# SA#110 Brief Report on SA4 Topics

## General Information

**Meeting Details:**
- SA#110 took place 9-12 December 2025, hosted by ATIS in Baltimore, US
- SA4 Chair: Gilles Teniou (Tencent/CCSA)
- Report presented at SA4#135 in Goa, India (9-13 February 2026)

## Overall Outcome Summary

The SA4 report to SA#110 was **noted**. Key approvals included:
- All SA4 CRs (Rel-12, Rel-17, Rel-18, Rel-19) were **approved**
- Draft TS 26.251 V2.0.0 (IVAS_Codec_Ph2) was **approved**
- IVAS verification test lab reports were **approved**
- SA4 chair input on WG Terms of Reference was sent back to SA4 for further discussion

### Key Plenary Discussion Points

**Workload Concerns:**
- Verizon raised concerns about SA4's capacity given the large number of proposed TRs, citing slow progress on FS_ULBC
- SA4 Chair clarified that slow progress was due to dependencies and related issues, not workload
- TSG SA Chair requested companies to prepare contributions on workload issues rather than raising them in the Chair report

**ToR and AI Work:**
- MediaTek commented on the postponed SA4 ToR and emphasized the need to progress AI-related studies
- TSG SA Chair indicated that SA4 ToR requires consensus within SA4 before TSG SA approval

**6G Planning:**
- TSG SA Chair requested information on 6G planning for the next TSG SA meeting

## IVAS Verification Reports

All test lab reports for IVAS Characterization Phase were **approved**:
- MESAQIN.com Listening Lab Report (SP-251447)
- FORCE Technology Listening Lab Report (SP-251448)
- Global analysis lab report

## New Release 20 Work Items

### Work Item (WID)

**Terminal Audio Quality Performance and Test Methods (SP-251352)**
- Status: **Approved**

### Study Items (SIDs)

**1. Study on Evaluation of QUIC-based Protocols for On-demand and Live Video Services (FS_QStream-MED) - SP-251353**
- Status: **Approved** (revised to SP-251659)
- Allocated TR numbers: TR 26.835 and TR 26.934

**2. IMS Data Channel Enhancements (SP-251354)**
- Status: **Approved** (revised to SP-251660)
- Allocated TR number: TR 26.814

**3. QUIC-based Media Delivery for Real-time Communication (FS_Q4RTC-MED) - SP-251355**
- Status: **Approved** (revised to SP-251661)
- Allocated TR number: TR 26.836
- Clarification: Focused on 5G but will consider new aspects introduced by 6G

**4. Study on Image Formats (SP-251356)**
- Status: **Approved** (revised to SP-251662)
- Allocated TR number: TR 26.892

**5. Study on Avatar Communication Phase 2 (SP-251357)**
- Status: **Approved** (revised to SP-251663)
- Revision: Removed repeated supporting company

**6. Study on Media Aspects for 6G System (SP-251620)**
- Status: **Approved** (revised to SP-251652)
- Allocated TR number: TR 26.870
- **Rapporteurs:**
  - Primary: Thomas Stockhammer (Qualcomm) - coordination of the study
  - Secondary: Elmira Ramazanirend (Vodafone) - Draft TR edition
- **Key Revisions:**
  - AN and Others impacts changed to "Don't Know"
  - SA5 included for charging and management impacts
  - SA1 included in objective 6 for service requirements
  - Additional supporting companies added
  - Non-3GPP member removed

## Specifications for Approval

**Draft TS 26.251 v2.0.0 - IVAS Codec Phase 2 (SP-251444)**
- Status: **Approved** (Rel-19)
- Contains fixed-point C code of the IVAS codec as electronic attachment (IVAS Software Version 3.0)
- Provides full and bit-exact EVS codec functionality for mono speech/audio signal input
- Optimized for encoding/decoding of stereo and immersive audio formats including:
  - Multi-channel audio (5.1, 5.1.2, 5.1.4, 7.1, 7.1.4)
  - Scene-based audio (Ambisonics up to order 3)
  - Metadata-assisted spatial audio (MASA)
  - Object-based audio (ISM up to 4 ISMs)
  - Combined formats: OSBA and OMASA
- Supports rendering including binaural rendering for headphones with head-tracking

