request, the legacy PWS procedures between gNB and AMF can only indicate cell-level PWS information.
And it is proposed that:
Proposal 1: For ETWS broadcast service area indication, RAN2 can discuss whether the format of warningAreaCoordinatesSegment for CMAS is sufficient for NTN deployment.
Proposal 2: For warningAreaCoordinatesSegment used to indicate the Geo-Fencing Maximum Wait Time, RAN2 to decide whether to discuss its impact on positioning triggering and TA update in NR NTN or leave it to UE implementation.
Proposal 3: For emergency broadcast service in a geographical area smaller than an NTN cell, RAN2 to discuss whether emergency broadcast service area information is needed for PWS procedures other than Write-Replace Warning Request. (Send LS to RAN3 if needed)

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3GPP TSG-RAN WG2 Meeting #130	R2-2504134
St. Julians, Malta, 19th – 23rd of May 2025	


Agenda item:	8.8.4
Source:	Nokia, Nokia Shanghai Bell
Title:	Open issues for MBS in Rel-19 NR NTN
WID/SID:	NR_NTN_Ph3 - Release 19
Document for:	Discussion and Decision
1	

Conclusion
This document has made the following observations:
Observation 1: Multiple services can be present within a single intended service area (ISA) and one service can be present in multiple ISAs. (i.e. many-to-many relationship, as agreed in RAN2#129). 
Observation 2: Including ISA in Service Announcement is one potential option, but not the primary solution RAN2 considers in Release 19.
Observation 3: ISA in Service Announcement will results in new requirements to the application function (AF) and also to Multicast/Broadcast Service Function (MBSF).
Observation 4: ISA in Service Announcement might require a coordination between the operator and the application function if the application shall know about ISA.
Observation 5: As per legacy NR RRC the MBS capable UE may send the MBS Interest Indication upon entering or leaving the broadcast service area.
Observation 6: As suggested in R2-2503057 during RAN2#129bis, RAN3 might have already defined all components in AMF to NG-RAN signalling which enable the mapping between FSAI, MBS session ID (TMGI) and ISA.
Observation 7: FSAI is used to improve cell reselection while it is not clear cell reselection enhancements are clearly in the scope of the WI for this MBS objective.
and proposed the following:
Proposal 1: Insert a list of service area IDs under each MBS-SessionInfo provided in MCCH.
Proposal 2: RAN2 does not consider including ISA in Service Announcement, irrespective of the SA4 response to R2-2501583. 
Proposal 3: RAN2 does not specify any new behaviour with respect to MBS Interest Indication when Rel-19 NTN capable UE enters or leaves the MBS broadcast service area.
Proposal 4: As FSAIs are configured per gNB or per cell, RAN2 does not pursue FSAI to intended service area mapping, which might have impact on core and service announcements (not limited to RAN2) for no major benefits.

3GPP TSG-RAN WG2 Meeting #130	R2-2504147
St Julian's, Malta, 19 - 23 May 2025

Title: 	Discussion on MBS broadcast over NTN
Source: 	Huawei, HiSilicon, Turkcell
Agenda Item:	8.8.4
Document for:	Discussion and decision

Conclusion
In this document, we discussed the support of broadcast service via NR NTN, and proposed the following:
Proposal 1: Indicate ISAs for each frequency in SIB21.
Proposal 2a: SIBx indicates (e.g., 1-bit) whether the cell may broadcast MBS broadcast services relevant in the whole cell coverage.
Proposal 2b: If SIBx does not indicate that the cell may transmit MBS broadcast services relevant in the whole cell coverage, a UE interested in receiving one or more MBS broadcast service but not in any ISA of the cell may skip reading MCCH.
Proposal 3a: The UE that has acquired MCCH and is out of the ISAs of the MBS service of interest shall monitor MCCH change notification and re-acquire MCCH again.
Proposal 4: The MCCH also indicates neighbour cells MBS session specific intended service area ID(s).
Proposal 5: To determine the ISA of an ISA ID indicated in MCCH of the serving cell for an MBS service in a neighbour cell, the UE can use the new SIB of the serving or of the neighbour cell.

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3GPP TSG-RAN WG2 Meeting #130											        R2-2504201
Malta, 19-23 May 2025

Agenda item:			8.8.4
Title:						Remaining issues for MBS service continuity over NTN
Source:					Continental Automotive
Document for:		Discussion and Decision

Conclusions

The following proposals have been made in this contribution:
Observation 1: In scenarios with quasi-earth-fixed or earth-moving cells, which are under the scope of RAN2 agreements, NTN cell(s) serving an intended MBS service area may change constantly over time, which will result in frequent updates in MBS service(s) and the associated ISAs.
Proposal 1: The network provides, in addition to broadcasting the intended MBS service area, MBS-specific service time estimates for intended MBS service areas, where serving NTN cell(s) continuously change.

3GPP TSG-RAN WG2 Meeting #130	R2-2504208
St. Julian’s, Malta,  May 19th – 23rd , 2025	


Agenda item:	8.8.4
Source:	Samsung
Title:	Open issues on Broadcast service area
WID/SID:	NR_NTN_Ph3-Core
Document for:	Discussion and Decision

Conclusion
In this contribution we discussed the following proposals.
Observation 1: RAN2 has agreed the ISA(s) of MBS broadcast service(s) can include portions of one or more NTN cells (e.g., the current serving cell and neighbor cells) and is semi-static which does not cause frequent updates.
Proposal 1: The new SIB of the geographic information for ISA(s) can be either area-specific or cell-specific (no spec. Impact).
Observation 2: If the serving cell SIB only include the ISA that covers a small portion of the serving cell (type-1 ISA) and does not include the ISA that covers the whole current serving cell and portions of neighbor cells (type-2 ISA), UE may wrongly determine it is not in any type-1 ISA in the serving cell and do no acquire MCCH, however UE may still in type-2 ISA and should acquire MCCH.
Proposal 2: For the ISA that covers the whole current serving cell and portions of neighbor cells, the serving cell’s SIB can 
Option 1: include explicit geographic area for this type of ISA and be area-specific. 
Option 2: include a one-bit indicator to indicate this type of ISA and be cell-specific. 

Observation 3: It is not clear what is the granularity of “the preconfigured area” identified by MBS FSA ID. If “the preconfigured area” identified by FSA ID is large, e.g., in the form of a Tracking Area Identifier (TAI) list and/or Cell ID list, multiple frequencies can map to one MBS FSA ID.
Observation 4: By combining the existing information of service-FSAI mapping in USD, FSAI-frequencies mapping in SIB21, and ISA-service mapping in MCCH, UE will consider one service associated to multiple frequencies (e.g., for multiple cells) and associated to multiple ISAs, but cannot know which frequency is used in the ISA UE located in.
Proposal 3: Provide the association between ISA ID and frequency in SIB21. 

3GPP TSG-RAN WG2 Meeting #130                                    	R2-2504311
St. Julians, Malta, 19 - 23 May 2025                                                                   	              
	 
Agenda item:	8.8.4
Source:	Qualcomm Incorporated
Title:	MBS broadcast service continuity
Document for:	Discussion and Decision

Conclusion
Following proposals are made.
Observation 1.	The existing procedure (e.g., via SIB21 or USD) is already sufficient for UE to map Frequency and MBS broadcast service(s).
Proposal 1	In new SIBxx, serving cell broadcasts the list of ISAs where neighbour cells in same or different frequency are also providing the same MBS service(s) and neighbor cell may belong to different satellite.
Proposal 2	Same as FSAIs, discuss whether ISA should also be exchanged between gNBs for service continuity.

3GPP TSG-RAN WG2 Meeting #130	R2-2504356
St. Julian's, Malta, May 19th – 23rd, 2025

Agenda item	:		8.8.4
Source	: 	Sharp
Title	: 	Remaining issues on intended service area
Document for	:	Discussion and Decision

Conclusion
In this paper, we made the following observations and proposals;

[MCCH re-acquisition]
Observation 1: As a result of ISA information modification in the new SIB, MCCH content may also be modified. In this case, UE needs to re-acquire MCCH.
Observation 2: UE cannot get the latest MCCH information in some cases if the UE re-acquire MCCH immediately after new SIB is changed.
Observation 3: However, based on the current mechanism, network can control the timing of the new SIB change and MCCH modification without causing any discrepancy between the MCCH and new SIB.

Proposal 1 ： No change is needed in the procedure for re-acquisition of MCCH for the introducing the new SIB.