## Change Requests

**EVS_Codec CRs (SP-251429)**
- 8 CRs to TS 26.445 (Rel-12)
- Status: **Approved**
- Note: Huawei commented that CRs to old frozen releases should be discouraged and only accepted for real FASMO corrections
- These CRs corrected references to other clauses

**All other SA4 CRs:**
- All Rel-17, Rel-18, and Rel-19 CRs submitted for approval were **approved** as is
- Admin CRs on TS 26.512 were **approved**

## Liaison Statements

### LS on External Resource Handling in IMS Data Channel

**Incoming LS from GSMA NG UPG (SP-251301)**
- Status: **Noted**
- **SA4 Response (SP-251622, revised to SP-251693):** **Approved**
- **Issue:** Ambiguity in handling external resource access in IMS Data Channel applications
- **SA4 Position:**
  - Acknowledged gaps in current TS 26.114 specification
  - Originally assumed DCSF and DC AS would be exclusive hosts for all content
  - Did not anticipate scenarios involving external resources
  - Plans to study this issue and provide clarifications as part of DC Enhancements (FS_DCE_MED) study in Release 20

### LS on Traffic Model Study in RAN WG1

**Incoming LS from RAN WG1 (SP-251304)**
- Status: **Noted** (SA in CC)
- SA4 recognizes importance of defining traffic models reflecting realistic traffic characteristics
- SA4 will provide input as work progresses for AI/ML Services and immersive communication services

## Work Item Summaries

**1. IVAS_Codec_Ph2 (SP-251375)**
- Source: vivo Mobile Communication Co., Ltd. (Rapporteur)
- Status: **Endorsed**

**2. Video Operating Points - Harmonization and Stereo MV-HEVC (VOPS) - SP-251503**
- Source: Apple Switzerland AG
- Status: **Endorsed**

## AI Traffic Characteristics Discussion

**Key Issue:**
- Several contributions (SP-251553, SP-251499, SP-251540, SP-251576, SP-251452) attempted to structure work on identifying AI/ML data traffic characteristics, proposing SA4 as lead WG
- Concerns raised by some companies that SA4 should not be the exclusive WG for AI traffic characteristics
- Tentative way forward proposed in SP-251625 but **no consensus reached**
- Document was **noted with no action to SA4**

**SA4 Chair Position:**
- Work in other WGs should not interfere with SA4's planned work on AI traffic characteristics in the context of media services
- SA4 should proceed with its work, report progress to SA (and potentially RAN WGs), and let them decide applicability to other cases beyond media applications

## Other Business

### Study on 3GPP AI/ML Consistency Alignment (FS_AIML_CAL)
- Study completed
- Draft TR 22.850 **approved** (SP-251698)
- LS to be sent to WGs for information

### Study on Modernization of Specification Format and Procedures for 6G
- Draft TR 21.802 presented for information
- Status: **Noted** (SP-251617)

### Release 21 Timeline Discussion

**Key Points:**
- Release 21 is the release for submission to IMT-2030 (6G)
- 3GPP normative work will be submitted to ITU-R before 2030
- ASN.1/OpenAPI freeze date is no earlier than March 2029
- Previous decision: Rel-21 timeline to be decided no later than June 2026
- Some groups (SA1, RAN Plenary) will finish Rel-20 work before June 2026

**Timeline Planning:**
- Joint session organized at TSG#111 (March 2026) for companies to share views on Rel-21 timeline
- TSG Chairs will provide joint input paper outlining proposed Rel-21 timeline
- Some Rel-21 dates (e.g., Stage-1 freeze) may be tentatively agreed at TSG#111
- Final approval of Rel-21 timeline targeted for TSG#112 (June 2026)
- First Rel-21 SID proposed at SA#110 (from SA1)

## Guidance and Actions to SA4

**No particular guidance** was provided to SA4.

**Action:** SA4 will report progress and plans related to AI traffic characteristics at the next SA plenary.