[Open Issues : Mapping between ISA and TMGI]
Observation 3 : Based on the agreement “If no intended service area is explicitly indicated (e.g. in SIBxx) for a MBS service the UE is interested into, existing behavior applies.” from last meeting, sessions that are not explicitly associated with the ISA should also be supported.
Observation 4 : The Legacy UE interprets the sessions included in MBS-SessionInfo-r17 IE are receivable regardless sessions are associated with any ISA or not.
Observation 5 : MBSBroadcastConfiguration containing session information associated with ISAs can be placed in r19 IE to avoid duplicate TMGI (i.e. reducing signalling overhead) and to support the backward compatible behaviour.

Proposal 2 : To avoid duplicate TMGI and to support the legacy UEs, MBS-SessionInfo(Ext)-r19 IE includes the ISA ID together with session information which is associated with ISA, and MBS-SessionInfo-r17 IE includes session information which is not associated with ISA .

Proposal 3 : If all sessions are associated with any ISA IDs as a current CR description, to support sessions which are not explicitly associated with ISA, new SIB contain entries which consists of only the ISA ID.

[new SIB signalling]
Proposal 4 : RAN2 discuss that among the entries in the list of ISA information contained in the new SIB, the entry for the ISA covering the whole cell includes the ISA ID.

[MBS interest indication transmission by UE within ISA]
Observation 6 : If UE is allowed to send MBSInterestIndication message from outside of the intended service area, UL resources are wasted by UEs which are not intended to receive the MBS service.

Proposal 5 : MBSInterestIndication message should not be sent by UE located outside of the intended service area. 

3GPP TSG RAN WG2 Meeting #130	R2-2504392
St.Julians, Malta, May 19th – 23rd, 2025
Agenda Item:	8.8.4
Source:	CMCC	
Title:	Considerations on broadcast service for NR NTN
Document for:	Discussion, Decision

Conclusion
Based on the discussions mentioned above, in this contribution we provide some discussions on MBS broadcast enhancements for NTN and have the following observations and proposals:
Proposal 1: It is proposed to provide the association between intended service area ID and frequencies in SIB21, and an example mapping option is as following:
SIB21 information element
-- ASN1START
-- TAG-SIB21-START

SIB21-r17 ::= SEQUENCE {
    mbs-FSAI-IntraFreq-r17                   MBS-FSAI-List-r17                OPTIONAL,  -- Need R
    mbs-FSAI-InterFreqList-r17               MBS-FSAI-InterFreqList-r17       OPTIONAL,  -- Need R
    lateNonCriticalExtension                 OCTET STRING                     OPTIONAL,
    ...




}

MBS-FSAI-List-r17 ::= SEQUENCE (SIZE (1..maxFSAI-MBS-r17)) OF MBS-FSAI-r17

MBS-FSAI-InterFreqList-r17 ::= SEQUENCE (SIZE (1..maxFreq)) OF MBS-FSAI-InterFreq-r17

MBS-FSAI-InterFreq-r17 ::= SEQUENCE {
    dl-CarrierFreq-r17         ARFCN-ValueNR,
    mbs-FSAI-List-r17          MBS-FSAI-List-r17
}










MBS-FSAI-r17 ::= OCTET STRING (SIZE (3))

-- TAG-SIB21-STOP
-- ASN1STOP
Observation 1: UE is already able to initiate the MBS Interest Indication procedure in several cases as in existing specification mentioned above.
Proposal 2: For the MBS Interest Indication initiation, we could just follow the legacy mechanism, further enhancement is not needed.

3GPP TSG-RAN WG2 Meeting #130	R2-2504421
St Julian's, Malta, 19th – 23rd May, 2025
Agenda Item:	8.8.4 
Source:    TCL.
Title:         Discussion on Supporting of MBS Broadcast Service
Document for:	Discussion and Decision

Conclusion
In this contribution, we have discussed the enhancements for supporting MBS broadcasting over NTN focusing on the intended MBS broadcasting area, the signalling design for controlling MBS broadcasting over NTN and the service continuity issues. Based on the above discussion, we following proposals:
Proposal 1:
The new SIBxx needs to include mapping between network identities (PLMNs, tracking areas, or mapped cell identities) and geographical area definitions to enable UEs to identify MBS intended service areas.
Proposal 2:
The new SIBxx should also provide mapping between network identities and geographical definitions of the complete satellite coverage area (including both MBS intended and non-intended regions), allowing UEs to determine it is within an intended service area or not.

3GPP TSG-RAN WG2 Meeting #130	R2-2504477
St.Julians, Malta, May 19th – 23rd, 2025

Agenda Item:	8.8.4
Source:	HONOR
Title: 	Discussions on the support of broadcast service
Document for:	Discussion and decision
1	

Conclusions
In this contribution, we discussed the issues related to intended service area in NTN. Based on the discussion, the following proposals are concluded:
Proposal 1a: (idle/inactive-3) UE could use the intended service area list related to one specific broadcast service in the USD to avoid acquiring the MCCH when UE is outside the MBS service area of this MBS broadcast service.
Proposal 1b: (idle/inactive-3) UE could use the association between the FSAI and intended service areas in SIB21 for cell reselection.
Proposal 2: The MII mechanism could be reused to report the ISA ID of the UE.
Proposal 3: The MBS intended service area mechanism should not be restricted to neither NTN cells nor NTN-capable UEs.
4	

3GPP TSG-RAN WG2 Meeting #130	R2-2504529
St. Julian’s, Malta, 19th - 23rd May, 2025	

Agenda Item		:	8.8.4
Source		:	LG Electronics Inc.
Title		:	Discussion on support for broadcast service in NTN
Document for		:	Discussion and Decision
1	

Conclusion
In this contribution, following statements are proposed:
Observation 1	When a UE receives a MBS service associated with ISA(s) from a serving cell and receives a list of neighbouring cells that provide the same MBS service, it interprets that the neighbouring cells also provide this MBS service for the corresponding ISA(s) and the other neighbouring cells do not provide this MBS service for the corresponding ISA(s). In this example case, there is no strong technical motivation to introduce additional signaling of ISA information that the neighbouring cell provides the same MBS service as the serving cell.
Observation 2	When UE in RRC_CONNECTED is not interested in any of MBS broadcast services provided in serving cell, it is redundant to maintain the MBS broadcast service reception capability.
Proposal 1	There is no need to introduce additional enhancements related to MBS service continuity.
Proposal 2	An MBS-capable UE in RRC_CONNECTED may initiate the MII procedure upon entering or leaving the intended service area.
Proposal 3	Add a note to section 5.9.4.2 of TS 38.331 as the intended service area can be considered as the broadcast service area.
4. 

3GPP TSG-RAN WG2 #130	R2-2504652
St. Julian’s, Malta, May 19th – 23rd, 2025

Agenda Item:	8.8.4
Source:	Ericsson
Title:	Support for broadcast services in NR NTN
Document for:	Discussion, Decision
1	

Conclusion
In the previous sections we made the following observations: 
Observation 1	A UE can prioritize a frequency when it is interested in an MBS broadcast service, and it can only receive that service by camping on that frequency.
Observation 2	A UE obtains the FSAI associated with an MBS broadcast service from the Service Announcement. A UE obtains the frequency associated with an FSAI from SIB21.
Observation 3	MBS FSA ID and their mapping to frequencies are provided to RAN nodes via OAM.
Observation 4	RAN nodes receive MBS FSA ID related to a MBS broadcast service during MBS Session Start/Update.
Observation 5	A gNB is informed by the AMF of the ISA(s) and FSA ID of the MBS broadcast service(s) it serves.
Observation 6	A gNB is unaware of the ISA(s) associated to MBS broadcast services provided by neighbouring RAN nodes.
Observation 7	There is an impact to RAN3 and SA2 WG if the ISA ID needs to be broadcast in SIB21.
Observation 8	Providing the association between ISA and frequencies via SIB has RAN3 impact which increases NW complexity and cannot work when SIB21 is not provided.
Observation 9	The Service Announcement can provide the ISA ID and FSA ID directly to the UE for frequency prioritization. This solution minimizes RAN impact and inter-node coordination.

Based on the discussion in the previous sections we propose the following:
Proposal 1	Prioritize MBS NTN service continuity enhancements based on scenario B.
Proposal 2	RAN2 discusses how to provide the association based on the LS reply from SA2/SA4.

5	

3GPP TSG-RAN WG2 #130	R2-2504662
St. Julian’s, Malta, May 19th – 23rd, 2025

Agenda Item:	8.8.4
Source:	Ericsson
Title:	MBS signalling details in NR NTN
Document for:	Discussion, Decision
1	

Conclusion
In the previous sections we made the following observations: 
Observation 1	It is highly likely that a gNB lacks knowledge of the ISA in neighbouring cells served by different gNBs.

Based on the discussion in the previous sections we propose the following:
Proposal 1	It is up to network implementation whether the new SIB describing the ISA(s) is cell specific or area specific.

5